bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of physical and microbiological factors on food container leakage
Authors: McEldowney S. , Fletcher M.
Published: March 2008

The effect of physical and microbiological factors on food container leakage was investigated in a container leakage model system (CLMS). The leakage of Acineto‐bacter calcoaceticus, Staphylococcus sp., Pseudomonas sp., Bacillus sp., a coryneform, Staph. aureus, and two biotest organisms (Enterobacter cloacae NC1B 8151 and Ent. aerogenes MB31) was studied. The rate of bacterial leakage (log10 cells/channel/s) was greater in the presence of a partial vacuum of 51–305 mm Hg than at atmospheric pressure. Fluid flow (ml) through leakage channels was increased by the application of vacuum. Leakage varied with vacuum, bacterial morphology, cell concentration, leakage channel size (0.78–120 μm2) and channel shape (straight or convoluted). The number of leaked cells was not proportional to vacuum or channel size. The effect of channel shape varied with bacterial species. Increased container medium viscosity decreased bacterial leakage. Fluid flow through leakage channels was generally reduced by the most viscous solution. Cells from biofilms and mono‐layers of Ac. calcoaceticus or Staph. aureus attached to nylon (Hyfax) or stainless steel surfaces underwent leakage. Mixed bacterial populations had characteristic leakage rates against vacuum different from the leakage pattern of individual species in the population. The composition of the leaked population was different from the original inoculum. The results indicated that container leakage is a complex process involving a range of interdependent factors.
Antigenic property of pediocin AcH produced by Pediococcus acidilactici H
Authors: Bhunia Arun K. , Johnson M.C. , Ray Bibek , Belden E.L.
Published: March 2008

Pediocin AcH, a bacteriocin of Pediococcus acidilactici H, inhibits the growth of several food spoilage and pathogenic bacteria. The antigenic property of partially purified pediocin AcH was tested by immunizing mice and a rabbit. Pediocin AcH was not immunogenic in these animals as determined by immunoblotting even after conjugation to bovine serum albumin. The non‐immunogenic nature of pediocin AcH, its non‐toxicity to laboratory animals and its hydrolysis by gastric proteolytic enzymes may be considered favourably in its possible use as a food preservative.
Preliminary development of a diagnostic test for Brucella using polymerase chain reaction
Authors: Fekete Andrea , Bantle J.A. , Halling Shirley M. , Sanborn M.R.
Published: March 2008

A highly sensitive and specific diagnostic test for Brucella based on polymerase chain reaction is under development in our laboratory. A commercially available PCR kit was used to create primers that allowed the amplification of a 635 bp fragment of a 43 kDa outer membrane protein gene from Brucella abortus strain 19. We successfully amplified the cloned gene present in the pMS64 plasmid and genomic Brucella S19 DNA. The amplified DNA was easily detected by agarose gel electrophoresis. Using both the pMS64 plasmid and Br. abortus S19 purified DNA as template each component of the PCR reaction was adjusted for the optimum amplification of the DNA sequence. Optimum specific amplification resulted when the primer annealing temperature was 60d̀C. The gene fragment was amplifiable in 25 different Brucella species and strains. To test the specificity of the reaction, DNA extracted from 17 micro‐organisms possibly associated with cattle were tested. No amplification was observed. The sensitivity of the reaction was determined with different concentrations of genomic Brucella strain 19 DNA. As little as 0.1 pg DNA (less than 100 brucella cells) could be detected. The specificity and sensitivity of PCR combined with its simplicity and speed suggests the potential of this technique for routine diagnosis of brucellosis.
Sporicidal action of alkaline glutaraldehyde: factors influencing activity and a comparison with other aldehydes
Authors: Power E.G.M. , Russell A.D.
Published: March 2008

The sporicidal efficacy of glutaraldehyde (2% w/v) was investigated under various conditions. Numerous factors influenced its activity: method of spore production, inherent spore resistance characteristics, alkalination, storage time and storage temperature. The sporicidal action of 2% alkaline glutaraldehyde at room temperature was compared with that of other aldehydes and commercially available formulations. Cidex (glutaraldehyde) and Sporicidin (glutaraldehyde + phenol full strength) were the most effective, followed by 8% (w/v) formaldehyde and 10% (v/v) Gigasept, a formaldehyde‐containing product. Five per cent (v/v) Gigasept and 10% (w/v) glyoxal also had good sporicidal activity, though that of Sporicidin (1 : 16) was poor. No activity was observed with 10% (w/v) butyraldehyde.
Lactobacilli isolated from sugary kefir grains capable of polysaccharide production and minicell formation
Authors: Pidoux M. , Marshall Valerie M. , Zanoni P. , Brooker B.
Published: March 2008

