bluuebunny/crossref_metadata_2025 huggingface dataset:
Anaerobic Fish Spoilage by Bacteria II. Kinetics of Bacterial Growth and Substrate Conversions in Herring Extracts
Authors: STRØM A. R. , OLAFSEN J. A. , REFSNES K. H. , LARSEN H.
Published: March 2008

The time course of the conversions of chemical components in herring extracts during anaerobic growth of Proteus sp., str. NTHC 153, Aeromonas sp., str. NTHC 154, and Enterobacter sp., str. NTHC 151 (Strøm & Larsen 1979) has been studied. When the Proteus sp. or the Aeromonas sp. were inoculated into the herring extracts and incubated at 15°C under anaerobic conditions, the sugar components (i.e. mainly ribose, free and bound) were the first substrates utilized. These compounds were converted to acetate and CO2 by the use of trimethylamine oxide (TMAO) as an external hydrogen acceptor. Growth of bacteria ceased when all TMAO was reduced to trimethylamine (TMA). By adding an extra amount of TMAO to the herring extracts an increased growth of the Proteus sp. and the Aeromonas sp. ensued. The increased growth occurred concomitantly with a further conversion of TMAO to TMA and of lactate to acetate and CO2. The Enterobacter sp., which did not utilize lactate, did not give an increased growth in herring extracts enriched with TMAO.
Resistogram Method for Differentiation of Strains of Candida albicans
Authors: WARNOCK D. W. , SPELLER D. C. E. , DAY JACQUELINE K. , FARRELL A. J.
Published: March 2008

This method is based on differences in the resistance of strains of Candida albicans to a number of selected chemicals used at critical concentrations. The method was applied to isolates from patients undergoing treatment for vaginal infection and it was found that particular strains were consistently present in individual patients, both in different specimens and on different occasions. It was also found that some patients harboured more than one strain of C. albicans. Inconsistencies in the resistograms of certain isolates tested on a number of occasions were resolved when the amount of inoculum used in the test was further standardized.
Symbiotic Properties of Antibiotic‐Resistant and Auxotrophic Mutants of Rhizobium leguminosarum
Authors: PAIN A. N.
Published: March 2008

A number of auxotrophic and antibiotic‐resistant mutants of Rhizobium leguminosarum were isolated and their symbiotic properties examined. Among the auxotrophic mutants tested, only those with an adenine requirement were found to be symbiotically defective and these were all non‐infective. Of the antibiotic‐resistant mutants isolated, only a minority of the rifampicin‐resistant mutants had a modified symbiotic phenotype and this was ineffective. Preliminary evidence suggests that the basis for the resistance in these mutants is a modified DNA‐dependent RNA polymerase.
The Morphology of Six Bacteriophages of Streptococcus thermophilus
Authors: ACCOLAS J.‐P. , SPILLMANN H.
Published: March 2008

The morphology of six phages of Streptococcus thermophilus, isolated in France from Gruyère cheese whey or yoghurt, was studied. They belong to Bradley's Group B and appear very similar. They possess a regular six‐sided head (size, 49–53 nm), of which the three‐dimensional structure is probably octahedral. The fairly long, non‐contractile tails (length, 200–224 nm; width, 8–9 nm) are flexible and regularly striated. They appear to be the juxtaposition of 60–63 annuli packed one above the other and are assumed to contain 240–252 capsomeres. In one preparation rare short‐tailed particles (tail length 130 nm) were also found. The tails have a terminal structure appearing either as a small plate, sometimes with a brush‐like appearance, or a plate with short prongs provided, in five out of the six phages studied, with a more or less long central fibre.
Phylogenetic Relationships between different D‐Xylose Biogroups in Wild‐type Salmonella typhimurium strains and a suggested Evolutionary Pathway
Authors: OLD D. C. , MORTLOCK R. P.
Published: March 2008

Sixty‐two wild‐type Salmonella typhimurium strains were characterized for their D‐xylose enzyme activities. Strains from the xylose strong biogroup synthesized high levels of D‐xylose isomerase and D‐xylulokinase and transported D‐xylose. Strains from the xylose weak biogroup synthesized only low levels of D‐xylulokinase and low, or no, levels of D‐xylose isomerase and were deficient in the ability to transport D‐xylose. These findings are discussed in the light of known phylogenetic relationships among the biotypes of Salm. typhimurium.
Effects of Divalent Metal Cations in the Growth Medium upon Sensitivity of Batch‐grown Pseudomonas aeruginosa to EDTA or Polymyxin B
Authors: BOGGIS W. , KENWARD M. A. , BROWN M. R. W.
Published: March 2008

The sensitivity of batch grown Pseudomonas aeruginosa to ethylenediaminetetraacetic acid (EDTA), ethyleneglycol‐bis(2‐aminoethyl ether)‐N, N‐tetraacetic acid (EGTA) and to polymyxin depended upon the nature and concentration of divalent metal cations (Ca2+, Mg2+, Ba2+, Mn2+, Sr2+, Zn2+, Fe2+, Al3+) present in the simple salts‐glucose growth medium. Sensitivity to the antibacterial agents was measured in terms of per cent decrease in optical density which was proportional to total count. The rate of decrease in optical density and the per cent decrease after a given time were proportional to the cation content of the growth medium. The lytic action of the agents correlated to some extent with the stability constants of the cation for the two chelating agents.

