bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of substrate shock on populations of starving aquatic bacteria
Authors: Straškrabová Věra
Published: March 2008

The effect of substrate (glucose) shock on starved mixed cultures of aquatic bacteria under conditions resembling the natural aquatic situation has been studied. The prevalent organism in the system was a Pseudomonas sp., and short‐term loss of viability and long‐term loss of several biochemical properties of this strain were observed. Glucose uptake rate and cell size of the population increased immediately after the shock and synchronous growth occurred subsequently. The population which became established after the shock exhibited lower glucose uptake rates at low substrate concentrations than the starved population. The relevance to similar phenomena which occur when aquatic bacteria are transferred to cultivation media is discussed.
Selective method for the isolation of Sporolactobacillus from food and environmental sources†
Authors: Doores Stephanie , Westhoff D.C.
Published: March 2008

A detection procedure was developed in which a modified Lactobacilli MRS medium was used to enrich for Sporolactobacillus from a variety of foods, feed, soil and environmental samples. Each sample was rinsed with 50 ml of a modified Lactobacilli MRS broth containing 1.0% (w/v) α‐methyl glucoside, 0.1% (w/v) potassium sorbate, 0.00224% (w/v) bromocresol green indicator, adjusted to pH 5·5 with acetic acid and incubated at 37°C for 7 d under 5% CO2. Volumes of 2 ml from each sample were heat shocked at 80°C for 5 min and 0.1 ml spread onto plates of Lactobacilli MRS agar (Difco), pH 5·5 and APT agar (BBL), pH 5·5. Plates were incubated for 5 d and suspect colonies were tested for catalase production, benzidine reaction, nitrate reduction, motility and Gram stain reaction. This method was demonstrated to be selective for Sporolactobacillus.
A note on a method to aid sampling populations for characteristics
Authors: Barrow P.A.
Published: March 2008

A method is described for determining the minimum sample size for examining characters in animal or microbial populations.
The effect of benzoyl peroxide on cutaneous micro‐organisms in vitro
Authors: Cove J.H. , Holland K.T.
Published: March 2008

The survival curves of cutaneous micro‐organisms in the presence of benzoyl peroxide were investigated. All the curves exhibited a shoulder prior to exponential cell death. Benzoyl peroxide was lethal to the cutaneous organisms tested and they varied in sensitivity increasing as follows: Propionibacterium acnes, Staphylococcus capitis, Staph. epidermidis, Staph. hominis, Prop, avidum, Prop. granulosum and Pityrosporum ovale.
The antimicrobial effect of dissociated and undissociated sorbic acid at different pH levels
Authors: Eklund Trygve
Published: March 2008

The minimum inhibitory concentration of sorbic acid has been determined for Bacillus subtilis, Bacillus cereus, Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans. The inhibition was shown to be due to both undissociated and dissociated acid, and the effect of each has been calculated in accordance with a proposed mathematical model. Although the inhibitory action of undissociated acid was 10–600 times greater than that of dissociated acid, the latter caused more than 50% of the growth inhibition at pH levels above 6 for most of the organisms tested.
A selective and indicative medium for groups of Penicillium viridicatum producing different mycotoxins in cereals
Authors: Frisvad J.C.
Published: March 2008

A medium, pentachloronitrobenzene‐rose bengal‐yeast extract‐sucrose agar (PRYES), for the isolation of moulds occurring during storage of cereals has been developed and compared with other selective media. The basal medium is yeast extract agar containing 15% sucrose (w/v). In addition to the sucrose content further selective measures include the addition of antibacterial antibiotics chloram‐phenicol and chlortetracycline (50 mg/l), the fungicides rose bengal (25 mg/l each), and pentachloronitrobenzene (1 g/l) and a low incubation temperature (20°C). Members of the Mucorales were completely inhibited, and fast‐growing species of other moulds were slightly inhibited, allowing important storage moulds to develop. The important ochratoxin A and citrinin‐producing Penicillium viridicatum group II was indicated by a typical violet brown reverse on PRYES. Producers of xanthomegnin and viomellein (P. viridicatum group I and P. aurantiogriseum) were indicated on PRYES by their yellow reverse and obverse colours. The medium was used for screening 40 samples of barley, and moulds with the characteristic colours were all identified as the species mentioned above.
The bactericidal, fungicidal and sporicidal properties of hydrogen peroxide and peracetic acid
Authors: Baldry M.G.C.
Published: March 2008

The antimicrobial properties of aqueous solutions of peracetic acid and hydrogen peroxide have been compared. Peracetic acid exhibited excellent antimicrobial properties, especially under acidic conditions. Reductions by a factor of 106 in the numbers of vegetative bacteria are obtained within 1 min at 25°C using a solution containing 1.3 mmol/l of peracetic acid. Rapid activity against bacterial spores and yeasts also occurs. Hydrogen peroxide is more effective as a sporicide than as a bactericide, with sporicidal action being obtained using a solution containing 0.88 mol/l. Bactericidal action is poor but hydrogen peroxide was bacteriostatic at concentrations above 0.15 mmol/l.
A note on the repair of the Escherichia coli nucleoid structure after heat shock
Authors: Pellon J.R.
Published: March 2008

The repair of the Escherichia coli nucleoid structure after heat shock (50°C, 5 min) was studied. After heat shock the repair process did not include the association of the nucleoid to protein structures as is the case after more severe heat treatments resulting in cell death or inactivation.
Fatty acid, isoprenoid quinone and polar lipid composition in the classification of Renibacterium salmoninarum
Authors: Embley T.M. , Goodfellow M. , Minnikin D.E. , Austin B.
Published: March 2008