Homo‐ and heterofermentative species of Lactobacillus have been isolated from sugary kefir grains. Most of the homofermentative strains fermented tagatose and aldonitol and presented 48–54% of homology with Lactobacillus paracasei ssp. paracasei NCDO 151 (ex Lactobacillus casei). The two variants of a heterofermentative species, although fermenting arabinose, were related to Lactobacillus hilgardii NCDO 264 (type strain) with 88% of homology. One of them produced polysaccharide from sucrose at pH 4–8 and 30°C; the best glucose conversion into polysaccharide was obtained from 3% of sucrose (81–8%), and the maximum production occurred about 35 hours after the end of the log phase of growth, in MRS sucrose broth. Polysaccharide formation did not occur above 40°C, a temperature at which no growth was observed. The two variants were forming minicells by abnormal divisions.
Microbiology of ‘obiolor’: a Nigerian fermented non‐alcoholic beverage
Authors: Achi O.K.
Published: March 2008

Obiolor is an acidic non‐alcoholic beverage prepared by fermenting sorghum and millet malts. The traditional process for the production and microbiological characteristics of the beverage were investigated. Bacillus spp., Lactobacillus plantarum and Streptococcus lactis were the associated micro‐organisms most actively involved. Yeasts were present in low numbers towards the end of the fermentation. Other micro‐organisms isolated did not appear to play a role in the fermentation process. Variations in the important microbial groups involved and their metabolic products were studied. Titratable acidity increased gradually until the end of the fermentation while the total soluble solids and pH declined. Acetobacter spp. were probably responsible for the unacceptability of the product after 24 h.
Heat shock protein synthesis and thermotolerance in Salmonella typhimurium
Authors: Mackey B.M. , Derrick Christine
Published: March 2008

The resistance of stationary phase Salmonella typhimurium to heating at 55°C was greater in cells grown in nutritionally rich than in minimal media, but in all media tested resistance was enhanced by exposing cells to a primary heat shock at 48°C. Chloramphenicol reduced the acquisition of thermotolerance in all media but did not completely prevent it in any.

The onset of thermotolerance was accompanied by increased synthesis of major heat shock proteins of molecular weight about 83, 72, 64 and 25 kDa. When cells were shifted from 48°C to 37°C, however, thermotolerance was rapidly lost with no corresponding decrease in the levels of these proteins. There is thus no direct relationship between thermotolerance and the cellular content of the major heat shock proteins. One minor protein of molecular weight about 34 kDa disappeared rapidly following a temperature down‐shift. Its presence in the cell was thus correlated with the thermotolerant state.
Study of haemolytic activity of some Campylobacter spp. on blood agar plates
Authors: Arimi S.M. , Park R.W.A. , Fricker C.R.
Published: March 2008

A total of 152 strains of Campylobacter jejuni, C. coli, C. laridis and C. fetus subsp. fetus were tested for haemolysis on blood agar plates. Distinct haemolysis was detected in 92.% (96/104) of strains of C. jejuni and 21.7% (5/23) of strains of C. coli on sheep blood heart infusion agar after incubation for 4 d microacrobically at 42°C. Haemolysis was also detected on horse blood heart infusion agar. Haemolysis was not detected at 37°C except with one of 50 strains of C. jejuni tested at this temperature, which was weakly positive. Campylobacter laridis was not haemolytic; C. fetus subsp. fetus, which does not grow at 42°C, showed no haemolysis at 37°C. Blood agar (Oxoid, BA Base No. 2) was not suitable for testing for haemolysis by these organisms. A microaerobic gas mixture containing hydrogen is better than that containing nitrogen because the medium has a brighter colour, making haemolysis casier to detect. There was no synergistic haemolysis with Staphylococcus aureus or Streptococcus agalactiae. The plate haemolysis test as described here may aid differentiation within the thermophilic campylobacters.
Purification and properties of three types of xylanases produced by an alkalophilic actinomycete
Authors: Tsujibo H. , Sakamoto T. , Nishino N. , Hasegawa T. , Inamori Y.
Published: March 2008

Three types of xylanases (l,4‐β‐D‐xylan xylanohydrolase, EC 3.2.1.8) were isolated from the culture filtrate of an alkalophilic actinornycete, Nocardiopsis dassonvillei subsp. alba OPC‐18. The enzymes (X‐I, X‐II and X‐III) were purified by acetone precipitation, chromatographies of DEAE‐cellulofine A‐800, Sephadex G‐75 and preparative isoelectric focusing. The purified enzymes showed single bands on sodium dodecyl sulphate polyacrylamide gel electrophoresis. The molecular weights of X‐I, X‐II and X‐III were 23000, 23000 and 37000, respectively. The pIs were 4.9 (X‐I), 5.3 (X‐II) and 4.1 (X‐III). The optimum pH levels for the activity of X‐I and X‐II were pH 7.0. X‐III was also most active at pH 7.0, but 62.5% of the activity remained even at pH 11. The optimum temperatures for the activities of X‐I and X‐II were 60°C and that of X‐III was 50°C. X‐I and X‐II were stable in the range of pH 6–10, and X‐III was stable in the range of pH 8–12 until 40°C for 30 min.
The effect of terrestrial effluents on the incidence of Aeromonas spp. in coastal waters
Authors: Araujo Rosa M. , Pares R. , Lucena F.
Published: March 2008

