bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermophilic Fermentation of Pig Faeces and Straw by Actinomycetes
Authors: GINNIVAN M. J. , WOODS J. L , O'CALLAGHAN J. R.
Published: March 2008

The ability of Thermomonospora fusca, Thermomonospora curvata and Pseudonorcardia thermophila to grow on and hydrolyse pig faeces and straw was studied in a 6 d batch culture at 55°C. T. fusca produced the highest levels of cellulase activity (3·3 mg/ml/h) and the greatest cellulose reduction (from 25 to 6% dry wt) in a pig faeces medium (10 g/l). Replacing half the pig faeces with grass straw reduced the cellulose breakdown (29 to 18% dry wt). Increasing the concentration of pig faeces to 30 and 50 g/l caused a decrease in cellulose breakdown. To achieve similar cellulose reductions in straws required NaOH pretreatment. All fermentations resulted in significant increases in digestible protein. The celluloses produced by the strains growing on pig faeces exhibited greatest activity in the pH range 5·9–6·4.
A Microperfusion Chamber for Studying the Growth of Bacterial Cells
Authors: DUXBURY T.
Published: March 2008

A microperfusion chamber for studying the growth of bacterial cells is described. It can be used with unmodified phase contrast systems. Both temperature and the composition of the growth medium can be changed by the operator during observation of bacteria. The use of the chamber is illustrated with observations on the effect of penicillin on Arthrobacter globiformis.
Vitamin B12 Production by the Gastro‐intestinal Microflora of Baboons Fed either a Vitamin B12 Deficient Diet or a Diet Supplemented with Vitamin B12
Authors: UPHILL PATRICIA F. , JACOB FREDERIKA , LALL PARVINDER
Published: March 2008

The vitamin B12‐producing capacity of micro‐organisms isolated from baboon faeces and gastric contents was measured using Lactobacillus leichmannii. The animals were fed either a diet deficient in or supplemented with vitamin B12 (controls). Samples of gastric and small intestinal contents, obtained at laparotomy from two young vitamin B12‐deprived baboons, contained varying quantities of vitamin B12. Many of the organisms isolated from these aspirates produced vitamin B12in vitro. The highest levels of vitamin B12 were produced by anaerobic organisms. Gastric juice samples from vitamin B12 deprived and control baboons contained similar types of organisms with like vitamin B12‐producing capacity. The vitamin B12 content, pH and total bacterial counts of gastric juice samples aspirated after a 6 h fast from vitamin B12 deprived baboons were not significantly different from those of the control animals. The pH values of gastric juice samples aspirated 18 h after feeding, however, were significantly lower than those of 6 h fasting samples in both groups. The mean vitamin B12 levels in the total volumes of gastric juice aspirated after each fasting period were similar. The possible involvement of the gastrointestinal flora in the vitamin B12 status of the baboon is discussed.
Clostridia from Grana Cheese
Authors: MATTEUZZI D. , TROVATELLI L. D. , BIAVATI B. , ZANI G.
Published: March 2008

Forty strains of proteolytic and saccharolytic clostridia isolated from Grana cheese were re‐identified by DNA‐DNA homology. Thirty culture collection strains were also examined for comparison. Organisms of the species Clostridium tyrobutyricum which present variability in phenotypic characteristics were found to constitute a homogeneous group, genetically unrelated to all the reference or competitor strains used. The proteolytic clostridia from cheese show a high level of homology with the reference strains C.sporogenes ATCC 319 and C. sporogenes ATCC 3584 and negligible homology with C. bifermentans ATCC 19299. Three strains with phenotypic characters very similar to those of the species C. butyricum present a level of DNA homology with C. butyricum ATCC 19398 ranging from 61–71%. In the light of the results obtained some taxonomic conclusions have been drawn.
Quantitative Studies on the Generation of Aerosols of Erwinia carotovora var. atroseptica by Simulated Raindrop Impaction on Blackleg‐infected Potato Stems
Authors: GRAHAM D. C. , QUINN C. E. , BRADLEY LYNNE F.
Published: March 2008

Quantitative studies on the generation of bacterial aerosols by simulated raindrop impaction on potato stems infected with the blackleg organism Erwinia carotovora var. atrosep:ica have shown that, theoretically, airborne transmission might result in re‐contamination of blackleg‐free potato stocks.
The Production of a Yeast Killer Factor in the Chemostat and the Effects of Killer Yeasts in Mixed Continuous Culture with a Sensitive Strain
Authors: YOUNG T. W. , PHILLISKIRK G.
Published: March 2008

In batch culture in a complex medium the killer yeasts NCYC 738 and NCYC 235 gave maximal killer activity when grown in the pH ranges 4·2–4·4 and 4·6–4·8 respectively. Incubation of culture filtrates of NCYC 738 for 10 h at 25 °C or 2 h at 29 °C resulted in a 50% reduction in activity. The addition of bovine serum albumin or gelatine to a complex medium stabilized killer activity. In a defined medium the addition of yeast extract stimulated the production of killer activity. When killer yeast NCYC 738 was grown in a chemostat, killer activity was influenced by temperature, pH and the rate at which the culture was stirred. The production of killer activity was growth‐linked and increased as dilution rate was raised to a maximum of 0·15 h”1. Steady state continuous cultures of the sensitive strain, NCYC 1006, were contaminated deliberately with either killer or killer‐cured strains. During the first 30 h cultivation, the cell concentration of both strains increased. Subsequently the sensitive strain was displaced from the culture. When killer‐cured NCYC 738 was added, the rate of displacement was proportional to the culture temperature. However, with killer NCYC 738 increase of temperature reduced the rate of displacement. When killer NCYC 235 was employed, a lowering of pH decreased the rate of displacement but had no effect when killer‐cured NCYC 235 was used.
Studies on the Significance of Three Bacillus species to the Ensiling Process
Authors: WOOLFORD M. K.
Published: March 2008

