bluuebunny/crossref_metadata_2025 huggingface dataset:
A Bacteriological Study of Stored, Sulphite Treated Peeled Potatoes
Authors: Lund Barbara M.
Published: March 2008

Peeled, sulphite treated potatoes were stored at 23° for 3 days or at 6° for 7 days in packs sealed with perforated or unperforated polythene or with Saran film. After storage, gas samples were withdrawn from the packs for analysis and viable counts made of micro organisms associated with the potatoes. There was a marked increase in the CO2 concentration and a corresponding decrease in O2 concentration in the unperforated packs; samples from these packs tended to have a lower bacterial count than samples from perforated packs. 180 bacterial isolates representing the spoilage flora were examined. At 23° the major groups of isolates were Gram negative bacteria attacking glucose fermentatively (Enterobacteriaceae) or oxidatively (fluorescent pseudomonads); isolates from storage at 6° were all pseudomonads most of which were fluorescent. Twentyeight % of the pseudomonads, but none of the fermentative isolates, were pectolytic.
Isolation of Ammonia‐oxidizing Autotrophic Bacteria
Authors: Soriano S. , Walker N.
Published: March 2008

Procedures are described for isolating ammonia‐oxidizing autotrophic bacteria in pure culture, using solid media made from purified agar and appropriate micromanipulations.
Bacterial Flora of Chicken Carcasses Treated with High Concentrations of Chlorine
Authors: Patterson J. T.
Published: March 2008

Laboratory experiments are described which aimed to find the effect on the initial and spoilage flora of broiler carcasses of immersion for 4 h in chilled water containing 200 or 400 p/m of free residual chlorine. Spoilage of such carcasses when held at 1° was mainly due to the normal Pseudomonas—Achromobacter type of flora, and the shelf life was extended by c. 20%. The value of such treatment is discussed.
Some Morphological and Physiological Properties of Microbacterium thermosphactum
Authors: Davidson C. M. , Mobbs P. , Stubbs J. M.
Published: March 2008

The properties of strains of Microbacterium thermosphactum obtained from various sources were investigated. All exhibited pleomorphism and occurred both as coccobacilli and as long rods. The change from one morphological form to another was followed by means of slide culture techniques. Electron micrographs of thin sections of M. thermosphactum were also examined. The medium and incubation temperature influenced the catalase and benzidine reactions. The practical implications and the possible taxonomic significance of the results are discussed.
Use of Selenite Reduction in Bacterial Classification
Authors: Lapage S. P. , Bascomb Shoshana
Published: March 2008

The ability of 548 strains of Gram negative rods to reduce selenite was investigated in parallel with their ability to produce H2S and reduce nitrate. Reduction of selenite was shown to be a reasonably good test compared with other tests used in classifying these organisms. The ability to reduce selenite often paralleled the ability to produce H2S; it did not parallel the ability to reduce nitrate.
Influence of the Maillard Reaction Products on Some Bacteria of the Intestinal Flora
Authors: Jemmali M.
Published: March 2008

Effects of the Maillard reaction products, which are obtained by heating glycine and dextrose solutions, on the cellular metabolism of some bacteria which constitute the intestinal flora were studied. Depending on the amounts present the growth rates and lag phases of the lactobacilli were increased, but growths of strains of Escherichia coli were unaffected, although their lag phases were extended.
Effect of Metallic Ions on the Antibacterial Activity of Boseimycin
Authors: Sinha Rabindra K.
Published: March 2008

An enhancement of the antibacterial activity of boseimycin against Staphylococcus aureus was observed in the presence of Zn2+ and Co2+ on a double gradient agar plate, but the activity was suppressed to a small extent by Ca2+. With Bacillus subtilis the enhancement effects were more pronounced, but there was no suppression with Ca2+.
Identification of Legume Nodule Bacteroids by the Fluorescent Antibody Reaction
Authors: Trinick M. J.
Published: March 2008

A fluorescent antibody technique which permits rapid identification of legume nodule bacteroids and which permits the separation of bacteroid material and laboratory grown cultures of close serological affinity is described. Specificity of fluorescein isothiocyanate γ‐globulin conjugates was increased with dilution. The ability of a medium sized clover nodule to produce sufficient bacteroid material for 20 fluorescent antibody stains allows increased accuracy and scope of the method. A single operator in 1 day may test > 400 nodules for one or more symbionts.
Microbial Flora of Raw and Pasteurized Egg Albumen
Authors: Barnes Ella M. , Corry Janet E. L.
Published: March 2008

Gram negative bacteria were the main spoilage organisms of raw albumen stored at 5, 10, 15 or 20° and were identified as strains of pigmented and nonpigmented Pseudomonas, Acinetobacter and Enterobacter liquefaciens. Only one unidentified Gram negative motile rod which failed to attack glucose was found to survive pasteurization in egg albumen (pH 9‐1) at 57.2° for 3 min. Other Gram negative bacteria isolated from one batch of stored albumen were shown to be heat sensitive, so that recontamination had probably occurred after pasteurization. Most of the organisms which survived pasteurization were found to be faecal streptococci, strains resembling Aerococcus viridans, Microbacterium lacticum and two groups (B and C) of unidentified catalase negative rods, or coccobacilli which in many respects resembled the atypical lactobacilli of Thornley & Sharpe (1959). Of these strains only the faecal streptococci and groups B and C were isolated from stored albumen. The effect of the spoilage flora on the ‘catalase’ activity of albumen before and after pasteurization has been studied in relation to the possibility of a ‘catalase’ test being used to monitor the pasteurization process.
The Ecology of Serotype 4B of Bacillus thuringiensis
Authors: Norris J. R.
Published: March 2008