The numbers of Aeromonas species were monitored for one year at 18 stations on the Barcelona coast. Their concentrations exceed those of faecal coliforms and faecal streptococci in all samples, both on the shoreline and at 500 m from the coast. The mean values of the three bacterial counts reflected the proximity of the terrestrial effluents. There was a positive correlation between aeromonads and faecal indicators on the shoreline but not at 500 m offshore. This reflected their common origin and different survival rates in seawater. When sterile sea water was inoculated with A. hydrophila ATCC 7966, the numbers decreased initially by three orders of magnitude before they began to multiply. The final count was related to the concentration of organic matter in the water.
The combined effect of incubation temperature, pH and sorbic acid on the probability of growth of non‐proteolytic, type B Clostridium botulinum
Authors: Lund Barbara M. , Graham Ann F. , George Susan M. , Brown D.
Published: March 2008

Lund, B.M., Graham, A.F., George, S.M. & Brown, D. 1990. The combined effect of incubation temperature, pH and sorbic acid on the probability of growth of non‐proteolytic, type B Clostridium botulinum. Journal of Applied Bacteriology69, 481–492.

It has been reported that non‐proteolytic strains of Clostridium botulinum will grow at 3.3°C, and they are therefore of concern in relation to certain chilled foods. The effects of combinations of inhibitory factors may be used to reduce the risk of growth of these bacteria in foods. The combined effect of pH values between 4.8 and 7.0, temperatures between 6° and 30°C, and sorbic acid concentrations up to 2270 mg/1 on the probability of growth from a single spore of non‐proteolytic, type B strains in a culture medium has been determined. A mathematical model has been developed that enables the effect of varying combinations of these factors on the probability of growth of non‐proteolytic, type B Cl. botulinum to be predicted.
Growth inhibition of selected food‐borne bacteria, particularly Listeria monocytogenes, by plant extracts
Authors: Chung King‐Thom , Thomasson W.R. , Wu‐Yuan Christine D.
Published: March 2008

Chung, K.‐T., Thomasson, W.R. & Wu‐Yuan, C.D. 1990. Growth inhibition of selected food‐borne bacteria, particularly Listeria monocytogenes, by plant extracts. Journal of Applied Bacteriology69, 498–503.

Six extracts from Chinese medicinal plants: Tin Men Chu, Sey Lau Pai, Siu Mao Heung, Bak Tao Yung, Kam Chin Chiu and Liao Ya, were tested for their inhibitory effect on selected food‐borne bacteria by the well assay technique. Among them, Tin Men Chu, Siu Mao Heung and Sey Lau Pai inhibited the growth of Staphylococcus aureus, Klebsiella pneumonia, Escherichia coli, Shigella flexneri, Streptococcus faecalis, Salmonella paratyphi, Salm. enteritidis, Enterobacter aero‐genes, Pseudomonas fluorescens, Proteus vulgaris, Alcaligenes faecalis, and three strains of Listeria monocytogenes. Two of these three extracts, Tin Men Chu and Siu Mao Heung, suppressed the growth of L. monocytogenes Scott A in cabbage juice. This inhibition was prevented by the addition of protein but not sodium chloride. Plant extracts show potential to control the growth of food‐borne bacteria.
A proposal for using previous experience in designing microbiological sampling plans based on variables
Authors: Smelt J.P.P.M. , Quadt J.F.A.
Published: March 2008

Smelt, J.P.P.M. & Quadt, J.F.A. 1990. A proposal for using previous experience in designing microbiological sampling plans based on variables. Journal of Applied Bacteriology69, 504–511.

A microbiological sampling system on the basis of variables is presented which requires only small numbers of replicates (n≥ 2). The system uses previous data on standard deviations of numbers of micro‐organisms in batches and is particularly useful for in‐plant situations. The discriminating power of the system is comparable to that of the current International Committee on Microbiological Specifications for Foods sampling schemes but uses more replicates.
The automatic maintenance of low dissolved oxygen using a photobacterial oxygen sensor for the study of microaerobiosis
Authors: Kavanagh E. , Hill S.
Published: March 2008

Kavanagh, E. & Hill, S. 1990. The automatic maintenance of low dissolved oxygen using a photobacterial oxygen sensor for the study of microaerobiosis. Journal of Applied Bacteriology69, 539–549.

Conventional galvanic and polarographic oxygen electrodes are not sensitive enough to investigate microaerobic phenomena such as nitrogen fixation. Two sensors are available for this application. They are the oxygen‐dependent changes in either the absorption spectrum of leghaemoglobin, or the light emission by photo‐bacteria. We have coupled the latter to the automatic feedback control of agitation for the maintenance of predetermined low dissolved oxygen concentrations (DOCs) in bacterial suspensions. This method is inexpensive, provides accurate control of DOC, and the photobacterium is easily propagated. We have used this equipment to determine the optimum DOC for microaerobic nitrogenase activity in the facultative anaerobe Klebsiella pneumoniae.
Barrier properties of the Gram‐negative cell envelope towards high molecular weight polyhexamethylene biguanides
Authors: Gilbert P. , Pemberton D. , Wilkinson Diane E.
Published: March 2008

Gilbert, P., Pemberton, D. & Wilkinson, D.E. 1990. Barrier properties of the Gram‐negative cell envelope towards high molecular weight polyhexamethylene biguanides. Journal of Applied Bacteriology69, 585–592.