The data support the theory that EDTA and polymyxin both act initially at a common site of action, namely the Mg2+ and Ca2+ cross bridges that stabilize components of the outer membrane.
A Note on the Enumeration of Epiphytic Bacteria by Microscopic Methods with Particular Reference to Two Freshwater Plants
Authors: HOSSELL JUDITH C. , BAKER J. H.
Published: March 2008

Bacteria on plant surfaces were examined using epifluorescence, bright‐field microscopy and an impression technique. Staining bacteria directly on the plant surface with phenolic aniline blue was found to be the best method to use for the determination of bacterial density. The effect on the estimation of population density of pretreatment of the plant with agents such as methanol and eosin yellowish was investigated. The average sizes of the bacterial populations on two freshwater plants, Rorippa and Lemna, estimated after staining by this method, were 5 times 106 and 9 times 106 bacteria cm‐z respectively.
Effect of R‐plasmid RP1 and Nutrient Depletion on the Resistance of Escherichia coli to Cetrimide, Chlorhexidine and Phenol
Authors: KLEMPERER RUTH M. M. , ISMAIL NAHLA T. A. J. , BROWN M. R. W.
Published: March 2008

The minimum inhibitory concentation of cetrimide and chlorhexidine for Escherichia coli is altered when R‐plasmid RPI is inserted into it. Using disinfectant‐agar plates as a test system, the sensitivity of Esch. coli to these disinfectants and to phenol was found to vary, not only with the presence of RPI, but also with the nutritional status of the inoculum. The different inocula also varied in their ability to bind H+ and there was some correlation between this property and chlorhexidine sensitivity.
Yersinia enterocolitica in Danish pigs
Authors: CHRISTENSEN S. G.
Published: March 2008

Yersinia enterocolitica serotype 0:3, the predominating pathogenic serotype in Danish pigs, was isolated consistently from the tonsils of pigs in six farms but not from those in another four farms during a one‐year survey, indicating a herd‐wise distribution. Only one positive culture was obtained from four specific‐pathogen‐free herds. The organisms were not recovered from samples of fodder, water and faeces from any of the infected farms. Strains of Y. enterocolitica were tested for sensitivity to antimicrobial agents.
Repeated Isolation of Yersinia enterocolitica from Pasteurized Milk in a Holding Vat at a Dairy Factory
Authors: HUGHES DENISE
Published: March 2008

Yersinia enterocolitica biotype 1 serotype 5a was repeatedly isolated from pasteurized milk in the same holding vat at a particular dairy factory. It is considered that the occurrence of this organism in pasteurized milk may be partially attributed to its ability to multiply at refrigeration temperatures and survive in inadequately ‘disinfected’ vats.
The Interaction of Glycerol and an lodophor Teat Dip
Authors: GODINHO K.S. , BRAMLEY A.J.
Published: March 2008

In vivo tests confirmed that significantly more Staphylococcus aureus can be recovered by swabbing from bovine teats dipped in an iodophor glycerol mixture than from teats dipped in an iodophor alone. In contrast no reduction in activity was detected when these materials were compared in a suspension test nor when they were used to treat excised pieces of teat skin. The recovery of Staph. aureus from teat skin by swabbing was shown to be greater in the presence of glycerol alone. It is concluded, therefore, that the addition of glycerol to an iodophor does not reduce bactericidal activity but its presence on teat skin increases the recovery of bacteria surviving disinfectant treatment. The significance of these results for the testing of teat disinfectants is discussed.
The Diagnosis of Pneumococcal Chest Infection by Counter‐Current‐Immunoelectrophoresis
Authors: SANDS R. L. , GREEN I. D.
Published: March 2008

A simple, inexpensive method of counter‐current‐immunoelectrophoresis was used to detect pneumococcal antigens in sputum, serum and pleural fluid. Antigens were detected in sputa from 69% of subjects with pneumococcal pneumonia and there was a good correlation with the certainty of the clinical diagnosis. Serum antigens were found in 12.5% of subjects with either a definite or a presumed diagnosis and in one case from a patient who was not thought to have pneumococcal pneumonia. The pathogenic importance of antigens in the sputa of patients with a history of chronic respiratory disease was uncertain. Counter‐current‐immunoelectrophoresis was more sensitive than routine bacteriological methods for demonstrating the presence of pneumococci in pleural fluids.
The Detection and Differentiation of Fibrinolytic Enzymes in Bacteria
Authors: JEFFRIES L. , BUCKLEY D. E.
Published: March 2008

Fibrinolytic enzymes produced by various bacteria were distinguished from activators of plasminogen and were further divided into trypsin‐like, thiol and metallo groups. Trypsin‐like enzymes of the serine subgroup were identified by the hydrolysis of a chromogenic tripeptide substrate highly specific for plasmin and were shown to occur in a wider range of bacteria than had previously been recorded. In addition to confirming the production of enzymes of this specificity by Pseudomonas maltophilia, Achromobacter lyticus and Streptomyces griseus, similar enzymes were found in five further species of Streptomyces, in certain strains of Corynebacterium pyogenes, Micrococcus luteus and Propionibacterium acnes and also in certain species of Bacteroides and Fusobacterium.
Effects of the Herbicide Barban and its Commercial Formulation ‘Carbyne’ on Nitrification in Soil*
Authors: QUILT P. , GROSSBARD ERNA , WRIGHT S. J. L.
Published: March 2008

Nitrification in soil was inhibited for at least 18 weeks following treatment with 200 parts/106 barban, either alone or formulated as Carbyne. During this time, neither Nitrosomonas nor Nitrobacter spp. could be detected in the soil. Periodic introduction of fresh soil failed to re‐establish nitrification, even with NH4+‐N supplementation. The solvent fraction of Carbyne inhibited nitrification only during the first two weeks. 3‐Chloroaniline, a metabolite of barban detected in soil treated with barban or Carbyne, caused only a temporary inhibition of nitrification at 50 parts/106. The presence of barban, either alone or in combination with solvent as Carbyne, appeared essential for the full and prolonged inhibition of nitrification.
A Note on Scanning Electron Microscopic Assessment of Stomacher Action on Chicken Skin
Authors: THOMAS C. J. , MCMEEKIN T. A.
Published: March 2008