Twentyfive separate isolates of serotype 4B of the aerobic sporeforming insect pathogen, Bacillus thuringiensis, have been obtained over the period 1961–68. Most of the isolates of this particular serotype were obtained from storage products insects infesting such places as grain stores, flour mills or ships carrying grain materials. In one instance the organism was isolated from insects infesting Guinea corn growing in the field. In comparison with the other serotypes of this bacillus the association with stored products environments is striking and, on several occasions, it has been possible to trace the distribution of the bacteria by movements of infested materials from one part of the world to another.
Some Effects of Preservatives on the Development of Bacterial Spores
Authors: Parker M. S.
Published: March 2008

The effects of preservatives on the development of spores of Bacillus subtilis have been examined using 2 indices of development sensitive to preservatives, namely, the swelling of spores prior to vegetative cell emergence and o.d. changes of spore suspensions during germination and outgrowth. The preservatives used fall into two categories: (1) inhibitors of germination (chlorocresol and mixed esters of p‐hydroxybenzoic acid), and (2) inhibitors of postgerminative development (cetrimide, aminacrine and phenylmercuric nitrate). None of the preservatives prevented the initial phase of spore swelling and it is suggested that this is attributable to a nonmetabolic (inanimate) hydration. The inhibition of germination by a category 1 preservative (chlorocresol) is readily reversible by washing and to prevent germination the preservative must be added early in the process. The inhibition of postgerminative development by a category 2 preservative (aminacrine) cannot be reversed by washing treated spores.
The Use of Sulphite‐containing Media in the Isolation of Clostridium welchii
Authors: Mead G. C.
Published: March 2008

An investigation was made of cultural conditions affecting the blackening of colonies due to sulphite reduction by Clostridium welchii and several other clostridia in the sulphite‐polymyxin‐sulphadiazine agar of Angelotti et al. (1962). Reducing conditions in the medium were more critical for blackening than for growth, and a simple, modified isolation method for Cl. welchii is described which provides optimal conditions for both processes.
The Keeping Quality of Pasteurized Egg
Authors: Wood E. C. , Youngs M.
Published: March 2008

Commercially produced pasteurized egg was stored in refrigerators at 36, 38 and 40°F and examined daily both organoleptically and bacteriologically. The counts at 20 and at 37°, as well as the coliform count, remained practically constant for a period, depending on the storage temperature, following which there was a sharp transition to a logarithmic phase. Using both bacteriological and organoleptic criteria, the egg remained satisfactory for at least 6 days provided the storage temperature did not exceed 38°F.
Determination of the Microbiological Status of Gnotobiotic Pigs
Authors: Hill I. R. , Kenwothy R.
Published: March 2008

A description of the techniques used for determining the microbiological status of gnotobiotic pigs is given. The procedures have been developed especially for the pig and involve comprehensive examination for bacteria, fungi, worms and arthropods, and a less complete examination for rickettsiae and viruses. Techniques used on live animals in germ free isolators and on postmortem samples are described.
The Adansonian Classification using the Heterotrophic Spectra of Chlorella vulgaris by a Simplified Procedure involving a Desk‐top Computer
Authors: Cullimore D. R.
Published: March 2008

Computer programs were developed for the desk‐top computer, Olivetti P101, with the object of enabling qualitative and quantitative numerical classification programs to be carried out. The system was successfully applied to the heterotrophic specta obtained using 20 carbon sources on 7 strains of Chlorella vulgaris. As a result of this and subsequent extrapolations, the algae were divided into one group of 3 strains and 4 other groups each containing one strain. A classification system was developed involving a dichotomous key.
Microbiology of Pigs and their Environment in Relation to Weaning
Authors: Hill I. R. , Kenworthy R.
Published: March 2008

On weaning, pigs were placed in a house of a type which is commonly used for early weaning or individually in cages in a controlled environment room. Micro‐organisms (11,631 isolates) recovered from air, food, faeces, water and pigs' skins were characterized and identified at the genus level. Pigs in the controlled environment harboured populations of lactobacilli and haemolytic serotypes of Escherichia coli greater than those of their littermates housed in a conventional piggery early‐weaning house. This was ascribed to the heavy faecal contamination of food in the troughs of the caged pigs, since the air in the controlled environment contained fewer micro‐organisms than that in the conventional piggery. The association of high numbers of faecal lactobacilli and haemolytic E. coli, and confinement in a controlled environment were not associated with the same amount of clinical disease and growth depression as was the combination of smaller numbers of the same organisms and conventional housing.
Enterocinogeny and Lysogeny in Enterococci
Authors: Tzannetis S. , Leonardopoulos J. , Papavassiliou J.
Published: March 2008

The enterocinogeny and lysogeny of enterococci was studied with a double layer agar method and 21 indicator strains of enterococci. Of 77 strains examined, 76 produced enterocine, and of 19 strains examined, 5 were sensitive to their own enterocine. All 77 strains were lysogenic when cultures killed with chloroform were examined for lysogeny by the method of Liegeois‐Müller & Fredericq (1952). By the same method, 4 of 7 strains were found to produce phages active against themselves.
An Improved Agar Medium for the Detection of Proteolytic Organisms in Total Bacterial Counts
Authors: Martley F. G. , Jayashankar S. R. , Lawrence R. C.
Published: March 2008

