bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlation between environmental monitoring of thermophilic campylobacters in sewage effluent and the incidence of Campylobacter infection in the community
Authors: Jones K. , Betaieb M. , Telford D.R.
Published: March 2008

Environmental monitoring of thermophilic campylobacters in liquid sewage effluent (primary settlement only) during 1988 and 1989 showed a prominent seasonablity with distinct peaks in May and June (the average number of bacteria per 100 ml of effluent in months other than May and June was 2244 and the average for the peak months was 50 778). Apart from September 1989, this seasonality coincided precisely with the seasonal variation of Campylobacter enteritis in the community with similar distinct peaks in May and June (the incidence of infection in May and June was twice or three times that in the other months).

Sampling of sewers showed that the campylobacters in the sewage effluent came mainly from abbatoir and animal processing plants with only a minor input from the community. Therefore, the seasonal peaks in the sewage effluent and in the community may not be dependent on human infections but on zoonotic infections which may also peak in May and June.
Microbial transformation of styrene by anaerobic consortia
Authors: Grbić‐Galić Dunja , Churchman‐Eisel Nina , Mraković Iskra
Published: March 2008

Methanogenic microbial consortia, originally enriched from anaerobic sewage sludge with ferulic acid or styrene (vinylbenzene) as sole organic carbon and energy sources, were used to study transformation of styrene under strictly anaerobic conditions. Styrene, which was added as the substrate in a range of concentrations from 0.1 to 10 mmol/l, was extensively degraded but no methane production was observed during incubation for eight months. The addition of yeast extract during the enrichment stage completely inhibited degradation of styrene. Gas chromatog‐raphy (GC), gas chromatography/mass spectrometry (GC/MS), high performance liquid chromatography (HPLC) analyses of the culture fluid, and GC analyses of the anaerobic headspace, indicated that the transformation of this arylalkene was initiated through an oxidation‐reduction reaction and that the favoured mechanism was most likely the addition of water across the double bond in the alkenyl side‐chain. The degradation proceeded through to carbon dioxide, the final product. Benzoic acid and phenol were transient compounds found in highest concentrations in the spent culture fluid and are suggested as the key intermediates of the transformation process. The tentative routes of anaerobic transformation partially overlap with those previously proposed for aromatic hydrocarbons such as toluene. Several pure cultures, which were tentatively identified as Clostridium spp. and Enterobacter spp., were isolated from the styrene‐degrading consortia. Two of these cultures were demonstrated to grow on styrene as sole carbon and energy source. Additionally, a pure culture of Enterobacter cloacae DG‐6 (ATCC 35929) which had been isolated previously from the ferulate‐degrading consortium, was shown to degrade styrene through to carbon dioxide.
A medium for the isolation, enumeration and rapid presumptive identification of injured Clostridium perfringens and Bacillus cereus
Authors: Hood A.M. , Tuck A. , Dane C.R.
Published: March 2008

A blood‐free egg yolk medium (BCP) containing pyruvate, inositol, mannitol and a bromocresol purple indicator in a nutrient agar base has been developed to initiate the growth of Clostridium perfringens. It is comparable to blood agar for the growth of normal, chilled stored vegetative cells and heat‐injured spores of Cl. perfringens and Bacillus cereus. It has the advantage over blood agar in exhibiting presumptive evidence of Cl. perfringens (production of lecithinase and inositol fermentation) after an overnight incubation at 43°C‐45°C. Pyruvate, catalase and other hydrogen peroxide degraders were found to remove toxins rapidly formed in media exposed to air and light. Free radical scavengers of superoxide, hydroxyl ions and singlet oxygen were ineffective. Without scavengers the formation of 10–20 μg/ml hydrogen peroxide in the exposed medium was indicated and found lethal to injured Cl. perfringens.

The BCP medium has been used successfully for the rapid identification and enumeration of Cl. perfringens in foods and faeces from food poisoning outbreaks and cases of suspected infectious diarrhoea. Greater recovery of severely injured vegetative Cl. perfringens could be obtained by pre‐incubation at 37°C of inoculated media for 2–4 h followed by overnight incubation at 43°C‐45°C. Tryptose‐sulphite‐cyclo‐serine and Shahidi‐Ferguson‐perfringens agar base were found to inhibit the growth of several strains of injured vegetative Cl. perfringens. This was not completely overcome by the addition of pyruvate. The inclusion of mannitol also allows the medium to be used for the presumptive identification of B. cereus. Growth and lecithinase activity are profuse on BCP. Heat‐injured spores are recovered equally well on BCP and blood agar. A scheme for the identification of some other clos‐tridia on BCP is presented.
Prevalence of Salmonella in chicken carcasses in Portugal
Authors: Machado J. , Bernardo F.
Published: March 2008

Machado, J. & Bernardo, F. 1990. Prevalence of Salmonella in chicken carcasses in Portugal. Journal of Applied Bacteriology69, 477–480.

During 1986–87 57% of 300 chicken carcasses yielded salmonellas where tested by a swabbing method. Serotypes isolated were Salmonella enteritidis (66%), Salm. agona (12%), Salm. newport (6%), Salm. saintpaul (6%), Salm. derby (4%), Salm. typhimu‐rium (3%), Salm. bardo (1%), Salm. ohio (1%) and untypable (2%). The results are compared with those of avian and human salmonellosis registered in Portugal during the same period.
Growth of, and aflatoxin production by Aspergillus parasiticus when in the presence of either Lactococcus lactis or lactic acid and at different initial pH values
Authors: Luchese Rosa H. , Harrigan W.F.
Published: March 2008

Luchese, R.H. & Harrigan, W.F. 1990. Growth of, and aflatoxin production by Aspergillus parasiticus when in the presence of either Lactococcus lactis or lactic acid and at different initial pH values. Journal of Applied Bacteriology69, 512–519.