Scanning electron microscopy was used in conjunction with normal microbiological procedures to evaluate the stomacher as a means of recovering bacteria from chicken skin. Stomaching removed most bacteria from the skin and viable counts of skin micro‐organisms obtained by this method were not significantly different from those obtained by blending. The stomacher represents a useful alternative to blending techniques commonly used to assess contamination of poultry carcasses.
Two New Tests for Differentiating between Strains of Campylobacter
Authors: RAZI M. H. H. , PARK R. W. A. , SKIRROW M. B.
Published: March 2008

Campylobacters can be differentiated by testing for the ability to grow anaerobically with nitrate or L‐aspartate.
Differentiation of Gram Positive and Gram Negative Bacteria in Transparent Acrylic Resin Emulsion Replicas of Surfaces of Plants
Authors: BIRKBY K. M. , PREECE T. F.
Published: March 2008

When acrylic resin emulsion (Rohm & Haas Primal AC‐33) is allowed to dry on a leaf surface, it can be peeled off to give a transparent replica of the surface with bacteria and fungi embedded in it. The distribution of micro‐organisms in the replica appears to reflect the patterns in which they occur naturally on the surface. The resin replicas may be stained by a variety of microscopical stains, the best of which is phenol‐acetic‐aniline blue, and are suitable for high power light microscopy.

Acrylic resin emulsion differs from widely used cellulose‐based materials in that permanent differentiated preparations of Gram positive and Gram negative stained bacteria may be produced from a wide variety of types of surface.
The Selective Activity of a Benzoxazole Brightener against Phytopathogenic Bacteria
Authors: GONZALEZ‐LOPEZ J. , RHODES‐ROBERTS MURIEL E. , PATON A. M. , FENLON D.
Published: March 2008

A cationic benzoxazole compound used commercially as an optical brightener was found to have a selective bactericidal effect at low concentrations on a wide range of bacterial phytopathogens; many strains of Agrobacterium, Corynebacterium, Erwinia, Pseudomonas and Xanthomonas were tested. Known phytopathogenic species of Corynebacterium, Pseudomonas and Xanthomonas were rapidly killed, whereas saprophytic strains of Corynebacterium and Pseudomonas were resistant to 500 parts/106. The phytopathogenic Erwinia spp. were inhibited only by the higher concentrations of AN, and some saprophytic E. herbicola var. herbicola strains were slightly sensitive. The extent and nature of this selective bactericidal property is examined and discussed. Resistant mutant colonies were very rarely encountered. The results are of significance in that the recognition of such phytopathogens under laboratory conditions is made easier. The resistance of Ps. aeruginosa to the compound and its almost unique ability to utilize it as a sole carbon source offer a means of isolating this organism.
Baird‐Parker Medium Supplemented with Acriflavine, Polymyxins and Sulphonamide for the Selective Isolation of Staphylococcus aureus from Heavily Contaminated Materials
Authors: DEVRIESE L. A.
Published: March 2008

Acriflavine was found to be less inhibitory to Staphylococcus aureus than to other staphylococci. Advantage was taken of this selective effect and of the synergistic action of polymyxins and sulphonamides on Proteus strains to improve the selective capacity of Baird‐Parker's Staph. aureus isolation medium. A supplement mixture containing acriflavine, sodium sulphamezathine and low levels of polymyxin in addition to the usual egg yolk and potassium tellurite is proposed for use with this medium.
The Effect of Erythrosine on the Surface‐associated Bacteria of the Rat Stomach and Caecum
Authors: ADAMS R. F. , CONWAY P. L.
Published: March 2008

Rats fed the food colour erythrosine had decreased numbers of fusiform bacilli on the caecal surface and of Lactobacillus fermentum on the non‐secreting epithelial tissue of the stomach. The effect was concentration dependent. Although for the L. fermentum population a bactericidal effect could not be completely excluded it is possible that erythrosine interfered with the surface association mechanism.
Sensitivity and Resistance to Growth Promoting Agents in Animal Lactobacilli
Authors: DUTTA G. N. , DEVRIESE L. A.
Published: March 2008

The minimal inhibitory concentrations of 11 growth promoting agents were determined by agar‐dilution method against 113 strains of lactobacilli isolated from caeca of pigs, cattle and poultry. Only Lactobacillus acidophilus strains were susceptible to avoparcin and all strains were resistant to copper sulphate. Resistance was noted in cattle and poultry strains against bacitracin, in pig strains against virginiamycin, and in pig and poultry strains against nitrovin. Resistance against carbadox, flavomycin, lincomycin, oleandomycin, spiramycin and tylosin was noted in strains from all three host species.
Selective Isolation and Enumeration of Actinomycetes using Rifampicin
Authors: ATHALYE MEDHA , LACEY J. , GOODFELLOW M.
Published: March 2008

Addition of rifampicin (5µg/ml) to a number of media allowed the selective isolation of Actinomadura strains from soil and enabled large numbers of ‘Thermomonospora (Thm.) chromogena’ and Streptomyces (St.) albus to be isolated from hay and straw. Saccharomonospora (S.) viridis was also tolerant to the antibiotic but was often inhibited by other isolates, while other bacteria including Micropolyspora faeni, ‘Thm. fusca’, Thermoactinomyces (Tha.) vulgaris and some other Streptomyces spp. were mostly sensitive, even to 2·5 µg/ml. Heating soil samples at 100°C for 15 min further decreased the number of unwanted bacteria growing on glucose‐yeast extract agar supplemented with 5 µg/ml of rifampicin.
The Value of Plasmid Profiles for Strain Identification in Lactic Streptococci and the Relationship between Streptoccocus lactis 712, ML3 and C2
Authors: DAVIES F. L. , UNDERWOOD H. M. , GASSON M. J.
Published: March 2008

