bluuebunny/crossref_metadata_2025 huggingface dataset:
The bacterial population of a blanket peat
Authors: Martin N.J. , Siwasin J. , Holding A.J.
Published: March 2008

The number of aerobic bacteria in a blanket peat decreased with depth from 26 times 106/g dry peat in the surface layers to 0.5 times 106/g dry peat at 30–40 cm down the profile, thereafter remaining roughly constant. Obligate psychrophiles comprised <2.5% of this population. Anaerobes were most numerous, 9 times 106/g dry peat at 6–10 cm depth, decreasing to 0.5 times 106/g at 20–30 cm. Calculations indicated that these counts, 103–104‐fold lower than the direct counts, substantially underestimated the active microbial population. Gram negative rods, the predominant aerobes in the surface layers, were replaced by unidentified Bacillus strains at 10–20 cm depth but became increasingly more numerous further down the profile. The Gram negative rods were the most numerous organisms/m2 but the Bacillus strains, one third of which were present as spores, made the largest contribution to the biomass/m2. Gram positive cocci, Arthrobacter and, infrequently, Nocardia were also isolated. Actinomyces‐like forms were the predominant obligate anaerobes and were approximately three times more numerous than clostridia and a curved Gram negative rod.
The effects of nutrient limitation and growth rate in the chemostat on the immunogenicity of Vibrio cholerae
Authors: Green J.A.
Published: March 2008

The possibility was examined of using the chemostat to produce cholera vaccine of immunogenicity similar or superior to that of conventional vaccine produced from organisms grown on nutrient agar. The immunogenicity in mice of vaccines prepared from organisms grown under carbon, nitrogen, magnesium and phosphate limitation each at low and high growth rates was inferior to that of conventional vaccine. It was concluded that under the conditions used in this study the chemostat could not be used to produce cholera vaccine of acceptable immunogenicity. The sensitivity of organisms grown under the same conditions in the chemostat to agglutination by specific agglutinating antiserum showed phenotypic variation and under carbon limitation was growth rate related, although the increased sensitivity to agglutination of carbon‐limited organisms at high growth rates was not paralleled by increased ability of these organisms to induce agglutinating antibodies.
The effects of low dissolved oxygen tension during the aerobic treatment of piggery slurry in completely mixed reactors*
Authors: Smith M.P.W. , Evans M.R.
Published: March 2008

The energy requirement for aerobic treatment of animal excreta is minimal when the dissolved oxygen (DO) level is as low as possible. The efficiency of continuous aerobic treatment at 15°C in terms of the removal of carbonaceous materials was found to be the same at DO levels as low as 1% of saturation as at high DO levels. However, up to 45% of the total input nitrogen and 90% of the soluble nitrogen were lost from the slurry during treatment at low DO. This loss was the result of the simultaneous occurrence of nitrification and denitrification within the completely mixed reactor. It was also observed that low DO levels favoured nitrification during aerobic treatment. This resulted from the activity of denitrifying bacteria which raised the pH and removed the inhibitory effect of acidic conditions upon the nitrifiers. Control of the pH value at pH 7.1 during aerobic treatment resulted in the complete oxidation of the ammonia content of piggery slurry.
Taxonomic studies on Corynebacterium beticola (Abdou)
Authors: Collins M.D. , Jones Dorothy
Published: March 2008

Morphological, physiological and chemical studies were performed on the type strain of Corynebacterium beticola in an attempt to clarify its taxonomy. The results indicate that Corynebacterium beticola is a Gram negative, facultatively anaerobic bacterium which should be assigned to the genus Erwinia as Erwinia herbicola.
An improved technique for the isolation of holotrich protozoa from rumen contents by differential filtration with defined aperture textiles
Authors: Williams A.G. , Yarlett N.
Published: March 2008

An improved differential filtration method for the isolation of preparations of the holotrich protozoa Dasytricha ruminantium and mixed Isotricha prostoma and I. intestinalis from rumen contents is described. The technique utilizes combinations of defined aperture Nylon or polyester textiles, which are superior to the sintered glass filters previously used in the isolation of rumen protozoa. Data obtained in a comparative study of some aspects of the metabolic activity exhibited by cell preparations isolated by the two filtration procedures are presented.
Contamination of broiler chickens by Staphylococcus aureus during processing; incidence and origin
Authors: Notermans S. , Dufrenne J. , van Leeuwen W.J.
Published: March 2008

Staphylococcus aureus was present in only small numbers (ca 10/g) on the skin of broiler chickens before processing. During processing, contamination of carcases with this organism increased to > 103/g of skin. Based on the results of phage typing, it was shown that the increase in contamination was due to a strain of Staph. aureus which was indigenous to the processing plant. Plucking and evisceration appeared to be the main stages at which contamination of carcases with Staph. aureus occurred.
A note on a new defined medium for ‘Pseudomonas tomato’
Authors: Bashan Y. , Okon Y. , Henis Y.
Published: March 2008

A synthetic medium based on d‐galactose as a single carbon source and either l‐asparagine, l‐glutamine or l‐threonine as a single nitrogen source has been developed for Pseudomonas tomato. The growth of Ps. tomato on this medium was equal to its growth on commonly used complex media.
Simple identification of anaerobic bacteria to genus level using typical antibiotic susceptibility patterns
Authors: Essers L.
Published: March 2008