An improved medium for the detection of proteolytic organisms has been developed by adding caseinate (1% w/v), citrate (0·015 m) and Ca2+ (0·02 m) to Standard Methods Agar. Its greater sensitivity compared with existing milk agar media is related to its ability to detect the first stage of casein breakdown as shown by the formation of a white zone of precipitation. This results from the deposition of insoluble para‐caseins, mainly para‐k‐casein, which is readily detected in the transparent medium. The extent of proteolysis exhibited by an organism is reflected both by the size and type of precipitation zone forming round the colony. No significant difference was found between total counts of raw milk samples measured on the new medium and standard methods agar. The new medium can thus be used for the simultaneous determination of proteolytic and total bacterial counts.
The Degradation of Nucleic Acids by Cytophaga johnsonii
Authors: Greaves M. P. , Vaughan D. , Webley D. M.
Published: March 2008

In growth experiments Cytophaga johnsonii rapidly degraded nucleic acids to release purine and pyrimidine bases and inorganic orthophosphate. The products were the same when the nucleic acids were added separately or were contained in autoclaved or ultrasonically disintegrated cells of Aerobacter aerogenes. Commercial preparations of RNA and DNA either inhibited or enhanced growth of the myxobacterium according to the medium used. When present as the major nutrient neither RNA nor DNA served as carbon or phosphorus sources and were poor nitrogen sources for C. johnsonii. The extra‐cellular nucleases, measured by a fluorimetric method, were produced mainly during the stationary phase of growth. Passage of the cell free culture fluid from C. johnsonii through Sephadex G 100 separated the ribonuclease and deoxyribonuclease activities. The deoxyribonuclease obtained after gel filtration is similar to deoxyribonuclease 1, being specific for high MW DNA and apparently inhibited by DNA of low MW.
The Dynamics of Decane and Glucose Utilization by a Pseudomonas sp. in Batch and Chemostat Cultures under Controlled Dissolved Oxygen Tensions
Authors: Maclennan D. G. , Pirt S. J.
Published: March 2008

A Pseudomonas sp. was grown in chemostat culture with either decane or glucose as sole carbon source. At a dilution rate of 0·1 h−1 the biomass concentration was directly proportional to the decane supplied up to a concentration of 8·2 g/l, of which 5·3 g were utilized and the remainder lost as vapour. The maximum biomass concentration was limited to 3 g of bacterial dry wt/1 by what appeared to be an inhibitory product. When the culture was grown under different controlled dissolved oxygen tensions (DOT) at a dilution rate of 0·1 h−1 with nitrogen‐limited growth the following observations were made: (1) the growth limiting DOT was 1·0‐3·0 mmHg with decane, and < 1·0 mmHg with glucose as carbon source; (2) to obtain the maximum ratio of oxygen uptake: carbon source uptake the DOT needed to be c. 6·0 mmHg: at lower values the degree of oxidation of products decreased; (3) with decane an appreciable proportion of the decane carbon utilized (c. 60%) appeared in unidentified products other than biomass and CO2.
The Hydrolysis of Tween 80 by Vibrios and Aeromonads
Authors: Chakrabarty A. N. , Adhya Sati , Pramanik M. K.
Published: March 2008

A total of 307 strains consisting of 89Vibrio cholerae, 37 NAG vibrios, 4Aeromonassp., 20Pseudomonas aeruginosa, 47 shigellae, 59Escherichia coli, 27Proteus mirabilisand 25 salmonellae were examined for their opacity reaction in Tween 80 agar medium. Strong reactions occurred with 87V. cholerae, 26 NAG vibrios, 2Aeromonasand 5Pseudomonasstrains; and weak and slow positive reactions were noted in only 6 strains of NAG vibrios and 3 ofPseudomonas; no reaction was observed among the remaining strains. The study showed that Tween 80 hydrolysis can be used as a test for characterization of theVibrioandAeromonasgroups and for their differentiation from the Enterobacteriaceae.
An Ecological Study of the Psychrotrophic Bacteria of Soil, Water, Grass and Hay
Authors: Druce R. G. , Thomas S. B.
Published: March 2008

A study of the psychrotrophic bacterial content, determined at 3–5°, of soil, grass and hay showed that these habitats were prolific sources of many different types of psychrotrophs, which sometimes exceeded 107/g. Untreated farm water supplies had a much lower content, few samples giving colony counts > 104/ml. Gram positive or Gram variable, nonsporeforming rods, resembling coryneform bacteria, constituted a relatively high proportion of the psychrotrophic microflora of soil, Gram negative rods only forming about 1/3 of the isolates. In contrast, Pseudomonas and Acinetobacter spp. and yellow or orange pigmented Gram negative rods were the predominant psychrotrophs in untreated water. Pseudomonas and a taxonomically heterogeneous group of yellow pigmented, Gram negative rods, a few of which resembled Flavobacterium and some Erwinia herbicola, together with Acinetobacter accounted for nearly 90% of the isolates from grass, but < 50% of those from hay, which had a more complex psychrotrophic microflora than had grass.
Studies of the Bacteriophage Kinetics of Multicellular Systems: A Statistical Model for the Estimation of Burst Size per Cell in Streptococci
Authors: Barron B. A. , Fischetti V. A. , Zabriskie J. B.
Published: March 2008

The determination of burst size in chaining or clustering bacteria involves experimental variables that must be considered in estimating burst size/cell and in contrasting the results of different experiments. Whereas the Poisson distribution is the model for single cell host systems, the statistical model presented here provides a method for evaluating the probability of obtaining a plate that reflects the lysis of more than one cell.
A Study of the Lipid Composition of Microbacterium thermosphactum as a Guide to its Taxonomy
Authors: Shaw N. , Stead D.
Published: March 2008