Plasmid DNA from lactic streptococci was subjected to electrophoresis on agarose gels. The plasmid profiles so obtained were strain specific and sufficiently stable to suggest their use in strain differentiation. A group of Streptococcus lactis strains, 712. 763 (ML3), 505 (C2) and 2031 (C2), found to have similar plasmid profiles, were shown to be closely related. Gene transfer by transduction and conjugation occurred between members of this group at frequencies comparable to those in homologous systems and temperate phages cross plated readily between their prophage cured derivatives.

Minor variations were, however, found between these four strains; slight differences in plasmid profiles, lysogenic status, prophage curability and temperate phage morphology were detected and it is suggested that these have evolved as a result of maintenance in different environments.
Efficiency of Selenite Cystine and TT Enrichment Broths for the Detection of Salmonella
Authors: BAILEY J. S. , COX N. A. , THOMSON J. E.
Published: March 2008

Comparisons of selenite cystine (SC) and TT enrichment broths for detecting salmonellas were made with pure culture suspensions, with samples of naturally or artificially contaminated foods and with poultry feed. Selenite cystine recovered higher numbers of salmonellas from pure cultures and ground beef, while TT broth recovered higher numbers from pork sausage and poultry feed. Differences in the recovery of salmonellas from other food products appeared to be insignificant. The use of both SC and TT is thus recommended for maximal recovery of these organisms.
The Effect of pH, Temperature and Certain Media Constituents on the Stability and Activity of the Preservative, Bronopol
Authors: MOORE K. E. , STRETTON R. J.
Published: March 2008

Various workers have obtained seemingly contradictory results for the activity of the preservative, bronopol. The effect of pH, temperature and certain media constituents on the stability and activity of bronopol has been investigated.

Bronopol has been found to be more active at higher pH values but also breaks down at a faster rate. If the activity of bronopol is measured by a system that takes a few minutes, then the true effect of pH on activity is assessed. If, however, the method takes several hours, especially in the presence of certain media constituents, then the compound may decompose significantly and the response to the compound thereby be influenced.
Production of Off Odours by Isolates from Poultry Skin with Particular Reference to Volatile Sulphides
Authors: THOMAS C. J. , McMEEKIN T. A.
Published: March 2008

Poultry skin free from psychrotrophic micro‐organisms was used to assess the abilities of isolates from poultry skin to produce off odours. Pseudomonas group I and II strains were the major off odour producers and the predominant volatile produced was methanethiol. Results obtained using skin as a spoilage substrate were similar to those obtained with leg muscle but a higher proportion of strains produced volatile sulphides from methionine and cystine supplemented media. Addition of glucose to the methionine medium inhibited methanethiol production.
Preparation and Properties of Spheroplasts from Aspergillus parasiticus with Special Reference to the de novo Synthesis of Aflatoxins
Authors: TYAGI J. S. , TYAGI A. K. , VENKITASUBRAMANIAN T. A.
Published: March 2008

Spheroplasts were prepared from Aspergillus parasiticus NRRL 3240 using β‐glucuronidase from Helix pomatia. They were osmotically fragile spherical structures which lysed when suspended in hypotonic buffers. Purity of the preparation was confirmed by phase‐contrast microscopy. Maximal conversion of mycelia to spheroplasts was achieved with 48 and 72 h old cultures. Spheroplasts were metabolically active as indicated by the incorporation of labelled thymidine, uridine and leucine into DNA, RNA and proteins, respectively. A significant incorporation of [methyl‐3H] thymidine into trichloroacetic acid‐insoluble material suggested the presence of thymidine kinase in this organism. Spheroplasts and lysates demonstrated the ability to incorporate labelled acetate into aflatoxins. Maximum incorporation was observed in those prepared from 96 h old cultures. Lysates were more efficient in de novo aflatoxin synthesis as compared to intact mycelia and spheroplasts.
A Study of Fatty Acids as a Taxonomic Tool for Dermatophyte Fungi
Authors: JONES MERIEL G. , NOBLE W. C.
Published: March 2008

The fatty acid composition of 64 strains from 15 species of dermatophyte fungi was studied by gas‐liquid chromatography. The percentage amounts of palmitic, palmitoleic, stearic, oleic and linoleic acids were measured. These proved to be very similar for all species, with considerable intraspecific variation. As a group, Epidermophyton floccosum strains could be distinguished but individual strains could not be assigned reliably to any species or genus. No significant changes due to age or formaldehyde treatment were noted.
Inactivation of Salmonella during anaerobic digestion of sewage sludge
Authors: Carrington E.G. , Harman Sarah A. , Pike E.B.
Published: March 2008