Simple yet comprehensive identification of anaerobic bacilli is possible to genus level when typical susceptibility patterns of antimicrobial substances are used in combination with the morphological characteristics of the bacteria. Paper discs were soaked with fosfomycin (100 μg), colistin (10 μg), everninomicin B (10 μg) and metronidazole (2 μg) and tested on sheep blood agar in a jar under anaerobic conditions. A dichotomous scheme has been suggested for the differentiation of the following genera: Actinomyces, Bacteroides, Bifidobacterium, Clostridium, Eubacterium, Fusobacterium, Lactobacillus, Leptotrichia, Propionibacterium and Selenomonas. The method gave preliminary results which can be used as guidance for subsequent species identification and for therapeutic advice, as antibiotic susceptibility depends very much on the genus of anaerobic bacilli.
Inhibition of growth of Brochothrix thermosphacta by palmitic acid
Authors: Macaskie Lynne E.
Published: March 2008

Palmitic acid was inhibitory to the growth of Brochothrix thermosphacta in liquid culture at 0.5 mmol/l. Uptake of [1‐14C]‐palmitic acid by the organism has been demonstrated, and was reduced at acid pH. These findings are discussed in relation to the known effects of fatty acids on bacteria.
Ecological studies on the occurrence of bacteria utilizing lactic acid at pH values below 4.5
Authors: Aries Vivienne , Cheney P.A. , Mossel D.A.A.
Published: March 2008

Sites within two cheese factories, a silage tower and silage pit and two pet food factories were investigated for lactic acid utilizing bacteria. The bacteria isolated, together with known lactic acid utilizing and aciduric bacteria, were tested for their ability to ‘alkalinize’ a fermented meat product containing more than 20 g/1 lactic acid at pH > 4.3 a ten‐fold dilution of this product and synthetic media, both at pH 4.5. Strains able to alkalinize the diluted product were 13 aerobic isolates (all Acetobacter spp.), nine anaerobic cultures, one strain of Megasphaera elsdenii and two strains of Clostridium tyrobutyricum. Eight of the aerobes could alkalinize undiluted product containing < 1 g/1 residual potassium sorbate, but had no effect on product containing > 3 g/1 sorbate; none of the anaerobic cultures was able to alkalinize undiluted product. Acetobacter spp., therefore, threatened the microbial stability of a fermented product containing < 3 g/1 potassium sorbate. The cultures able to alkalinize diluted product were all from sites contaminated with whey, silage or fermented product for at least 2 d, suggesting substantial accumulation of lactic acid utilizing bacteria at these sites.
A conductance method for the assay and study of bacterial trimethylamine oxide reduction
Authors: Easter M.C. , Gibson D.M. , Ward F.B.
Published: March 2008

Bacterial growth and trimethylamine oxide (TMAO) reduction were measured by following the change in conductance of the growth medium. The method was used as a reliable taxonomic test for the ability of bacteria to reduce TMAO. Conductance measurements were also applied to assaying the enzyme TMAO reductase in resting cells of the marine alteromonad NCMB 400: the enzyme was only active under anaerobic conditions with pyruvate, lactate and formate being good donors; the KmTMAO was 93 ± 16 μmol/1; TMAO reductase activity was inhibited by several N‐oxides including nitrite and nitrate, and was relatively resistant to cyanide. The relevance of conductance measurements and the significance of TMAO reduction are discussed.
The description of strains of anaerobic ‘corroding’ organisms isolated from soft tissue infections in cats and dogs
Authors: Love Daria N. , Jones R.F. , Bailey Marilyn
Published: March 2008

Thirty‐eight strains of Gram negative anaerobic ‘corroding’ rods were isolated from subcutaneous abscesses and pyothorax in cats and dogs. These organisms all exhibited the colony morphology and biochemical properties of organisms described as Bacteroides ureolyticus (Jackson & Goodman 1978) except that they did not hydrolyse urea and they had a guanine plus cytosine ratio of 39–44 mol%. As described for Bact. ureolyticus, 11 of the strains were non‐motile. The remaining 27 strains were motile and exhibited a single polar flagellum when examined by negative staining with phosphotungstic acid in an electron microscope. The motile organisms resembled the so‐called ‘anaerobic vibrios’ or Vibrio succinogenes except that these organisms are curved do not liquefy gelatin and are thought by some to have a G + C ratio of 49 mol%. The non‐motile strains fitted no group described previously.
Experimental ecological studies on H2 plasmids in the intestine and faeces of the calf
Authors: Timoney J.F. , Linton A.H.
Published: March 2008

In vivo transfer of a typical H2 plasmid (pJT4) was not detected in groups of calves experimentally given large numbers of donor and genetically marked recipient Escherichia coli strains when the calves were muzzled and so denied oral contact with their surroundings. Transfer to the marked recipient and to a number of other Esch. coli strains was, however, observed when muzzles were not used or were removed during an experiment. pJT4 was transferred in voided faeces at 30°C but not at 37°C. These results suggest that H2 plasmids do not transfer in the intestine and most probably are acquired by conjugations in the animal's environment. Experiments with calves using sets of isogenic strains of Esch. coli, with and without pJT4, showed that the presence of the plasmid greatly increased the persistence of the host organism in the intestine. Strains with the plasmid persisted for 20 d or longer; strains cured of the plasmid decreased rapidly in number after 7 days. This phenomenon may be an important factor in the epidemicity in the calf of strains of Salmonella typhimurium that carry H2 plasmids.
Accumulation of carbohydrate by Escherichia coli B/r/1 during growth at low water activity
Authors: Roller S.D. , Anagnostopoulos G.D.
Published: March 2008