The activities of Bacillus coagulans, Bacillus licheniformis and Bacillus polymyxa were examined in a defined environment prepared to simulate a grass with low contents of dry matter and water‐soluble carbohydrates. All of these organisms produced lactic and acetic acids, and their growth was not suppressed by these fermentation products nor by low pH. The acid content of silages made by inoculation with lactic acid bacteria alone and in combination with each of the bacilli was greater than in the silages containing each of the bacilli alone. The acid content of the silages with lactic acid bacteria was not increased by the presence of bacilli. It is concluded that bacilli can compete with lactic acid bacteria for substrate but contribute little to the fermentation and in this context should be discouraged.
Oxidative Metabolism of a Pigmented Mutant of Rhizobium meliloti and its Revertants
Authors: DOGRA R. C. , VYAS THE LATE S. R.
Published: March 2008

Non‐infective pigmented mutants of Rhizobium meliloti have been obtained by u.v. irradiation. The majority of colourless revertants of a pigmented mutant obtained by u.v. irradiation nodulated the host plant indicating that pigmentation in rhizobium and ability to nodulate are genetically linked and may have some pleiotrophic effect. All the nodulating revertants and the parent strain oxidized pentoses, hexoses, dihexoses, tricarboxylic acid (TCA) cycle intermediates and related compounds at a higher rate than the non‐nodulating revertants and pigmented mutant. Significant differences in the oxidation of pentoses and TCA cycle intermediates in nodulating and non‐nodulating revertants indicate that these two energy yielding pathways are operating less efficiently in non‐nodulating revertants and suggests that the working of these two pathways may be essential for the nodulation process.
Production of Escherichia coli Heat‐labile Enterotoxin in Fermenter Dialysis Culture
Authors: LANDWALL P. , MÖLLBY R.
Published: March 2008

Production of Escherichia coli heat‐labile enterotoxin was investigated with one porcine and one human strain in three different media under different cultivation conditions. Cultivation in aerated fermenters at pH 7·0 yielded 10–20 times more enterotoxin/ml of culture fluid than cultivation in shake flasks. A trypton‐yeast extract medium was optimal in fermenter cultures. Comparatively good yields of enterotoxin in fermenters were also obtained in a glucose‐salts medium. Continuous feeding of glucose and salts during fermenter cultivation resulted in a lower production of enterotoxin/mg of bacterial cells. Since this decrease in specific yield could be reversed by using dialysis culture, it was concluded that inhibition of toxin formation was due to the accumulation of extracellular low molecular weight metabolites. The highest yield of enterotoxin in dialysis culture was 80 ED50 ml−1 (rabbit jejunal loop test) which is at least eight times more toxin than in ordinary fermenter culture and 80 times more toxin than in shake flask cultures.
Growth of Various Bacteria on Polycyclic Aromatic Hydrocarbons and N‐2–Fluorenylacetamide
Authors: MARTINSEN CHARLENE S. , ZACHARIAH PRINCE K.
Published: March 2008

Several heterotrophic bacteria grew in nutrient broth medium containing high concentrations (10−5 M) of the potent carcinogenic compounds, benz[a]pyrene, 3‐methylcholanthrene or N‐2–fluorenylacetamide. They were capable of metabolizing the polycyclic aromatic hydrocarbons to smaller molecules and utilized these compounds as the sole source of carbon and energy. Identification of the metabolites formed from benz[a]pyrene revealed that the major metabolite (3‐hydroxybenz[a]pyrene) of mammalian systems did not accumulate in any of these cultures when the standard fluorometric assay was used. Benz[a]pyrene metabolism profiles with high‐pressure liquid chromatography also exhibited no accumulation of any metabolites (hydroxy, quinone and diol derivatives).
Characterization of Poultry Isolates of Staphylococcus aureus by a New Set of Poultry Phages
Authors: GIBBS P. A. , PATTERSON J. T. , THOMPSON J. K.
Published: March 2008

A set of phages has been isolated from strains of Staphylococcus aureus, non‐typable with the International (human) phage set, recovered from processed poultry. This set of phages could distinguish three main groups of strains, and biochemical tests confirmed these divisions, members of each group exhibiting characteristics of both ‘human’and ‘animal’strains. A high proportion of strains from all three phage groups was enterotoxigenic.
Development and Evaluation of a Potency Index Screen for Detecting Mutants of Penicillium chrysogenum Having Increased Penicillin Yield
Authors: BALL C. , McGONAGLE M. P.
Published: March 2008

U.v.‐treated conidia of an industrial strain of Penicillium chrysogenum were spread on a growth‐limiting agar medium. Colonies arising from the survivors were surrounded with a spore suspension of Bacillus subtilis to which penicillinase had been added. After appropriate incubation, discrete zones of bacterial inhibition, with sizes limited by the penicillinase, appeared around each colony. Using the criterion of potency index (diameter of inhibition zone divided by diameter of colony) strains were selected that subsequently gave improved penicillin production in shake‐flasks. The technique also ranked correctly four industrial strains in order of their known penicillin‐producing capacity. Employing three operators, 5000 isolates could be screened in each experiment and approx. 15000 strains could be screened in a month.
The Effects of Nisin on the Microbial Flora of the Dental Plaque of Monkeys (Macaca fascicularis)
Authors: JOHNSON I. H. , HAYDAY H. , COLMAN G.
Published: March 2008

Nisin was incorporated in a soft diet and fed to eight monkeys for five months. At the end of this period dental plaque was removed from one site in the mouths of these animals and from a similar site in eight control animals. Twelve different selective media were used for the cultivation of the bacteria in the plaque. Streptococci, Haemophilus spp. and Gram negative anaerobes were the organisms most frequently isolated. There was some evidence that streptococci constituted a lesser proportion of the flora in the nisin‐fed animals.
A Method for the Demonstration of Extracellular Hydrolysis of Poly‐β‐Hydroxybutyrate
Authors: MALIK K. A. , CLAUS D.
Published: March 2008

A simple method has been developed for the rapid demonstration of extracellular hydrolysis of poly‐β‐hydroxybutyrate (PHB).