Aspergillus parasiticus was grown in a modified Lab‐Lemco tryptone broth both as a single culture and in association with Lactococcus lactis. Total aflatoxin (B1 + G1) production was higher in the mixed cultures. This stimulation persisted when different batches of media, inoculation procedures and makes of ingredients were used. Aflatoxin yields increased in media with an initial pH of 4.2 compared with a pH close to neutrality. Hydrochloric and/or lactic acid had little effect. The substitution of half the carbon content of the medium by lactate resulted in stimulation or reduction on aflatoxin production when the initial pH was 4.2 or 6.8, respectively.
Adhesion of bacillus spores in relation to hydrophobicity
Authors: Rönner U. , Husmark Ulrika , Henriksson A.
Published: March 2008

Rönner, U., Husmark, U. & Henriksson, A. 1990. Adhesion of bacillus spores in relation to hydrophobicity. Journal of Applied Bacteriology69, 550–556.

The adhesion of spores of five different Bacillus species to solid surfaces of different hydrophobicity was evaluated. The spore surface hydrophobicity was measured using hydrophobic interaction chromatography (HIC). A large variation in hydrophobicity was found among the spores of the different species tested. The degree of adhesion of spores to the solid surfaces was consistent with the results obtained using the HIC method. The most hydrophobic spores, according to the HIC method, adhered in a much larger extent to the hydrophobic surfaces. Furthermore, spores generally adhered to a greater extent to hydrophobic and hydrophilic surfaces than did the vegetative cells.
Growth inhibitory and biocidal activity of some isothiazolone biocides
Authors: Collier P.J. , Ramsey A.J. , Austin P. , Gilbert P.
Published: March 2008

Collier, P.J., Ramsey, A.J., Austin, P. & Gilbert, P. 1990. Growth inhibitory and biocidal activity of some isothiazolone biocides. Journal of Applied Bacteriology69, 569–577.

Similar patterns of growth inhibition were observed for the three biocides, benzisothiazol‐3‐one (BIT), 5‐chloro‐N‐methylisothiazol‐3‐one (CMIT) and N‐methylisothiazol‐3‐one (MIT) against Escherichia coli ATCC 8739 and Schizo‐saccharomyces pombe NCYC 1354. After periods of induced stasis, proportional to biocide concentration, growth proceeded at an inhibited rate. Extrapolation of the static periods and inhibited growth rates against biocide concentration gave minimum growth inhibitory concentration estimates of 0.1–0.5 μg/ml for CMIT, 15–20 μg/ml for BIT and 40–250 μg/ml for MIT. Patterns of growth inhibition by CMIT and induced morphological changes in inhibited cultures suggested this com‐pound to also inhibit initiation of DNA replication. Growth inhibitory activity was rapidly quenched by the addition of thiol‐containing materials such as glutathione and cysteine. The activity of CMIT was additionally quenched by the presence of the non‐thiol amino acids valine and/or histidine. These results suggest that the chlorinated isothiazolones can react with amines as well as with essential thiol groups.
Synergism within polyhexamethylene biguanide biocide formulations
Authors: Gilbert P. , Pemberton D. , Wilkinson Diane E.
Published: March 2008

Gilbert, P., Pemberton, D. & Wilkinson, D.E. 1990. Synergism within polyhexamethylene biguanide biocide formulations. Journal of Applied Bacteriology69, 593–598.

Polyhexamethylene biguanides (PHMB) are mixtures of polymeric biguanides with an average polymer length (n) of 5, but containing high (n > 15, mol. wt 3300) and low molecular weight material (n= 2, mol. wt 400). Studies involving discrete molecular weight fractions of PHMB have shown that antimicrobial activity of PHMB increases with increasing polymer length. Cell suspensions which had not been subjected to centrifugation and/or washing during their preparation were employed. Whilst activity was still observed to increase with n, the trend was much reduced as n exceeded six. Centrifugation and washing of cells markedly increased the activity of high but not low molecular weight materials and corresponded to losses upon centrifugation of envelope lipopolysaccharide (LPS). Such envelope LPS represented high affinity binding sites on the surfaces of the cells. Combinations of various molecular weight fractions of PHMB were evaluated against filter‐washed cells and revealed a profound synergy between extremes of polymer length.
Azospirillum lipoferum and Azospirillum brasilense surface polysaccharide mutants that are affected in flocculation
Authors: Michiels K. , Verreth C. , Vanderleyden J.
Published: March 2008

Michiels, K., Verreth, C. & Vanderleyden, J. 1990. Azospirillum lipoferum and Azospirillum brasilense surface polysaccharide mutants that are affected in flocculation. Journal of Applied Bacteriology69, 705–711.

Surface polysaccharide production by Azospirillum is demonstrated by fluorescence of colonies grown on media containing the fluorescent dye Calcofluor, which binds to β‐linked polysaccharides. Mutants showing decreased and increased levels of fluorescence are obtained from Azospirillum lipoferum strain Sp59b by chemical mutagenesis, and from A. brasilense strain 7030 by Tn5 mutagenesis.

The A. brasilense 7030 fluorescence mutants produce wild‐type levels of exo‐polysaccharide in their culture supernatant fluids, but are affected in flocculation in liquid culture. On the basis of these observations, we postulate that an A. brasilense surface polysaccharide, different from the exopolysaccharide, is involved in both Calcofluor staining and flocculation.