The antimicrobial activities of four discrete molecular weight fractions of polyhexamethylene biguanides towards a number of Escherichia coli strains have been investigated. Whilst activity of the polymers was observed to increase in proportion to polymerization number, the dependence of activity upon molecular weight was five times greater towards sphaeroplasts than towards whole cells. This suggested that the cell envelope, whilst not conferrring complete resistance to the agents, did provide a significant exclusion barrier. Comparison of the activities towards rough and deep‐rough lipopolysaccharide strains showed growth inhibitory activity, but not bactericidal activity nor respiratory inhibition, to be enhanced in the rough strains. Uptake studies showed mixed H‐ and C‐type adsorption with significantly greater numbers of high‐affinity binding sites being associated with rough than deep‐rough lipopolysaccharide. The binding affinity of polyhexamethylene biguanides towards cells was also enhanced in the rough strains. Binding affinity was, in all cases, significantly reduced in the presence of magnesium and suggested a mechanism of self‐promoted uptake for these biocides, facilitated through core lipopolysaccharide.
Changes in microbial populations during anaerobic flax retting
Authors: Donaghy J.A. , Levett P.N. , Haylock R.W.
Published: March 2008

Donaghy, J.A., Levett, P.N. & Haylock, R.W. 1990. Changes in microbial populations during anaerobic flax retting. Journal of Applied Bacteriology69, 634–641.

The bacterial flora of industrial and laboratory scale anaerobic flax rets were determined at intervals throughout the rets. Although after an initial lag period total bacterial numbers remained roughly constant there were fluctuations in the bacterial species constituting the total. Pure culture rets and enzyme assays were used to determine which strains had retting potential. Of the strains demonstrated to have retting ability Bacillus licheniformis and B. subtilis were numerically dominant from 10 to 40 h and were succeeded in dominance by Clostridium acetobutylicum and Cl. felsineum.
Ethanol tolerance, sugar tolerance and invertase activities of some yeast strains isolated from steep water of fermenting cassava tubers
Authors: Ekunsanmi T. J. , Odunfa S. A.
Published: March 2008

Ekunsanmi, T.J. & Odunfa, S.A. 1990. Ethanol tolerance, sugar tolerance and invertase activities of some yeast strains isolated from steep water of fermenting cassava tubers. Journal of Applied Bacteriology69, 672–675.

Thirteen yeasts isolated from the steep water of fermenting cassava tubers were screened for ethanol tolerance. Three strains which showed measurable growth in medium containing 10% (v/v) ethanol were also sugar‐tolerant and grew well in medium containing 25% (w/v) glucose. One of the strains, YC3, was found to possess much higher invertase activity than the other two and could be of value in ethanol production from molasses. Further search for industrially useful yeasts in African fermented foods is suggested.
A comparison of the sterol content of multiple isolates of the Candida albicans Darlington strain with other clinically azole‐sensitive and ‐resistant strains
Authors: Howell S.A. , Mallet A.I. , Noble W.C.
Published: March 2008

Howell, S.A., Mallet, A.I. & Noble, W.C. 1990. A comparison of the sterol content of multiple isolates of the Candida albicans Darlington strain with other clinically azole‐sensitive and ‐resistant strains. Journal of Applied Bacteriology69, 692–696.

The mechanism of azole resistance of Candida albicans NCPF 3310 (the deposited culture of the Darlington strain) has been investigated but never fully explained. Seven isolates of this strain, from various sources, were examined by gas chromatography‐mass spectrometry to detect changes in the sterol composition following passage through many laboratories over several years. Five of the seven, including one recently isolated from the patient, were found to be similar to each other in sterol content, containing large amounts of fecosterol. Of the remaining two, one was thought to be a sensitive variant, both produced only small quantities of fecosterol and resembled the normal clinical strains and other azole‐resistant strains in sterol content. The sterol composition of the Darlington strain was unique and apparently stable to prolonged in vitro experimentation and passage through the patient.
Wool‐colonizing micro‐organisms capable of utilizing wool‐lipids and fatty acids as sole sources of carbon and energy
Authors: Musallam Azza A. Al , Radwan S.S.
Published: March 2008

Al Musallam, A.A. & Radwan, S.S. 1990. Wool‐colonizing micro‐organisms capable of utilizing wool‐lipids and fatty acids as sole sources of carbon and energy. Journal of Applied Bacteriology69, 806–813.