The carbohydrate content of Escherichia coli B/r/1, grown in a glucose or arabinose‐limited salts medium in a chemostat, increased by a factor of 2–4 when the water activity (aw) of the medium was reduced to 0.986 by addition of NaCl, KCl or sucrose. The biomass decreased by 30–45%. The sucrose system resulted in the lowest biomass and carbohydrate content. The monosaccharide part of the accumulated carbohydrate consisted of glucose or glucose and arabinose in the cultures fed glucose and arabinose, respectively, and accounted for 50% or more of the total carbohydrate in the NaCl and KCl systems and 16.79% in the sucrose system. In addition, the K+ content depended on the solute and related inversely to the monosaccharide content, being highest in the sucrose system. The combined molarity of the monosaccharide and K+ was deduced to be far in excess of that required for osmotic equilibration of the cultures, especially in the sucrose system. These observations are discussed in the context of osmoregulation, the effects of solutes on glucose metabolism and the morphological changes that occur in cultures at low aw.
A note on fermentation reactions of anaerobic bacteria on a solid medium
Authors: Occhionero M. , Luzzi I. , Mastrantonio P. , Panichi G. , Pantosti A.L.
Published: March 2008

A new technique is described for fermentation tests of anaerobes in which the fermentation reactions are carried out on cystine trypticase agar plates to which fermentable substances (Taxo discs) are added. This technique is simple, sensitive and reproducible.
A note on the separation of natural mixtures of bacterial menaquinones using reverse‐phase high‐performance liquid chromatography
Authors: Collins M.D.
Published: March 2008

Natural mixtures of bacterial menaquinones were separated according to the length and degree of hydrogenation of the polyisoprenoid side‐chain using reverse‐phase high‐performance liquid chromatography. The chromatographic system described affords a sensitive and rapid means of menaquinone characterization.
Physiological and pathological characteristics of Erwinia chrysanthemi isolates from potato tubers
Authors: Cother E.J. , Powell Vivienne
Published: March 2008

Nine isolates of Erwinia chrysanthemi from rotting potato tubers were compared with six type or reference strains of this species. Phenotypic properties of the potato isolates closely agreed with those of Erw. chrysanthemi pv. zeae and with the characteristics proposed for Dickey's infrasubspecific subdivision IV (1979) and Samson & Nassan‐Agha's biovar 3 (1978), where Zea mays was among the most common host species. Pathogenicity tests on 20 ornamental and agricultural species showed only Cyclamen sp. and Z. mays to be susceptible. In Ouchterlony double diffusion tests, antisera to whole live cells of one potato strain reacted with four of the six pathovars of Erw. chrysanthemi. Tuber isolates did not produce blackleg symptoms in inoculated stems. The rationale of intensive pathogenicity testing is discussed.
Incidence of antibiotic‐resistant Escherichia coli in milk produced in the west of Scotland
Authors: Johnston D. W. , Bruce J. , Hill J.
Published: March 2008

Antibiotic‐resistant Esch. coli were found in 10.6% of milk samples collected from 998 farms in the west of Scotland. The incidence of both Esch. coli and antibiotic‐resistant Esch. coli in milk was higher when the cattle were housed day and night than when they were outdoors. Of the 1125 Esch. coli isolates tested 22.2% were antibiotic resistant and of these 42.4% were resistant to more than one antibiotic. Escherichia coli carrying up to six resistance determinants were isolated. The possible implications to animal and human health are discussed.
Development of a blood‐free Campylobacter medium: screening tests on basal media and supplements, and the ability of selected supplements to facilitate aerotolerance
Authors: Bolton F.J. , Coates D.
Published: March 2008

The capacity of six basal media to support the growth of thermophilic campylobacters was tested. The most successful was Nutrient Broth No. 2 (Oxoid) solidified with New Zealand agar but it gave at best only a 9% recovery rate. Various blood products, iron compounds, detoxifying agents, reducing agents, growth stimulants and an antimetabolite were added to the selected basal medium and counts of inoculated organisms were compared with counts on basal medium containing 5% lysed horse blood. Of 22 supplements tried only blood, Fildes' peptic digest of blood, haematin, iron salts, charcoal, sodium metabisulphite and sodium pyruvate greatly improved the basal medium. The ability of these supplements used singly and in combinations to facilitate aertolerance of campylobacters was investigated. Two aspects of aerotolerance were tested; (a) the ability of the supplements to sustain the viability of campylobacters seeded onto culture plates left on the bench for up to 6 h before microaerobic incubation; and (b) the ability of the supplements to facilitate the growth of campylobacters at increasing oxygen tension (6, 10 and 17% oxygen). A combination of 0.4% charcoal, 0.025% ferrous sulphate and 0.025% sodium pyruvate was found to be as effective as blood in both tests.
A note on the antibiotic susceptibilities of Clostridium perfringens serotypes isolated from meat
Authors: Smart J.L. , Truman M.L. , Stringer M.F.
Published: March 2008

The susceptibilities to six antibiotics have been determined of Clostridium perfringens serotypes isolated from beef, pork and lamb carcases and from minced beef. Generally similar results were obtained to those of previous studies of mainly clinical isolates. Fourteen of the 229 strains tested were resistant to tetracycline; three of these, from the same beef carcase, were also resistant to erythromycin.
Egg‐yolk trypticase soy agar for the enumeration of heat‐damaged spores of Clostridium sporogenes
Authors: Michels M.J.M. , Kagei R.F.
Published: March 2008