The inactivation of Salmonella duesseldorf in sewage sludge during anaerobic digestion was investigated at 35 and 48°C with mean retention periods of between 10 and 20 days. Digesters were fed daily with raw sludge containing added Salm. duesseldorf after removal of digested sludge. During steady operation, the levels of Salm. duesseldorf in the digested and the feed sludge were determined and their specific rates of decay were estimated. The latter were: (i) greater at 48°C than at 35°C for the same retention time; (ii) similar for retention periods greater than 15 d, but lower for 10 d; (iii) greater when the level of salmonellas in the feed was lower. Gas production, a measure of steady state, was gradually lost when the mean retention period was reduced to 6.7 d. In experiments in which a single dose of Salm. duesseldorf was added to digesting sludge, the inactivation appeared to follow first‐order kinetics at 35°C and the decimal decay rate, 1.6/d, was similar to that in the daily feeding experiments (1.4/d) with larger and similar inocula of Salm. duesseldorf. At 48°C, however, the rate of inactivation declined with decreasing time from inoculation suggesting that the culture contained cells differing in thermal resistance. The degrees and rates of inactivation of salmonellas in those experiments were greater than in full‐scale digesters, because the latter seldom operated under conditions ideal for inactivation or because indigenous salmonellas are more resistant.
Relative value of staphylocoagulase and fibrinogen affinity for the identification of Staphylococcus aureus
Authors: Carret G. , Flandrois J.P. , Bismuth R. , Saulnier M.
Published: March 2008

Identification of Staphylococcus aureus depends on demonstration of either coagulase, thermonuclease or protein A. Another possibility is afforded by measuring the affinity of Staph. aureus for fibrinogen with a passive haemagglutination technique. The proposed test can detect 98.8% of Staph. aureus strains. The validity of the test described was confirmed by using strains in primary culture on inhibitory media and methicillin‐resistant strains. Under these conditions the test was more reliable than the coagulase test.
The role of oxygen in the microbial spoilage of luncheon meat cooked in a plastic casing
Authors: Bell R.G. , Lacy Karen M. De
Published: March 2008

The shelf life at 25°C of chub‐packed luncheon meat was inversely related to oxygen (O2) availability within the casing. With fibrous casings that are freely permeable to O2, shelf life was less than 3 d. With plastic casings of low O2 permeability, the shelf life was 7 d when air was trapped in the emulsion during the casing filling process, 14 d when air was not trapped (normal vacuum‐stuffing) and greater than 28 d when vacuum‐stuffed chubs were stored in hydrogen (H2). The initial spoilage bacteria, Bacillus spp., grew only at the surface unless air was trapped in the emulsion when growth occurred throughout the luncheon meat. Bacillus spp. failed to grow on luncheon meat stored under H2. Oxygen availability within the casing determined both the site and rate of microbial spoilage of chub‐packed luncheon meat.
Enrichment of linear alkylbenzenesulphonate (LAS) degrading bacteria in continuous culture
Authors: Hršak D. , Bošnjak M. , Johanides V.
Published: March 2008

Absract

Enrichment experiments were carried out in continuous‐flow units using a mineral medium with commercial linear alkylbenzenesulphonate (LAS) as the limiting carbon‐ and energy‐source. The mixed bacterial culture originating from the waste water of a detergent plant consisted of five strains belonging to the genus Pseudomonas and two strains each of the genera Achromobacter and Acinetobacter. The cultivation conditions corresponding to dilution rates of 0.025‐0.1 h‐1 and LAS concentrations of 20–50 mg/1 were examined. During the experiments the composition of mixed cultures and the kinetics of LAS biodegradation were followed. Continuous‐flow enrichment experiments resulted in the selection of six bacterial cultures with different compositions of individual species and capability to utilize LAS. From the original seven strains at lower dilution rates (0.025 and 0.05 h‐1) six were selected, excluding Pseudomonas sp. 3, while at the highest dilution rate (0.1/h‐1) five strains were selected after eliminating Pseudomonas sp. 5 and Achromobacter sp. 1. All enriched mixed cultures were more efficient in primary than in ultimate LAS degradation. Two of the culture strains were able to achieve primary LAS degradation (Pseudomonas sp. 1 in mineral medium with LAS as the sole carbon‐ and energy‐source and Acinetobacter sp. 3 in medium supplemented by yeast extract and nutrient broth).

None of the strains could degrade LAS completely, which indicates that many types of interactions based on combined metabolic attack as well as those based on provision of specific nutrients, may exist between culture members during the complete LAS bio‐oxidation.
A note on the growth of Thiothrix in road drainage ditches
Authors: Jones J.G. , Jay F.M.S. , Hilton J.
Published: March 2008

Macroscopic growth of Thiothrix‐has been observed in ditches which drained a road under which furnace slag and limestone had been used as hard core. Extremely high sulphide concentrations, pH and total ion concentrations in one ditch may have contributed to the absence of Thiothrix spp. at this site.
The effect of sublethal injury by heating, freezing, drying and gamma‐radiation on the duration of the lag phase of Salmonella typhimurium
Authors: Mackey B.M. , Derrick Christine M.
Published: March 2008

The duration of the lag phase of Salmonella typhimurium surviving heat, freezing, drying and gamma‐radiation was used to indicate the time needed to repair sublethal injury. Following equivalent lethal treatments, heat and freeze‐injured cells needed longer to repair than those injured by drying or gamma‐radiation. Measurement of repair on membrane filters showed that in a heat‐injured population having a lag time of 9 h, some individual cells needed up to 14 h to recover maximum tolerance to 3% NaCl.
Enterotoxigenicity of Staphylococcus aureus strains isolated from poultry: raw poultry carcases as a potential food‐poisoning hazard
Authors: Harvey J. , Patterson J.T. , Gibbs P.A.
Published: March 2008

Staphylococcus aureus strains were isolated from end‐of‐lay poultry carcases obtained from a plant at two different stages of processing before and after storage at different temperatures. These strains were supplemented with Staph. aureus strains isolated from poultry from a wide range of sources and biotyped, phage typed, and tested for production of enterotoxins A‐E. The isolates were found to consist of poultry and human specific strains and each of these groups contained strains able to produce enterotoxin. Poultry strains produced only enterotoxin D whereas human strains produced enterotoxins A, C and D. The hen carcases used in storage experiments were found to be naturally contaminated with enterotoxin D producing staphylococci. No enterotoxin D could be detected on any of the carcases even after storage at temperatures which allowed multiplication of the organisms to occur (final Staph. aureus counts ranged from 102 to 107/16 cm2 of breast skin).
A bacteriostatic mixture for milk samples and its effect on bacteriological, cytological and chemical compositional analysis
Authors: Pettipher G.L. , Rodrigues Ubaldina M.
Published: March 2008