This is based on the use of thin PHB strips or films placed on inoculated mineral agar in Petri dishes or in liquid media.

It has been tested on various strains of different species of bacteria and the results showed complete agreement with the conventional overlayer method.
A Note on the Diagnosis of Ratoon Stunting Disease of Sugarcane by Negative‐Stain Electron Microscopy of the Associated Bacterium
Authors: TEAKLE D. S. , KONTZE DONNA , APPLETON JULIE M.
Published: March 2008

After negatively staining with 1% (w/v) sodium phosphotungstate (pH 6·5) or 1% (w/v) ammonium molybdate (pH 6·5), the cell wall, cytoplasmic membrane and mesosomes of the RSD‐associated bacterium obtained from the fibrovascular fluid of infected sugarcane were usually clearly displayed. The cells measured 0·19–0·39 μm (av. 0·27 μm) in width and 0·6–3·4 μm in length. Few mesosomes were visible and the cells were approx. 40% wider (0·27–0·52 μm, av. 0·38 μm) when stained with 1% (w/v) uranyl acetate (pH 3·0–4·2). Freezing and thawing the suspension before negative staining with sodium phosphotungstate did not greatly affect the size of the cells or resolution of the mesosomes. Glycine (0·25 M) as the suspending medium, fixation in 2% (w/w) glutaraldehyde, or placing wet instead of dry specimen grids in the electron microscope resulted in wider cells usually lacking mesosomes.
Strain Identification in Rhizobium Using Intrinsic Antibiotic Resistance
Authors: JOSEY D. P. , BEYNON J. L. , JOHNSTON A. W. B. , BERINGER J. E.
Published: March 2008

The variation in intrinsic resistance to low levels of eight antibiotics was used as an identifying characteristic for 26 Rhizobium leguminosarum strains. The pattern of antibiotic resistance of each strain was a stable property by which rhizobia isolated from root nodules of inoculated Pisum sativum could be recognized. The antibiotic tests for strain identification with R. leguminosarum were applied to R. phaseoli. It was necessary to include reference cultures in tests with this species, as the tests most suitable for the R. leguminosarum strains showed some variability with R. phaseoli.
A Modification of the Mycoplasma Serum‐Drop Growth Inhibition Test
Authors: MØLLER B. R.
Published: March 2008

A modification of the serologic mycoplasma growth inhibition test is described. It is based on application of a drop of antiserum directly onto the centre of an inoculated agar plate provided with a slightly concave agar surface. The special apparatus devised for the preparation of these plates is described. This modified serum‐drop method is more sensitive than other growth inhibition tests used today and is equally specific.
Sterilization by means of Hydrogen Chloride: Influence of Process Parameters on Biocidal Activity
Authors: LELIEVELD H. L. M. , VAN EIJK H. M. J.
Published: March 2008

At ambient temperatures, hydrogen chloride is a strong bactericide. At a partial hydrogen chloride pressure of 30 mm Hg, the number of spore‐bearing colony forming units present in straw dust particles of 0–32 μm was reduced by a factor‐of more than 50 000 within 60 s. Naked spores of Bacillus subtilis were reduced in viability by a factor of 100 000 within only 10 s. Viability of vegetative cells of various kinds of bacteria was reduced by a factor of more than 107 within 10 s. The method of administration of the gas influenced the sterilization and had to be adapted to the geometry of the surfaces to be sterilized. The smaller the dust particles, the better the sterilization, seemingly due to the lower degree of inhibition of diffusion of gas to the microorganisms enclosed in the particles. Increases in treatment time and concentration of hydrogen chloride enhanced the sterilizing effect to a lesser extent when large dust particles were involved. The partial water vapour pressure did not influence the sterilization between 0.3 and 6 mm Hg. An increase in temperature decreased the sterilizing effect.
A Portable Device for Concentrating Bacteriophages from Large Volumes of Freshwater
Authors: SEELEY N. D. , MALLARD G. , PRIMROSE S. B.
Published: March 2008

A portable apparatus for concentrating bacteriophages from up to 200 1 of raw water is described. With this apparatus eight morphologically diverse phages were concentrated from 201 ‐to 10 ml with recoveries of 14–66%, representing concentration factors of x280‐x1320. The apparatus was also used to concentrate indigenous phages from 251 samples of river water.
Preservation of Mycoplasmas on Anhydrous Silica Gel
Authors: THORNS C. J.
Published: March 2008

1. 26 strains of mycoplasmas were successfully preserved on anhydrous silica gel crystals for 80 weeks at +4°C.

2. There was a sharp decline in viability of the strains if they were stored at room temperature.

3. This preservation technique is simple to perform and requires only inexpensive equipment.
A Simple Method for Long‐term Preservation of Stock Cultures of Lactic Acid Bacteria
Authors: JUVEN B. J.
Published: March 2008

Strains of Lactobacillus sp., Leuconostoc sp. and Streptococcus sp. were preserved for 6–24 months at ambient temperature, partially dehydrated on granular pumice stone. To date, all the cultures stored by this technique have remained viable and no changes in the cultural or biochemical characteristics were observed.
Recovery of Spores of Bacillus stearothermophilus from Thermal Injury
Authors: LABBE R. G.
Published: March 2008