The lipid composition of Microbacterium thermosphactum has been investigated. The major phospholipids were phosphatidylglycerol, bis‐phosphatidylglycerol and phosphatidylethanolamine. The glycolipid fraction contained an acylated glucose and trace amounts of a glycosyl diglyceride, tentatively identified as dimannosyl diglyceride. The fatty acid components of the lipids were predominantly C15 and C17 branched chain isomers. The lipid composition of this organism was compared with that of other Corynebacteriaceae and Lactobacillaceae and it is suggested that the present classification should be retained.
The Identity of Streptococcus faecalis ATCC 9790
Authors: Smith D. G.
Published: March 2008

The widely used strain Streptococcus faecalis ATCC 9790 (originally S. lactis R) has been examined by 16 differential tests. The strain showed a close resemblance to the S. faecium group, giving identical results in 12–13 of the tests. Only 2–3 of the characteristics tested were shared with S. faecalis and varieties. It is proposed that strain ATCC 9790 be re‐named S. faecium var. durans.
The Decarboxylation of l‐lysine by Pseudomonas aeruginosa isolates
Authors: Stewart D. J.
Published: March 2008

Pseudomonas aeruginosa NCIB 9685 was shown to have an l‐lysine carboxylase optimally active at pH 8‐0 and which showed little or no activity below pH 5·8. For these and other reasons, indicator media were found to be unsuitable for the detection of the enzyme in this organism. All of a further 129 Ps. aeruginosa isolates were active in the decarboxylation of l‐lysine at pH 8·0.
Further Studies on Long Term Preservation of Marine Bacteria
Authors: Greig Mary A. , Hendrie Margaret S. , Shewan J. M.
Published: March 2008

Total viable counts were made on 49 strains of bacteria (44 marine and 5 nonmarine) which had been freeze dried in 1958 and subsequently stored at room temperature. Viability checks were also performed on the organisms which, in addition to having been freeze dried in 1958, had also been suspended in glycerol‐nutrient broth and stored in the frozen (−29°) state. After 10 years 9% of the cultures in the freeze dried form and 41% of those stored in glycerol‐nutrient broth at −29° were nonviable. The highest viable counts were found among the corynebacteria and micrococci, the lowest with the vibrios and photobacteria.
The Evaluation of Media used to Enumerate Sulphate Reducing Bacteria
Authors: Mara D. D. , Williams D. J. A.
Published: March 2008

Several media were used to enumerate bacteria in cultures of Desulfovibrio vulgaris, the most suitable being a modification of Iron Sulphite Agar (Oxoid). This medium was also suitable for the enumeration of D. desulfuricans and, with extra salt, D. salexigens. Cultures of D. africanus and D. gigas were enumerated in a lactate‐sulphate agar medium which gave higher counts than similar media described in the literature. These media were suitable for counting the organisms in pure and mixed cultures. Neither of these media can be used successfully to enumerate Desulfotomaculum spp.
An Improved Nephelometer Culture Flask
Authors: Thayer D. W.
Published: March 2008

A nephelometer flask of new design is described. It consists of a 250 ml Erlenmeyer flask with a dam placed across the neck and a cuvette fused to the base at an angle of 5° from the horizontal. The flask allows the use of volumes of up to 50 ml without contamination of the cotton plugs.
A Digital Computer Program for the Statistical Analysis of Heat Resistance Data Applied to Bacillus stearothermophilus Spores
Authors: Navani S. K. , Scholefield J. , Kibby M. R.
Published: March 2008

A digital computer program is described which fits log‐linear regression lines to survival curves and thermal destruction time lines and performs appropriate statistical tests. The use of the program is illustrated with heat resistance data from 4 strains of B. stearothermophilus spores at 8 time–temperature relationships. D, F, zD and Q10 values were calculated by the computer program. The heat resistance of the strains was in the order of B <C <A <D.
Effect of Sodium Chloride on the Heat and Radiation Resistance and on the Recovery of Heated or Irradiated Spores of the Genus Bacillus
Authors: Briggs A. , Yazdany S.
Published: March 2008

Increasing concentrations (2, 4 and 8% w/v) of NaCl in the heating medium reduced the heat resistance of spores of Bacillus stearothermophilus but had no effect on the heat or radiation resistances of B. pumilus, B. subtilis and B. subtilis var. niger or on the radiation resistance of B. stearothermophilus. Increasing heat damage rendered all the spores increasingly sensitive to NaCl in the recovery medium.

The presence of NaCl during heating reduced the subsequent NaCl sensitivity of B. pumilus, B. subtilis and B. subtilis var. niger but increased that of B. stearothermophilus. Increasing doses of γ radiation rendered the spores of B. stearothermophilus increasingly sensitive to NaCl in the recovery medium. The effect was less pronounced with B. pumilus, whilst B. subtilis and B. subtilis var. niger showed little change in their post‐irradiation sensitivity to NaCl. The presence of NaCl during γ irradiation had no effect on the subsequent pattern of postirradiation NaCl sensitivity.
Studies on Freshwater Bacteria: Effect of Medium Composition and Method on Estimates of Bacterial Population
Authors: Jones J. G.
Published: March 2008

The effects of various inorganic and organic components used in media for estimating numbers of freshwater bacteria were determined. The inorganic elements appeared to affect the count obtained more than did the organic components. Of the media tested, none could support growth better than the CPS medium of this laboratory. The casein and glycerol concentration was optimal and variation in other organic components had little effect on counts. The surface spread plate was the most suitable method of estimating viable numbers and the effect of numbers of colonies counted on the distribution obtained is discussed.
Comparative Injuriousness to Plants of Erwinia spp. and Other Enterobacteria from Plants and Animals
Authors: Lakso J. U. , Starr M. P.
Published: March 2008