It is shown by DNA hybridization that the genetic loci affected in the A. brasilense 7030 fluorescence mutants are different from the A. brasilense exoB and exoC loci, which are involved in exopolysaccharide production.
Alterations in the major heterotrophic bacterial populations isolated from a still bottled mineral water
Authors: Morais Paula V. , Costa M.S. Da
Published: March 2008

Morais, P.V. & Da Costa, M.S. 1990. Alterations in the major heterotrophic bacterial populations isolated from a. still bottled mineral water. Journal of Applied Bacteriology69, 750–757.

The heterotrophic bacterial population of a bottled mineral water stored in returnable glass bottles and in polyvinyl chloride (PVC) bottles at room temperature was studied over 9–12 months. The plate counts in R2A medium incubated at 22d̀ and 37d̀C were low initially, increasing to 104‐105 cfu/ml within a few days of bottling. The number of bacteria recovered at 22d̀C from PVC bottles was fairly constant during the storage period, but the population isolated at 37d̀C decreased markedly after storage for 1 year. The major components of the population were Pseudomonas strains, one of which was identified as Pseudomonas vesicularis. Major changes took place during storage; two groups of bacteria (B and C) were dominant initially, but during the latter period of storage other groups (F, G and H) increased in number.
Isolation of some new sulphur bacteria from activated sludge
Authors: Emtiazi G. , Habibi M.H. , Setareh M.
Published: March 2008

Emtiazi, G., Habibi, M.H. & Setareh, M. 1990. Isolation of some new sulphur bacteria from activated sludge. Journal of Applied Bacteriology69, 864–870.

During studies on bulking of activated sludge some new sulphur micro‐organisms, which were able to grow aerobically and anaerobically on reduced sulphur compounds, were isolated on thiosulphate agar. These were capable of autotrophic and heterotrophic growth on a wide range of substrates. In view of their ability to oxidize reduced sulphur compounds, and because one of them was an oxidase‐ and catalase‐positive, Gram‐negative, motile coccus (0.36–0.48 μm) it was named Thiosphaera persica. The second one was an oxidase‐ and catalase‐positive, Gram‐negative, motile rod (1.32–1.80 μm) and was named Thiobacillus persica. The third one was oxidase‐negative, catalase‐positive, motile, Gram‐negative and polymorphic and was named Sulphobacter polymorpha.
The combination effect of pH, SO2, ethanol and temperature on the growth of Leuconostoc oenos
Authors: Britz T.J. , Tracey R.P.
Published: March 2008

A factorial design was used to determine the main effects and interactions of pH (3.6, 3.8 and 4.0), SO2 (25 and 50 mg/l), ethanol (7%, 10% and 13%, v/v) and temperature (15°C and 25°C) on the growth of 54 Leuconostoc oenos strains. These differed greatly in their ability to survive adverse conditions. Under the test conditions, temperature had a profound effect on growth. The power pH values of 3.6 and 3.8 had a marked inhibitory effect on growth, as did at the lower temperature of 15°C. The higher concentrations of SO2 (50 mg/l) and ethanol (13%) had the greatest inhibitory effect on growth, and with a synergistic effect when both SO2 and ethanol were added to the test medium. Based on these results, five strains were selected that were best capable of surviving the adverse conditions studied. These strains will be used for further study on the induction of malolactic fermentation in wine.
Yersinia enterocolitica and related species isolated in the Pesaro and Urbino area (Italy) from 1981 to 1986
Authors: Pianetti A. , Bruscolini F. , Baffone W. , Brandi G. , Salvaggio L. , Biffi M.R. , Albano A.
Published: March 2008

A total of 23 strains of yersinias, Y. enterocolitica (17), Y. frederiksenii (5) and Y. intermedia (1) characterized according to bio‐serogroup and phage type, were isolated from human, animal and environmental samples during a 5‐year period. It appears that in the Pesaro–Urbino area Yersinia spp. are infrequent and the strains of Y. enterocolitica belong to environmental and rarely to human pathogenic bioserogroups. and accepted 22 May 1989
Inhibition of Candida adhesion to buccal epithelial cells by an aqueous extract of Allium sativum (garlic)
Authors: Ghannoum M.A.
Published: March 2008

The effect of pre‐incubation of either Candida or buccal epithelial cells (BEC) with different concentrations of aqueous garlic extract (AGE) was investigated, as well as the effect of mouth rinse with AGE on the adhesion of yeast to BEC. Adhesion of Candida spp. to BEC was significantly reduced after both short and long time exposure of yeast to AGE. A similar inhibition of adherence was observed upon pre‐incubation of BEC with AGE. The adherence‐inhibition activity of AGE treatment was antagonized by thiols such as l‐cysteine, glutathione and 2‐mercaptoethanol. In addition, germ‐tube formation was suppressed when C. albicans cells were pretreated with AGE. There was a significant reduction in the adherence of yeasts to BEC collected immmediately or 15 min after an oral rinse with AGE. No statistical significance in the adhesion of BEC collected 30 min after oral rinse with AGE and control BEC was observed. The diminished adherence of C. albicans to BEC after exposure to various concentrations of garlic may have clinical relevance.
Survival strategy of Escherichia coli and Enterococcus faecalis in illuminated fresh and marine systems
Authors: Barcina I. , González J.M. , Iriberri J. , Egea L.
Published: March 2008