Twenty‐one strains of Renibacterium salmoninarum were degraded by acid methanolysis and the non‐hydroxylated fatty acid esters released examined by thin‐layer and gas chromatography. The fatty acid profiles were composed almost exclusively of methyl‐branched fatty acids with 12‐methyltetradecanoic (anteiso‐C15), 13‐methyltetradecanoic (iso‐C15) and 14‐methylhexadecanoic (anteiso‐C17) as major components. Polar lipids of the test strains were examined by two‐dimensional thin‐layer chromatography. All of the organisms possessed very characteristic polar lipid patterns consisting of diphosphatidylglycerol, two major and six or seven minor glycolipids, and two unidentified minor phospholipids. In all cases the major menaquinone components consisted of unsaturated menaquinones with nine isoprene units. The lipid data support the integrity of the genus Renibacterium and can be used to separate it from Corynebacterium and from coryneform bacteria which also contain lysine in the wall peptidoglycan.
Autoaggregating Yersinia enterocolitica express surface fimbriae with high surface hydrophobicity
Authors: Faris A. , Lindahl M. , Ljungh Å. , Old D.C. , Wadström T.
Published: March 2008

For 13 strains of Yersinia enterocolitica, there was a good correlation between the production of the broad‐spectrum, mannose‐resistant Yersinia haemagglutinin (MR/Y HA), the presence of fimbriae and high surface hydrophobicity. Each of these characters was expressed in cultures grown at low (< 32°C) but not at high (> 35°C) temperatures.
Biochemical and chemical studies on Bacteroides multiacidus and Bacteroides hypermegas
Authors: Shah H.N. , Collins M.D. , Kroppenstedt R.M.
Published: March 2008

Biochemical and chemical studies were performed on representative strains of Bacteroides hypermegas and Bact. multiacidus in an attempt to clarify their taxonomy. The results of the present and earlier studies indicate that Bact. hypermegas and Bact. multiacidus are distinct species. On the basis of DNA base composition, enzyme patterns and lipid criteria it is suggested that both species should be excluded from the genus Bacteroides.
Actinomyces denticolens Dent & Williams sp. nov: a new species from the dental plaque of cattle
Authors: Dent V.E. , Williams R.A.D.
Published: March 2008

Dent, V.E. & Williams, R.A.D. 1984. Actinomyces denticolens Dent & Williams sp. nov: a new species from the dental plaque of cattle. Journal of Applied Bacteriology56, 183–192.

Six strains of actinomyces isolated from the dental plaque of cattle were assigned presumptively to the genus Actinomyces on the basis of Gram reaction, cellular and colony morphology and acid end‐products of metabolism. This assignment was confirmed by the peptidoglycan composition which is shared with Actinomyces species from dental plaque. These cattle strains formed a homogeneous group on the basis of cell wall carbohydrate components, DNA base composition, polypep‐tide molecular weight distribution and physiological reactions but could not be classified with any recognised species of Actinomyces. A new taxon Actinomyces denticolens is proposed for these strains.
The antimicrobial properties of two commonly used antiseptic mouthwashes—Corsodyl and Oraldene
Authors: Ashley K.C.
Published: March 2008

Ashley, K.C. 1984. The antimicrobial properties of two commonly used antiseptic mouthwashes—Corsodyl and Oraldene. Journal of Applied Bacteriology 56>, 221–225.

The antimicrobial activities of the mouthwashes Corsodyl and Oraldene against common buccal organisms were essentially similar. The concentration of the active substance in the two mouthwashes was well in excess of the minimum inhibitory concentrations determined. Also a rapid lethal effect on the bacteria was found which, when combined with the previous property, may well account for the usefulness of these products in infectious conditions.
L‐Rhamnose utilisation in Salmonella typhimurium
Authors: Akhy M.T. , Brown C.M. , Old D.C.
Published: March 2008

Akhy, M.T., Brown, C.M. & Old, D.C. 1984. L‐Rhamnose utilisation in Salmonella typhimurium. Journal of Applied Bacteriology56, 269–274.

L‐Rhamnose is degraded by strains of Salmonella typhimurium by isomerisation to L‐rhamnulose, phosphorylation to L‐rhamnulose‐1‐phosphate and cleavage to lac‐taldehyde and dihydroxyacetone phosphate. The enzymes involved are, respectively, rhamnose isomerase (Rhal), rhamnulokinase (RhuK) and an aldolase (Ald). Strains able to grow rapidly on L‐rhamnose contained a high‐affinity uptake system for 3H‐L‐rhamnose that was induced by L‐rhamnose and repressed by D‐glucose. The synthesis of Rhal and RhuK was also induced by L‐rhamnose but was not repressed by D‐glucose. The synthesis of Ald was constitutive. Data are presented on some strains which grow very slowly on L‐rhamnose and on others which do not utilise it.
Effect of temperature on the microbial flora of herring fillets stored in air or carbon dioxide
Authors: Molin G. , Stenström Inga‐Maj
Published: March 2008

Molin, G. & Sxenström, I‐M. 1984. Effect of temperature on the microbial flora of herring fillets stored in air or carbon dioxide. Journal of Applied Bacteriology56, 275–282.