To determine their degree of injuriousness to plants, 148 cultures of Erwinia and other enterobacteria, including 45 ‘Erwinia‐like’ isolates from animals, were examined comparatively by tests for hypersensitivity reaction, stalk rot and leaf blanching of corn seedlings, lesions on excised bean pods and on cowpea seedlings, rots of excised plant tissues and liquefaction of carboxymethylcellulose and pectate gels. The degree of harmfulness could be expressed as a standardized Erwinia injuriousness score calculated from numerical expressions of symptoms produced by a culture on cowpea seedlings compared with those produced by two reference cultures known to be phytopathogenic and, hence, injurious. The results indicate that, of the 45 Erwinia‐like isolates from animals tested, 16 were not injurious to plants, 13 were only slightly injurious, and 16 were as injurious to certain test plants as some Erwinia strains generally considered to be phytopathogenic.
Improved Synthetic Medium for the Growth of Rhizobium
Authors: Sherwood Marie T.
Published: March 2008

A modification of Bergersen's synthetic medium gave improved growth of Rhizobium. When potassium was included in the medium the biotin concentration could be decreased from the recommended 150–250 to 0·5 μg/l. Growth of 15 strains from 6 Rhizobium spp. was compared in the original and modified media and the responses of those strains to biotin, thiamine and calcium pantothenate noted.
Selective Media in Air Sampling: A Review
Authors: Kingston D.
Published: March 2008

Under field conditions wanted micro‐organisms are often present in the air in small numbers and form a small proportion of the total flora. Selective techniques would be useful, but may be difficult to devise as airborne micro‐organisms are easily damaged and passing air over organisms deposited on slit sampler plates may be traumatic. Selective media may be avoided by using indicator media or animal inoculation, or the organisms may be transferred to selective conditions after some growth has taken place. Five selective agents are discussed: specific nutrients, anaerobic incubation, temperature, antibiotics, and other added selective chemicals. A table of references for isolating individual organisms is given.
A Selective Medium for Agrobacterium radiobacter Biotype 2
Authors: New P. B. , Kerr A.
Published: March 2008

A selective medium has been developed which allows a quantitative estimation of numbers of Agrobacterium radiobacter biotype 2 in soil and in crown gall tissue. In the soils tested, both tumour inducing and saprophytic forms of biotype 2 occurred.
Antigenic Properties of Yeasts of Various Genera
Authors: Campbell I.
Published: March 2008

Antigenic properties are listed of 46 species of 12 genera of yeasts. With the exception of capsulate strains, in which cell wall antigens are masked, ali were aggiutinable by one or more of 6 specific antisera. Brettanomyces, Debaryomyces, Hawenula, Hanseniaspora, Nadsonia, Sacoharomycodes and Schizosaccharomyces are composed of antigenically identical species, but differences occur among the genera. Within the genera Candida, Kloeckera, Pichia and Torulopsis antigenic differences allow distinction of species or groups of species. Most species tested are antigenically distinct from brewing strains of Saccharomyces, and if present as contaminants of brewing yeast are readily detectable by fluorescence microscopy.
Pseudomonas fluorescens Biotype G, the Dominant Fluorescent Pseudomonad in South Australian Soils and Wheat Rhizospheres
Authors: Sands D. C. , Rovira A. D.
Published: March 2008

Estimates of the numbers of fluorescent pseudomonads in 15 different soils and in rhizospheres of wheat growing in these soils showed that they constituted only 0·06% and 0·27% of the bacterial population in the soil and rhizospheres, respectively. The counts showed that the variability between replicate samples was 6‐fold greater for the fluorescent pseudomonads than for general aerobic bacteria. This high variability supports the hypothesis that there is a heterogeneous distribution of fluorescent pseudomonads through soil where they probably occur as discrete colonies associated with particulate organic matter. One hundred and eightysix cultures of fluorescent pseudomonads were tested for their reactions on 27 biochemical and nutritional tests and sensitivity to 8 antibiotics. The cultures were grouped according to 6 tests (gelatin hydrolysis, levan production, denitrification and ethanol, trehalose and sorbitol utilization) which would place them into recognized biotypes. On the basis of these GLDETS tests 65% and 59% of the isolates from soil and rhizosphere, respectively, fell into biotype G of Pseudomonas fluorescens. Only in 4 of the 15 soils were other biotypes more abundant than biotype G. Amongst the isolates outside this dominant biotype G those from the wheat rhizosphere had a higher proportion giving positive GLDETS tests than did those from soil.
Genetic Transformation in Bacillus with Respect to Antibiotic Production
Authors: Biswas G. D. , Sen S. P.
Published: March 2008

The possibility of intraspecific and interspecific transformation in Bacillus with respect to antibiotic production has been investigated. In intraspecific transformation in B. subtilis 5 of 10 strains used as recipient were transformed; the frequency of transformation was 0·1–0·7%. Both antibiotically inactive and active strains could be transformed.

