bluuebunny/crossref_metadata_2025 huggingface dataset:
Aerobic Deterioration of Wheat, Lucerne and Maize Silages Prepared with Lactobacillus acidophilus and a Candida spp.
Authors: MOON NANCY J. , ELY LANE O. , SUDWEEKS E. M.
Published: March 2008

Aerobic deterioration of lucerne, maize and wheat silages was characterized by rapid increases in yeast and mould flora which oxidized lactic and volatile acids resulting in increased temperature and pH. While populations of yeasts and moulds were similar, temperature increases were slightly greater for silages inoculated with Lactobacillus acidophilus and Candida spp. After 48 h the pH of the inoculated silages was higher in general and concentrations of acids were lower than controls. Bacterial growth was slight although continued lactic acid production was probable. In contrast to lucerne and maize silages, the pH of wheat silage remained stable during this period because of high butyric levels, but temperature and yeast populations increased. After 48 h the pH rose above 5 in maize and lucerne, and bacterial growth and metabolic activity resumed resulting in volatile and non‐volatile acid production from carbohydrate fermentation and deamination of amino acids. During this phase of aerobic deterioration yeast growth slowed or stopped, but temperatures remained high and pH continued to climb probably because of production of ammonia. The changes in gross composition of the silages did not follow any particular pattern. Losses in dry matter were small (2.5–4.0%) and changes in individual components probably reflect this loss rather than substantial changes. Protein availability in the lucerne silages undoubtedly decreased, as protein losses were high. It is concluded that the aerobic deterioration of silage is enhanced by the addition of L. acidophilus and Candida spp. at ensiling.
Resistance of Micro‐organisms to Inactivation by Gaseous Ethylene Oxide
Authors: DADD A. H. , DALEY GABRIELLE M.
Published: March 2008

A simple method for the exposure of micro‐organisms to ethylene oxide on membrane filters in a modified desiccator has been devised and used to study microbial resistance to the gaseous sterilant and the term ‘R‐value’ is suggested to express this. The resistance of many known species and isolates has been assessed and compared. Several species of Bacillus were isolated from natural habitats and their spores were found to be more resistant than the strain of Bacillus subtilis var. niger (NCTC 10073) frequently used to monitor ethylene oxide sterilization. However, endospores of some bacterial species exhibited little resistance. Fungal spores and vegetative bacteria exhibited low resistance to the sterilant except after drying in organic material when they appeared more resistant than spores of B. subtilis var. niger. It was concluded that resistance to ethylene oxide did not correlate with resistance to heat, irradiation or other chemical disinfectants, or to the existence in the endospore form per se.
Combinations of Clavulanic Acid and other β‐lactam Antibiotics against Strains of Pseudomonas aeruginosa, Serratia marcescens and other Bacteria
Authors: ROGERS D. T. , RUSSELL A. D.
Published: March 2008

Combinations of clavulanic acid, a new β‐lactamase inhibitor, with five cephalosporins and one cephamycin were tested against cell‐free β‐lactamases obtained from Serratia marcescens, Pseudomonas aeruginosa and an Enterobacter strain, 265A. Cefotaxime was the most resistant antibiotic and cephalothin the most sensitive antibiotic to β‐lactamases. Low concentrations of clavulanic acid gave some protection against the Serratia and Pseudomonas enzymes. The most active source of β‐lactamase was the 265A strain, against which only cefotaxime was highly resistant. Clavulanic acid had only a slight inhibitory effect on this enzyme, which was confirmed by an agar method, and potentiated slightly the activity of cephalothin and cefoxitin against two β‐lactamase producing strains of Staphylococcus aureus. Lysis by cephalothin of one strain of S. marcescens was potentiated in the presence of clavulanic acid.
Changes in Preservative Sensitivity for the USP Antimicrobial Agents Effectiveness Test Micro‐organisms
Authors: AL‐HITI M. M. A. , GILBERT P.
Published: March 2008

Chemically defined and semi‐defined media were designed for the preservative‐efficacy testing micro‐organisms designated by the United States Pharmacopoeia, in which the organisms went into the stationary phase of growth at an optical density (E470) of 1.0, because of depletion of a single carbon, nitrogen or phosphate source. Aspergillus niger was grown on solid media containing concentrations of these nutrients which limited the rates of mycelial development and sporulation density. The ability of the micro‐organisms to survive and grow in the presence of chlorhexidine diacetate, benzalkonium chloride and thiomersal varied markedly with the nutrient‐depletion of the inocula. No universal pattern of sensitivity emerged among microorganisms. Only A. niger showed little overall change in preservative sensitivity. These results highlight the need to define more adequately growth media and conditions for the production of inocula for antimicrobial challenge tests.
A Pyrolysis Gas‐liquid Chromatography Study of Clostridium botulinum and Related Organisms
Authors: GUTTERIDGE C. S. , MACKEY B. M. , NORRIS J. R.
Published: March 2008

Low resolution pyrolysis gas‐liquid chromatography could differentiate the following groups of Clostridium botulinum and related organisms: (1) Cl. botulinum type A. proteolytic types B and F and Cl. sporogenes; (2) Cl. botulinum types C and D. and (3) Cl. botulinum type E and non‐proteolytic types B and F. Toxin types A and B could be distinguished from type E and from type F.
Soft Rot Erwinia Bacteria in the Atmospheric Bacterial Aerosol
Authors: QUINN C. E. , SELLS I. ANN , GRAHAM D. C.
Published: March 2008