Bacillus stearothermophilus grown in nutrient broth produced a product which promoted recovery from thermal injury of its spores. This phenomenon was observed with nutrient agar as the plating medium but not with a medium composed of Trypticase, Phytone, dextrose and phosphate (TPDP). Recovery of injured spores was greatest in such a medium if it contained starch or charcoal. Trypticase soy agar and dextrose tryptone agar were markedly inferior to TPDP medium.
Effect of Inorganic Cations on the Biocidal and Cellular Activity of Glutaraldehyde
Authors: GORMAN S. P. , SCOTT EILEEN M.
Published: March 2008

Increased bactericidal activity was observed on addition of inorganic cations to both acid and alkaline glutaraldehyde solutions. Mg2+ ion in particular potentiated activity and this was attributed to cell surface effects due to osmotic forces resulting in greater uptake of disinfectant, reduction in cell volume and interference with enzyme activity associated with the cell wall.
Synergism between Chlorhexidine and Polymyxins against Pseudomonas aeruginosa
Authors: AL‐NAJJAR A. R. , QUESNEL L. B.
Published: March 2008

Chlorhexidine acts synergistically with the polymyxins B and E causing increased and rapid release of cell contents from Pseudomonas aeruginosa. While the polymyxin target molecule is phospholipid, evidence is provided for the proposal that the primary target for Chlorhexidine action is a protein component of the cytoplasmic membrane.
The Selectivity of Carbohydrate Assimilation by the Anaerobic Rumen Ciliate Dasytricha ruminantium
Authors: WILLIAMS A. G.
Published: March 2008

The extent of selectivity in the uptake and metabolism of soluble carbohydrates by the rumen ciliate Dasytricha ruminantium has been examined. The protozoon was not selective in the uptake of available carbohydrates and did not appear to regulate sugar entry by preferential or sequential utilization so that there was a concomitant assimilation of all utilizable soluble‐sugars regardless of molecular size or metabolic effects. The presence of readily fermentable substrates did not preclude the uptake and subsequent effects of the toxic monomers mannose and glucosamine hydrochloride. The characteristics of galactose co‐utilization differed from those of other monosaccharides examined. Although non‐metabolizable substrates did not impede the uptake or metabolism of effective substrates, maximum metabolite production rates were not maintained in the presence of slowly utilized substrates.
Effect of Packaging under Carbon Dioxide, Nitrogen or Air on the Microbial Flora of Pork Stored at 4°C
Authors: ENFORS S.‐O. , MOLIN G. , TERNSTRÖM A.
Published: March 2008

Changes in the microbial flora of pork packed in laminated plastic bags and stored at 4 °C were studied in an initial atmosphere of carbon dioxide, nitrogen or air. The time needed for the total aerobic count at 28 °C to reach 5 × 106 organisms/cm2 was about 7 times longer in carbon dioxide than in air, whilst in nitrogen it was about twice as long.

The predominant organisms on fresh pork taken directly from the processing line were: Acinetobacter calcoaceticus, non‐fluorescent Pseudomonas spp. and Flavobacterium spp. After storage in air for 7 d, more than 90% of the flora consisted of non‐fluorescent Pseudomonas spp. After storage in nitrogen for 10 d, 70% of the flora consisted of non‐fluorescent Pseudomonas spp. with lower levels of fluorescent Pseudomonas spp., Kurthia zopfii, Aeromonas hydrophila and Lactobacillus plantarum. The non‐fluorescent Pseudomonas spp. could be divided into three different groups, on proteolytic and lipolytic ability; the distribution of the groups was markedly different between pork loins stored in air and nitrogen.

On pork stored in carbon dioxide for 21 d the flora consisted of L. plantarum together with lower levels of heterofermentative lactic acid bacteria. When the storage time in carbon doxide was prolonged to 35 d, the proportion of heterofermentative lactic acid bacteria increased to about 50% of the flora.
Evaluation of Culture Media for the Isolation of Salmonellas from Sewage Sludge
Authors: EDGAR D. , SOAR M. S.
Published: March 2008

Ten samples of sewage sludge were examined by various methods for the isolation of salmonellas using three types of enrichment broth: Muller‐Kauffmann Tetrathionate Broth (MKTB), Selenite F Broth (SFB), and Brilliant Green Broth (BGB), two temperatures (37°C and 43°C) and three selective media: Deoxycholate Citrate Agar incubated aerobically (DCA), and anaerobically (DCA(N)), Brilliant Green Agar (BGA), and Bismuth Sulphite Agar (BSA). The results suggest that a combination of pre‐enriched MKTB incubated at 37°C and plated on to BGA at 24 and 48 h was the best method, but when examining contaminated material such as sewage sludge, it appears unwise to rely on one single method.
An Automatic Colorimeter and its use in Evaluating the Growth Response of an Anaerobic General Fatty Acid Auxotroph to cis‐ and trans‐Octadecenoic Acids
Authors: HAZLEWOOD G. P. , REYNOLDS M. J. , DAWSON R. M. C. , GUNSTONE F. D.
Published: March 2008

The construction and mode of operation of an automatic colorimeter is described. In illustrating its use to assess bacterial growth, it was shown that trans‐octadecenoates were more stimulatory to the growth of a fatty acid auxotrophic Butyrivibrio sp. than cis‐octadecenoates.
Isolation of Yersinia enterocolitica from Milk and a Dairy Farm in Australia
Authors: HUGHES DENISE
Published: March 2008

Forty‐eight isolates obtained from pasteurized milk and cream, raw milk, and various sites on a dairy farm were identified as Yersinia enterocolitica biotype 1 but were unusual in their ability to ferment lactose. The majority belonged to serotype 5a. Serotypes 5b, 6, 13/15 and 23/15 were also found. A few isolates were not typable. There is no evidence that strains isolated in this study are pathogenic for humans. Their presence in pasteurized products and growth at refrigeration temperatures are, however, cause for concern.
Effect of Storage at 1° and 4°C on Viability and Injury of Staphylococcus aureus, Escherichia coli and Streptococcus faecalis
Authors: PATTERSON THE LATE T. E. , JACKSON H.
Published: March 2008