A bacitracin producing strain, MB 294, of B. subtilis transformed 3 strains; an inactive strain, B(49)3, was transformed to the production of an antibiotic indistinguishable from bacitracin. MB 294 itself was transformed by only 1 of the 4 strains of B. subtilis used as donor; in one case it acquired the property of elaborating an antifungal antibiotic while retaining its antibacterial activity. All attempts at transformation of B. cereus, B. circu‐lans, B. firmus, B. laterosporus and B. megaterium with B. subtilis DNA failed.
Transformation in Streptomyces with Respect to Antibiotic Production
Authors: Biswas G. D. , Sen S. P.
Published: March 2008

Transformability of a large number of Streptomyces strains was examined with respect to antibiotic production. Of 8 antibiotically inactive strains studied, 3 could be transformed to antibiotic production by treatment with the deoxyribonucleic acid of antibiotically active strains. When both the donor and the recipient strains were antibiotically active, 3 of 32 pairs of strains examined yielded positive transformations. The recipient strains acquired the antimicrobial spectra of the donor antibiotics; in some cases the chemical properties, including Rf values in several solvent systems, of the antibiotic substances elaborated by some of the donor and transformant strains were found to be similar. Although an antibiotically inactive mutant of S. viridifaciens could be transformed to antibiotic production by treatment with the DNA of S. aureofaciens NCIB 8234, all attempts at transformation in the Streptomyces strains producing the tetracycline group of antibiotics failed. A candicidin producing strain of S. griseus NCIB 8891 acquired antibacterial property when transformed with the DNA of S. griseus MA 8. A strain of Streptomyces sp. A(22) 3 transformed 4 other strains of Streptomyces.
A Simple Technique for the Quantitative Assessment of Gram Positivity
Authors: Smith D. G.
Published: March 2008

A simple technique for assessing the Gram positivity of dried smears of bacteria is described. Standardized smears on glass slides are decolourized for a specified time and the colorimetric level of crystal violet loss into the decolourizer taken as a measure of Gram positivity. The technique gives comparative values between strains and has been successfully used in several different experimental conditions.
The Observation of Myxobacterial Fruiting Bodies
Authors: Smit Marlene , Clark A. G.
Published: March 2008

The use of thin, absorbent discs as growth substrates for the study of the gross morphology of fruiting myxobacteria is described. Their advantages over herbivore pellets are discussed.
Optimum Growth Parameters of Lactic Streptococci used for the Production of Concentrated Cheese Starter Cultures
Authors: Cogan T. M. , Buckley D. J. , Condon S.
Published: March 2008

As a preliminary to producing continuous cultures of lactic streptococci, several parameters affecting growth rate in broth culture were studied. The optimum pH for growth of 3 strains was c. 6.4. The results indicate that continuous cultivation should not be done above c. 27° and that, in the case of Streptococcus lactis C10, excessive aeration should be avoided. Sparging with CO2 was unnecessary and with N2 was deleterious to growth.
A Rapid, Inexpensive Bacterial Count Technique using Agar Droplets
Authors: Sharpe A. N. , Kilsby D. C.
Published: March 2008

A simple method is described for obtaining viable counts of aerobic bacteria. Dilutions are prepared in molten agar and colonies allowed to form in droplets (0·1 ml) of appropriate dilutions. Samples can be processed c. 3 times faster by this technique than with a standard pour plate method: it reduces costs, work and incubation time. Counts obtained with the droplets compare favourably with those obtained by pour plates.
Use of the Coulter Counter to Count Cells of Streptococcus faecalis
Authors: Andrew M. H. E. , Westwood N.
Published: March 2008

The suitability of the Coulter electronic particle counter for counting chains of cells of Streptococcus faecalis was investigated. Growth curves produced from electronic counts had similar characteristics to curves produced from nephelometer readings, viable pour plate counts and total counts performed with a Thoma counting chamber. The validity of comparing counts obtained using different counting parameters is discussed.
The Evaluation of Sterilization and Pasteurization Processes from Temperature Measurements in Degrees Celsius (°C)
Authors: Shapton D. A. , Lovelock D. W. , Laurita‐Longo R.
Published: March 2008

A new unit (MF value) is proposed for evaluating conventional and very high temperature sterilization processes and its relationship to the F value is described. A series of new units (P values) is proposed for the evaluation of pasteurization processes. Tables are given for the evaluation of sterilization and pasteurization processes using the method of ‘integration by addition‘, described by Patashnik, from temperatures measured in degrees Celsius.
Polyangium luteum Krzemieniewski in Pure Culture
Authors: Kühlwein H. , Schlicke B.
Published: March 2008

A strain of Polyangium luteum was isolated from rabbit dung and grown in pure culture. This strain is described.
Microbiological Quality Control of Sterilized Products: Evaluation of a Model Relating Frequency of Contaminated Items with Increasing Radiation Treatment
Authors: Tallentire A. , Dwyer J. , Ley F. J.
Published: March 2008

A model describing the dependence of the proportion of items contaminated (P) in a population of items on radiation dose (D) has been developed. The model was evaluated for a range of doses assuming a Poissonian distribution of micro‐organisms on items prior to and during irradiation and radiation inactivation according to ‘multiple‐hit’ kinetics; curves relating P and D were constructed. The influence on curve shape of changing the initial average number of micro‐organisms on items and of varying parameters of microbial sensitivity to radiation was assessed. Consideration was given to the value of using sub‐process radiation doses in microbiological quality control testing.
Lactobacilli Causing Spoilage of Acetic Acid Preserves
Authors: Dakin J. C. , Radwell Jill Y.
Published: March 2008