Using a Casella High Volume Airborne Bacteria Sampler, the soft rot coliform bacteria Erwinia carotovora var. carotovora and E. carotovora var. atroseptica were caught from the open air during rainfall in mid to late summer, autumn and early winter, but not in late winter, spring or early summer. They were not found every time it rained, and never when the weather was dry. The bacteria were caught close to potato crops, but there were several occasions when they were found at sites where there were no such crops or at times of year after potato crops had been harvested. The sources of the organisms are uncertain, but those obtained close to potato crops may have originated there. The results are considered to provide further evidence that airborne spread and subsequent deposition of viable bacteria could cause contamination of Erwinia‐free potato stocks, and suggest that rainfall is a major generator of the general atmospheric bacterial aerosol.
Cell Wall‐mediated Changes in Sensitivity of Bacillus megaterium to Chlorhexidine and 2‐Phenoxyethanol, Associated with Growth Rate and Nutrient Limitation
Authors: GILBERT P. , BROWN M. R. W.
Published: March 2008

The resistance of chemostat‐grown cultures of Bacillus megaterium (asporogenous) to the bactericidal action of chlorhexidine and 2‐phenoxyethanol varied with growth rate and nutrient‐limitation. Phosphate‐limited cultures (P‐lim) showed little change in sensitivity to either drug with changes in growth rate. Magnesium‐limited (Mg‐lim) and carbon‐limited (C‐lim) cultures, however, increased in sensitivity to both agents as growth rate was increased from 0.13–0.45 h. Minimum lytic concentrations of the agents were not significantly different for protoplasts prepared from these suspensions except of Mg‐lim when sensitivity to chlorhexidine increased with growth rate. Lysozyme sensitivity of the cells varied with growth rate and nutrient limitation. Results support the idea that in addition to other effects of growth rate and nutrient‐limitation environmentally‐induced changes in envelope structure and/or composition radically influenced penetration of these agents to their targets.
Thermal Activation and Dry‐heat Inactivation of Spores of Bacillus subtilis MD2 and Bacillus subtilis var. niger
Authors: GURNEY TESSA R. , QUESNEL L. B.
Published: March 2008

Spores of Bacillus subtilis MD2 and Bacillus subtilis var. niger were heat activated for different times at 60° and 80°C. Strain MD2 required considerable heat activation while B. subtilis var. niger did not. Maximum germination rates increased with heat activation dose and declined subsequently without loss of germinability. Germination rates and percentages were considerably greater in tryptone glucose extract (TGE) than in nutrient broth. The addition of 2°° dimethyl sulphoxide did not increase germination in nutrient broth. The spores of var. niger are more resistant to dry‐heat than MD2 although they are less resistant to moist heat. Survivor curves in the dry‐heat range 140°‐170°C gave D‐values from 4–123 to 0.106 min for MD2 and 5.679 to 0.233 min for var. niger recovered on TGE agar. D‐values were lower on poorer media. The z‐values for MD2 and var. niger on TGE were 18.7°C and 21.25d̀C respectively.
Thiaminase Activity Amongst Strains of Clostridium sporogenes
Authors: PRINCEWILL T.J.T.
Published: March 2008

All the 28 strains of Clostridium sporogenes type I tested produced thiaminase. Only 2 of the 16 strains of Cl. sporogenes type II tested were positive for the enzyme; these gave a weak positive reaction. The single strain of Cl. sporogenes type III behaved in a manner similar to the strains of type I, giving a strong positive thiaminase reaction. Thiaminase production amongst the strains of Cl. sporogenes does in the main support the cultural, biochemical and immunological properties described earlier.
Radioiodination of Enterotoxin from Clostridium perfringens Type A using Chloramine T
Authors: SKJELKVALE R.
Published: March 2008

Procedures were examined for labelling enterotoxin isolated from Clostridium perfringens type A. with 125I using chloramine T as the oxidizing agent. The iodination method was evaluated critically to establish the optimal conditions for the preparation of iodinated enterotoxin with a high specific radioactivity and without impairing the immunospecificity and biological activity. The use of 250 μg/ml of chloramine T in the reaction mixture. 500–1000 μCi of Na125I/10 μg of enterotoxin and a reaction time of 40 s at pH 7–0 produced 125I‐enterotoxin of both high specific radioactivity and immunospecificity which retained its biological activity. No damage or aggregate formation due to the iodination process was observed. Enterotoxin labelled with high specific activity (135 μCi μg) showed extensive dissociation of 125I when stored at 4°C and—20°C. In contrast, toxin labelled with low specific activity (7 μgCi/μg) was stable for as long as two months. The immunoreactivity of all labelled preparations was essentially unchanged after storage for one month.
The Occurrence of Bacillus cereus in some Dried Foods Including Pulses and Cereals
Authors: BLAKEY LINDA J. , PRIEST F. G.
Published: March 2008

In a survey of 39 dried food samples which represented 12 different pulses and cereals. 22 (56%) were found to be contaminated with Bacillus cereus. The numbers varied between 1 times 102 and 6 times 104 organisms/g. During normal cooking procedures and on storage at room temperature, the B. cereus resident on red lentils and kidney beans increased to a level at which enterotoxin production could become significant. Some physiological characteristics including deoxyribonuc‐lease (DNase) and ribonuclease (RNase) secretion and salicin fermentation did not correlate with the ability or otherwise of a strain to cause food poisoning. Nevertheless, serotype 8 strains were prevalent on these foods and these have been implicated in both the diarrhoeal and vomiting‐type food poisoning syndromes.
Quality Control of Solid Culture Media: A Comparison of the Classic and the So‐called Ecometric Technique
Authors: MOSSEL D. A. A. , ROSSEM FRANCINE VAN , KOOPMANS MIRESE , HENDRIKS MIEKE , VEROUDEN MARJON , EELDERINK INEKE
Published: March 2008

Some selective culture media, prepared from commercially available dried preparations function poorly, and the same applies to an occasional non‐selective culture medium. This calls for systematic monitoring of media before they are used in actual diagnostic work. Classic plating or dilution‐to‐extinction techniques are often found too cumbersome. Hence a simple streaking technique (‘ecometric’ evaluation) was developed earlier for this purpose. It was subsequently simplified further and its accuracy and precision were assessed in this study.