Two keratinolytic fungi, Chrysosporium keratinophilum and Malbranchea anamorph of Uncinocarpus reesii, and another three wool‐colonizing fungi not previously reported to be keratinolytic, Aspergillus fumigatus, A. flavus and Scopulariopsis Candida, were isolated from soil samples baited with animal wool. These fungi were tested for their ability to utilize wool‐lipids as sole source of carbon and energy. The lipid contents of wool of various animals ranged between 2 and 5%. The different lipid extracts were similar in composition; they contained steryl esters, sterols, fatty acids, fatty alcohols and monoacylglycerols. The predominant acyl moiety in wool‐lipids of different animals was linolenic acid (18:2). The five fungi tested grew well on an inorganic medium supplemented with total wool‐lipids as sole sources of carbon and energy. Individual lipid classes fractionated by preparative thin layer chromatography and suspended into inorganic medium were able to support fungal growth as sole carbon sources. These fungi and another eight wool‐colonizing strains. C. tropicum, C. zonatum, C. anamorph of Arthroderma curryei, Microsporum cams, M. distortum, Trichophyton interdigitale, Emmonsia parva and Myceliophthora vellerae could also utilize standard lipids and fatty acids (cholesterol and palmitic and linoleic acids)‐ Evidence for the uptake and degradation of chloesterol by C. keratmophilum is presented.
Growth and nitrogenase activity of Azotobacter vinelandii on soil phenolic acids
Authors: Moreno J. , Rubia T. de la , Ramos‐Cormenzana A. , Vela G.R.
Published: March 2008

Moreno, J., de la Rubia, T., Ramos‐Cormenzana, A. & Vela, G.R. 1990. Growth and nitrogenase activity of Azotobacter vinelandii on soil phenolic acids. Journal of Applied Bacteriology69, 850–855.

Growth and nitrogenase activity (acetylene reduction) of Azotobacter vinelandii were studied in soil suspensions supplemented with p‐hydroxybenzoic, vanillic, p‐coumaric and ferulic acids. Nitrogenase activity was detected only when the microorganism was cultured on p‐hydroxybenzoic acid, suggesting that this compound could be utilized as a carbon source by A. vinelandii for the maintenance of its biological activities under certain environmental conditions.
Heterotrophic plate counts and the isolation of bacteria from mineral waters on selective and enrichment media
Authors: Manaia Célia M. , Nunes Olga C. , Morais Paula V. , Costa M.S. Da
Published: March 2008

Manaia, C.M., Nunes, O.C., Morais, P.V. & da Costa, M.S. 1990. Heterotrophic plate counts and the isolation of bacteria from mineral waters on selective and enrichment media. Journal of Applied Bacteriology69, 871–876.

The heterotrophic plate counts of 15 brands of bottled non‐carbonated mineral waters were examined and found to be generally high and variable. Four selective or enrichment media for the enumeration of coliforms (m‐Endo LES and m‐lauryl sulphate agar) and Pseudomonas aeruginosa (cetrimide‐nalidixic acid agar and malachite green broth) were used to isolate several species of Gram‐negative bacteria. Strains identified as CDC gr IVc‐2 and Comamonas (Ps.) acidovorans were the two most commonly isolated. Considerable variation in populations was seen between the brands, as well as between two batches of the same mineral water.
Isolation and propagation of phages naturally associated with the aizawai variety of Bacillus thuringiensis
Authors: Inal J.R.M. , Karunakaran V. , Burges H.D.
Published: March 2008

This study describes the isolation of a phage, using mitomycin C and u.v. light, from each of four strains (HD67, HD130, HD228 and HD248) of Bacillus thuringiensis H‐serotype 7 (var. aizawai). It also describes the isolation of two indicator strains (12.13 and HD 102) for these phages (φHD67, φHD130, φHD228 and φHD248) and the ideal conditions, using these indicator strains, for maximum phage production.
Numerical taxonomy of Micrococcaceae isolated from Spanish sheep's milk cheeses
Authors: García M.C. , Otero A. , García M.L. , Sierra M. , Moreno B.
Published: March 2008

Fifty‐three strains of Micrococcaceae isolated from Spanish sheep's milk cheeses were subjected to numerical analysis using 43 unit characters. At the 80% similarity level (SSM) nine clusters (49 strains) were observed. At the 53% similarity level (SJ) nine clusters were also found. Cluster composition was not markedly affected by the coefficient used. Novobiocin‐resistant, coagulase‐negative staphylococci formed clusters of closely related species. However, novobiocin‐sensitive, coagulase‐negative strains fell into heterogeneous groups. The test that best separated the nine groups formed with both coefficients (SSM and SJ) was urease production. Aesculin hydrolysis, haemolytic activity (SSM), oxidation of mannose and phosphatase production were also useful characters.
Association of bacteria with the fungal fermentation of soybean tempe
Authors: Mulyowidarso R.K. , Fleet G.H. , Buckle K.A.
Published: March 2008