In heat‐resistance studies with spores of Clostridium sporogenes BC‐2, an improved recovery medium was needed for severely heat‐damaged spores as that used previously—Wynne medium in Miller‐Prickett tubes—did not allow accurate counts of spores because of gas formation and disruption of agar. Initial tests with pour plates of Viande‐Levure medium containing egg‐yolk gave much increased counts for spores previously heated for 50 min at 112°C; this increase was attributed to the presence of egg‐yolk. Addition of egg‐yolk to Reinforced Clostridial Agar, All‐Culture Medium and Trypticase Soy Agar showed that Trypticase Soy Agar with egg‐yolk was the best recovery medium. For the final formulation, the value of supplementation with cysteine‐HCl and methylene blue was also shown. The resultant Egg‐yolk Trypticase Soy Agar is conveniently prepared from BBL Trypticase Soy Agar (40 g) with the addition of 0.4 g/l cysteine‐HCl, 4 mg/1 of methylene blue and 2% Oxoid egg‐yolk emulsion aseptically to the melted basal medium. For optimal spore counts, pour plates are incubated anaerobically for 5–7 d at 30°C.
Characterization of black‐pigmented Bacteroides strains isolated from animals
Authors: Laliberté Monique , Mayrand D.
Published: March 2008

The aims of the study were: the isolation of strains of black‐pigmented Bacteroides from the gingival sulcus of different animals, their biochemical and immunological characterization and comparison of their properties for classification within the genus. A total of 104 strains, isolated from cats, dogs, racoons and a jaguar, were characterized on the basis of fermentation of carbohydrates, metabolic end products, haemagglutination studies, enzymatic activities, catalase production and indirect immunofluorescence. No differences were observed between the strains regardless of their animal origin. The strains did not ferment carbohydrates, produce phenylacetic acid, show an array of enzyme activities or agglutinate sheep red blood cells. They were catalase‐positive and so differed from the human oral strains of Bact. gingivalis. Immunofluorescence microscopy revealed that the animal strains shared at least one major antigen with Bact. gingivalis but none with Bact. asaccharolyticus. Apart from their catalase activity, the animal strains isolated were similar to those of human Bact. gingivalis strains.
An electron microscope study of wheat straw composted as a substrate for the cultivation of the edible mushroom (Agaricus bisporus)
Authors: Atkey P.T. , Wood D.A.
Published: March 2008

The degradation of wheat straw, during composting, to produce the growth substrate for the edible mushroom (Agaricus bisporus), and subsequent colonisation by the fungal hyphae, was studied by electron microscopy which revealed an ecological succession of micro‐organisms, initially dominated by a largely bacterial flora with few fungi. Later in the composting process actinomycetes were dominant. The initial rise in numbers of vegetative bacterial cells was followed by a steady decline and the appearance of spore forms. Several modes of microbial attack were observed. The most rapid degradation occurred initially on the cuticle and in the phloem and spread to a general degradation of all the plant tissue types present. Microbial attachment on the plant cell walls was non‐uniform. As a result of these processes many of the plant fibres became separated but the final material still retained considerable structural integrity. Agaricus bisporus mycelium rapidly covered the surface of the straw but colonised the internal straw tissues more slowly. Surface‐growing hyphal cells were encrusted with needle‐like crystals presumed to be calcium oxalate.
Observations on the enumeration of moulds in food and feedingstuffs*
Authors: Jarvis B. , Seiler D.A.L. , Ould Angela J.L. , Williams A.P.
Published: March 2008

This paper considers the technical problems associated with the quantitative analysis of mould in foods and feedingstuffs. It seeks to define a philosophy concerning the use of quantitative mycological data in advisory, investigatory and quality assurance situations and stresses the need for quantitative estimates always to be aligned with qualitative assessment of the mycoflora of foods and feedingstuffs.
A note on hydrolytic enzymes of Corynebacterium equi
Authors: Mutimer M.D. , Woolcock J.B.
Published: March 2008

One hundred and five strains of Corynebacterium equi from various sources were examined for the production of 11 extracellular enzymes. Only lipase and phosphatase activity were detected in all strains. A small number of strains produced deoxyribonuclease but these strains were not confined to any one source. It seems likely that C. equi does not rely on a powerful array of extracellular enzymes to induce pathology.
Separation of bacteria from a methanogenic wastewater population by utilizing a self‐generating Percoll gradient
Authors: Scherer P.
Published: March 2008

Bacteria from a methanogenic wastewater population could be separated with a self‐generating density gradient of Percoll. The separation was performed by centrifugation for 30 min at 30000 g in a simple angle‐head rotor. Three types of bacteria were concentrated to apparent homogeneity in different bands; these were attributed to the methanogens Methanosarcina and Methanothrix, and to the dissimilatory sulphate‐reducing bacterium Desulfovibrio. The described technique will contribute to a rapid diagnosis of the bacterial types that are active in waste‐water treatment.
Mechanism of chemical manipulation of the heat resistance of Clostridium perfringens spores
Authors: Ando Yoshiaki , Tsuzuki Toshibumi
Published: March 2008

The mechanism(s) of chemical manipulation of the heat resistance of Clostridium perfringens type A spores was studied. Spores were converted to various ionic forms by base‐exchange technique and these spores were heated at 95°C. Of the four ionic forms, i.e. Ca2+, Na+, H+ and native, only hydrogen spores appeared to have been rapidly inactivated at this temperature, when survivors were enumerated on the ordinary plating medium. However, the recovery of the survivors was improved when the plating medium was supplemented with lysozyme, and more dramatically when the heated spores were pretreated with alkali followed by plating in the medium containing lysozyme. In contrast to crucial damage to germination, in particular to spore lytic enzyme, no appreciable amount of DPA was released from the heat‐damaged H‐spores. These results suggest that a germination system is involved in the thermal inactivation of the ionic forms of spores, and that exchangeable cation load plays a role in protection from thermal damage of the germination system within the spore. An enhancement of thermal stability of spore lytic enzyme in the presence of a high concentration of NaCl was consistent with the hypothesis.
The effect of parabens on DNA, RNA and protein synthesis in Escherichia coli and Bacillus subtilis
Authors: Nes Ingolf F. , Eklund Trygve
Published: March 2008