The microbial development on fillets of herring from the Baltic Sea was studied at temperatures from 0–15d̀C in air or 100% carbon dioxide (96–100% CO2). The shelf‐life of the fillets, defined as the time for the ‘total aerobic count’ to reach 1 times 107 c.f.u./g increased with decreased temperature from 1 d at 15d̀C to 7 d at 0d̀C (air). The corresponding values in CO2 were 3 d and 33 d, respectively. The initial flora of the herring fillets was dominated by Alteromonas putrefaciens and Pseudo‐monus spp. and so was the spoilage flora after storage in air (together 62–95% of the flora; ail temperatures). Alteromonas putrefaciens predominated slightly at 2d̀C to 15 C. while Pseudomonas spp. dominated at 0d̀C. The Pseudomonas flora was mainly split between Ps. fragi, Ps. fluorescens and a heterogenous group of unidentified Pseudomonas spp. The proportions were not influenced by temperature. In 100% CO2 at the time of spoilage the flora consisted of a significant number of Lactobacillus spp. Below 4d̀C the domination was almost complete while at 10d̀C and 15d̀C Enterobacteriaceae, Vibrionaceae and Alt. putrefaciens were also found. It was concluded that the microbiological shelf‐life of herring fillets is improved by refrigeration storage in 100% CO2 but for good results the temperature should not exceed 2d̀C.
Fast‐growing bacteria from nodules of cowpea (Vigna unguiculata (L.) Walp.)
Authors: Dakora F.D. , Vincent J.M.
Published: March 2008

Dakora, F.D. & Vincent, J.M. 1984. Fast‐growing bacteria from nodules of cowpea (Vigna unguiculata (L.) Walp.) Journal of Applied Bacteriology56, 327–330.

First plating from nodules of cowpea frequently yielded fast‐growing large colonies, either apparently uniform or associated with small colony forms typical of the expected slow‐grower (Bradyrhizobium). Most cultures from single large colonies nodulated both cowpea and siratro (Macroptilium atropurpureum), but all such nodules revealed Bradyrhizobium alone or associated with a fast‐growing form. Six of nine plants inoculated with a mixed inoculum of slow and fast forms had nodules occupied by both although in no case was the fast‐grower able to secure solo invasion. Most of the fast‐growing forms shared some internal antigens with Rhizo‐biurn meliloti and/or R. trifolii; none reacted with antiserum to Bradyrhizobium CB 756.
Lack of correlation between the presence of plasmids and fimbriae in Yersinia enterocolitica and Yersinia pseudotuberculosis
Authors: Skurnik M.
Published: March 2008

Skurnik, M. 1984. Lack of correlation between the presence of plasmids and fimbriae in Yersinia enterocolitica and Yersinia pseudotuberculosis. Journal of Applied Bacteriology56, 355–363.

Thirty‐nine strains of Yersinia enterocolitica and 10 strains of Yersinia pseudoluber‐culosis were studied for the presence of fimbriae, plasmids and two plasmid associated phenotypic expressions, autoagglutination and Ca2+ dependent growth at 37d̀C. All of the strains studied became fimbriated, which was confirmed by electron microscopy and haemagglutination tests. Fimbriation was not correlated with the presence or absence of plasmids.
Production of amylase by Aspergillus foetidus on rice flour medium and characterization of the enzyme
Authors: Michelena V.V. , Castillo F.J.
Published: March 2008

Michelena, V.V. & Castillo, F.J. 1984. Production of amylase by Aspergillus foetidus on rice flour medium and characterization of the enzyme. Journal of Applied Bacteriology56, 395–407.

Aspergillus foetidus ATCC 10254 was selected from nine starch‐utilizing microorganisms for its high amylolytic activity. This mould produced high levels of extracellular α‐amylase in rice starch medium and degraded the available starch efficiently. Optimal conditions for enzyme production on 2.0% rice medium included 28d̀C, initial pH of 6.6, and supplementations with 0.02% NaNO2, 0.08% KH2PO4, and 0.08% corn steep liquor. Eleven‐fold purification of the enzyme was obtained after ammonium sulphate and ethanol precipitations from spent medium. The molecular weight was estimated at 41 500. Optimum pH and temperature for enzyme activity were 5.0 and 45d̀C. Michaelis‐Menten constants were 1.14 mg/ml on amylopectin, 2.19 mg/ml on soluble starch and 7.65 mg/ml on amylose. Amylose produced substrate inhibition while glucose or maltose did not inhibit the enzyme. This α‐amylase may be used as a saccharifying enzyme for rice starch. Aspergillus foetidus ATCC 10254 also presents a potential for treatment of starch‐containing waste waters.
Isolation of Yersinia enterocolitica and related species from porcine samples obtained from an abattoir
Authors: Harmon M.C. , Swaminathan B. , Forrest J.C.
Published: March 2008

Harmon, M.C., Swaminathan, B. & Forrest, J.C. 1984. Isolation of Yersinia enterocolitica and related species from porcine samples obtained from an abattoir. Journal of Applied Bacteriology56, 421–427.

Swabs of swine carcasses and samples of porcine tongue and trim obtained from an abattoir were examined for the presence of Yersinia enterocolitica and related species (Y. intermedia, Y. kristensenii and Y. frederiksenii). Three enrichment media (phosphate buffered saline, sorbitol‐bile salts‐phosphate buffered saline, and a modified Rappaport's broth) were compared at 4d̀C for their efficiency of recovery of Y. enterocolitica and related species. Two secondary enrichment procedures (post‐enrichment in modified Rappaport's broth for 2 d at 25d̀C and treatment with 0.5% KOH in 0.5% NaCl) also were evaluated. The porcine isolates were characterised by biochemical and serological examination, speciation, and biotyping. Eight of 43 samples were positive for Y. enterocolitica and related species. The combination of incubation in sorbitol‐bile salts‐phosphate buffered saline for 21 d at 4d̀C followed by post‐enrichment in modified Rappaport's broth yielded maximum number of isolates. All isolates, except one, were avirulent as determined by auto‐agglutination, calcium dependence at 37d̀C, and HeLa cell invasiveness tests.
Two unusual budding bacteria isolated from a swimming pool
Authors: Sly L.I. , Hargreaves Megan H.
Published: March 2008

Sly, L.I. & Hargreaves, M.H. 1984. Two unusual budding bacteria isolated from a swimming pool. Journal of Applied Bacteriology56, 479–486.