Bacteria grew to viable populations of 108–109 cfu/g during the fermentation of soybeans into tempe with the fungus, Rhizopus oligosporus. Bacillus pumilus and B. brevis were the predominant bacterial species, reaching populations of approximately 108 cfu/g during the 48 h fermentation. Species of Streptococcus faecium, Lactobacillus casei, Klebsiella pneumoniae and Enterobacter cloacae also contributed to the fermentation and achieved populations of 106–107 cfu/g. and accepted 25 May 1989
Development of an expert system for bacterial identification: study of a prototype for identifying β‐galactosidase positive enterobacteria
Authors: Gavini F. , Lefebvre B. , Hamze M. , Izard D.
Published: March 2008

A prototype of an expert system for the identification of β‐galactosidase positive Enterobacteriaceae has been developed, for use with the API 20 EC kit. The system is implemented in Prolog on an IBM PC AT with 640 K of central memory and 20 megabytes of secondary memory. Its objectives are to highlight errors that can occur when the kit is in use. It can indicate the presence of new groups or species and give advice or suggest additional tests for the differentiation of the new species from those included in the kit.
Changes in bacterial populations during red tides caused by Mesodinium rubrum and Gymnodinium catenatum in North West Coast of Spain
Authors: Romalde J.L. , Toranzo Alicia E. , Barja J.L.
Published: March 2008

Heterotrophic bacterial communities associated with four red tides caused by Mesodinium rubrum and Gymnodinium catenatum in two Galician Rias (North West Spain) were examined. Three of these were produced by the Mesodinium rubrum and the causative organism of a toxic bloom was Gymnodinium catenatum. In early stages of all the blooms, the diversity decreased but the total marine bacterial counts increased by one or two logs. Vibrio numbers were also incremented by two logs in two blooms of M. rubrum, while in the other bloom of this organism and in the red tide caused by G. catenatum a decrease in number of these bacteria was observed. A total of 116 bacterial strains were identified at the genus level and grouped into 12 phena. During the decomposition processes of two blooms of M. rubrum a zooplanktonic‐type bacterial succession was observed (Vibrio, pseudomonads and Moraxella‐Acinetobacter). On the other hand, during decomposition of the other red tide of M. rubrum and the bloom of G. catenatum, a typical phytoplanktonic‐type succession occurred, as Pseudomonas and Moraxella groups became dominant for all the process. These results support the conflicting taxonomical position of M. rubrum. After the blooms, the changes in the community point towards the restablishment of the normal bacterial flora of the estuary (increase in diversity and decreases of bacterial numbers). Only the Vibrio strains, isolated from the non‐toxic first and second red tides, displayed cytotoxic activities. A relationship among bacterial cytotoxicity and toxic effects of blooms cannot therefore be established.
Malolactic fermentation in Chardonnay: growth and sensory effects of commercial strains of Leuconostoc oenos
Authors: Rodriguez Susan B. , Amberg E. , Thornton R.J. , McLellan M.R.
Published: March 2008

Samples of fermenting Chardonnay juice were inoculated with five commercial cultures of Leuconostoc oenos to promote malolactic fermentation. Controls were not inoculated with malolactic starter cultures; one was held under the same conditions as the juice inoculated with malolactic starter cultures and the other was held under conditions in which malolactic fermentation was inhibited. Bacterial growth and chemical composition of the wines were monitored for eight weeks after the wines were inoculated with the yeast starter culture. The five strains of L. oenos differed in growth kinetics and rates of malic acid degradation. Significant differences were detected among the finished wines subjected to sensory evaluation.
Growth of Listeria monocytogenes at refrigeration temperatures
Authors: Walker S.J. , Archer P. , Banks J.G.
Published: March 2008

The growth of three strains of Listeria monocytogenes at refrigeration temperatures (‐0.5 to 9.3°C) in chicken broth and/or UHT milk was determined using a rocking temperature gradient incubator. Minimum growth temperatures ranged from ‐0.1 to ‐0.4°C for the three strains. Lag times of 1–3 d and 3 to >34 d were observed with incubation at 5 and 0°C respectively. Corresponding generation times ranged from 13–24 h at 5°C and 62–131 h at 0°C. The type of culture medium had an influence on both the rate and extent of growth. Incubation of cultures at 4°C before inoculation caused a marked reduction in the lag time when compared with cultures which had been previously incubated at 30°C.
Fermentation of cassava peels for the production of cellulolytic enzymes
Authors: Ofuya C.O. , Nwajiuba C.J.
Published: March 2008

Cassava peels were used as a substrate for the production of cellulolytic enzymes. Under solid substrate fermentation conditions and a Rhizopus sp., thermostable cellulolytic enzymes were produced. Optimal production temperature and pH were 45°C and 5.6 respectively. Kinetic studies of the enzymes showed that the cellulase C1 activity was optimal at pH 5.0 and 50°C, whereas that of cellulase Cx was optimal at pH 7.0 and 60°C. The enzymes degraded ca 44% of sorghum grains in 6 h, thus suggesting a possible use in saccharification processes. The results also showed the possibility of re‐cycling cassava peels as a cheap substrate for the enzyme industry. and accepted 6 June 1989
Electronic particle counting for evaluating the quality of air in operating theatres: a potential basis for standards?
Authors: Seal D.V. , Clark R.P.
Published: March 2008