After it had been found that the simplified ecometric procedure allowed a reasonably accurate analysis of the selective and productive properties of media, it was used to evaluate 16 selective media, currently used in food microbiology. Results obtained agreed well with observations on the functioning made during routine examination of various foods. Finally an attempt was made to assess whether ecographic inoculation would allow the study of micro‐organisms under repressive conditions, particularly refrigeration temperature. It appeared that this was indeed possible.
Lactose Hydrolysing Enzymes in Streptococcus lactis and Streptococcus cremoris and also in some other Species of Streptococci
Authors: FARROW J. A. E.
Published: March 2008

Two types of Streptococcus lactis could be identified: cheese starter strains, which contain β‐phosphogalactosidase and ferment lactose rapidly to lactate, and non‐dairy strains, which contain both β‐galactosidase and β‐phosphogalactosidase and ferment lactose slowly to a variety of end products. All strains had homolactic glucose fermentations and heterolactic galactose fermentations. Other species of streptococci were examined for lactose hydrolysing enzymes and found to contain β‐phosphogalactosidase, except Strep, thermophilus and Strep. faecium which had high levels of β‐galactosidase. Discrepancies were found in the lactose hydrolysing enzymes content when the cells were treated in different ways.
Pyrolysis Gas Chromatography of Pseudomonas and Acinetobacter Species
Authors: FRENCH G. L. , GUTTERIDGE C. S. , PHILLIPS I.
Published: March 2008

Low resolution pyrolysis gas chromatography was performed on five species of Pseudomonas and two species of Acinetobacter. Conventional species groups could be differentiated by canonical variates analysis, and visual examination suggested that subspeciation would have been possible with more data.

Carbowax 20M has been used as the stationary phase for the majority of published work on pyrolysis gas chromatography of micro‐organisms. However, with this material baseline resolution was poor, analysis times were long and column deterioration was relatively rapid. Peak area reproducibility on a single column averaged 10%, but it proved impossible to achieve quantitatively similar pyrograms on a new column. These serious drawbacks of Carbowax 20M limit the usefulness of this stationary phase for pyrolysis gas chromatography of micro‐organisms.
Evaluation of Enzyme‐linked Immunosorbent Assay (ELISA) for Serological Identification of Different Rhizobium Strains*
Authors: KISHINEVSKY B. , GURFEL DEBORA
Published: March 2008

A double‐antidody sandwich method of enzyme‐linked immunosorbent assay (ELISA) previously used for serotyping of peanut Rhizobium isolates was applied for serological identification of fast‐ and slow‐growing Rhizobium strains belonging to different species. This technique is highly sensitive for specific detection of culture and nodule antigens and enabled the rapid screening of large numbers of nodules.

ELISA absorbance values of heat‐treated, ultrasonically and mechanically disintegrated cells of the tested strains were consistently higher than those of untreated cells.

The antisera to strains R. leguminosarum 250V and R. meliloti 111 obtained from individual rabbits differed in their suitability for ELISA, although they were very efficient in homologous agglutination reactions. The ELISA reactions of culture and nodule antigens were identical for all strains investigated.
A Note on Bile Acids Transformations by Strains of Bifidobacterium
Authors: FERRARI ANNAMARIA , PACINI NOVELLA , CANZI ENRICA
Published: March 2008

The hydrolysis of sodium taurocholate and glycocholate was a common feature among 52 strains from 14 species belonging to the genus Bifidobacterium. Forty‐eight strains were able to hydrolyse both these conjugated bile acids, yet four strains failed to split the amide bond of either. Twenty‐eight strains were checked for the ability to transform sodium cholate, chenodeoxycholate, deoxycholate and lithocholate; only 13 of these strains formed minimal quantities of monochetoderivatives from cholic acid, while none of them was able to transform the other tested bile acids.
Isolation and Characterization of Bacteria from the Baltic Sea
Authors: NEILSON A. H.
Published: March 2008

A bacteriological examination was done on samples of water and sediment from three localities in the Baltic. The highest numbers of bacteria were recovered from areas subjected to pollution. The isolates included members of the family Enterobacteria‐ceae, the genus Pseudomonas and strains of Aeromonas hydrophila, Alteromonas putrefaciens and some Gram positive bacteria. It is suggested tentatively that H2S production in the black sediments was caused by Alt. putrefaciens. None of the isolates had an absolute requirement for NaCl, although all of them were salt‐tolerant to varying degrees, and most were able to grow aerobically at salinities comparable with those found in seawater. Isolates belonging to the family Enterobacteriaceae were, however, unable to grow anaerobically under comparable conditions. Freshwater strains of several genera of the family Enterobacteriaceae and of Aeromonas hydrophila and Aer. sobria displayed salt tolerance identical with that of the Baltic isolates. One strain each of Escherichia coli, Klebsiella pneumoniae and Yersinia enterocolitica survived well during three weeks at 17°C in artificial seawater lacking both carbon and nitrogen sources. These results suggest the need for a re‐evaluation of the persistence of potentially pathogenic bacteria in the sea.
Isolation and Characterization of Bacteria from the Swedish West Coast
Authors: NEILSON A. H.
Published: March 2008