The effect of methyl, propyl and butyl esters of p‐hydroxybenzoic acid on DNA and RNA synthesis has been tested in toluenized cells of Escherichia coli and Bacillus subtilis. Both RNA and DNA synthesis of these bacteria were inhibited. The inhibitory concentrations were higher than those previously reported for growth inhibition. Protein synthesis in cell‐free extracts (S‐30 fraction) of B. subtilis was even more sensitive to parabens than DNA and RNA synthesis, while protein synthesis in Esch. coli was largely unaffected.
Selective media for three biovars of Agrobacterium
Authors: Brisbane P.G. , Kerr A.
Published: March 2008

Three selective media for the isolation of the three known biovars of Agrobacterium are described. Selectivity was based on carbon and nitrogen sources; L(—)‐arabitol for biovar 1, erythritol for biovar 2 and a combination of tartrate and D‐glutamate for biovar 3. The new media were compared with existing selective media. Recovery of agrobacteria from soil was very efficient and discrimination between the three biovars was satisfactory except for tartrate‐utilising biovar 1 isolates which grew on the biovar 3 medium. Some strains of Pseudomonas sp. isolated from crown galls on vine could utilise octopine as a source of carbon and nitrogen.
Factors influencing the resistance of biological monitors to ethylene oxide
Authors: Dadd A.H. , McCormick Kathleen E. , Daley Gabrielle M.
Published: March 2008

The resistance of bacterial spore monitors is markedly influenced by the environmental conditions existing during development of the spores and, subsequently, in the preparation and evaluation of the monitor. Sporulation medium, suspending medium, pasteurization and storage conditions influence resistance of spores ofBacillus subtilisvar.nigerto ethylene oxide, but incubation temperature and age of sporulating culture appear to be unimportant. The conditions under which the spore suspension is dried on the supporting medium of the monitor exerts a major influence on resistance. Spores exposed to ethylene oxide are abnormally susceptible to damage by shaking with Ballotini, a method frequently used to recover spores from monitors. Nutritional conditions, pH and temperature of incubation influence the ability of survivors to form colonies on solidified media.
The microflora of stored coleslaw and factors affecting the growth of spoilage yeasts in coleslaw
Authors: Brocklehurst T.F. , White Cathryn A. , Dennis C.
Published: March 2008

Saccharomyces dairensis and Sacch. exiguus were isolated as the spoilage flora of coleslaw stored at 5° and 10°C. The growth of these yeasts in mixtures of mayonnaise with vegetable was inhibited by onion. Mayonnaise alone killed the yeasts, primarily because of its content of acetic acid and this effect increased as the temperature was increased and as the pH was decreased. Addition of cabbage or carrot tissue removed the lethal effect of mayonnaise and allowed spoilage, by absorbing acetic acid and increasing the pH.
Numerical taxonomy of some non‐saccharolytic and saccharolytic Bacteroides species
Authors: Knivett V.A. , Shah H.N. , McKee A.S. , Hardie J.M.
Published: March 2008

Various Bacteroides spp. were examined by physiological tests, presence of specific enzymes, antibiotic sensitivity, menaquinone composition and a few miscellaneous tests. The data matrix containing 58 strains and 55 unit characters was examined using Gower's similarity coefficients (SG) and included matching negative character states and multistate characters. The highly saccharolytic strains were separated from the less saccharolytic and non‐fermentative strains at the 55% similarity level; while at the slightly higher level of 63% strains of Capnocytophaga (formerly Bact. ochraceus) were recovered as a compact phenon distinct from other saccharolytic species. The phenogram was divided into 6 clusters at 72% similarity level. Most of the ‘Bact. fragilis group’ of species clustered in one phenon while Bact. melaninogenicus ssp. melaninogenicus, Bact. bivius and a new species, Bact. denticola, formed another group. Another phenon comprised the saccharolytic non‐pigmented species closely related to Bact. oralis such as Bact. buccalis and Bact. pentosaceus. The less saccharolytic strains of Bact. melaninogenicus ssp. intermedius and Bact. disiens were recovered in a distinct phenon. The low affinity (less than 55% similarity) between the two subspecies of Bact. melaninogenicus emphasised the need for reclassifying these taxa into separate species. The non‐fermentative and very weakly saccharolytic strains formed good taxospecies. The separation of this cluster into three subclusters is in excellent agreement with chemotaxonomic data now available.
The protective effect of some food ingredients on Staphylococcus aureus MF31
Authors: Hurst A. , Hughes A.
Published: March 2008

The upper limiting temperature of growth of Staphylococcus aureus MF31 in heart infusion broth (HI) was about 44°C but addition of monosodium glutamate (MSG) and soy sauce permitted the organism to grow above this temperature. This effect is similar to that of NaCl. Tomato ketchup, Worcestershire and HP sauces added to HI did not allow growth at the non‐permissive temperature of 46°C but death was delayed. Staphylococcus aureus died in unsupplemented chicken meat slurry at 46°C but grew at 48°C in slurry supplemented with 5.8% NaCl and survived incubation for 18 h at 50°C in slurry supplemented with 5.8% NaCl and 5% MSG. Cultures grown at 37°C had a D60 value of 2 min in 50 mmol/l Tris (pH 7.2) buffer. Cultures grown at 46°C in HI containing 5.8% NaCl had a D60 value of 8 min in Tris buffer. Addition of 5.8% NaCl plus 5% MSG to the buffer increased the D60 by a factor of about 7 for both cultures. In storage experiments at room temperature, the culture grown at 37°C and at 46°C plus 5.8% NaCl died at about the same rate in salami. In milk powder, however, the count of 37°C culture decreased from 109/g to 106/g in 5 weeks while the count of 46°C culture remained unchanged. In cottage cheese, freeze‐dried rice and macaroni, the 37°C cultures also died more rapidly. It is suggested that cultures grown at 46°C plus 5.8% NaCl may be suitable for experiments with artificially contaminated foods.
Hydrolysis of Fraction 1 leaf protein and casein by rumen entodiniomorphid protozoa
Authors: Coleman G.S.
Published: March 2008