Two unusual strains of budding bacteria were isolated on a Millipore Pseudomonas Count Water Tester during routine monitoring of Pseudomonas aeruginosa counts in a swimming pool. The first isolate has been identified as Blastobacter sp. It was a yellow‐pigmented, Gram negative rod‐shaped organism with a polar holdfast by which it attached to solid surfaces or other cells to form rosettes. The cells reproduced by asymmetric division or budding at the free pole of the cell, producing motile daughter cells with a single polar flagellum. The second isolate, which has not yet been identified, was a red‐pigmented, Gram negative rod‐shaped organism which produced one or more buds at each pole of the cell. Cell division appears to occur by both binary fission and by budding. Both organisms were strict aerobes, catalase and oxidase positive and did not produce acid from glucose in Hugh and Leifson medium.
Changes in metabolism and cell size of the anaerobic bacterium Selenomonas ruminantium 0078A at the onset of growth in continuous culture
Authors: Silley P. , Armstrong D. G.
Published: March 2008

Silley, P. & Armstrong, D.G. 1984. Changes in metabolism and cell size of the anaerobic bacterium Selenomonas ruminantium 0078A at the onset of growth in continuous culture. Journal of Applied Bacteriology56, 487–492.

Initial metabolism of Selenomonas ruminantium 0078A in continuous culture was characterized by a high lactate and low volatile fatty acid production; this was associated with poor growth as determined by bacterial dry weight production, yet individual cells were considerably larger than those of the inoculum. Biomass production increased, cell size decreased and the fermentation pattern reverted to the characteristic low lactate and high volatile fatty acid production after approximately 90 h growth.
Amylolytic lactic acid bacteria in fish silage
Authors: Lindgren S. , Refai O.
Published: March 2008

An ∝aL‐amylase activity has been observed in lactic acid bacteria occurring initially in fermented fish silage. The organisms belong to the genus Leuconostoc. The main fraction of the amylolytic enzyme produced by one of the isolated bacteria is cell‐bound and is released into the medium at a late stage of growth. Treating cells with ultrasound or Triton X‐100 increases enzyme activity in the culture filtrate. The pH range for enzyme activity is 5.0–7.0, with an optimum at pH 6.0. The enzyme is extremely labile at pH 8.0 and is inactivated at temperatures above 50°C at pH 5.8. Two enzyme fractions were found by isoelectric focusing, the main one at pH 5.00 and another at pH 4.5. Chromatography on DEAE cellulose gave two active peaks.
Heat injury and recovery of Streptococcus faecium associated with the souring of chub‐packed luncheon meat
Authors: Bell R. G. , Lacy Karen M. De
Published: March 2008

The presence of NaCl in the heating medium provided some protection from lethal heat damage for cells of a Streptococcus faecium strain isolated from luncheon meat whereas the presence of NaNO2 either alone or in addition to NaCl, had no significant effect on cell survival. Subsequent recovery and growth of heat‐damaged cells was retarded by the presence of NaCl. When NaNO2 was present in addition to NaCl the inhibitory effect of the latter was reduced. These principal components of the luncheon‐meat‐cure are apparently opposed in their activities on post‐heating recovery and growth of Strep. faecium. Product stability, i.e. duration of the lag before growth occurs, is directly related to the severity of the heat treatment and to the concentration of NaCl in the product. Therefore the resistance of pasteurized chub‐packed luncheon meat to streptococcal spoilage during storage at temperatures conducive to microbial growth results from a prolonged heat‐induced salt‐maintained pre‐growth adjustment phase rather than to any inherent inhibitory property of the luncheon meat to the growth of non‐heat‐damaged Strep. faecium cells.
Isolation, screening and characterization of thermophilic Bacillus species isolated from dairy products
Authors: Chopra A. K. , Mathur D. K.
Published: March 2008

Proteolytic thermophilic bacterial cultures (171 strains) were isolated from different milk and milk products. After screening these isolates for protease production in a liquid medium, fifty that exhibited enzyme activity in excess of 100 units/ml were selected and identified. Twenty‐nine were Bacillus stearothermophilus (constituting 58% of the total), twelve were B. coagulans, five were B. circulans and four were B. licheniformis. Skim milk powder contributed the maximum number of B. stearothermophilus (64.7%) followed by raw milk (63.2%) and pasteurized milk (44.4%). When the culture supernatant liquids from the selected isolates were given heat treatment, five cultures retained 100% protease activity at 65°C for 30 min. Protease of B. stearothermophilus RM‐67 had the maximum heat resistance because it retained 87.5% of its activity at 70°C for 30 min.
The adhesion of coagulase negative staphylococci to human skin and its relevance to the bacterial flora of milk
Authors: Brooker B.E. , Fuller R.
Published: March 2008

Twenty‐eight isolates of coagulase negative staphylococci were obtained from nipple swabs provided by one non‐lactating woman and five nursing mothers. All but two of these isolates were shown by scanning electron microscopy to adhere to the surface of human skin. Experiments with frozen sections of human skin confirmed and extended these results by showing that isolates exhibited one of three patterns of adhesion, suggesting that there are three different adhesion receptors on epidermal cells. It is proposed that adhesion of staphylococci to the nipple and areolar epidermis provides a mechanism whereby large numbers of bacteria, nourished by residues of milk and saliva, are maintained on the surface of the skin.
Herbicide effects on the population growth of some green algae and cyanobacteria
Authors: Maule A. , Wright S.J.L.
Published: March 2008