Of the bacteriostats tested, that comprising boric acid, glycerol, potassium sorbate and nystatin was the most suitable in preventing the multiplication of bacteria, yeasts and moulds in milk whilst causing least change in the Direct Epifluorescent Filter Technique (DEFT) count of bacteria and somatic cells. The DEFT and plate count of bacteria and the DEFT count of somatic cells were reduced after preservation and storage. The relationships between the plate count of fresh milk samples and the DEFT count and plate count of the same samples after preservation and storage for 3 d at room temperature (20–22°C) had correlation coefficients (r) of 0.80 and 0.85, respectively. The relationship between the Coulter count of somatic cells in fresh milk and the DEFT count of somatic cells in stored preserved milk had a correlation coefficient of 0.90. The addition of the bacteriostatic mixture to milk affected the determination of protein by the Milkoscan and lactose by the Infra Red Milk Analyser. It did not affect the estimation of the other milk components (fat, protein or lactose) by either instrument.
‘Atypical’ mycobacteria in milk
Authors: Dunn Beth L. , Hodgson D.J.
Published: March 2008

Seventy‐seven isolates of ‘atypical’ mycobacteria were obtained from 288 raw milk samples but no isolates were made from 76 samples of pasteurized milk. Thirty‐two clinically important ‘atypical’ mycobacteria were isolated.
The effect of the carbohydrate growth substrate on the glycosidase activity of hemicellulose‐degrading rumen bacterial isolates
Authors: Williams A.G. , Withers Susan E.
Published: March 2008

Thirteen strains of hemicellulose‐degrading bacteria isolated from the rumen were grown on ten different monosaccharide, disaccharide and hemicellulosic poly‐saccharide substrates in vitro, and the range and specific activities of the glycosidase enzymes formed were determined. Alkaline phosphatase activities were also measured. The specific activities were affected by the carbohydrate source supplied in the growth medium and were usually reduced in glucose grown cells, and less frequently following growth on cellobiose; the responses to other substrates were both enzyme and organism dependent. In several of the strains examined many of the enzymes were found following growth on all of the substrates tested, although there were wide variations in the specific activities. The activities of several of the glycosidases were increased after growth on hemicellulosic polysaccharides.
A note on evidence for involvement of pectolytic enzymes in the infection process of Medicago sativa by Rhizobium meliloti
Authors: Martianez‐Molina E. , Olivares J.
Published: March 2008

Evidence has been obtained of the implication of pectolytic enzymes in the infection of alfalfa roots by Rhizobium meliloti.
A note on some factors affecting the survival of Rhizobium cultures during freeze drying and subsequent storage
Authors: Dye M.
Published: March 2008

Viable counts of Rhizobium before and immediately after freeze drying in sucrose‐peptone medium (SPM) showed that neither culture age nor cell concentration affected survival. SPM gave greater protection during drying than either dextran‐sucrose‐glutamate medium or distilled water. The half‐lives of freeze‐dried cultures stored at 4°C were estimated using an accelerated storage test and were dependent on both the strain and the suspending medium used. It is recommended that Rhizobium cultures, prepared by the procedures used in the Rothamsted Collection of Rhizobium, should be redried at intervals of 30 years.
Cellulolytic bacteria in buffalo rumen
Authors: Sinha R.N. , Ranganathan B.
Published: March 2008

The influence of three different feeds, wheat straw, sorghum and berseem, on total and cellulolytic bacterial counts in the buffalo rumen at different time intervals from 0 to 8 h after feeding was studied. Berseem feeding supported maximum growth of rumen bacteria in general and cellulolytic bacteria in particular. Wheat straw supported the poorest growth.

The types of cellulolytic bacteria recovered from the rumen of adult buffaloes were Ruminococcus albus, R. flavefaciens, Bacteroides succinogenes, Butyrivibrio fibrisolvens, Clostridium lochheadii, Cl. longisporum and other Clostridium spp. Cellulolytic cocci were present in smaller numbers than rod forms in the rumen of wheat‐straw‐fed buffaloes, whereas the cocci outnumbered rod forms in sorghum‐and berseem‐fed buffaloes.
Effect of inoculation sequence and nutrients upon Streptococcus mutans BHT and Streptococcus mitior LPA‐1 growing on human teeth in an artificial mouth
Authors: Donoghue Helen D. , Hudson D.E. , Perrons C. J. , Dibdin G.H. , Rapson Gillian , Shellis R.P. , Wilson Constance M.
Published: March 2008

Human teeth in an artificial mouth were inoculated with Streptococcus mutans BHT, Streptococcus mitior LPA‐1, or sequentially with both organisms. Incubation was continued for 90 h. Mixed populations were largest when a nutrient supplement containing 5–0% (w/v) sucrose was supplied. Fewer organisms were recovered from experiments with synthetic saliva only, or when a supplement containing 0–05% (w/v) glucose was available. The inoculation sequence determined the total viable count and a larger population resulted when Strep, mutans was the initial colonizer (P < 0–01). Strep, mutans was always able to become established even when super‐infected on to a 24 h plaque of Strep, mitior. The final proportion of Strep mutans was lower when it was the superinfecting organism and the sucrose (P < 0–01) or glucose (P < 0–05) nutrient supplement was provided. This work confirms the importance of inoculation sequence and presence of sugars in plaque accumulation and demonstrates the fundamental role of microbial interactions in this process.
Death, injury and revival of chemically treated Bacillus subtilis spores
Authors: Gorma S.P. , Hutchinson E.P. , Scott E.M. , McDermott L.M.
Published: March 2008