Cell‐free extracts of fourteen individual species of rumen ciliate protozoa and of mixed rumen ciliates degraded Fraction 1 leaf protein. For Entodinium caudatum and Eudiplodinium maggii the optimum pH was 3·2. The maximum rates of proteolysis (in µmol acid soluble‐tyrosine formed/mg protein/h) were 0·16 to 5·7 with protozoa grown in vivo and 0·38 to 6·4 with protozoa grown in vitro. The highest rates were obtained with Entodinium caudatum and E. simplex and the lowest with the cellulolytic species grown in vivo. Km values (mg/ml) ranged from 0·42 to 19 with protozoa grown in vivo and 0·35 to 13·3 with protozoa grown in vitro. All single species (with one exception) whether grown in vivo or in vitro degraded Fraction 1 leaf protein faster (1·4 to 21 times) than casein. Partial inhibition of the activity of Entodinium caudatum was obtained with pepstatin and N‐ethylmaleimide and almost complete inhibition with leupeptin suggesting the presence of ‘carboxyl’ and ‘thiol’ enzymes.
Isolating samples in the chamber of a steam‐formaldehyde sterilizer
Authors: Hurrell D.J. , Line S.J. , Cutts D.W.
Published: March 2008

The construction and use of an electrically operated closure device, together with a control system, for securing samples from a non‐inflammable atmosphere is described. An outline of the device for use with a low temperature steam‐formaldehyde (LTSF) sterilizer is given.
A new mannose‐resistant haemagglutinin in Klebsiella
Authors: Old D.C. , Adegbola R.A.
Published: March 2008

Strains of Klebsiella of the species (or ‘patho‐bio‐sero‐geogroups’) Kl. atlantae, Kl. edwardsii and Kl. rhinoscleromatis produced neither haemagglutinins (HAs) nor fimbriae; strains of Kl. ozaenae were HA‐ but some produced type‐6 fimbriae; and strains of Kl. pneumoniae (sensu stricto) and Kl. aerogenes that produced the mannose‐sensitive HA (MS‐HA) formed type‐1 fimbriae. Most strains of Kl. aerogenes produced, in addition, one or both of the mannose‐resistant HAs, MR/K‐HA or MR/P‐HA. The former, associated with type‐3 fimbriae, was produced by 95%, and the latter by 57%, of the Kl. aerogenes strains. Some of the properties of the MR/P‐HA, apparently a non‐fimbrial HA not previously recognised in Klebsiella, are described.
A note on inoculum reproducibility: a comparison between solid and liquid culture
Authors: Al‐Hiti M.M.A. , Gilbert P.
Published: March 2008

The level of reproducibility for replicate determinations of drug sensitivity was significantly greater for liquid than for solid cultures and decreased markedly with the density of colonies upon seeded agar plates. Inocula of Escherichia coli and Pseudomonas aeruginosa were significantly less sensitive towards chlorhexidine when derived from liquid rather than solid culture. We therefore suggest that only liquid cultures be used for the preparation of challenge inocula for regulatory tests of antimicrobial activity.
A new direct plate method for the enumeration of Escherichia coli in frozen foods
Authors: Hall L.P.
Published: March 2008

Hall, L.P. 1984. A new direct plate method for the enumeration of Escherichia coli in frozen foods. Journal of Applied Bacteriology56, 227–235.

A new method has been devised, incorporating a resuscitant stage, which allows direct isolation of Escherichia coli biotype I, Irregular type II and Irregular type VI. Rapid indole tests on the distinctive colonies produced enable determinations of E. coli biotype I to be made within 24 h. This method employs materials of low cost and achieves complete recovery of injured cells. It also detects not only anaerogenic strains but those which are slow in producing acid from lactose or give negative results by other methods. If required, further study of isolates can be made after the indole test. Comparisons were made between conventional methods, the new method and a similar direct plate method. The implications of the higher counts obtained by the two latter methods are discussed in relation to microbiological specifications and standards for frozen foods.
Hypochlorite effects on spores and spore forms of Bacillus subtilis and on a spore lytic enzyme
Authors: Gorman S.P. , Scott E.M. , Hutchinson E.P.
Published: March 2008

Gorman, S.P., Scott, E.M. & Hutchinson, E.P. 1984. Hypochlorite effects on spores and spore forms of‐Bacillus subtilis and on a spore lytic enzyme. Journal of Applied Bacteriology56, 295–303.

Spores of Bacillus subtilis NCTC 10073 were converted to ion‐exchange (Ca, H) forms and coat‐defective (urea‐mercaptoethanol, urea‐dithiothreitol‐sodium lauryl sulphate) forms. The resistance of these to sodium hypochlorite (1000 parts/106 free chlorine) was compared and related to uptake from which the assumed monolayer capacities were calculated. Hypochlorite effects on spore protoplasts and cortical fragments were also examined in relation to DPA and hexosamine release. A spore lytic enzyme was extracted and examined in respect of hypochlorite activity. The results are discussed in terms of the mechanism and site of action of hypochlorite on the bacterial spore.
A comparison of isolation procedures for salmonellas from polluted water using two forms of Rappaport's medium
Authors: Fricker C.R.
Published: March 2008

Fricker, C.R. 1984. A comparison of isolation procedures for salmonellas from polluted water using two forms of Rappaport's medium. Journal of Applied Bacteriology56, 305–309.