Some effects of visible light on Escherichia coli and Enterococcus faecalis in natural freshwater and seawater were studied by plate counts, colony area measurements, and direct counts. A large number of somnicells (non‐culturable cells) were noted in illuminated systems as compared with non‐illuminated ones. Colony areas were significantly smaller in illuminated systems. Indirect activity measurements were used to test the effects of visible light on the ability of E. coli and Ent. faecalis to metabolize substrates ([14C]glucose) in natural waters. In illuminated systems, a decrease of glucose uptake was observed. When percentages of assimilation and respiration with respect to the total glucose uptake were analysed a decrease of assimilation percentages and an increase of respiration percentages were observed. In addition, differences in glucose uptake, assimilation and respiration by enteric bacteria were detected for E. coli at the beginning of the experiments between fresh‐and seawater and these were interpreted as a toxic effect exerted by seawater on E. coli cells. Differences between species, natural waters and parameters studied (excepting glucose assimilation) were detected in the illuminated systems. We concluded, however, that enteric bacteria under visible light illumination show a general survival strategy characterized by reaching progressively a somnicell stage which can be defined in terms of their (1) inability to form colonies on standard bacteriological media, (2) inability to incorporate substrates, and (3) inactivation of biosynthetic processes. and accepted 8 June 1989
Survival of dehydrated cells of Salmonella typhimurium LT2 at high temperatures
Authors: Kirby R.M. , Davies R.
Published: March 2008

Cells of Salmonella typhimurium LT2 were dehydrated on hydrophobic membranes (Millipore FGLP2500) placed in a controlled atmosphere chamber held at 57% equilibrium relative humidity (ERH) and 37°C. Dehydration for 48 h under the above conditions increased the heat resistance of Salm. typhimurium LT2 when measured as the surviving fraction after a heat challenge of 135°C for 30 min. Results also showed that little or no death occurred during heat challenges of 1 h at temperatures of up to 100°C. The survival of Salm. typhimurium LT2 was measured as the ability to form colonies on solid media tryptone soy broth plus 1.2% agar (TSBA) after 24 h at 37°C. Incorporation of sodium pyruvate, at a concentration of 0.2% into the recovery medium, did not enhance the recovery of heated Salm. typhimurium LT2. Dehydrated cells of S. typhimurium LT2 showed a triphasic death curve. Increasing the period of dehydration from 48 h to 34 d, reduced initial numbers due to die off but did not alter the shape of the subsequent survival curve. and accepted 22 June 1989
Lack of precision in commercial identification systems: correction using Bayesian analysis
Authors: Berger S.A.
Published: March 2008

Commercial microbial identification systems rank the relative likelihood of species identity on the basis of in vitro reactions only. Failure to consider the prevalence of individual taxa results in a spurious demotion of common species; and a tendency toward over reporting of rare microbes. The incorporation of Bayesian analysis into identification matrices can provide for a realistic ranking of bacterial species which fulfil given biocode schemes. and accepted 22 June 1989
Inhibition of the growth of enteropathogenic bacilli by bacteriocins produced by micro‐organisms from the sediment of wells
Authors: Padilla C. , Brevis P. , Said A. , Molina R.
Published: March 2008

The bacterial flora of the sediment of 20 wells of water for human consumption in the rural area of the VII Region in Chile was examined. Fourteen strains of bacteria, from different wells, produced bacteriocins which inhibited the growth of Salmonella typhi, Salm. typhimurium, Shigella sonnei and enterotoxigenic Escherichia coli. About 50% of these strains contained plasmids of different molecular weight and a large number of these codified for bacteriocins. The results suggest what is required to implement an efficient, simple and economical biological system for the purification or control of the number of enteropathogenic bacilli of well water in the rural area. and accepted 28 June 1989
Protein profiles of Capnocytophaga species
Authors: Khwaja Kauser J. , Parish Patricia , Aldred M.J. , Wade W.G.
Published: March 2008

Ninety‐seven strains of Capnocytophaga isolated from the oral cavity and the type strains of C. ochracea, C. sputigena and C. gingivalis were compared by one‐dimensional SDS‐PAGE of whole cell proteins. The protein patterns were highly reproducible and were used as the basis for numerical taxonomic analysis. The clusters containing the type strains of C. ochracea and C. sputigena segregated at the 78% similarity level. Some of the eight clusters obtained at this level showed good correlation with grouping based on the results of biochemical testing for lactose and galactose fermentation and nitrate reduction. No consistent association was found between protein profiles and colony type, size or colour or cell length but all agar‐adherent colony types segregated into a single cluster. and accepted 25 July 1989
Coliforms as a measure of sewage contamination of the River Zambezi
Authors: Feresu Sara B. , Sickle J. Van
Published: March 2008

The effect of releasing untreated sewage from Victoria Falls Town into the Zambezi river was determined by bacteriological examination of water samples collected upstream of Victoria Falls and for 22 km downstream. Most probable numbers of faecal coliforms and Escherichia coli were estimated. Water upstream of the falls, on the Zimbabwe side of the river, contained between seven and 130 E. coli per 100 ml. This section of the river was free from major sources of faecal pollution. Below the falls, but before the Victoria Falls Town sewage outfall, numbers of E. coli were between 1.8 × 102 and 1.4 × 104/100 ml, indicating the existence of a sewage discharge other than that from Victoria Falls Town. The river was also highly polluted from the Victoria Falls Town sewage outfall to a point 18.6 km downstream. The highest E. coli count was 3.3 × 104/100 ml and declined slowly to 1.4 × 103/100 ml 18.6 km downstream of the outfall.
Isolation and identification of staphylococci from milk powders produced in Northern Ireland
Authors: Harvey J. , Gilmour A.
Published: March 2008