Twentyseven cultures of lactobacilli, isolated from 27 packs of spoiled vinegar preserves, which originated from 21 manufacturers and included 12 varieties of product, were examined according to the system of Rogosa & Sharpe and by other tests. One culture conformed to the characteristics of Lactobacillus casei var. casei; 2 cultures to those of L. brevis; 4 cultures to those of L. buchneri; and 20 to those of L. fructivorans. On the basis of the results and an examination of the literature it is suggested that L. trichodes is a synonym of L. fructivorans.
The Survival of Erwinia amylovora in Airborne Particles: Tests in the Laboratory and in the Open Air
Authors: Southey R. F. W. , Harper G. J.
Published: March 2008

The causative organism of fire‐blight, Erwinia amylovora, survives well when contained in small airborne particles held in the laboratory at relative humidities between 40 and 90 %. Although greater loss of viability occurred when simulated aerosols were exposed to the open air, there were still significant numbers of organisms viable after 2 h.
Studies on the Mode of Action of the Phenolic Antibacterial Agent Fentichlor against Staphylococcus aureus and Escherichia coli II. The Effects of Fentichlor on the Bacterial Membrane and the Cytoplasmic Constituents of the Cell
Authors: Hugo W. B. , Bloomfield Sally F.
Published: March 2008

Fentichlor produces rapid and marked damage to cell membranes of Staphylococcus aureus and Escherichia coli causing leakage of 260 nm material and pentose from whole cells, and lysis of spheroplasts of E. coli. Investigations indicate that Fentichlor‐induced membrane damage is related to bactericidal activity. Bacteriostatic concentrations of 10 μg/ml or less do not stimulate leakage while at higher concentrations there is a marked relationship between loss of viability and of metabolic pool material released. Drug concentrations producing 99·99% kill within 1 h correspond closely to minimum concentrations required to produce total loss of 260 nm material from the pool. Membrane damage caused by bactericidal concentrations of drug is irreversible and under conditions optimal for enzyme activity additional leakage of 260 nm material resulting from autolytic breakdown of insoluble nucleic acids also occurs. There is no evidence that Fentichlor produces precipitation of cell cytoplasmic constituents.
Studies on the Mode of Action of the Phenolic Antibacterial Agent Fentichlor against Staphylococcus aureus and Escherichia coli II. The Effects of Fentichlor on the Bacterial Membrane and the Cytoplasmic Constituents of the Cell
Authors: Hugo W. B. , Bloomfield Sally F.
Published: March 2008

Investigations of the effect of low concentrations of Fentichlor on the metabolic activities of Staphylococcus aurew and Escherkhk coli indicate that the bacteriostatic action of the drug results from a specific inhibition of metabolic reactions within the cell which are energy‐requiring. Bacteriostatic concentrations of Fentichlor inhibit energy dependent uptake of amino acids, assimilation of amino acids and glucose into cellular material and total protein synthesis. In contrast, energy‐independent uptake of amino acids and the uptake of glucose is little affected. These concentrations do not inhibit respiratory enzymes and selective inhibition of energy metabolism by Fentiohlor probably results from a disruption of the mechanism of energy coupling within the cell.
The Isolation of Salmonellae from the Bursa of Fabricius of Chickens Latently Infected with these Organisms
Authors: Williams‐Smith H.
Published: March 2008

A nalidixic acid resistant mutant of Salmonella typhimurium was isolated more frequently from the Bursa of Fabricius than from the caecal contents, caecal tonsil, liver or spleen of chickens that had been given a culture of this mutant by mouth. Salmonellae were also isolated more frequently from the Bursa than from the caecal contents of naturally infected chickens.
Nitrofurantoin Media for the Isolation of Pseudomonas aeruginosa
Authors: Thom A. R. , Stephens Mary E. , Gillespie W. A. , Alder V. G.
Published: March 2008

Selective and enrichment media containing nitrofurantoin were compared with media containing cetrimide in the isolation of Pseudomonas aeruginosa from contaminated specimens. The nitrofurantoin media were as sensitive as cetrimide media, were easier to prepare and use and constant in performance.
Bacteria Associated with the Intestinal Wall of the Fowl (Gallus domesticus)
Authors: Fuller R. , Turvey A.
Published: March 2008

Using histological and cultural techniques bacteria associated with the intestinal wall of the chick have been demonstrated. The main sites of adhesion were the crop, ileum and caecum. The pattern of attachment was characteristic for each site.
Stimulation of Yeast Sporulation by Glycerol
Authors: Patel P. V. , Miller J. J.
Published: March 2008

Summary: Glycerol stimulated sporulation of Saccharomyces cerevisiae Hanson, especially when the cells were precultured in a complex growth medium instead of a chemically defined medium. Optimum spore yields occurred with 1–4% of glycerol but some were produced in 16% glycerol. Sporulation in glycerol was much less sensitive to ammonium sulphate inhibition than it was in acetate. Growth occurred with glycerol as sole carbon source and glutamic acid as sole nitrogen source, but not with ammonium sulphate as the sole nitrogen source.
Production of Flavour‐enhancing Materials by Streptomycetes: Factors affecting the Production 5′‐Mononucleotides
Authors: Schwartz J. , Margalith P.
Published: March 2008

Summary: Although extracellular accumulation of 5′‐nucleotides in streptomycetes is usually scarce one organism (772) formed considerable quantities of flavour‐enhancing 5′‐mononucleotides. A number of fermentation parameters were examined. Manganese ions, barbiturates and antibiotics appreciably affected the accumulation of such nucleotides. A 4‐fold increase in the formation of 5′‐inosinic acid was achieved by incorporating barbiturates in the medium, while substantial amounts of 5′‐guanylic acid could be also detected in presence of some antibiotics.
The Adansonian Taxonomy and the Deoxyribonucleic Acid Base Composition of some Gram Negative, Yellow Pigmented Rods
Authors: McMeekin T. A. , Stewart D. B. , Murray J. G.
Published: March 2008