Six herbicides were tested for their effects on the population growth of a range of green algae and cyanobacteria by an easily replicated low‐volume liquid culture technique using Repli‐dishes. Diuron, propanil and atrazine were most inhibitory, chlorpropham was intermediate and MCPA and glyphosate were least inhibitory. Chlorpropham was more inhibitory to green algae than to cyanobacteria. The effects of chlorpropham and 3‐chloroaniline, a metabolite, on populations of the cyanobacteriumAnacystis nidulansand the algaChlamydomonas reinhardiiwere monitored in larger scale batch cultures. Both compounds reduced the growth rate although in some cases there was partial recovery. 3‐Chloroaniline was less inhibitory than the parent herbicide chlorpropham.
Immunochemical and biological studies of antigens isolated from a strain of Bacteroides fragilis
Authors: Meisel‐Mikołajczyk Felicja , Rokosz Alicja , Sawicka‐Grzelak Anna , Zuijderduijn J. , Beckmann Ilse , Paelinck Juliette
Published: March 2008

Phenol/water‐extracted lipopolysaccharide and a fraction HM, extracted with acetate buffer pH 2.0, from Bacteroides fragilis strain 62/73 are antigenically different as shown by immunodiffusion, passive haemagglutination, haemagglutination inhibition and preliminary chemical investigations. Biological activity, assessed with the local Shwartzmann reaction, was demonstrated for the lipopolysaccharide whereas antigen HM was almost inactive in this test. HM is immunogenic in rabbits. Antibodies against HM were detected in seven out of ten sera of healthy humans.
The effect of sodium sulphacetamide and sodium mandelate in brilliant green agar on the growth of salmonellas
Authors: Jones P.W. , Collins P. , Hayle A.J.
Published: March 2008

An assessment was made of the ability of 425 isolates of salmonellas, belonging to 54 serotypes, to grow on seven selective media. Several isolates of Salmonella dublin and Salm. paratyphi B failed to grow on brilliant green agar supplemented with sodium sulphacetamide and sodium mandelate. On this medium the colonies of 30 isolates which were able to grow were extremely small after 20 h incubation, and consequently their recognition was difficult. The sodium sulphacetamide was responsible for the reduction in colony size.
An improved enzyme‐linked immunoassay for the detection and quantification of the entomocidal parasporal crystal proteins of Bacillus thuringiensis subspp. kurstaki and israelensis
Authors: Wie Siong I. , Hammock B.D. , Gill Sarjeet S. , Grate Elizabeth , Jr. R.E. Andrews , Faust R.M. , Jr. L.A. Bulla , Schaefer C.H.
Published: March 2008

An improved and simplified enzyme‐linked immunosorbent assay (ELISA) was developed for the detection and quantification of parasporal crystalline toxins from Bacillus thuringiensis subsp. kurstaki. The improved procedure involved pretreatment of the polystyrene cuvettes with glutaraldehyde before antibody coating. A direct comparison of treated and untreated cuvettes is provided. ELISAs were then used for the analysis of the entomocidal crystalline proteins in commercial and experimental formulations of B. thuringiensis subspp. kurstaki and israelensis.
Mesophilic aerobic Gram negative cellulose degrading bacteria from aquatic habitats and soils
Authors: Mullings Rosanne , Parish J.H.
Published: March 2008

New procedures have been developed for the isolation and purification of aerobic and facultatively anaerobic bacteria able to utilize cellulose as sole source of carbon and energy. Wood pulp medium was used for enrichment, and bacterial cellulose, obtained from cultures of Acetobacter aceti subsp. xylinus, was employed as carbon substrate during purification and for the rapid screening of colonies for cellulolytic activity. The methods have revealed several new groups of Gram negative cellulose‐degrading bacteria, including organisms that form differentiated colonies superficially similar to myxobacterial sori. The organisms formed several phenetic clusters, three of which contained reference strains of Cellvibrio fulvus, Pseudomonas fluorescens var. cellulosa and Cytophaga hutchinsonii. No cellulose degrading cluster included non‐cellulose degrading strains. Most of the cellulose degraders studied were flagellated and, of these, the majority had polar or lophotrichous flagella, although one cluster included peritrichously flagellated organisms. The cellulose degraders in this study included five organisms that grew on nitrate‐free medium; these appeared in two different clusters. A few Gram positive isolates appeared to belong to the genera Streptomyces and Thermoactinomyces.
Colony morphogenesis in a group of cellulose degrading Gram negative rods from brackish habitats
Authors: Mullings Rosanne , Parish J.H.
Published: March 2008

Cellulose degrading bacteria were isolated from brackish Phragmites reed beds near the Humber Estuary. Of 23 strains brought into pure culture, all developed characteristic differentiated colonies on certain media. On the basis of colour of the colonies (pseudosori) the organisms could be allocated to two groups, XMo and XMb. Related strains were isolated from a similar habitat on the Dee Estuary. Numerical taxonomy showed the group to be relatively diverse but, with a single exception, the XMo and XMb organisms appeared in separate clusters. The organisms were weakly motile or non‐motile and certain cells had a polar flagellum. Pigments isolated from one strain had u.v. spectral characteristics similar to those of the xanthomonadins; the organisms may therefore be related to Xanthomonas.
Observations on the structure of kefir grains and the distribution of the microflora
Authors: Marshall Valerie M. , Cole Wendy M. , Brooker B.E.
Published: March 2008