Milk powders (37 samples) from five different processing centres (A, B, C, D and E) were examined for total viable counts, total staphylococcal counts and staphylococcal enterotoxins. All powders from centres A, B and C contained low numbers of total viable bacteria and staphylococci but five from centres D and E had high total and staphylococcal counts. Nine different staphylococcal species were encountered in low count powders with a wide range of species occurring at each of the five centres. Three species (Staphylococcus capitis, Staph. saprophyticus and Staph. cohnii) were found whose natural hosts are humans. High count powders all contained added fat of various types and had a much more restricted staphylococcal microflora in which Staph. saprophyticus and Staph. cohnii predominated. None of 384 staphylococcal strains isolated were found to be Staph. aureus. In addition, no enterotoxins were detected.
Inactivation of Legionella pneumophila by monochloramine
Authors: Cunliffe D. A.
Published: March 2008

Chloramination which is used in South Australia to control the growth of Naegleria fowleri, was investigated to see if it would also control that of Legionella pneumophila. It was found that L. pneumophila was more sensitive than Escherichia coli to monochloramine. At 1.0 mg/l, a 99% kill of L. pneumophila was achieved in 15 min compared with 37 min for a 99% kill of E. coli. Combined with the stability of monochloramine, even at elevated temperatures, the results suggest that this disinfectant would control the growth of L. pneumophila in water distribution systems.
Physiological variants of Saccharomyces cerevisiae and Kloeckera apiculata from palm wine and cashew juice
Authors: Owuama C.I. , Saunders J.R.
Published: March 2008

Physiological variants of Saccharomyces cerevisiae and Kloeckera apiculata have been identified in oil palm wine and cashew juice from Nigeria. Genomic DNA from the four S. cerevisiae variants had a % G + C of 36–41% while that of K. apiculata was 32.2%. Fermentation of cashew juice produced wine of alcoholic contents of 10% with S. cerevisiae, 8% with K. apiculata and 9.3% with both yeasts simultaneously. and accepted 31 August 1989
Numerical analysis of electrophoretic protein patterns of ‘Achromobacter’group B, E and F strains from human blood
Authors: Holmes B. , Costas M. , Wood A.C. , Kersters K.
Published: March 2008

Thirty‐two clinical strains representing ‘Achromobacter’groups B, E and F were characterized by one‐dimensional SDS‐PAGE of cellular proteins. All the strains were isolated from blood samples from hospital patients in the United Kingdom. The protein patterns, which contained 40 to 45 discrete bands, were highly reproducible and were used as the basis for a numerical analysis which included all the protein bands. The 32 ‘Achromobacter’ strains formed two clusters at the 77% S level. The first, phenon 1, included the 28 group B and the two group E strains and the second, phenon 2, contained the two strains of group F. The strains in each phenon were characterized by a clearly distinct pattern of protein bands. Phenon 1 could be further divided at the 87% S level into three subphenons which correlated with differences in the principal bands found between 40.0 and 42.5 kD. Strains of group E clustered with group B strains from which they could not be distinguished by protein patterns. We conclude that high resolution PAGE combined with computerized analysis of protein patterns provides a useful method for the classification of this group of bacteria. Reference strains of each of the PAGE types identified are available from NCTC for inclusion in future studies.
Psychrotrophic strains of Bacillus cereus producing enterotoxin
Authors: van Netten P. , van de Moosdijk A. , van Hoensel P. , Mossel D. A. A. , Perales I.
Published: March 2008

In investigations on three outbreaks of Bacillus cereus food poisoning in Spain and The Netherlands, the causative strains grew within a temperature range of 4·37†C, but not at 43†C. Such psychrotrophic types were found to occur in various dairy products (including ca 25% of 35 samples of pasteurized milk) and some mousses and cook/chill meals. Growth of and enterotoxin production by psychrotrophic B. cereus could be prevented by temperatures below 4†C and pH‐values not exceeding 5·0.
Amylase programming during the life cycle of Myxococcus coralloides
Authors: Farez‐Vidal M. Esther , Fernandez‐Vivas Antonia , Arias J. M.
Published: March 2008

Starch induces Myxococcus coralloides to secrete amylase. Amylase production has been observed during various stages of the life cycle of this myxobacterium both in liquid and solid media. Secretion was very high during vegetative growth at the end of the exponential growth phase in all media. During myxospore formation (glycerol‐induced and fruiting‐body formation) amylase activity decreased and finally ceased in the mature myxospores. During germination of glycerol‐induced myxospores and fruiting‐body myxospores a progressive increase in this activity was observed.
Behaviour of Listeria monocytogenes in meat and its control by a bacteriocin‐producing strain of Lactobacillus sake
Authors: Schillinger U. , Kaya M. , Lücke F.‐K.
Published: March 2008

Lactobacillus sake Lb 706 can release a bacteriocin inhibitory to Listeria monocytogenes. In MRS broth, viable counts decreased rapidly when Lact. sake Lb 706 was added, whereas growth of the listerias was not affected by a bacteriocin‐negative variant of the same Lactobacillus strain. Inhibition of L. monocytogenes was also observed in pasteurized minced meat inoculated with Lact. sake Lb 706. The bacteriocin produced is apparently effective in meat. However, the effect of the bacteriocin producer was less evident in minced meat than in broth. In comminuted cured raw pork filled into casings (German‐type ‘fresh Mettwurst’), L. monocytogenes was able to grow at a pH of 6.3, but addition of Lact. sake Lb 706 prevented the growth of listerias during the first few days after manufacture. At normal pH (5.7) L. monocytogenes did not multiply and addition of Lact. sake Lb 706 reduced viable counts of listerias by about one log cycle. Lactobacillus sake Lb 706 therefore may have some potential as a protective culture in meat products.
The lethal effect of carrot on Listeria species
Authors: Nguyen‐the C. , Lund Barbara M.
Published: March 2008