Most of the bacteria isolated from water and sediment samples from a locality off the west coast of Sweden had an absolute requirement for Na+. On the basis of phenotypic characterization and determination of DNA base composition, the strains could be assigned to the genera Beneckea, Alteromonas and Pseudomonas. Apart from a group of sulphide‐forming alteromonads, none of the isolates appeared to be identical with organisms described previously.
A Note on the Detection of Penicillin Acylase Activity in Escherichia coli by the Reaction of Ampicillin with Biuret Reagent
Authors: BAKER W. L.
Published: March 2008

Ampicillin reacts with biuret reagent in a novel manner to give an absorption peak at 410 nm. Treatment of ampicillin with penicillin acylase from Escherichia coli ATCC 9637 or whole cells of the same organism results in loss of biuret‐reacting properties. The reaction could possibly form the basis of a screening test for penicillin acylase.
Fluorimetric Assay of the Activity of Extracellular Lipases of Pseudomonas fluorescens and Serratia marcescens
Authors: ROY R. N.
Published: March 2008

A fluorimetric assay was carried out on the activity of extracellular lipase concentrations obtained from Serratia marcescens and Pseudomonas fluorescens using as substrates fatty acyl esters of 4‐methylumbelliferone (4‐methylumbelliferone elaidate, 4‐methylumbelliferone nonanoate, 4‐methylumbelliferone butyrate, 4‐methylumbelliferone palmitate and 4‐methylumbelliferone oleate) at pH 4.0, 6.0, 8.0 and 10.0. The Ser. marcescens and Ps. fluorescens were cultured in Pope and Skerman's basal medium (Skerman 1957) supplemented with 0.5% (w/v) of a commercial medium. The extracellular lipases were isolated and purified by ammonium sulphate precipitation. The assay was carried out by relating the fluorescent intensity emitted by two lipase concentrations on five substrates against four standard curves. These standard curves were prepared by estimating the intensity of fluorescence given by varying dilutions of 4‐methylumbelliferone at the four pH levels. The results indicated that the oleic ester of 4‐methylumbelliferone was a suitable substrate at pH 8.0 and pH 10.0. These pH values were also optimum for fluorescent intensity on substrates of 4‐methylumbelliferone elaidate, 4‐methylumbelliferone butyrate and 4‐methylumbelliferone palmitate. However, on substrate 4‐methylumbelliferone nonanoate, the optimum pH was 4.0.
A Note on the Sensitivity of Chlorine‐stressed Bifidobacteria to Nalidixic Acid
Authors: SARTORY D. P.
Published: March 2008

Bifidobacterium adolescentis, normally resistant to 200 μg/ml nalidixic acid, became sensitive to 10 μg/ml nalidixic acid after 15 min exposure to chlorinated sewage effluent (0–08 mg/1000 ml of residual chlorine). After exposure to 0.7 mg/1000 ml of residual chlorine, Bifidobacterium adolescentis became sensitive to 5 μg/ml nalidixic acid.
Pseudomonas tolaasi in Mushroom Crops: A Note on Primary and Secondary Sources of the Bacterium on a Commercial Farm in England
Authors: WONG W. C. , PREECE T. F.
Published: March 2008

Primary sources of Pseudomonas tolaasi Paine on a mushroom farm were the peat and limestone used in the casing process. The pathogen could not be detected in the farm soil, water supply, the mushroom spawn used, or in compost after spawning, but was isolated from the casing (peat/limestone mixture) layer of symptom‐free mushroom beds and both the casing layer and compost of beds bearing diseased mushrooms. Secondary sources were numerous once the pathogen was present in mushroom beds. These included symptomless and diseased mushrooms, the fingers and shoes of people handling the crop, their baskets, knives and ladders. Ps. tolaasi could be isolated from dust in the air in infected houses and also from floors. Spores of infected mushrooms may transport the bacterium, as did sciarid flies and mites which are common pests of mushroom crops.
Standard Test Set and a Computer‐generated Diagnostic Register for Gram negative Fermentative Rods
Authors: SCHINDLER J. , DUBEN J. , HAUSNER O. , ZIKMUNDOVÁ V. , LAPÁČKOVÁ J. , PAUČKOVÁ V.
Published: March 2008

A simple two‐step method for the identification of Gram negative fermentative rods is based on interpretation of test results by means of a computer‐generated diagnostic register. The first step is based on 10 tests, the second on six. Of 1451 strains routinely isolated in clinical laboratories 84% were identified in the first step. If the second step was included, the efficacy of the system rose to 99.17%. Disagreements with the conventional method in the first step are discussed.
Characterization of a Thermostable α‐Amylase from Bacillus licheniformis NCIB 6346
Authors: MORGAN F. J. , PRIEST F. G.
Published: March 2008

With one exception (NCIB 9668), the extracellular amylases from 10 strains of Bacillus licheniformis were thermostable and retained more than 98% of their original activity after incubation at 85°C for 60 min. The enzyme from B. licheniformis NCIB 6346 was purified 30‐fold by ion‐exchange chromatography and was characterized. It had an endo‐action on starch yielding maltopentaose as the major product, and was identified as an α‐amylase. The purified enzyme had a molecular weight of 62 650, was stable between pH 7 and 10 and was maximally active at 70‐90°C at pH 7.0. It closely resembled commercial thermostable α‐amylases in its general properties and it is concluded that B. licheniformis provides a good source of these enzymes.
A Novel Method of Assaying Antimicrobial Agents by Particle Microelectrophoresis
Authors: FURR J. R. , DAVIES GILLIAN , ADEBIYI A. R. A. , RUSSELL A. D.
Published: March 2008