Airborne particle counting in eight size ranges (0.5 → 20 μm), by computerized electronic equipment, was compared with the numbers of bacteria‐carrying particles (BCP) assessed by slit sampling in ultra‐clean and turbulently ventilated operating theatres. In the ultra‐clean theatre the number of particles of 5–7 μm size range correlated with BCP while peaks in the numbers of particles <3 μm and > 15 μm corresponded with activity. Comparative relationships also occurred in the turbulently ventilated theatre but the use of this equipment in that environment cannot yet replace counts of airborne bacteria. We consider that electronic particle counting in the 0–20 μm size range may be used to judge the performance of a clean air operating theatre distribution system, including efficiency and integrity of the filter/seal systems and the presence or absence of entrainment of bacteria and other particles. The sampling techniques and analysis of particle concentration results described here may be a suitable basis for standards.
Serogroups of potato pathogenic Erwinia carotovora strains: identification by lipopolysaccharide electrophoretic patterns
Authors: Murray J. , Fixter L.M. , Hamilton I.D. , Perombelon M.C.M. , Quinn C.E. , Graham D.C.
Published: March 2008

Lipopolysaccharides were purified from 51 strains of Erwinia carotovora subsp. carotovora, atroseptica and betavasculorum representing 12 different serogroups. Analysis of the lipopolysaccharides by SDS‐PAGE showed that, irrespective of the strain or serogroup from which they were extracted, the lipopolysaccharides were composed of up to 30 components. The mobility of the components decreased in a regular fashion giving a ladder‐like appearance on the gel. The relative mobilities of components of lipopolysaccharide from each serogroup was constant so that each serogroup gave an easily identifiable ladder profile. The potato pathogenic serogroups I, XVIII, XX and XXII were examined in detail. Of 20 strains received as serogroup I, 18 gave a pattern identical to an authentic serogroup I strain. The two strains which did not give the same pattern were shown by immunological tests not to be serogroup I. Five atroseptica strains of serogroup XXII gave a distinct pattern characteristic of the serogroup while atroseptica strains of serogroups XVIII (four strains) and XX (five strains) gave patterns that could not be distinguished from each other. Analysis of lipopolysaccharides by SDS‐PAGE has been shown to be an alternative to immunological tests to identify serogroups of Erwinia carotovora associated with blackleg. It is also capable of differentiating these serogroups from erwinia serogroups not normally regarded as causing blackleg. The analysis has the advantage that, irrespective of serogroup, a positive result is always obtained.
The survival and transfer of microbial contamination via cloths, hands and utensils
Authors: Scott Elizabeth , Bloomfield Sally F.
Published: March 2008

Survival and transfer of bacteria from laminated surfaces and cleaning cloths were investigated under laboratory conditions. Drying produced substantial reductions in numbers of recoverable organisms and achieved satisfactory decontamination of clean laminate surfaces. On soiled surfaces and on clean and soiled cloths, Gram‐positive and some Gram‐negative species survived for up to 4 h, and in some cases up to 24 h. Where contaminated surfaces or cloths came into contact with the fingers, a stainless steel bowl, or a clean laminate surface, organisms were transferred in sufficient numbers to represent a potential hazard if in contact with food.
Survival of genetically engineered Escherichia coli in natural soil and river water
Authors: Chao W.L. , Feng R.L.
Published: March 2008

Twelve derivatives of Escherichia coli strain HB101 which contained different sizes of plasmids ranging from 3.9 Kb to 48 Kb and encoding resistance to various antibiotics were used. When these organisms were introduced into natural river water, the population declined rapidly and by day 3, the majority (i.e. more than 99.9%) of them could no longer be detected on antibiotic‐amended culture plates. If the river water was filter sterilized first, the added organisms maintained their population for up to 7 d without any significant decrease in numbers. Similar results were also observed in sterilized tap water or distilled water. This indicated that the disappearance of these organisms in the aquatic environment was caused mainly by biotic factor(s). The loss of the ability to grow in the presence of antibiotics by some of the E. coli was not observed unless they were allowed to grow in the antibiotic‐free environment first. When the test organisms were added to natural silt loam, a large portion of the original population still remained viable after 16 d. There was no relationship between the percentage survival of E. coli in natural river water and the sizes of plasmid harboured. On the other hand, when these bacteria were added to natural soil, survival appeared to increase as plasmid size increased. and accepted 19 August 1989
Studies on the earthy‐musty odours in natural water (IV). Mechanism of earthy‐musty odour production of actinomycetes
Authors: Aoyama K.
Published: March 2008