Staphylococcus aureus and Escherichia coli incubated at 1° or 4°C became increasingly sensitive to Mannitol Salt Agar and Violet Red Bile Agar respectively. The increased sensitivity was most marked with exponential phase cultures. Streptococcus faecalis was refractory to similar treatments. The viability of all 3 organisms on selective and non‐selective media is reported.
Relationships Amongst the Fast‐growing Rhizobia of Lablab purpureus, Leucaena leucocephala, Mimosa spp., Acacia farnesiana and Sesbania grandiflora and their Affinities with Other Rhizobial Groups
Authors: TRINICK M. J.
Published: March 2008

Colony characteristics, growth in litmus milk, precipitation in calcium glycerophosphate medium and utilization of carbon sources of the root‐nodule bacteria isolated from the tropical legumes Leucaena, Mimosa, Acacia, Sesbania and Lablab were similar to fast‐growing rhizobia of temperate legumes, particularly Rhizobium meliloti. In agglutination tests, isolates from each host shared antigens with one or more of five Rhizobium strains from Leucaena. Infective characteristics of the fast‐growing rhizobia were studied in modified Leonard jars and in agar culture. Cross‐infections by rhizobia between these plants were common and the association often effective. Lablab was effectively nodulated by its own fast‐growing isolate but only formed root swellings, possibly ineffective pseudonodules, with the other isolates. Slow‐growing rhizobia which were able to nodulate Macroptilium atropurpureus were unable to form nodules on these legumes except Lablab which was considered more akin to the cowpea group. All fast‐growing isolates nodulated, often effectively, Vigna unguiculata and V. unguiculata ssp. sesquipedalis. The isolate from Lablab also effectively nodulated a number of other tropical legumes which have previously only been reported to nodulate with slow‐growing nodule bacteria and it also produced ineffective nodulation on Medicago sativa. This is the first record of an effective fast‐growing isolate from Lablab.
Water Relations of Glucose‐catabolizing Enzymes in Pseudomonas fluorescens
Authors: PRIOR B. A. , KENYON C. P.
Published: March 2008

Examination of the catabolism of glucose via the Entner‐Doudoroff pathway by standard enzyme assays showed that the activity of glucose‐6‐phosphate dehydrogenase, glucokinase and 2‐ketoglu‐conokinase plus phosphoketogluconate reductase was completely inhibited at aw values less than 0.965, 0.98 and 0.96 respectively when NaCl was used to adjust the aw. The other glucose‐catabolizing enzymes were inhibited to a lesser degree. When sucrose was used to control aw, glucokinase and glucose‐6‐phosphate dehydrogenase were inhibited at 0.92 aw but the other enzymes remained active below 0.86 aw. Enzymes were relatively active at reduced aw when adjusted with glycerol and most remained active even at 0.80 aw. When aw was controlled by potassium glutamate, the activity of glucokinase and glucose‐6‐phosphate dehydrogenase was markedly less inhibited than by NaCl at similar aw. Possible reasons for the variation in activity by glucose‐catabolizing enzymes in response to aw controlled by various solutes could be location of the enzyme in the cell, ability of the solute to penetrate the cell and ability to withstand high salt and sucrose concentrations. When the aw of the growth medium was reduced to 0.98 by glycerol, NaCl and polyethylene glycol 400, levels of glucokinase were significantly reduced while higher levels of glucose dehydrogenase and gluconate dehydrogenase were induced. This suggests that reduction in aw could regulate the routes of catabolism in the Entner‐Doudoroff pathway. When sucrose was used to control aw of the growth medium high levels of most enzymes were induced, suggesting catabolism of the sucrose by the organism.
Studies on Acid Tolerance of Rhizobium trifolii in Culture and Soil
Authors: BROMFIELD E. S. P. , JONES D. GARETH
Published: March 2008

Several experiments were carried out in an attempt to isolate and adapt strains of Rhizobium trifolii to growth at low pH on citrate‐phosphate buffered yeast‐extract mannitol agar (CPYEM). In another experiment, two streptomycin resistant strains (7A strr and 16 strr) with contrasting tolerances to acidity in culture were evaluated for survival in acid upland soils.

No acid tolerant clones were isolated from three strains on CPYEM suggesting that there were no cells with greater tolerance of low pH present. The stepwise subculture of several strains on media of decreasing pH also failed to increase their acid tolerance. Growth initiation on CPYEM at pH 4–4 was a function of the number of viable cells in the inoculum and was accompanied by a rise in pH.

In three acid soils, strain 7A strr was more persistant than 16 strr, whereas in culture the converse was true. Survival of these strains in the acid soils was inversely related to acid production on the medium of Norris (1965) in agreement with Norris's hypothesis. Ameliorating soil pH with lime improved the persistency of both strains. Prior exposure of 7A strr and 16 strr to the acid soils failed to improve subsequent survival in these soils.
A Note on the Separation of Natural Mixtures of Bacterial Menaquinones using Reverse Phase Thin‐layer Chromatography
Authors: COLLINS M. D. , SHAH H.N. , MINNIKIN D. E.
Published: March 2008

Natural mixtures of bacterial menaquinones were separated according to the length and degree of saturation of the polyisoprenyl side‐chain using ready made Merck RP‐18F254 reverse phase thin‐layer chromatography plates. The system described affords a simple and rapid means of menaquinone characterization.
Characterization of Fusobacterium Species Isolated from Soft Tissue Infections in Cats
Authors: LOVE DARIA N. , JONES R. F. , BAILEY MARILYN
Published: March 2008