Increasing concentrations of chlorhexidine, streptomycin, neomycin, gentamicin and kanamycin reduced the mobility of, and negative charge on, Escherichia coli cells. This finding has formed the basis of a novel method for assaying these antibacterial agents.
A Note on the Occurrence of Bacillus cereus and Other Species of Bacillus in Indian Spices of Export Quality
Authors: SEENAPPA M. , KEMPTON A. G.
Published: March 2008

Four unprocessed Indian spices sampled at the point of export were shown to be highly contaminated with bacteria. Bacillus cereus was detected in more samples of these spices than any other spore‐forming aerobe.
Microbiological Aspects of Cold Cleaning with an lodophor of Milk Pipeline Installations
Authors: RICHARD J.
Published: March 2008

Over a period of three years bacteriological comparisons were made of a method of cleaning pipeline milking machines with (1) cold iodophor solution (cold method), (2) a chlorinated alkaline solution at 55‐60°C circulated for 10 min (hot method), and (3) acidified boiling water (ABW method). Rinse samples from the entire installations gave the best results with the ABW method. The cold method favoured a psychrotrophic flora, coliform bacteria or lactic streptococci, depending on the part of the milking machine rinsed; the hot method tended to cause a build‐up of the heat‐resistant flora. In spite of this, the two methods can give acceptable results provided that the installations are correctly designed and constructed.
Properties of Pseudomonads Causing Spoilage of Vegetables Stored at Low Temperature
Authors: BROCKLEHURST T. F. , LUND B. M.
Published: March 2008

Twenty‐four strains of pectolytic, fluorescent pseudomonads were isolated from soft rots of celery stored at 0.4‐1°C and five strains were isolated from soft rots in cabbage stored at 1°C. When inoculated into the vegetable from which they were isolated these bacteria caused soft rot of wounded, but not of unwounded tissue. According to their biochemical reactions, the organisms were divided into three groups; Group 1 (15 strains) were identified with Pseudomonas fluorescens Biotype II (Doudoroff & Palleroni 1974) (Ps. marginalis); Group 2 (12 strains) and Group 3 (two strains) would be included in the ‘Miscellaneous strains’of Ps. fluorescens described by the above authors. One strain biochemically representative of Group 1 showed a maximum growth rate at 27°C (doubling time, 0.88 h) and a doubling time at 0.2°C of 14.9 h. A strain representative of Group 2 showed a maximum growth rate at 29°C (doubling time 0.96 h) and a doubling time at 0.2°C of 16.6 h. Neither strain grew at 36°C. The temperature characteristics (calculated for the range 0.2‐20.8°C) were 83 011 and 79 534 J/mol, respectively. The mean doubling time for the remaining Group 1 strains at 0.2°C was 17.6 h and for remaining Group 2 strains was 17.1 h.
A Comparison of Alternative Methods to Viable Count for Indicating Growth of Mycoplasma gallisepticum in Liquid Culture
Authors: SNELL G. C.
Published: March 2008

In an attempt to find a more rapid method than a viable count for estimating growth of Mycoplasma gallisepticum in broth culture, seven alternative methods were each examined for their correlation with viable counts, reproducibility and time taken to obtain results. Opacity measurement was the quickest and showed closest correlation with viable count and also high reproducibility. The other methods examined showed either lack of sensitivity or reproducibility or poorer correlation with viable count.
Metabolism of Acetate and Hydrogen by a Mixed Population of Anaerobes Capable of Converting Cellulose to Methane*
Authors: KHAN A. W. , MES‐HARTREE MARY
Published: March 2008

A methanogenic system found in cellulose‐enriched cultures produced CH4 from CO2‐reduction at 19‐24 mmol/l/d, and converted acetate to CH4 at 9‐11 mmol/l/d. Acetate to CH4 conversion occurred on approximately mol/mol basis and was not affected by the presence of H2. Methane formation, from probable intermediates of cellulose degradation, decreased in the order, H2‐CO2 >, acetate > ethanol > pyruvate > lactate > propanol > propionate > butanol > acetaldehyde > isobutanol > formate > methanol. Conversion of acetate to CH4 appears to be brought about by the long filamentous bacteria which are also present in acetate‐enriched cultures.
Thermostability of Proteases and Lipases from a Number of Species of Psychrotrophic Bacteria of Dairy Origin
Authors: GRIFFITHS M. W. , PHILLIPS J. D. , MUIR D. D.
Published: March 2008

Proteases and lipases from a number of different species of psychrotrophic bacteria isolated from dairy products are resistant to heat treatments of 77°C for a holding time of 17 s and 140°C for a holding time of 5s. A further treatment combining the 77°C for 17 s heating process with a heat treatment involving a temperature of 55°C for 1 h was also examined. The proteases and, to a lesser extent, the lipases were also resistant to the treatments in combination. The resistance of proteases and lipases to inactivation by a treatment of 55°C for 1 h varied between and within species. Therefore, this treatment may not have a widespread practical application.
Role of Bacteriocin During Plaque Formation by Streptococcus salivarius and Streptococcus sanguis on a Tooth in an Artificial Mouth
Authors: RUSSELL C. , TAGG J. R.
Published: March 2008