When shredded or sliced carrots were inoculated with Listeria monocytogenes the number of viable listerias decreased rapidly. On carrot slices stored at 8°C there was a decrease after 3 d followed by an increase, after 7 d, to numbers similar to those present initially. The numbers of spoilage micro‐organisms increased throughout storage at 8°C. Carrots macerated in a Stomacher Lab Blender also showed an antilisterial activity which resulted in a decrease in number of viable bacteria and in sublethal damage. The effect was shown by five carrot cultivars and acted on nine strains of L. monocytogenes and single strains of L. innocua, L. ivanovii, L. seeligeri, L. welshimeri. This antilisterial effect was heat‐labile, was inactivated after a few hours at 4°C or at 30°C and was active over the pH range 5.8 to 7.0. Maceration of carrots in an Atomix blender for 1 min or in liquid nitrogen destroyed the antilisterial activity.
Removal of faecal indicator bacteria and bacteriophages from the common mussel (Mytilus edulis) under artificial depuration conditions
Authors: de Mesquita Maria Margarida F. , Evison Lilian M. , West P.A.
Published: March 2008

Artificial self‐purification (depuration) of mussels (Mytilus edulis) was undertaken at three temperatures, under conditions similar to those likely to be experienced in the commercial shellfish industry of the UK. During a 72 h depuration period, samples of mussel flesh were examined for three faecal indicator bacteria, Escherichia coli, Group D faecal streptococci and sulphite‐reducing Clostridium spores, and two types of bacteriophage. There was a statistically significant difference in the elimination rate of faecal indicator bacteria compared with the slower rate for both bacteriophages.
Decreased DNA damage by acid and increased repair of acid‐damaged DNA in acid‐habituated Escherichia coli
Authors: Raja N. , Goodson M. , Smith D.G. , Rowbury R.J.
Published: March 2008

A study of the conjugal transfer of ColV,I‐K94 tn10 from acid‐treated donors suggested that acid‐habituated recipients repair acid‐damaged plasmid DNA better than those that are not habituated. The presence of an increased repair activity for acid‐damaged DNA in habituated cells was confirmed by isolating pBR322 from acid‐treated organisms; habituated cells produced more transformants when transformed by it than did non‐habituated ones. Additionally, agarose gel electrophoretic studies of pBR322 DNA isolated from acid‐damaged cells and tests of its transforming activity both indicated that plasmid DNA in habituated cells is less damaged by extreme acidity than is that in non‐habituated organisms.
Rapid differentiation of the species of the genus Bacteroides sensu stricto by capillary gas chromatography of cellular carbohydrates
Authors: Engelhard E. , Mutters R.
Published: March 2008

Whole‐cell hydrolysates of Bacteroides fragilis, the type species of the genus Bacteroides Castellani and Chalmers 1919, and the genetical closely related species B. vulgatus, B. ovatus, B. eggerthii, B. distasonis, B. uniformis, B. thetaiotaomicron, B. stercoris, B. merdae, and B. caccae were used to determine characteristic carbohydrate patterns by capillary gas chromatography. On the basis of the chemical derivatization of the carbohydrates seven characteristic peaks for peracetylated aldononitriles and nine characteristic peaks for peracetylated o‐methyloximes were selected from the carbohydrate fingerprints of the reference strains to prepare a dichotomous identification key. The classification of an unknown strain supposed to belong to the formerly called ‘Bacteroides fragilis group’is possible with this key. Some of the advantages of the technique were that the identification of Bacteroides fragilis‐like strains requires only 4–5 h after primary isolation and that the bacteria can be exposed to oxygen because viability of the organisms is not necessary. Sophisticated anaerobic techniques can therefore be avoided for identification.
The survival of Listeria monocytogenes in cottage cheese
Authors: Hicks S. J. , Lund Barbara M.
Published: March 2008

Because of the difficulty of ensuring that cottage cheese is produced in conditions that prevent contamination with Listeria monocytogenes, the ability of this bacterium to survive in cottage cheese from three sources was investigated (a) during shelf‐life at chill temperature and (b) in conditions of temperature abuse. Three batches of creamed cottage cheese, from three sources, received within 24 h of production, were inoculated with L. monocytogenes strain F6861 and stored at 4, 8 or 12°C for 14 d. The three batches differed in their initial pH, titratable acidity and content of lactic acid and of lactic acid bacteria. No increase in numbers of L. monocytogenes occurred in the cottage cheeses during storage in these conditions. The numbers of listeria decreased; the rate of decrease differed in products from the three sources and was least in the product with the highest pH and lowest content of lactic acid. Acid formation by lactic acid bacteria during storage of the products probably contributed to the inhibition of listeria.
The microflora of soak water during tempeh production from various beans
Authors: Ashenafi M. , Busse M.
Published: March 2008

The microflora of soak water was studied during the soaking of horsebean, pea, chickpea and soybean for tempeh production. Lactic streptococci dominated the flora in both unacidified and acidified soak water. Coliforms and yeasts were found only in unacidified soak water. Growth of micro‐organisms in acidified and unacidified soak water resulted in a decrease in pH value of the cooked beans. Microbial acidification during soaking is considered to be important in tempeh production.
Staphylococcus aureus S‐6: factors affecting its growth, enterotoxin B production and exoprotein formation
Authors: Nychas G. J. , Tranter H. S. , Brehm Rossalyn D. , Board R. G.
Published: March 2008

The growth of Staphylococcus aureus S‐6, enterotoxin production and exoprotein formation were always higher in NZ‐amine A medium compared with brain heart infusion medium. The formation of exoproteins, including enterotoxin B, per bacterial cell in static culture was influenced by the addition of glucose.