A total of 35 strains of Gram negative anaerobes, belonging to the genus Fusobacterium and isolated from subcutaneous abscesses and pyothorax in cats, have been examined morphologically and biochemically. Gas chromatography and biochemical analysis placed them into four species—Fusobacterium necrophorum (seven strains), F. russii (22 strains), F. naviforme (four strains) and F. nucleatum (two strains). It is considered that subcutaneous abscesses and pyothorax result from contamination from the oral cavity and upper respiratory tract. The disproportionate numbers of isolation of F. russii may reflect differences in the predominant flora in this region of cats compared to man. The ambiguity of the concept in current literature of the ability of organisms to convert threonine to propionate is discussed.
Treatment of Cresol, Phenol and Formalin using Fixed‐film Reactors
Authors: SAYAMA N. , ITOKAWA Y.
Published: March 2008

The degradability of phenol, cresol and formalin, separately or in mixtures, was studied in a laboratory‐scale, submerged fixed‐film reactor and in a prototype trickling‐tower plant with recirculation of aerated effluent. The rates of degradation could be increased by 10–15 times by acclimating the reactors to increasing concentrations of disinfectants in the feed increasing daily from 10 to 1000 mg/1. After acclimation, detectable levels of disinfectants were only found in the liquor of the batch‐operated fixed‐film reactor after 24 h when the concentration of the daily dose exceeded 1100–1500 mg/1 and in the continuously‐fed trickling tower plant, when the feed concentration exceeded 1500 mg/1. It was possible in the reactor to treat cresol efficiently after acclimation to formalin and vice versa. Acclimation was shown to reduce diversity of bacterial species, the dominant isolates being Pseudomonos aeruginosa and other pseudomonads.
Relations of Selected Types of Micro‐organisms with the Vernal Phytoplankton Bloom in the Tvärminne Area, Southern Coast of Finland
Authors: VÄÄTÄNEN P.
Published: March 2008

The fluctuations of selected types of micro‐organisms were considered in relation to the vernal phytoplankton bloom, consisting mainly of diatoms, in the Tvärminne area in March‐June 1978. Water samples were taken almost daily from the surface layer during the bloom, which comprised two biomass (chlorophyll a) peaks.

Viable bacteria corresponded closely with the course of the bloom, the bacterial maxima occurring some days after the phytoplankton maximum. The bacteria apparently multiplied by mainly utilizing organic compounds released from decaying phytoplankton cells.

Proteolytic bacteria had their maximum below the ice in the low‐salinity surface layer, but showed a positive correlation with the bloom. They evidently utilized proteins supplied by domestic effluents as well as those released from phytoplankton cells. Yeasts showed no distinct connection with the bloom; they were probably unable to compete for nutrients with bacteria. The low numbers of yeasts during the bloom can mainly be ascribed to the mixing occurring after the break‐up of the ice, which decreased the yeasts of terrestrial origin in the surface layer.
Growth of Bacteria on Meat at Room Temperatures
Authors: GILL C. O. , NEWTON K. G.
Published: March 2008

The development of spoilage flora and the growth of individual psychrotrophs and pathogens on meat held at 20 or 30°C were studied. Under aerobic conditions psychrotrophic pseudomonads accounted for 60% of the spoilage flora at 20°C, but <20% at 30°C where they were displaced by species of Acinetobacter and Enterobacteriaceae which included both mesophilic and psychrotrophic strains. Mesophiles dominated the anaerobic spoilage flora at 30°C when clostridia were the major species, but at 20° the flora contained mesophiles and psychrotrophs in similar proportions and was dominated by Enterobacteriaceae. These results were largely predictable from the growth rate data for individual organisms.

Interactions between species occurred more frequently at 20°C than at 30°C. When pathogenic species were grown at 20 or 30°Cin competition with equal numbers of psychrotrophic spoilage organisms, no interactions were observed. When pathogens were grown in competition with high numbers of psychrotrophs, only Lactobacillus growing anaerobically inhibited Salmonella typhimurium and Escherichia coli, but other pathogens were inhibited to varying degrees depending on the competing species and the incubation conditions. In general, the degree of inhibition was greater at 20 than at 30°C and facultative organisms were more susceptible under anaerobic than aerobic conditions. It appears that the cumulative stresses of low pH, suboptimal temperatures and competition with large numbers of saprophytic organisms can inhibit many of the pathogens likely to be present on meat. The organisms least affected by the conditions on meat surfaces, Salmonella and Esch. coli, are likely to be the main hazards on meat of normal pH held at room temperatures.
Binding of Pseudomonas aeruginosa Lectin to Rhizobium sp.
Authors: GILBOA‐GARBER N. , MIZRAHI L.
Published: March 2008

Binding sites for the mannosephilic lectin of Pseudomonas aeruginosa and for concanavalin A were found on the nitrogen‐fixing symbiont Rhizobium sp. which infects Phaseolus lathyroides, and on the root cells of its host. The interaction between these lectins and the Rhizobium or the root cells was demonstrated by adsorption tests and by mannose‐specific peroxidase‐binding to the lectin‐coated bacteria. Treatment of the bacteria with formaldehyde, phenol, ethanol or boiling did not alter their ability to adsorb the lectins. The growth‐rate of the Rhizobium was unaffected when the Pseudomonas lectin was added to the culture medium. Addition of these lectins to the Rhizobium cells used for seedling infection led to an increased bacterial adsorption to seedling roots and to enlargement of nodule size, but did not increase nodulation.
Spreading of Salmonellas during Cattle Slaughtering
Authors: STOLLE A.
Published: March 2008

The spread of salmonellas during the slaughtering of cattle in the Berlin (West) slaughterhouse was investigated. The slaughterline was divided into 12 areas. During the first examination, which lasted eight months, the equipment and implements at each stage of slaughter, and faeces of cattle were tested. Salmonellas were not isolated from any of the 226 samples of faeces whereas 14 isolations (1.8%) were made from the 768 swabs taken from equipment. Most isolates were obtained within the step of opening the abdominal cavity.