Bacteriocinogenic strains of Streptococcus salivarius antagonized Strep. sanguis on blood agar and in Todd‐Hewitt broth with, but not without, sucrose. Each organism produced plaque in vitro but, after a mixed inoculum with both organisms, the numbers of Strep. sanguis rapidly fell to <0.01% plaque organisms. A non‐bacterio‐cinogenic mutant of Strep. salivarius was itself inhibited by Strep. sanguis in the plaque‐producing system; derivatives of Strep. sanguis partially resistant to bacteriocin in the plate test nevertheless failed to co‐habit plaque with bacteriocinogenic Strep. salivarius. The latter could suppress Strep. sanguis in established monoculture plaque but only if sucrose were continuously supplied. It was concluded that the effect of bacteriocin in plaque formation by these streptococci is linked to other as yet unknown properties which may account for the absence of Strep. salivarius from plaque in vivo.
The Effects of pH and Levels of Organic Matter on the Death Rates of Salmonellas in Chicken Scald‐tank Water
Authors: HUMPHREY T. J.
Published: March 2008

The immersion scalding of chicken carcases at 52°C for 2.5 min was found to result in the accumulation of bacteria and organic matter in the water. Disassociation of ammonium urate present in chicken faeces caused the pH value of the water to fall rapidly from 8.4 to 6.0. This pH was maintained for most of the time the tank was in operation. The change in pH value greatly increased the heat resistance of some common salmonella serotypes with a strain of Salmonella typhimurium being the most resistant, having a D52°C value of 34.5 min. The pH value of the water was found to be close to the optimum for the heat resistance of salmonellas. In scald water at pH 5.9–6.0 the death rate of Salm. typhimurium was shown to be independent of organic matter levels indicating that pH was the major influence on heat resistance.
A Note on Positive BACTEC Readings Produced by Mycoplasma
Authors: CARSKI T. R. , BROMAN R. L. , GIUDICE R. A. DEL
Published: March 2008

Five of nine mycoplasma strains tested were associated with a positive radiometric reading, suggesting that Mycoplasma spp. should be considered during the subculturing of clinical materials found positive upon screening by the BACTEC system
A Note on the Persistence of Salmonella havana and Faecal Coliforms on a Naturally Contaminated Piggery Effluent Disposal Site
Authors: CHANDLER D. S. , CRAVEN J. A.
Published: March 2008

Following application of effluent from apparently healthy pigs to land, Salmonella havana was isolated from kilogram samples, irregularly and at low frequency, for eight months from soil and for nearly two from pasture. Faecal coliform organisms on the effluent disposal site decreased rapidly in numbers during the first month following application of effluent at the start of the autumn. They were then maintained at about 100 organisms/g of topsoil until late in the following spring.
The Identification of Enterobacteriaceae from Breweries: Combined Use and Comparison of API 20E System, Gel Electrophoresis of Proteins and Gas Chromatography of Volatile Metabolites
Authors: VAN VUUREN H. J. J. , KERSTERS K. , DE LEY J. , TOERIEN D. F.
Published: March 2008

The API 20E system was applied and evaluated for the identification of 60 bacterial contaminants, isolated from South African lager beer breweries and tentatively identified as Enterobacteriaceae. The results were compared with the groupings obtained by polyacrylamide gel electrophoresis of soluble proteins and by gas chromatography of volatile metabolites. Numerical analysis of the results obtained by all three methods revealed an excellent overall agreement.
A Selective Medium for the Enumeration of Streptococcus bovis by Membrane Filtration
Authors: ORAGUI J. I. , MARA D. D.
Published: March 2008

A new selective medium (membrane‐bovis agar) for the detection and enumeration of Streptococcus bovis is described. It has been successfully used to quantify this organism in polluted waters, sewage and faeces of humans and farm animals. This medium is based on the ability of Strep. bovis to utilize ammonium sulphate as its sole source of nitrogen. Streptococcus faecalis, Strep. faecium, Strep. equinus, Strep. salivarius. Strep. mitis and other bacteria commonly found in water, sewage and faeces are completely inhibited.

Streptococcus bovis appear to be the predominant faecal streptococci in the faeces of farm animals and absent in the faeces of humans. A total of 541 characteristic colonies (on m‐BA), isolated from various sources were identified to species level. Over 97% proved to be Strep. bovis. Therefore, routine confirmatory tests on colonies growing on this medium would appear to be unnecessary.
A Note on the Estimation of Microbial Growth Rates from Rates of Substrate Utilization
Authors: TAN K. H. , GILL C. O.
Published: March 2008

A graphical method is described for estimation of the specific growth rates (μ) of microbial cultures during exponential growth under constant conditions from measurements of rates of substrate utilization or product formation.
Numerical Taxonomy Analysis of Bacteria Isolated from the Completed ‘Most Probable Numbers’ Test for Coliform Bacilli
Authors: AUSTIN B. , HUSSONG D. , WEINER R. M. , COLWELL R. R.
Published: March 2008

Lactose‐fermenting bacteria were isolated from oyster, water and sediment samples tested to determine the Most Probable Number (MPN) of coliforms present. The completed test series was used to enumerate the total number of coliforms. The strains from the completed tests of the MPN analysis were compared with named reference cultures, for which 100 phenotypic characters were recorded and the taxonomic data analysed by methods of numerical taxonomy. The isolates were recovered in 13 phenetic groups, defined at or above the 80% similarity level. Nine phena were identified as Acinetobacter calcoaceticus, Chromobacterium violaceum, Citrobacter freundii, Erwinia herbicola, Escherichia coli, Hafnia alvei, Klebsiella pneumoniae, Serratia liquefaciens, and Ser. marcescens. Of these, Ac. calcoaceticus and C. violaceum were isolated exclusively from oyster tissue samples and strains of the other taxa from both water and oyster samples. Some strains of Esch. coli, Er. herbicola, H. alvei and bacteria that were not Enterobacteriaceae were found to lose the ability to ferment lactose, following storage on laboratory media. Identifications from diagnostic keys, rapid identification systems and IMViC patterns were not always in agreement.
A Comparison of Minerals Modified Glutamate Medium with Other Media for the Enumeration of Coliforms in Delicatessen Foods
Authors: ABBISS J. S. , WILSON JENNIFER M. , BLOOD RUTH M. , JARVIS B.
Published: March 2008