Lactate and amino acids were used by Staph. aureus S‐6 in media without additional glucose. When both media were supplemented with glucose, lactic and acetic acids were produced. Different electrophoretic patterns for exoprotein formation were obtained when the organism was grown in shaken or static culture.
A note on deacidification activity of Schizosaccharomyces pombe in plum must of variable compositions
Authors: Joshi V.K. , Sharma P.C. , Attri B.L.
Published: March 2008

The effects of varying levels of pH, ethanol, SO2 and N sources on the deacidification activity of Schizosaccharomyces pombe during plum must fermentation were examined. The deacidification activity of the yeast was rapid at pH 3·0–4·5 but was adversely affected at pH 2·5 in the initial stages of wine fermentation. Plum must with 150 ppm SO2 was effective in enhancing the activity, while the major effect of higher SO2 concentration in the must was the slower start of the process. The addition of ammonium sulphate in must enhanced the acid reduction. The deacidification activity of the yeast was quite susceptible to higher concentrations of ethanol (5–15%). The colour of the wine depended on the quantity of acid utilized by the yeast and the phenomenon was reversible. Red colour units of the wine were positively correlated with acidity, whereas blue and yellow units were inversely related to this character.
A chemically mediated amperometric biosensor for monitoring eubacterial respiration
Authors: Richardson N.J. , Gardner S. , Rawson D.M.
Published: March 2008

The development of a novel biosensor system for measuring the respiratory activity of whole eubacterial cells is described. The biosensor incorporates a physically immobilized layer of cells held in intimate contact with an amperometric transducing electrode and uses a chemical mediator, potassium ferricyanide, to divert electrons from the respiratory system of the bacteria to the poised electrode. The current thus produced is proportional to the level of respiratory activity of the immobilized bacterial cells and can be monitored by a computer interface system. The paper outlines the principles of the biosensor and describes the results of a screen of potentially useful eubacteria. Also described are the effects of physical parameters on the sensor and a strategy for the long term preservation of the biosensor by freeze‐drying.
Preliminary in vitro evaluation of the antimicrobial activity of terpenes and terpenoids towards Erwinia amylovora (Burrill) Winslow et al.
Authors: Scortichini M. , Rossi Maria Pia
Published: March 2008

The antimicrobial activity of 20 10% (v/v) solutions in ethanol of terpenes and terpenoids at several concentrations was tested against Erwinia amylovora NCPPB 595 in the liquid medium 523. The test organism responded differently to the chemicals. At 600, 900 and 1200 mg/l, none of the compounds reduced the growth of the bacterium. At 1500 mg/l, only some of the chemicals significantly inhibited growth x‐Pinene. β‐terpinene, dihydrocarveol, isopulegol and linalool reduced growth of suspensions of 1 × 103 cfu/ml, whereas β‐pinene was more effective when challenged with larger numbers of cells (i.e. 1 × 105 cfu/ml and 1 × 107 cfu/ml). At 1500 mg/l, geraniol and citronellol exerted a bactericidal activity regardless of the concentrations of the test organism.
Methods for recovery and immunodetection of Xanthomonas campestris pv. phaseoli in navy bean seed
Authors: Wong W.C.
Published: March 2008

Non‐selective enrichment procedures were evaluated for recovery of Xanthomonas campestris pv. phaseoli (fuscans strain) from artificially inoculated navy bean seed. A marked increase in recovery of the pathogen was obtained when the mixtures (bacterium plus bean seed) were suspended in Pseudomonas Agar F medium at 28°C for 48 h. Detection of this pathogen by indirect immunofluorescence microscopy (IF) and indirect enzyme‐linked immunosorbent assay (ELISA) with a specific monoclonal antibody was compared. The IF system was not only more sensitive but also more reliable than ELISA for detection of the pathogen. The method is particularly useful for evaluation of the common bacterial blight status of seedlots before planting out.
Characteristics of glucoamylase from Aspergillus terreus
Authors: Ali S. , Hossain Z.
Published: March 2008

Glucose was the only product of starch hydrolysis liberated by glucoamylase. The enzyme was a glycoprotein with an isoelectric point at pH 3·4 and was optimally active at pH 4·0 and 60°C. It was remarkably stable over a wide range of pH and at elevated temperatures. Divalent Mg2+’and Ca2+ slightly stimulated glucoamylase activity. The enzyme exhibited specificity for substrates containing α(1 → 4) glucosidic linkages and the Km for starch hydrolysis was 4·0 g/l.
Production of cell wall dissolving enzymes by Erwinia carotovora subsp. atroseptica in vitro at 27°C and 30°5C
Authors: Lanham P.G. , Mcllravey K.I. , Perombelon M.C.M.
Published: March 2008

Cultures of Erwinia carotovora subsp. atroseptica, grown at 27°C and 30·°C in different liquid media were assayed for activities of pectate lyase, polygalacturonase and cellulase. Total production of both pectate lyase and of polygalacturonase was 3–6 times less at 30·5°C than at 27°C; secretion of pectate lyase was similarly affected. Cellulase was cell bound and its production was not affected by the temperatures investigated. Growth, protein synthesis and protease activity were similar at the two temperatures and production of enzyme activity at 27°C and 30·5°C was independent of the growth medium.
Effects of gaseous environment and temperature on the storage behaviour of Listeria monocytogenes on chicken breast meat
Authors: Hart C.D. , Mead G.C. , Norris A.P.
Published: March 2008