In a second survey 61 (4.3%) of 1392 swab samples and 2 (0.75%) of 267 faeces samples were positive. Of the different processing steps, cutting off the hooves and loosening the skin of legs gave the highest recovery of salmonellas. Moderate recoveries were obtained after opening the abdominal cavity. Removal of head, loosening the skin of head, removing the hide and splitting the breastbone and the carcass did not result in the isolation of the organism. Salmonella anatum was the most common isolate. The same serotypes were isolated from both carcasses and equipment.
The Survival of Marine Bacteria under Starvation Conditions
Authors: JONES K. L. , RHODES‐ROBERTS MURIEL E.
Published: March 2008

The survival under starvation conditions of two selected strains of marine bacteria, a yellow Pseudomonas sp. (strain 95A) and an unidentified oxidative peritrichate Gram negative rod (strain 41), was investigated. The 50% survival times of suspensions in phosphate buffer depended on cell density and were often more than 20 d. A capacity to scavenge atmospheric nitrogenous compounds led to a marked increase in the viability of cell suspensions of 104 cells/ml. Intracellular poly‐β‐hydroxybutyrate (PHB) prolonged the survival of strain 95A. Strain 41 contained more intracellular protein and this was degraded during starvation in ammonia‐free air. Prolonged survival was not explicable in terms of low adenylate charge states. The ‘maintenance energy’requirements of strains 95A and 41 in chemostat cultures were 0.042 and 0.04 g glucose/g dry wt/h respectively, compared with dilution‐rate‐dependent values of 0.051 to 0.856 for Escherichia coli. The low maintenance energy requirements would not alone explain the long viability. Thus no peculiar physiological property such as nitrogen‐scavenging, ability to survive at the expense of intracellular PHB or protein, abnormally low cellular protein content, low maintenance energy requirements or a low adenylate charge state fully account for the starvation resistance of these marine bacteria.
The Role of Thiamine as a Factor for the Growth of Brochothrix thermosphacta
Authors: MACASKIE LYNNE E. , DAINTY R. H. , HENDERSON P. J. F.
Published: March 2008

Thiamine enhances growth of the meat spoilage organism, Brochothrix thermosphacta. It fulfils some, but not all, of the yeast‐extract requirement of this organism. Oxythiamine acts as a growth inhibitor at high concentrations and the inhibition is readily reversed by thiamine. The possible roles of thiamine in the metabolism of Br. thermosphacta are discussed.
A Note on the Detection of Phytopathogenic Bacteria within the Leaf by a Differential Staining Procedure
Authors: BASHAN Y. , KRITZMAN G. , SHARON EDNA , OKON Y. , HENIS Y.
Published: March 2008

A simple differential staining procedure for demonstrating infection within the leaf tissue by Pseudomonas tomato, Ps. lachrymans and Xanthomonas vesicatoria has been developed. It is based on (1) clearing of plant tissue with a mixture of glycerol, lactic acid, phenol and water; (2) treating the leaf tissue with boiling KOH; and (3) staining with aniline blue‐chloralhydrate. When observed under a light microscope, the bacteria appear dark blue, whereas the leaf tissue appears transparent and colourless.
Aeromonas hydrophila: Ecology and Toxigenicity of Isolates from an Estuary
Authors: KAPER J. B. , LOCKMAN H. , COLWELL R. R. , JOSEPH S. W.
Published: March 2008

A microbiological survey of Aeromonas hydrophila in Chesapeake Bay and its tributaries showed that this species is ubiquitous, occurring in numbers ranging from <0.3/l to 5 × 103/ml in the water column and ca. 4.6 × 102/g in sediment. It was recovered from water samples collected at several locations in Chesapeake Bay representing various salinity regimes, but the numbers of A. hydrophila in higher salinity water, i.e. 15O/OO, were low. Results of stepwise multiple linear regression analysis showed that concentrations of A. hydrophila were correlated with total, aerobic, viable, heterotrophic, bacterial counts, and, in addition, were inversely related to salinity and to concentration of dissolved oxygen. Seasonal occurrence was recorded, with fewer strains of A. hydrophila encountered during the winter months. The potential pathogenicity of A. hydrophila strains isolated from Chesapeake Bay was estimated by testing selected isolates for toxigenicity, using the Y‐1 adrenal cell assay. Of 116 isolates tested, 83 (71%) produced a cytotoxic response, a characteristic found to be correlated with the lysine decarboxylase and Voges‐Proskauer reactions. Eight of 11 strains tested, which elicited fluid accumulation in the rabbit ligated ileal loop assay, also provoked a cytotoxic reaction in the Y‐l adrenal cell assay. Results of the study indicate that large numbers of toxigenic A. hydrophila can be found in an estuary and such strains may be pathogenic for man and/or animals.
Rapid Identification and Serotyping of ‘Bacteroides fragilis’ in Clinical Material by Direct Immunofluorescence
Authors: GRZELAK‐PUCZYNSKA IRENA , MEISEL‐MIKOŁAJCZYK FELICJA
Published: March 2008

Material from 32 patients, mostly after abdominal surgery, was examined by the direct immunofluorescence test (IFT) using the conjugates against six ‘Bacteroides fragilis’ serotypes. In most cases ‘B. fragilis’ strains could be detected in direct smears of the clinical material. There was good agreement between the results obtained by IFT and cultural methods.
Nutritional Requirements of the Micro‐organisms Active in the Oxidation of Ferrous Iron in Acid Mine Leach Liquors
Authors: RAWLINGS D. E.
Published: March 2008