A comparative assessment has been made of the performance of minerals modified glutamate medium (MMGM), lauryl sulphate tryptose broth (LST), MacConkey broth (MAC) and brilliant green bile broth (BGBB) in the enumeration of coliform organisms present in soft cheese, cooked meat and pâté. The medium MMGM was superior in sensitivity to the other three media and compared favourably with them in specificity; BGBB was inferior to the other media tested.
A Note on the Separation of Natural Mixtures of Bacterial Ubiquinones using Reverse‐phase Partition Thin‐layer Chromatography and High Performance Liquid Chromatography
Authors: COLLINS M. D. , JONES DOROTHY
Published: March 2008

Natural mixtures of bacterial ubiquinones (coenzyme Q) were separated according to the length of the polyisoprenyl side‐chain using reverse‐phase thin‐layer chromatography and high performance liquid chromatography. The chromatographic systems described afford a rapid and sensitive means of ubiquinone characterization.
A Chemical Indicator for the Rapid Measurement of F0 Values
Authors: BUNN JAYNE L. , SYKES I. K.
Published: March 2008

A new chemical indicator for monitoring steam sterilization processes has been calibrated in F0 units. The effective temperature range for F0 measurements using this device has been shown to lay between 115 and 123°C. The effective F0 range of the device has been shown to be 4–23 F0 units. Using the device, measurements can be made within 0.5 units of conventionally calculated F0 values.
Effect of the Copper Content of Distillery Spent Wash on its Utilization for Single‐cell Protein Production by Geotrichum candidum, Hansenula anomala and Candida kruzei
Authors: QUINN J. P. , BARKER T. W. , MARCHANT R.
Published: March 2008

Geotrichum candidum, Hansenula anomala and Candida kruzei were grown in batch and continuous culture on samples of the spent wash from a malt whiskey distillery containing levels of dissolved copper up to 22 mg/l. In batch culture some inhibition of growth at the higher copper concentrations and as much as a sixfold accumulation of copper in the biomass were observed. In Geotrichum candidum this accumulation occurred in three distinct phases during the period of batch growth. Although biomass yields in mixed continuous culture declined with increasing dilution rate there was a corresponding increase in cell copper concentration such that total copper removal from the medium remained approximately constant.
The Effect of Monensin on Pure and Mixed Cultures of Rumen Bacteria
Authors: HENDERSON C. , STEWART C. S. , NEKREP F. V.
Published: March 2008

The antibiotic monensin was added to pure cultures of Bacteroides ruminicola, Selenomonas ruminantium, Anaerovibrio lipolytica and Megasphaera elsdenii. These organisms, representing succinate‐ and propionate‐producing rumen bacteria, were not affected by monensin up to 10 μg/ml. Methanobacterium ruminantium was slightly inhibited by monensin, Butyrivibrio fibrisolvens, Ruminococcus albus and Streptococcus bovis were inhibited to differing extents by monensin at concentrations between 0.1 and 10 μg/ml. Bacteroides succinogenes was inhibited at first by monensin at >0.5 μg/ml but after a prolonged lag phase adapted to grow in the presence of monensin at concentrations below 5 μg/ml.

Monensin (1 μg/ml) almost completely stopped the digestion of chopped straw and dewaxed cotton fibres by rumen contents incubated in vitro. The digestion of grass and powdered filter paper was not significantly reduced under these conditions, but when the concentration of monensin was increased to between 3 and 5 μg/ml, the digestion of these substrates was reduced.
A Note on the Identities of Organisms Causing Black Spot Spoilage of Meat
Authors: GILL C. O. , LOWRY P. D. , DI MENNA MARGARET E.
Published: March 2008

Four fungal species,Cladosporium cladosporioides, C. herbarum, Penicillium hirsutumandAureobasidium pullulanswere isolated from meat spoiled by black spot and shown to produce black spot colonies when inoculated on to sterile meat slices which were incubated at — 1°C.Penicillium hirsutumgrew only on the meat surface but the other species penetrated into the tissues, apparently in response to arid conditions at the surface. It is clear from these observations that the traditional association of black spot spoilage withC. herbarumalone is incorrect.
The Relationship of Capsular‐type of Staphylococcus epidermidis to Virulence and Induction of Resistance in the Mouse
Authors: ICHIMAN Y. , YOSHIDA K.
Published: March 2008

Biochemical, immunological and morphological properties of mouse virulent Staphylococcus epidermidis strains ATCC‐31432, SE‐360 and SE‐10 isolated from clinical specimens were compared. Heat‐killed organisms and cell surface polysaccharides extracted from cell surface fractions induced resistance in mice only against challenge with the homologous strain. Hyperimmune rabbit serum prepared with these strains passively protected mice against challenge infection only with the homologous strain. Protective activity in immune sera was absorbed by homologous whole cell and cell surface polysaccharide, but not by heterologous organisms and cell surface polysaccharide. In agar diffusion tests, cell surface polysaccharides from strains ATCC‐31432, SE‐360 and SE‐10 produced single precipitin lines only with the homologous antiserum. The outermost layer of ultra‐thin sections of the three strains was labelled by homologous but not by heterologous ferritin‐conjugated serum. Biochemical analysis of the cell surface polysaccharides showed that they were composed of hexosamine, glycerol, phosphorous, alanine, glycine and phenylalanine. The three strains ATCC‐31432, SE‐360 and SE‐10 were regarded as different from each other. Thirteen of 300 fresh isolates of Staph. epidermidis randomly selected from human clinical specimens proved to be virulent for mice. With ATCC‐31432, SE‐360 and SE‐10 tentatively designated as capsular‐type I, type II and III, respectively, a majority of mouse virulent strains belonged to capsular‐type II.
A Note on the Use of the Spiral Plater to Study the In Vitro Effects of Amoxycillin, Spectinomycin and Chloramphenicol on a Porcine Escherichia coli
Authors: MASTERS P. J. , PALMER G. H.
Published: March 2008