The resistance of spores of Bacillus subtilis NCTC 10073 to glutaraldehyde, sodium hypochlorite and povidone‐iodine was compared. Revival of treated spores was examined by use of defined germination media and conditions, protein denaturing agents, ultrasonics and heat. Revival, obtained after treatment with each of the three chemical agents, originated under different sets of conditions and was of two recognisably distinct types. The results, including the evidence of electron microscopy, are discussed in terms of chemical‐spore reactivity and the implications on their use and suitability as chemical sterilizers.
A note on bile tolerance in Streptococcus agalactiae
Authors: Davis G.H.G. , Pham A.V.
Published: March 2008

Streptococcus agalactiae strains isolated from humans were found to be able to grow in the presence of high levels of bile but not in media containing levels of bile salts or surfactants commonly considered equivalent to bile in selective media.
A note on the microbial spoilage of undercooked chub‐packed luncheon meat
Authors: Bell R.G. , Lacy Karen M. De
Published: March 2008

Contrary to expectations slight undercooking (68.5°C instead of 70°C for 90 min) dramatically increased the shelf‐life of chub‐packed luncheon meat stored at 25°C. The pH of undercooked chubs fell rapidly to below 5.0 as a result of the growth of enterococci. The accumulated acid prevented the growth of Bacillus spores and gave the luncheon meat a not unpleasant tangy flavour. Degradative changes associated with the spoilage of commercially cooked chub‐packed luncheon meat did not occur, even after 42 d storage. Apparently, post‐cooking fermentation by enterococci can effectively convert a perishable product into a ‘shelf stable’ one by lowering the pH below 5.0.
Quantitative test for Bacteroides nodosus pilus protein by an agglutination‐absorption test
Authors: Every D.
Published: March 2008

A pili agglutination‐absorption test (PAAT) was developed for the quantitative measurement of pilus protein in cultures of Bacteroides nodosus and to quantify pili yields during purifications. The test was calibrated by recording the amount of pilus protein required to absorb a measurable amount of anti‐pili antibody from antiserum. The amount of anti‐pilus antibody in absorbed and unabsorbed serum was specifically measured by a Bact. nodosus K‐agglutination test. The PAAT could be calibrated using any combination of crude or pure pili preparations and specific anti‐pili serum or non‐specific anti‐Bact. nodosus serum. This had advantages over the use of radioimmunoassay (RIA) and enzyme‐linked immunosorbent assay (ELISA) techniques for measurement of pili because they require the use of highly purified reagents for calibration. The minimum quantity of pilus protein measurable by PAAT was 0.1 μg per test which was similar in sensitivity to that reported for RIA and ELISA. The reagents used in PAAT were stable for at least six months. The amount of pilus protein per bacterium as measured by PAAT was directly proportional to the average number of pili per bacterium as measured by electron microscopy. The test was Bact. nodosus serotype specific.
A note on procedures for inoculum development for the production of solvents by a strain of Clostridium butylicum
Authors: Gapes J.R. , Larsen V.F. , Maddox I.S.
Published: March 2008

Heat‐shocking of cultures, and the number of sub‐cultures performed, profoundly influence solvent production by a strain of Clostridium butylicum. This has important implications for methods of inoculum development prior to seeding the main fermenter.
A note on a prodigiosin‐producing pseudomonad isolated from a lowland river
Authors: Moss M.O.
Published: March 2008

A Gram negative, oxidase‐positive, bacterium which produced prodigiosin has been isolated during a survey of freshwater chromobacteria. It forms colonies with an adherent, rubbery texture on solid media and a flocculent growth in liquid culture. The organism will not grow at temperatures above 30°C nor will it tolerate concentrations of sodium chloride in excess of 0.5%.
Isolation of Yersinia enterocolitica and related species from the faeces of cows
Authors: Davey G.M. , Bruce J. , Drysdale E.M.
Published: March 2008

A total of 203 samples of faeces from 124 cows was examined for the presence of Yersinia enterocolitica and related species by a variety of isolation procedures. Cold enrichment at 5°C for three weeks, followed by plating on cefsulodin‐irgasannovobiocin agar yielded Yersinia species most frequently. Yersinia enterocolitica or related species were isolated from 50% of the cows.
The R‐factors of multiple antibiotic resistant faecal coliforms isolated from a domestic dog
Authors: Minton N.P. , Marsh J. , Atkinson T.
Published: March 2008

The antibiotic resistant faecal flora of a domestic dog suffering from an acute enteric infection was examined. The flora exhibited overall resistance to a wide variety of antibiotics. However, following restoration of the animal to normal health, overall resistance to ampicillin (Ap), tetracycline (Tc), chloramphenicol (Cm) and streptomycin (Sm) was lost, although low numbers of bacteria resistant to these four antimicrobial agents could still be isolated up to one year later. A total of 11 strains were purified for further study. All 11 were positively identified as Escherichia coli and shown to be resistant to various combinations of the above antibiotics, and additionally to kanamycin (Km). Each strain harboured from one to five plasmids, although only four proved capable of transferring antibiotic resistance to Escherichia coli K‐12. One of the strains was found to harbour two conjugal plasmids pNJ101 (60 Md) and pNJ102 (133 Md) which coded for resistance to Cm, Tc, Ap and Cm, Tc, Km respectively. A third plasmid pNJ103 (29 Md) remains cryptic. The possession of the two plasmids pNJ101 and pNJ102 appears to be an unstable situation as variants arose harbouring one or other of the plasmids.
Collaborative trial of the direct epifluorescent filter technique (DEFT), a rapid method for counting bacteria in milk
Authors: Pettipher G.L. , Fulford Rosemary J. , Mabbitt L.A.
Published: March 2008