The nutritional requirements for the oxidation of ferrous iron in acid mine water by fixed films of micro‐organisms were investigated. Supplementing the mine leach liquor with additional ammonium, phosphate and potassium did not improve the efficiency of ferrous iron oxidation. The minimum non‐limiting requirement of the ferrous iron oxidizing organisms for these nutrients was (mg/l): ammonium, 10; phosphate, 45, and potassium, 2·5. A strain of Thiobacillus was isolated which was able to grow on a medium to which only dihydrogen potassium phosphate, ferrous sulphate and agar had been added.
Iron Oxidation not Coupled to Growth in Thiobacillus ferrooxidans in Presence
Authors: ROY P. , MISHRA A. K.
Published: March 2008

Growth and iron oxidation by Thiobacillus ferrooxidans are affected by the presence of silver, molybdenum, uranium and copper. Growth is more sensitive to the presence of these metals than the iron oxidation system of the bacterium. Silver toxicity is much more specific than molybdenum and uranium. Iron oxidation is inhibited at only 0.1 parts/106 of silver which is 300 and 5000 times less than the minimum inhibitory concentration of molybdenum and uranium, respectively. Copper and zinc at concentrations as high as 2000 and 15 000 parts/106, respectively, have no influence on the iron oxidation rate. In the presence of silver, molybdenum, uranium and copper below their minimum inhibitory concentrations as well as in the absence of nitrogen, phosphorus and potassium, iron oxidation is not coupled to growth.
A Note on the Inhibition of Pseudomonas aeruginosa by a Modification of Brilliant Green Agar for Improved Salmonella Isolation
Authors: WALKER A. P.
Published: March 2008

A strain of Pseudomonas aeruginosa having colonies that resemble those of salmonellas on brilliant green agar is almost totally inhibited by the addition of 1.0 mg/ml of sulphacetamide to the medium. Low numbers of Ps. aeruginosa grew equally well on brilliant green and nutrient agar, but 106–107 organisms were needed before any growth appeared on the medium containing sulphacetamide. During 12 months of routine use of the sulphacetamide medium, involving almost 3000 plates, Ps. aeruginosa has been isolated as a contaminant only once. Forty‐seven salmonella serotypes were grown on the sulphacetamide brilliant green agar in the same period.
Isolation and properties of psychrotrophic and psychrophilic, pectolytic strains of Clostridium
Authors: Brocklehurst T.F. , Lund Barbara M.
Published: March 2008

Fourteen strains of pectolytic clostridia have been isolated that were capable of growth at 5–10°C in 7 d; two strains were psychrophiles and failed to grow at 20°C in 14 d and the remainder were psychrotrophs. The bacteria formed pectate lyase enzymes and were capable of degrading potato tissue; they are therefore a potential cause of soft rot of potatoes stored at low temperatures. Doubling times for representative strains were 15–19 h at 10°C and 21–53 h at 5°C. Twelve strains were classified with Group I Clostridium species and two strains with Group II. In the case of one strain the mature spores were not released from the sporangium. Electron microscopy of ultrathin sections of this strain showed the presence of disorganized lamellar structures associated with the spore coat.
Influence of Clostridium saccharolyticum on cellulose degradation by Acetivibrio cellulolyticus*
Authors: Khan A.W. , Murray W.D.
Published: March 2008

The interrelationship between Acetivibrio cellulolyticus and Clostridium saccharolyticum, two anaerobes recently isolated from a methanogenic cellulose‐enriched culture, was studied in an examination of the role of saccharolytic anaerobes in habitats where cellulose is converted to methane. The presence of Cl. saccharolyticum decreased cellulose degradation by A. cellulolyticus as a result of substrate competition. Nevertheless A. cellulolyticus provided essential growth factor(s) and assimilable sugars including glucose which A. cellulolyticus itself does not utilize. Cl. saccharolyticum converted sugars to acetic acid and H2, known substrates for methanogens, and ethanol and lactic acid, known substrates for sulphate reducing bacteria. In natural habitats, the presence of both methanogens and sulphate reducing bacteria is essential for the existence of cellulolytic anaerobes.
An enzyme system hydrolysing the polysaccharides of Xanthomonas species
Authors: Sutherl I.W.
Published: March 2008

Enzymes hydrolysing the exopolysaccharides of Xanthomonas campestris and related species (xanthan) have been obtained from a Bacillus species isolated by enrichment culture. Growth on xanthan induced a number of enzymes acting on the xanthan molecule. These included one or more β‐glucanohydrolases and β‐glucosidases, together with mannosidases. The former activities were also present in cultures grown in the presence of laminaran or scleroglucan, but not in simple synthetic media with glucose as substrate. Partial purification of the enzymes active on glucans was achieved by ammonium sulphate precipitation and chromatography on DEAE‐sepharose and CM‐sepharose. The specificity of the β‐glucosidase and the β‐glucanohydrolase were investigated. Several β‐glucans were hydrolysed to glucose and disaccharides, but there was no activity against β→ 6 linked polymers, cellulose azure or microcrystalline cellulose. Carboxymethylcellulose was hydrolysed, as were laminaran, scleroglucan and pachyman. Activity was greater against the β→ 4 linked glucans than against the β→ 3 linked glucans tested. As periodate‐oxidized laminarin was also hydrolysed, it was concluded that the glucanohydrolase acted as an endoenzyme. The β‐glucosidase had a pH optimum at about 8–2 and a temperature optimum at 45°C; it showed higher activity against o‐nitrophenyl‐D‐glucopyranoside, cellobiose, trehalose and sophorose than against gentibiose.
A note on two uses for impedimetry in brewing microbiology
Authors: Evans H.A.V.
Published: March 2008

Abstact

The forcing test used in the brewing industry is shortened from a few weeks to a few days using a new protocol employing impedimetry. The generation times of four different brewing yeasts growing in brewery wort were calculated from measurements obtained using impedimetry.