The mixed flora of yeasts and lactobacilli of kefir is held together in non‐dispersible structures which build up into large grains. The fibrillar extracellular material of the matrix in which the microflora is embedded was stained by ruthenium red and periodic acid‐thiosemicarbazide silver proteinate, indicating that it was largely composed of carbohydrate. It is suggested that the carbohydrate is of bacterial origin and that this is produced by a population of lactobacilli which resides within the matrix and which separates non‐carbohydrate‐producing populations of lactobacilli and yeasts so that sheet‐like structures are formed which show asymmetry, with yeasts predominating on one side and lactobacilli on the other.
A microdilution method for drug sensitivity testing of fish associated bacteria at 22°C
Authors: Michel C. , Suprin Lucienne , de Kinkelin P.
Published: March 2008

When applied to the psychrophilic and psychrotropic bacteria associated with diseases of fish, the disc‐diffusion method generally fails to provide correct estimates of minimal inhibitory concentrations (MIC). A microdilution method using a medium containing agar (15 g/l) and 10 selected drugs has been developed. Serial four‐fold dilutions of the drugs were performed in specially designed dilution plates, which were prepared and stored at −30° or −70°C. Although its reliability sometimes appeared to be influenced by the temperature at the time of testing, the temperature and duration of freezing and the nature of the drugs, the microtest provided results as accurate as other reference methods. In repeated experiments very rare major discrepancies were noted and minor variations of one dilution step were below 10%, except with tetracyclines and the sulphonamide‐trimethoprim mixture. The advantages of the method and the optimum conditions for use in fish disease diagnosis are specified.
Psychrotrophic bacterial flora of raw ewes’milk, with particular reference to Gram negative rods
Authors: Nuñez J.A. , Chavarri F.J. , Nuñez M.
Published: March 2008

The microbial flora of 141 samples of raw ewes’milk was determined, before and after storage for 72 h at 4° and 7°C. Penicillin‐resistant bacteria represented ca 61% of 1760 psychrotrophic isolates from refrigerated milk samples. Pseudomonas fluorescens and Pseudomonas fluorescent group‐related strains predominated (ca 86%) in the Gram negative psychrotrophic microflora. Leuconostoc dextranicum was the most frequent Gram positive psychrotrophic species isolated.
Volatile compounds associated with the aerobic growth of some Pseudomonas species on beef
Authors: Dainty R. H. , Edwards R. A. , Hibbard C. M.
Published: March 2008

Five strains representing four clusters of meat spoilage pseudomonads were grown on sterile beef at 5°C. After 7 days incubation sensory assessments were made and the chemical composition of the headspace gases determined by gas chromatography‐mass spectrometry. There was good correlation between odour descriptions and chemical data for three of the strains. The most numerous types of product were esters and sulphur‐containing compounds. Of 45 compounds identified only 1‐undecene was common to all the tested strains.
Anaerobic ureolytic bacteria from caecal content and soft faeces of rabbit
Authors: Crociani Franca , Biavati B. , Castagnoli Paola , Matteuzzi D.
Published: March 2008

Forty strains of ureolytic bacteria were isolated from the caecal content and soft faeces of seven rabbits by the anaerobic roll tube method and were characterized. The isolates were identified with Clostridium coccoides, Cl. innocuum, Peptostreptococcus productus, P. micros, Peptococcus magnus, Fusobacterium russii and Fusobacterium sp. Urease activity of representative strains of the various species was also determined. The study indicated that strongly‐ureolytic anaerobic bacteria are present in the caecum of the rabbit.
Effect of various gas atmospheres on the growth and survival of Campylobacter jejuni on beef
Authors: Hänninen M.‐L. , Korkeala H. , Pakkala P.
Published: March 2008

Pieces of fresh beef were inoculated with three strains of Campylobacter jejuni. The meat was then allocated to three treatments: (a) vacuum packaged, (b) packaged in an atmosphere of 20% CO2+ 80% N2, and (c) packaged into sterile Petri dishes in anaerobic cultivation boxes, which were filled with a gas mixture of 5% O2+ 10% CO2+ 85% N2. The packaging material in the first two treatments was PA 80/PE 100–PE 100/PA 80/PE 100. The survival of Campylobacter cells was followed at 37°C, 20°C and 4°C for 48 h, 4 days and 25 days, respectively. At 37°C the counts of two Campylobacter strains increased in each package treatment for 48 h. At 20°C and at 4°C the counts of the same two strains decreased by 1 to 2 log units and 0.5 to 1 log unit, respectively, during storage. The survival of the two strains was about the same in all package treatments. The third strain was the most sensitive of the strains studied. At 37°C its numbers increased only in the optimal gas atmosphere; at 20°C the strain was not detectable after 24 to 48 h storage and at 4°C after 4 days storage. The aerobic plate counts were determined for all samples at the same time as Campylobacter counts. The high indigenous bacterial numbers of the meat samples did not appear to have a great effect on the survival or growth of campylobacters.
Soft rot Erwinia bacteria in surface and underground waters in southern Scotland and in Colorado, United States
Authors: McCarter‐Zorner Nancy J. , Franc G.D. , Harrison M.D. , Michaud Janet E. , Quinn C.E. , Sells I. Ann , Graham D.C.
Published: March 2008