The efficiency of Rappaport's broth (RB10) and Rappaport's broth containing novobiocin (NRB10) were compared for the isolation of salmonellas from polluted water, both as direct enrichment media and after pre‐enrichment in buffered peptone water. Ninety samples were examined and 41 were found to contain salmonellas by at least one of the procedures used. Direct inoculation of the sample into RB10 resulted in the recovery of salmonellas from only 29.3% of the samples found to be positive. The use of NRB10 as a direct enrichment medium increased the percentage recovery to 78.0% of the total positive samples. Pre‐enrichment in buffered peptone water allowed the recovery of salmonellas from a total of 41 samples whereas direct enrichment recovered them from only 32. No significant difference was demonstrated in the efficiencies of RB10 and NRB10 in recovering salmonellas after pre‐enrichment in buffered peptone water. Three selective agars were used; no significant difference in their ability to recover salmonellae was demonstrated.
A note on ‘plotless’ methods for estimating bacterial cell densities
Authors: Roser D. , Nedwell D.B. , Gordon A.
Published: March 2008

Roser, D., Nedwell, D.B. & Gordon, A. 1984. A note on “plotless” methods for estimating bacterial cell densities. Journal of Applied Bacteriology56, 343–347.

‘Plotless’ techniques for determining population densities have been developed for, and applied to, higher plant populations. They can often be carried out more rapidly than techniques involving total counts of individuals in plots, or quadrants, but such plotless techniques have not been generally applied to the estimation of densities of bacterial cells. Direct microscopical counting of cell numbers in a field of view, an example of a plot‐related method, has been traditionally used for micro‐bial cell counts. In this study ‘plot’ and ‘plotless’ methods on a variety of bacterial samples are compared. Estimates of bacterial cell density were obtained by measuring the distance of cells from a fixed point in a field of view. The values, which were more rapidly obtained, were directly correlated with total cell counts. Although there was some apparent deviation from a perfect 1:1 relationship with total counts, as indicated by a correlation coefficient less than 1.0, there were no significant differences between the replicated counts of bacteria on samples of tissue from the surface of Hypholoma basidiocarps (P < 0.05). This indicated that the methods of enumeration were comparable. The distance‐related estimates could readily be obtained from fields of view with cell densities varying over several orders of magnitude. It was more rapidly applied, particularly at high density, and the method was applicable not only to random cell distributions but also to the non‐random distributions encountered when microbial cells aggregated into micro‐colonies. The method appears to be particularly well‐suited for automated, digitized, direct counting procedures, as well as to estimating bacterial numbers on membrane filters and natural substrates.
A note on the temperature tolerance of Legionella
Authors: Dennis P.J. , Green D. , Jones B.P.C.
Published: March 2008

Dennis, P.J., Green, D. & Jones, B.P.C. 1984. A note on the temperature tolerance of Legionella. Journal of Applied Bacteriology56, 349–350.

A strain of Legionella pneumophila serogroup 1 isolated from the environment had a decimal reduction time in water at 50d̀C (D50) of 111 min, a D54 of 27 min and a D58 of 6 min. There was little loss of viability at 46d̀C. Other environmental organisms, a Pseudomonas sp., a Micrococcus sp. and a coliform survived less well at these temperatures. A species of Sarcina had a survival time greater than the L. pneumophila at all the temperatures tested. Other strains of legionellas were tested at 50d̀C and decimal reduction times calculated. These ranged from 80 min for another strain of L. pneumophia serogroup 1 to 216 min for L. bozemannii. Legionella micdadei did not survive well at 50d̀C.
Comparative study on Salmonella isolation from sewage—contaminated natural waters
Authors: Alcaide Elena , Martinez J.P. , Garay Esperanza
Published: March 2008

Alcaide, E., Martinez, J.P. & Garay, E. 1984. Comparative study on Salmonella isolation from sewage contaminated natural waters. Journal of Applied Bacteriology56, 365–371.

A comparative study of five factors influencing the isolation of salmonellas from sewage‐contaminated natural waters was carried out. The effect of pre‐enrichment in buffered peptone water was compared with single‐step enrichment in NR10 broth incubated at 43d̀C. A modification of NR10 has been compared with the original composition. Bismuth sulphite agar (BSA), Hektoen enteric agar (HE) and brilliant green agar (BGA) have been used as plating media. Other factors considered have been temperature of the water and sampling site. A total of 759 salmonella strains belonging to 36 different serotypes has been recovered in a two‐year study. All five factors considered in the study have shown a significant effect on the recovery of salmonellas. The combination of direct enrichment in NR10, followed by BSA or HE as plating media was most effective for the isolation of Salmonella. The influence of water temperature and characteristics of the sampling sites have also been discussed.
A survey of lactic acid bacteria in Italian silage
Authors: Grazia L. , Suzzi Giovanna
Published: March 2008

Grazia, L. & Suzzi, G. 1984. A survey of lactic acid bacteria in Italian silage. Journal of Applied Bacteriology56, 373–379.