Summary: The numerical taxonomy technique of Sneath (1957) was used to differentiate types of Gram negative, yellow pigmented rods isolated from food products. DNA base ratios were determined for representative isolates from each of the major groups formed. A determinative scheme using features extracted from the data has been suggested. The problems of nomenclature of organisms of this type are discussed.
Electronmicroscopic Observations on the Degradation of Cellulose Fibres by Cellvibrio fulvus and Sporocytophaga myxococcoides
Authors: Berg B. , Hofsten B. v. , Pettersson G.
Published: March 2008

Summary: Cellvibrio fulvus and Sporocytophaga myxococcoides were grown on different types of cellulose fibres and the degradation was followed by means of light and electron microscopy. The very compact fibres prepared from cotton were degraded slowly by C. fulvus. The bacteria penetrated into the lumen of the fibres, accumulated there in large numbers, and degraded the fibres from within. Sporocytophaga myxococcoides attacked fibres both from the outside and from within by making close contact with the cellulose. Lignin free pulp fibres, which have a very open structure, were rapidly degraded by both kinds of bacteria. Cellvibrio fulvus also degraded these fibres from within. It is concluded that structure of the fibre greatly influences the rate at which different kinds of cellulolytio bacteria decompose cellulose.
The Semi Large‐scale Production, Extraction, Purification and Properties of an Antibiotic Produced by Bacillus licheniformis Strain 2725
Authors: Woolford M. K.
Published: March 2008

Summary: Production, extraction, purification and properties of an antibiotic produced by Bacillus liclieniformis, strain 2725 are described. Extraction efficiency was c. 50% with 8–10 g of product/350 1 batch culture, the product having an activity of 2000 units/mg (0·5 μg/ml) against Staphylococcus aureus Paler. The antibiotic was a peptide, was active against Gram positive and negative bacteria; it was stable over a wide pH range, its bactericidal activity was enhanced by serum, but it had a high toxicity and was haemolytic.
Production of Flavour‐Enhancing Materials by Streptomycetes: Strain Improvement and Fermentation*
Authors: Schwartz J. , Margalith P.
Published: March 2008

Summary: Mutation work and the adaptation of streptomycete 772 to certain antimetabolites resulted in increased production of 5′‐nucleotides, including 5′‐guanylic acid (5′‐GMP), concerned with flavour potentiation. The formation of each nucleotide was considerably affected by the composition of the medium. Na barbitone increased the biosynthesis of 5′‐inosinic acid by blocking the pathway to 5′‐GMP, while the 8‐azaguanine adapted strains were no longer sensitive to the action of the drug. These results are discussed in view of the current concepts of metabolic control mechanisms.
Viability of Clostridial Spores and the Requirements of Damaged Organisms III. The Effect of Delay in Plating after Exposure to the Bactericidal Influence
Authors: Futter B. V. , Richardson G.
Published: March 2008

Summary: Post‐treatment recovery patterns of damaged spores of Clostridium welchii have been investigated. Heat damaged spores showed an early reactivation during storage but counts subsequently declined. Spores damaged by very low intensity γ‐radiation showed a considerable degree of increased recovery during post‐treatment storage. With radiation at higher intensities there was evidence only of a low rate of reactivation when storage was at 4°, and at 21° counts decreased. Progressive loss in viability was also shown in ethylene oxide treated spores on kaolin powders though in the presence of albumin this trend was arrested. A dependence of count on atmosphere of incubation, demonstrated also in 3 other species, was shown to develop during post‐treatment storage.
An Evaluation of Procedures for Enumerating Bacteria in Activated Sludge
Authors: Pike E. B. , Carrington E. G. , Ashburner Patricia A.
Published: March 2008

Summary: A procedure for counting viable heterotrophic bacteria in activated sludge was evolved from a study of the effects of modifications to procedures at the different stages of enumeration. Optimal counts were obtained with Casitone‐glycerol‐yeast extract agar (CGY) with incubation for 6 days at 22°. Homogenization of mixed liquor was conveniently performed, with minimal lethal effect on the bacteria, by treating samples, diluted 1/10 in sodium tripolyphosphate solution (5 mg/1), in a boiling tube immersed in the Kerry ultrasonic cleaning bath for 1 min. Counts were significantly affected by the pH value of diluent and CGY, but not by the homogenization method or by treating homogenized samples with enzymes or N‐acetyl cysteine, or by adding colloidal peptizing agents to the diluent. Replicate colony counts showed variances greater than the mean, although precision increased with increasing number of colonies/dish; there was a direct relationship between colony counts and volume plated for up to c. 1000 colonies/dish. Counts on spread plates tended to be higher and more precise than on dilution frequency plates, although the 2 methods showed satisfactory correlation. Counts were not significantly affected by the method of sampling and preparing the initial dilution, and it was considered prudent to examine samples immediately after collection.
The Use of Density Gradient Centrifugation for the Separation of Germinated from Nongerminated Spores
Authors: Prentice G. A. , Wolfe F. H. , Clegg L. F. L.
Published: March 2008

Summary: The density gradient centrifugation of a suspension of spores of B. subtilis 8057 on both sucrose and renografin gradients gave 2 distinct fractions. Germination evidence suggested that the heavier fraction consisted of dormant spores and the less dense fraction, germinated spores. It is concluded that density gradient centrifugation may provide a useful technique for the separation of germinated from nongerminated spores.