The use of the Spiral Plater to count bacteria during a minimum inhibitory concentration determination is described for amoxycillin, spectinomycin and chloramphenicol against a porcine Escherichia coli (Abbotstown strain). Chloramphenicol was bacteriostatic. Spectinomycin showed slow bactericidal activity. Amoxycillin was rapidly bactericidal.
Effect of Support Material on the Development of Microbial Fixed Films Converting Acetic Acid to Methane*
Authors: MURRAY W. D. , BERG L. VAN DEN
Published: March 2008

A study of the development of methanogenic fixed films on pieces of polyvinyl chloride plastic, etched glass and baked clay showed that support material markedly affected the rate of attachment and growth of bacteria converting acetic acid to methane. Film development, as indicated by the rate of acetate conversion to methane and carbon dioxide, was threefold faster on fired clay than on either PVC plastic or etched glass. Scanning electron micrographs showed that the film of bacteria attached to clay was thick and uniform, while the film attached to PVC plastic was thin although still uniform. Attachment to etched glass was spotty. The characteristics of clay which made it a superior support appeared to be its rough, porous surface which offered attachment sites to the micro‐organisms and the presence of minerals in the clay, particularly iron which is known to stimulate methanogenesis and growth.
The Detection of Microbial Spoilage in Canned Foods Using Thin‐layer Chromatography
Authors: ACKLAND M. R. , TREWHELLA E. R. , REEDER JULIA , BEAN P. G.
Published: March 2008

Thin‐layer chromatography was investigated as an inexpensive alternative to traditional microbiological techniques for the detection of microbial growth in canned vegetables. It was compared with culture methods, pH determination and direct microscopy in batches of canned vegetables with a known incidence of spoilage.
A Note on a Selective Isolation Medium for the Thermophilic Actinomycete Thermomonospora chromogena
Authors: McCARTHY A. J. , CROSS T.
Published: March 2008

Thermomonospora chromogena was isolated from mushroom compost by spreading diluted suspensions on an agar medium containing kanamycin at 25 µg/ml. The antibiotic prevented the growth of other thermophilic actinomycetes on media incubated at 50°C and significantly reduced the growth of associated bacteria.
Studies Concerning the Prediction of Intracellular Water Activity of Bacteria Grown at Reduced Water Activities
Authors: CHIRIFE J. , ALZAMORA S. M. , FONTAN C. FERRO
Published: March 2008

The water activity of various salts, macromolecules and mixed salt‐macromolecule solutions has been determined. The results indicate that interactions between salts and macromolecules can be ignored for predicting the water activity of mixed aqueous solutions.
The Relevance of the Distribution of Micro‐organisms Within Batches of Food to the Control of Microbiological Hazards from Foods
Authors: KILSBY D. C. , PUGH M. E.
Published: March 2008

The distribution of micro‐organisms within batches of food is identified as log‐normal and this distribution has practical implications in the control of microbial hazards in foods. These implications are explained as effects upon counting procedures, changes in levels through processes, detection of low levels of micro‐organisms, the use of indicator groups, presence/absence tests, consumer safety calculations, and sample unit size analysed.
A Study of Rapid and Simplified Confirmatory Tests for Clostridium perfringens
Authors: MEAD G. C. , LEÓN LUCY PÁEZ DE , ADAMS B. W.
Published: March 2008

Strains of Clostridium perfringens and culturally similar species which also may grow on selective isolation media for this organism were examined by conventional confirmatory tests, the API ZYM system and by individual tests for phosphatase and glutamic acid decarboxylase activity.

API ZYM tests, involving 19 different enzymes, confirmed the known similarity between Cl. perfringens, Cl. absonum, Cl. paraperfringens and Cl. sardiniensis but effectively distinguished this group from Cl. bifermentans, Cl. celatum, Cl. perenne and Cl. sordellii. A similar separation was achieved by a single test for acid phosphatase which could be applied to individual colonies on a plating medium.

Because the acid phosphatase test was found to be of greater value than nitrate reduction in distinguishing Cl. perfringens, it could replace the latter in the usual series of confirmatory tests. It is suggested that strains from Cl. perfringens isolation media should be screened for acid phosphatase activity at the purification stage and only positive strains subjected to further tests.

It was found that Cl. perfringens could not be distinguished from the other species on the basis of glutamate decarboxylase activity.
Rapid Counting of Bacteria in Rinses of Milking Equipment by a Membrane Filtration ‐ Epifluorescent Microscopy Technique
Authors: McKINNON C. H. , MANSELL R.
Published: March 2008

Membrane filtration and epifluorescent microscopy were used for the rapid enumeration of bacteria in rinses of milking equipment. Rinse solution (10 ml) was filtered through a 0.6 µm pore size Nuclepore membrane filter and the bacteria retained stained with acridine orange. The clump count of orange fluorescing bacteria on the membrane correlated well with the corresponding plate count (r=0.83). The technique is rapid, taking approximately 10 min, and is sufficiently sensitive to detect 1000 bacteria ml rinse (equivalent to 5 × 103 bacteria/m2 of milking equipment surfaces by the method currently in use).