An anaerobic liquid enrichment method followed by plating on a selective medium revealed that the soft rot coliform bacterium Erwinia carotovora subsp. carotovora was generally present in water from drains, ditches, streams, rivers and lakes (including reservoirs) in southern Scotland and in Colorado, United States, in mountainous, upland and arable areas through the year. Many sites were remote from susceptible or diseased crops. Erwinia carotovora subsp. atroseptica was isolated much less frequently and no Erwinia bacteria were isolated from underground waters. Erwinia bacteria were also found in rain‐water in Scotland, in winter snow from mountain passes in Colorado, and in sea water from the west and east coasts of Scotland and from the coasts of Oregon, California, Texas, Louisiana and Florida. The significance of the occurrence of these bacteria in water is discussed in relation to the control of blackleg and soft rot diseases of potato by production of Erwinia‐free stocks.
Detection of post‐pasteurization contamination of cream by impedimetric methods
Authors: Griffiths M.W. , Phillips J.D.
Published: March 2008

Impedimetric methods for evaluating post‐pasteurization contamination and shelf‐life of cream were assessed. Over 94% of the samples tested were in agreement, using selected cut‐offs of 20 h for detection time measured at 21°C with creams containing inhibitors for the growth of Gram positive bacteria on standard plate count agar as growth media, and 3.2 × 107 cfu/g for plate counts obtained on cream which had been pre‐incubated in the presence of inhibitors for the growth of Gram positive organisms, and on cream stored at 6°C for 7 d. Agreement between the impedimetric method and plate count was not as good if either Brain Heart Infusion or Milk Agar was used in place of Plate Count Agar in the former technique. A poor correlation was obtained between plate count methods for enumerating post‐pasteurization contamination and keeping quality with impedimetric measurements on cream alone. It was possible, with a reasonable degree of certainty, to determine if cream had suffered post‐pasteurization contamination within 20 h of production.
A note on catalase enhanced recovery of acid injured cells of Gram negative bacteria and its consequences for the assessment of the lethality of L‐lactic acid decontamination of raw meat surfaces
Authors: Van Netten P. , Van der Zee H. , Mossel D. A. A.
Published: March 2008

Addition of catalase (150 units/ml) to a rich infusion agar used for solid medium repair of acid injured pathogenic Enterobacteriaceae increased the recovery of such populations by 1–2 log cycles entailing an equal size reduction in the true lethality of this mode of processing for safety.
A note on the use of the non‐central t‐distribution in setting numerical microbiological specifications for foods
Authors: Malcolm S.
Published: March 2008

An exact procedure is described and used to determine k values and probabilities of rejection used in the application of variables sampling plans to foods. Comparison of quantities so obtained to those calculated by Kilsby et al. (1979), who used an approximation procedure, reveals that for small samples the approximation can lead to probabilities of rejection which are larger than those obtained using the exact procedure. It is recommended that the exact procedure be used in the application of these plans.
A note on the enzymic action and biosynthesis of a nitrile‐hydratase from a Brevibacterium sp.
Authors: Bui K. , Maestracci M. , Thiery A. , Arnaud A. , Galzy P.
Published: March 2008

The effect of different compounds on the enzymic action of the nitrile‐hydratase used for the bioconversion of nitriles was studied. An excess of acrylonitrile as a substrate was shown to inhibit the activity of the enzyme. This inhibition occurred only at relatively high substrate concentrations (0.2 mol/l or more). The nitrile bioconversion products (acrylamide, propionamide) and their structural analogues (acrylic acid, thioacetamide) were shown to inhibit the enzyme competitively. The most important inhibition found was that of cyanide (Ki= 0.004 mol/l), a break down product of some nitriles. By using an acetamidase‐negative mutant, amides were shown to inhibit biosynthesis of nitrile‐hydratase. An identical result was obtained with thioacetamide, a non‐substrate compound for acetamidase. This compound repressed the biosynthesis of nitrile‐hydratase by both the wild type and the acetamidase‐negative mutant to the same extent.
A note on the effect of combined ultrasonic and heat treatments on the survival of thermoduric streptococci
Authors: Ordoñez J.A. , Sanz B. , Hernandez P.E. , Lopez‐Lorenzo P.
Published: March 2008

Ordonez, J.A. Sanz, B. Hernandez, P.E. Lopez‐Lorenzo, P 1984, A note on the effect of combined ultrasonic and heat treatments on the survival of thermoduric streptococci. Journal of Applied Bacteriology, 56, 175–177.

The combined destructive effect of ultrasonic waves and heating on microorganisms has been investigated using as a model two species of thermoduric streptococci. Ultrasonic and heat treatments applied simultaneously were much more destructive than the additive effect of the two agents considered independently. Compared with heat alone, the simultaneous application of ultrasonic vibration and heat reduced the resistance of the organisms 6–11.fold.
Production and metabolism of lignans by the human faecal flora
Authors: BORRIELLO S.P. , SETCHELL K.D.R. , AXELSON M. , LAWSON A.M.
Published: March 2008

Lignans have, until recently, been found only in plants. Enterolactone and enterodiol are the major lignans present in the urine of humans and have a potential physiological protective role against cancer. It has been shown that these compounds can be formed in vitro by human faecal flora and that enterodiol is oxidized to enterolactone by bacteria that are present in stools at a concentration of up to 103/g. It was also possible to produce both of these lignans in vitro from linseeds and from secoisolariciresinol, a precursor present in linseed, by bacteria present in stools, at a concentration of between 103 and 104/g. Enterolactone was produced from matairesinol, a more abundant plant lignan than secoisolariciresinol, after incubation with a mixed faecal flora under both aerobic and anaerobic conditions. In each case conversion was dependent on the presence of viable bacteria. These findings indicate that a number of different pathways operate to produce enterolactone and enterodiol depending on the ingested dietary precursor.
Menaquinone composition of mycolic acid‐containing actinomycetes and some sporoactinomycetes
Authors: COLLINS M.D. , GOODFELLOW M. , MINNIKIN D.E. , ALDERSON G.
Published: March 2008