Portions of skinless chicken breast meat (pH 5·8) were inoculated with a strain of Listeria monocytogenes and stored at 1, 6 or 15°C in (1) aerobic conditions; (2) 30% CO2+ air; (3) 30% CO2+ N2; and (4) 100% CO2. When samples were held at 1°C the organism failed to grow under any of the test conditions, despite marked differences between treatments in spoilage rate and ultimate microflora. At 6°C counts of L. monocytogenes increased ca 10‐fold in aerobic conditions before spoilage of the meat, but only when the inoculum culture was incubated at 1°C rather than 37°C. In CO2 atmospheres growth of L. monocytogenes was inhibited on meat held at 6°C, especially under 100% CO2. By contrast, storage at 15°C led to spoilage of the meat within 2 d, in all gaseous environments, and listeria levels increased up to 100‐fold. Differences in the behaviour of L. monocytogenes on poultry and red meats are discussed.
Ammonium and glutamate assimilation by tryptophan‐catabolic variants of Bradyrhizobium japonicum USDA 26
Authors: Kaneshiro T.
Published: March 2008

Tryptophan‐catabolic variants, tan 4b and 18ac, of Bradyrhizobium japonicum USDA 26 were isolated from enrichment cultures in nitrogen (N)‐limited media containing either ammonium or glutamate. Presence of exogenous tryptophan (trp) in the medium led to sparse restricted growth and elicited selective growth of tan‐coloured variants over that of parental USDA 26. A 36% increase in cellular uptake‐accumulation of the ammonia analogue [14C]‐methylamine was found with trp‐induced tan 18ac cells over that measured with either ammonium‐induced tan 18ac or trp‐induced tan 4b. The assimilation patterns of uniformly labelled [14C]‐glutamate also differed when tan 18ac was compared with tan 4b. These studies of tan variants isolated from enrichment cultures suggest that bradyrhizobial populations can be manipulated by changing the N sources that limit their growth.
SGAP‐10C agar for the isolation and quantification of Aeromonas from water
Authors: Huguet J.M. , Ribas F.
Published: March 2008

Glutamate starch penicillin (GSP) medium was used for the simultaneous isolation of Pseudomonas and Aeromonas. Modifications to reduce the number of Pseudomonas and background flora and to improve the recovery of Aeromonas from water samples are described. The original medium was modified by adding glucose and ampicillin. The addition of 10 μg/l of C‐glucose to the medium (SGAP‐10C) permitted better recuperation of stressed cells of aeromonads and the ampicillin reduced the numbers of Pseudomonas. The best temperature for the recovery of aquatic aeromonads was 28°C. The recovery of different species of Aeromonas on SGAP‐10C was 93%. The selectivity of the medium was validated because 95·5% of 28 colonies tested with an Aeromonas‐like morphology belonged to the genus Aeromonas. Moreover, when 45 strains of different genera were cultured on the medium, only Vibrio alginolyticus presented a confusing morphology. When the SGAP‐10C was compared with GSP with 45 river samples, the new medium gave a significantly better recovery of Aeromonas spp., especially when large numbers of Pseudomonas spp. were present. SGAP‐10C used at 28°C and 48 h was an efficient selective medium for the isolation of Aeromonas from fresh waters.
A membrane filter procedure for assaying cytotoxic activity in heterotrophic bacteria isolated from drinking water
Authors: Lye D.J. , Dufour A.P.
Published: March 2008

Cytotoxic activity assays of Gram‐negative, heterotrophic bacteria are often laborious and time consuming. The objective of this study was to develop in situ procedures for testing potential cytotoxic activities of heterotrophic bacteria isolated from drinking water systems. Water samples were passed through 0·45 μm membrane filters which were then placed upon appropriate media and incubated. After incubation, each membrane filter was transferred to the surface of Y‐1 mouse adrenal cells overlaid with 1% agar. The filters were removed after exposure for 15 min. The Y‐1 cells were then incubated at 37°C in 2·5% CO2 for an additional 24 h. The release of putative cytotoxic and cytotonic products from the bacterial colonies was recognized by zones of cellular lysis and injury of Y‐1 cells that appeared immediately beneath the membrane. Cytotoxic strains of Aeromonas, Vibrio, Escherichia, and Legionella spp. were readily recognized by this method. About 1% of the bacteria isolated from drinking water also released cytotoxic products. This frequency was dependent upon the primary medium used and the density of bacteria present. The majority of cytotoxic strains isolated from drinking water also expressed protease activity (95%) and haemolytic activity (70%). This in situ membrane filter procedure is a facile method for simultaneously testing many different bacterial colonies.
Inoculation of Lolium rigidum with Clavibacter sp., the toxigenic bacteria associated with annual ryegrass toxicity
Authors: Riley I.T. , McKay A.C.
Published: March 2008

I.T. RILEY AND A.C. McKAY. 1991. A series of experiments was undertaken to induce the development of Clavibacter sp. in Lolium rigidum with both cultured and field sources of bacterial inoculum by artificial inoculation and inoculation in association with the vector nematode Anguina funesta. Bacterial colonization of the host was reliably achieved only with a bacterial inoculum from the field in conjunction with A. funesta. Although in a few instances bacterial gummosis in the host was observed when it was artificially inoculated with cultured bacteria, these bacteria no longer appeared to be pathogenic.