Lactic acid bacteria, isolated from Italian ensiled products, were represented by strains of the genera Lactobacillus and Leuconostoc. The predominant strains were heterofermentative lactobacilli, with Lactobacillus buchneri being the most frequent. Among homofermentative lactic acid bacteria, strains of Lact. plantarum and Lact. casei were recovered. Almost all strains utilized malic acid and showed good acid‐tolerance, but only some of them were able to metabolize malic acid at extremely low pH; these were five homofermentative lactobacilli (4 Lact. plantarum and 1 Lacr. casei var. casei) and two heterofermentative lactobacilli (Lact. cellobiosus and Lactobacillus sp.).
A method for the enumeration of male‐specific bacteriophages in sewage
Authors: Havelaar A. H. , Hogeboom W. M.
Published: March 2008

Havelaar, A.H. & Hogeboom, W.M. 1984. A method for the enumeration of male‐specific bacteriophages in sewage. Journal of Applied Bacteriology56, 439–447.

Male‐specific bacteriophages adsorb to F‐pili and thus can only infect male host strains. A method was developed for the selective enumeration of these phages, based on the observation that in sewage there are few phages capable of infecting F‐‐salmonellas—usually less than 10 pfu/ml. Using a male Salmonella strain, constructed by the introduction of the plasmid F'42 lac::Tn5 into Salmonella typhimu‐riumphage type 3, plaque counts in secondary effluent were found to be in the range of 60–8200 pfu/ml. Practically all the phages detected had a host range restricted to male Salmonella or Escherichia coli strains, were resistant to chloroform and their infectivity was inhibited by RNase. Electron microscopy of lysates revealed phage particles that were morphologically identical to the male‐specific single‐strand RNA phages. Similar results were obtained with a strain of Salm. indiona carrying F'42 lac. A derivative of the Salm. typhimurium LT2 strain carrying an F‐plasmid (F'42 lac fin P301) derepressed for fertility inhibition by the resident plasmid pSLT was equally sensitive to male‐specific phages, but from sewage samples many other phages infecting F‐E. coli but not F‐Salmonella were isolated using this host strain.
Artificially induced symbiotic associations of L‐form bacteria and plants
Authors: Aloysius Sriyani K. D. , Paton A.M.
Published: March 2008

Aloysius, S. K. D. & Paton, A.M. 1984. Artificially induced symbiotic associations of L‐form bacteria and plants. Journal of Applied Bacteriology56, 465–477.

L‐forms of a small but varied selection of bacteria were found to enter viable plant cells and establish novel symbiotic relationships. Evidence is presented for the ability of the L‐forms to spread and to express at least some of their metabolic functions within plant tissue.
A note on isolation of spontaneous glucose‐resistant mutants of Bacillus subtilis
Authors: Majumdar S. , Das S.K. , Basu S. , Bose S.K.
Published: March 2008

Majumdar, S., Das, S.K., Basu, S. & Bose, S.K. 1984. A note on isolation of spontaneous glucose‐resistant mutants of Bacillus subtilis. Journal of Applied Bacteriology56, 493–494.

The addition of double doses of glucose delayed the initiation of sporulation in Bacillus subtilis B34 by 42 h. Heat‐treatment of the culture within the delay period, (selectively killing the vegetative cells and leaving the spores unaffected) followed by immediate plating, afforded a good method for isolating spontaneous glucose‐resistant sporulation mutants.
A note on salmonella excretion in the black headed gull (Lams ribibundus) feeding at sewage treatment works
Authors: Fricker C. R.
Published: March 2008

Fricker, C. R. 1984 A note on salmonella excretion in the black headed gull (Larus ribibundus) feeding at sewage treatment works. Journal of Applied Bacteriology56, 499–502.

The range of salmonella serotypes found in sewage sludge and in the faeces of black headed gulls (Larus ribibundus) feeding on the sludge was investigated. A close association was demonstrated between the serotypes found in both types of sample. Salmonella takoradi (a serotype which is uncommon in Scotland) appeared in the sludge for two short periods during the twelve week study and on both occasions it was later found in the gull faeces. It was shown that gulls become infected after feeding on contaminated sewage sludge but that the infection is probably shortlived.
Growth and end‐product formation in fermenter cultures of Brochothrix thermosphacta ATCC 11509T and two psychrotrophic Lactobacillus spp. in different gaseous atmospheres
Authors: Blickstad Elisabeth , Molin G.
Published: March 2008

The effects of different gaseous atmospheres were determined on the maximum specific growth rate (μmax) and end‐product formation by Brochothrix thermosphacta ATCC 11509T, Lactobacillus viridescens SMRICC 174 and Lactobacillus sp. SMRICC 173 (homofermentative). The highest μmax‐values for Lact. viridescens (0.47/h) and Broc. thermosphacta (0.49/h) were obtained in air. Under anaerobic conditions μmax was reduced, an atmosphere containing CO2 alone giving the greatest reduction. Lactobacillus sp. 173 did not grow in air or N2. Aerobic growth was obtained by adding peroxidase while anaerobic growth occurred in the presence of 5–20% CO2. Carbon dioxide alone reduced the growth rate. All test organisms produced mainly lactic acid anaerobically. Lactobacillus viridescens also produced ethanol while Broc. thermosphacta produced small amounts of ethanol and formic acid. With O2 present, the number of end‐products increased for all organisms. Lactobacillus sp. 173 produced small amounts of acetic acid and acetoin together with lactic acid. Oxygen induced acetic acid production in Lact. viridescens and Broc. thermosphacta. Aerobically, Broc. thermosphacta also produced a large amount of acetoin and smaller amounts of 2,3‐butanediol, iso‐valeric acid and iso‐butyric acid. The production of lactic acid by Broc. thermosphacta was completely prevented under strictly aerobic conditions. All test organisms consumed O2 during aerobic growth. Hydrogen peroxide was produced by Lact. viridescens and Lactobacillus sp. 173.