The menaquinones of 141 actinomycetes representing the genera Caseobacter, Mycohacterium, Nocardia, Rhodococcus and some related taxa lacking mycolic acids were examined by mass spectrometry. The mycolic acid‐containing strains were assigned to four groups on the basis of the predominant isoprenologue detected: (i) Rhodococcus coprophilus, R. equi, R. erythropolis, R. globerulus, R. rhodnii, R. rhodochrous and R. ruber contained dihydrogenated menaquinones with eight isoprene units; (ii) Nocardia asteroides, N. brasiliensis, N. carnea, N. otitidis‐caviarum and N. transvalensis contained tetrahydrogenated menaquinones with eight isoprene units; (iii) Caseobacter polymorphus, R. bronchialis, R. rubropertinctus and R. terrae and representatives of twenty‐one approved species of Mycobacterium contained dihydrogenated menaquinones with nine isoprene units; (iv) a single strain of ‘Mycobacterium album’, contained unsaturated menaquinones with nine isoprene units. Actinomycetes containing meso‐diaminopimelic acid, arabinose and galactose in the wall peptidoglycan but lacking mycolic acids were recovered in two groups: tetrahydrogenated menaquinones with eight isoprene units were the main components from ‘Nocardia’ autotrophica and Pseudonocardia thermophila whereas Saccharopolyapora hirsuta and Pseudonocardia spp. contained tetrahydrogenated menaquinones with nine isoprene units. Promicromonospora citrea and ‘skin coryneforms’ with LL‐diaminopimelic acid and glycine in the wall peptidoglycan also contained tetrahydrogenated menaquinones with nine isoprene units as the major isoprenologue. In contrast, representatives of the genera Kitasatoa, Microellobosporia, Streptomyces and Streptoverticillium were characterized by the presence of complex mixtures of tetra‐, hexa‐ and octa‐hydrogenated menaquinones with nine isoprene units. The menaquinone data correlate well with other developments in actino‐mycete systematics and confirm earlier suggestions that menaquinone analyses are of value in both the classification and identification of actinomycetes. Indeed, the data suggest that minimal descriptions of wall chemotype IV taxa should ideally include information on menaquinone composition.
An assessment of Bacteroides fragilis group organisms as indicators of human faecal pollution
Authors: ALLSOP K. , STICKLER D.J.
Published: March 2008

Membrane filtration techniques were used to enumerate Bacteroides fragilis group (BFG) organisms and Escherichia coli in a variety of natural waters, the influents and effluents from three types of sewage treatment plants and faeces of various animals. The results suggest that BFG organisms die off more rapidly than E. coli in water and that animal faeces are not a significant source of BFG. It is suggested that the ratio of BFG to E. coli in water may be used to indicate the proximity of a source of human faecal contamination.
The scope and limitations of four methods for the rapid identification of Enterobacteriaceae in foods
Authors: VILLAGARCIA N.
Published: March 2008

Four methods for the identification of Enterobacteriaceae in cooked frozen meat have been appraised. Although these methods could be modified to improve efficiency they could be clearly classified into two categories: (i) those that allow identification to genus level and which often cannot discriminate between two genera without the help of additional reactions; (ii) those that allow identification to species level and which only occasionally require additional reactions to differentiate one species from another. A different evaluation criterion was followed for each of these categories. In the first, as methods lead to final identification by means of data furnished by the manufacturer or via a number code which does not indicate probability, reactions were compared with those obtained by classical methods. In the second group, every number code admits three possibilities and indicates a probable biotype for each, thus reducing the risk of faulty interpretation on the part of the operator while also compensating for deficiencies of certain reactions. Evaluation was therefore based on the percentage of correctly identified cases per species. Efficiencies of the main biochemical reactions are also discussed.
A note onYersinia enterocoliticain a swine farm watershed
Authors: WALKER P.J. , GRIMES D.J.
Published: March 2008

Swine faeces from three pig farms in the La Crosse River watershed near La Crosse, Wisconsin, were sampled forYersinia enterocolitica; 19 presumptive isolates were recovered and biochemically confirmed asY. enterocolitica.Simultaneously, during a 2mD2 cm rainfall, the confluences of runoff water flowing from the swine holding pens and of nearby streams also were sampled; a single isolate was obtained from one holding pen runoff‐stream confluence. Biochemical analysis showed that the water isolate was a biotype identical with that of a swine isolate from the adjacent farm. These results demonstrate one possible mechanism for the introduction ofY. enterocoliticainto water supplies; faecal material from swine, a suspected natural reservoir of the bacterium, is transported via runoff water to streams.
The effect of pH on the selection of carbaryl‐degrading bacteria from garden soil
Authors: LARKIN M.J. , DAY M.J.
Published: March 2008

At an alkaline pH and in an aqueous solution carbaryl hydrolyses to form 1‐naphthol, methylamine and carbon dioxide, but it is much more stable at an acid pH. Soil perfusion column experiments indicated that the rate of carbaryl degradation at pH 6.0 to 7.0 was limited by the rate of chemical hydrolysis. Bacterial communities of at least 12 and 14 members were selected in continuous cultures using carbaryl as the sole carbon and nitrogen source at pH 6.0. These communities were supported by the slow formation of hydrolysis products and a carbaryl‐degrading bacterium was not selected after > 2000 h. A bacterial community of at least eight members was selected using equimolar 1‐naphthol and methylamine as its sole carbon and nitrogen source. In contrast, after a lag of between 10 and 50 days, soil perfusion column and continuous culture enrichments at pH 5.2 and 5.0, respectively, led to the selection of a Pseudomonas sp. which could utilize carbaryl as its sole carbon and nitrogen source.