The direct epifluorescent filter technique (DEFT) is a new rapid method which uses membrane filtration and epifluorescent microscopy for counting bacteria in milk. A collaborative trial of the DEFT was conducted between six laboratories. Each laboratory obtained a highly significant relationship between the DEFT count and plate count with a correlation coefficient generally > 0.9 but there were significant differences between these relationships. The repeatability of the DEFT, although ca 1·5 times worse than that of the plate count, was of a level acceptable in practice. Reproducibility of the DEFT was ca 3 times that of the plate count. This poor reproducibility was probably mainly due to counting errors. Possible reasons for this and ways of reducing counting errors are discussed.
Plasmids encoding trimethoprim resistance in bacterial isolates from man and pigs
Authors: Mee B.J. , Nikoletti Suzanne M.
Published: March 2008

Trimethoprim (Tp) resistant Gram negative bacteria were isolated from humans and pigs. The bacterial hosts were characterized by their resistance pattern and biotype. The presence of transferable Tp plasmids was demonstrated in 86% of 59 porcine isolates and 37% of 49 human isolates. The Tp R‐plasmids carried a diversity of resistance determinants such as Tc, Cm, Sp, Sm and Su. Incompatibility tests distinguished two major groups, Inc FIV and Inc N. Thirty of 99 Tp R‐plasmids isolated from pigs were grouped as Inc FIV and three as Inc N. Eleven of 26 Tp R‐plasmids isolated from humans were grouped as Inc FIV and eight as Inc N. The results of molecular weight determination of Tp R‐plasmids performed by agarose gel electrophoresis were consistent with the existence of two groups—larger R‐plasmids (76 to 104 Md) belonging to Inc FIV and lower molecular weight R‐plasmids (25 to 36 Md) belonging to Inc N. Results from this study indicate that the Tp R‐plasmids isolated in Perth have evolved independently from those described in Europe and the United Kingdom. There is also evidence for their local spread between Escherichia, Klebsiella, Enterobacter, Citrobacter and Acinetobacter from man and animals.
Neutralization of the activity of eight disinfectants by organic matter
Authors: Gélinas P. , Goulet J.
Published: March 2008

The effect of organic matter on the activity of eight disinfectants was evaluated. Three types of interfering substrates (whole milk powder, dried beef blood and fish meal) were tested according to the method of Whitmore and Miner adapted to the AOAC use‐dilution method. Glutaraldehyde and to a certain extent, chlorhexidine acetate and the amphoteric surfactant kept their disinfecting activity after contact with high concentrations of organic matter. The quaternary ammonium compound as well as the quaternary ammonium‐glutaraldehyde complex were more readily neutralized whereas anionic acid, iodophor and sodium hypochlorite did not tolerate the presence of organic matter. The neutralizing activity of powders was correlated to their solubility and composition.
The effect of variation of thermal processing on the microbial spoilage of chub‐packed luncheon meat
Authors: Bell R.G.
Published: March 2008

Process pasteurization values for reference temperature 70°C (P70) were calculated from the temperature profiles of 250 g luncheon meat chubs cooked under experimental conditions. A simple equation relating Process P70‐value and the time and temperature of cooking was derived. With minimal cooking (P70= 40) the surviving microflora (103/g) was dominated by species of Lactobacillus, Brochothrix and Micrococcus. These organisms were destroyed by more intensive cooking (P70= 105), leaving a flora (102/g) composed of Bacillus and Micrococcus species. The spoilage that developed after 14 d storage at 25°C reflected the severity of the heat treatment received by each chub: with P70 between 40 and 90, a Streptococcus spoilage sequence occurred; with P70 between 105 and 120, a Bacillus/Streptococcus spoilage sequence occurred; with P70 of 135 and above, a Bacillus spoilage sequence occurred. Cooking to a P70= 75 was adequate to reduce the surviving microflora to the 102/g level associated with current good manufacturing practice.
Studies of the extracellular proteolytic activity produced by Propionibacterium acnes
Authors: Ingram Eileen , Holland K.T. , Gowland G. , Cunliffe W.J.
Published: March 2008

Of several commercial media tested, trypticase soya broth containing 0.4% (w/v) D‐sorbitol was superior as a growth medium for the production of extracellular proteinase by Propionibacterium acnes (strain P‐37). Extracellular proteinase, production of which was shown to be growth‐associated by both batch and continuous culture studies, was partially purified by 70% (NH4)2SO4 saturation, Sephadex G‐75 chromatography and ion exchange on DEAE‐Sephadex A‐50. It was shown to be a heterogeneous mixture of at least three molecular species of enzyme. Proteinase I was inhibited by EDTA (10‐3 mol/l) and PMSF (5 millimol/l) and stimulated by CaCl2 (190% at 10‐3 mol/l). It had a molecular weight of 20 to 30000 and a broad pH optimum from 6.5 to 7.5. Proteinase II was an alkaline proteinase with a molecular weight of 30 to 40000 which was not significantly inhibited by EDTA (10‐2 mol/l) nor stimulated by CaCl2. Proteinase III represented a minor proportion of the recovered proteolytic activity, had a molecular weight of 20 to 30000 and was most active in the alkaline pH range. This enzyme was inhibited by EDTA (10‐4 mol/l) and PMSF (5 millimol/l), and stimulated by CaCl2 (250% at 10‐2 mol/l).