Many reservoirs for water supply have been troubled with earthy‐musty odour compounds—2‐methylisoborneol (2‐MIB) and geosmin. Both of these compounds are terpenoid and related to the metabolite of l‐methionine. An experiment using [CD3]methionine and [14CH3]methionine showed that the C‐2 methyl group in 2‐MIB originate from l‐methionine. In the incubation experiment with 10–1000 mg/l of l‐methionine, 2‐MIB and geosmin appeared in the earlier stages, in greater amounts than in the control. The maximum production of 2‐MIB and geosmin increased considerably in the experiments with 10 and 100 mg/l of l‐methionine. The effective time for l‐methionine addition was after 1 d. Additions after 3 and 5 d were similar to the control. In the incubation experiment with 10–1000 mg/l of folic acid, 2‐MIB and geosmin increased only during the 1000 mg/l addition. There seems to be little doubt that l‐methionine takes part in the metabolism of 2‐MIB and geosmin.
Molecular taxonomic studies on Streptococcus uberis types I and II. Description of Streptococcus parauberis sp. nov.
Authors: Williams Annette M. , Collins M.D.
Published: March 2008

The nucleotide sequences of 16S ribosomal‐RNA of Streptococcus uberis types I and II were determined by reverse transcriptase. Comparative analysis of the sequence data showed that the two types are phylogenetically distinct and worthy of separate species status. A new species Streptococcus parauberis is proposed for the type II strains. The type strain of Strep. parauberis is NCDO 2020. and accepted 24 August 1989
Survival of Legionella pneumophila within cysts of Acanthamoeba polyphaga following chlorine exposure
Authors: Kilvington S. , Price Jackie
Published: March 2008

The association between Legionella pneumophila and the free‐living amoeba Acanthamoeba polyphaga was studied. Intracellular growth of L. pneumophila within amoebic trophozoite was confirmed by kinetic growth experiments, light and electron microscopy. Cysts produced from infected trophozoites were found to protect the legionellas from at least 50 mg/l free chlorine. The ability of L. pneumophila to survive within the cysts of A. polyphaga is suggested as a possible mechanism by which the organism evades disinfection and spreads to colonize new environments.
Differentiation of Erwinia carotovora subsp. carotovora and Erwinia carotovora subsp. atroseptica isolated from potato by Western blot and subsequent indirect ELISA
Authors: Alarcon B. , Lopez M. M. , Cambra M. , Gorris M. T. , Guerri J.
Published: March 2008

Electrotransfer of protein bands from a polyacrylamide gel to a hydrophobic poly‐vinylidene difluoride (PVDF) membrane (Western blot) and their serological determination by indirect ELISA (immunoblotting) were used to differentiate Erwinia carotovora subsp. carotovora (Ecc) from Erwinia carotovora subsp. atroseptica (Eca). Ninety strains: 69 Ecc, 19 Eca and two Erwinia chrysanthemi (Echr) were examined. Eight polyclonal antisera against whole cells, glutaraldehyde fixed cells, glycopro‐teins, and somatic antigens were prepared. Antisera produced with glutaraldehyde fixed cells did not recognize any band of the protein pattern. The remaining antisera recognized a limited number of bands. Two protein bands allowed differentiation of the two subspecies by the antisera against glycoproteins. One band with an estimated molecular weight of 36000 Da was present in the 19 Eca strains tested and another band with an estimated molecular weight of 35 000 Da was present in the 69 Ecc strains, except for three cases. The strains of Echr showed a band with an estimated weight of 33 000 Da.
Ultra‐violet‐resistant mutants of Bacillus thuringiensis
Authors: Jones D.R. , Karunakaran V. , Burges H.D. , Hacking A.J.
Published: March 2008

One of the main disadvantages of using Bacillus thuringiensis as an insecticide is that the spore and crystal preparations applied to foliage are readily washed away by rain and are inactivated by sunlight. Spores from some strains of B. thuringiensis have been shown to be highly sensitive to u.v. light. This study has demonstrated how mutants with increased resistance to u.v., isolated by successive rounds of u.v. irradiation, and additionally with increased specific pathogenicity can be isolated. These techniques should be applied to strains that are frequently used in the industrial production of B. thuringiensis toxin.
The effect of temperature, water activity and sorbic acid on ketone rancidity produced by Penicillium crustosum Thom in coconut and palm kernel oils
Authors: Kinderlerer Judith L. , Hatton P.V.
Published: March 2008

In a model system medium‐chain fatty acids (MCFA) C6–C12 in coconut and palm kernel oil are converted to methyl ketones, one carbon atom less than the parent fatty acids, by two strains of Penicillium crustosum Thom. Conversion rates of up to 32% were seen for decanoic acid at 25°C. The optimum temperature for ketone production was 25°C in liquid suspension culture. Coconut oil contains 3.23 mmol/g MCFAs compared with 2.34 mmol/g for palm kernel oil. Coconut oil is more prone to fungal spoilage (growth and ketone production) than palm kernel oil. The main end product of fermentation was 2‐undecanone reflecting the high concentration of dodecanoic acid in the substrates. Ketonic rancidity is fungal engendered. The reaction can be controlled by reducing the temperature (4°C), reducing the water activity (0.91) or by addition of sorbic acid (20 mmol/l).
Enumeration by a miniaturized method of Escherichia coli, Streptococcus bovis and enterococci as indicators of the origin of faecal pollution of waters
Authors: Pourcher Anne‐Marie , Devriese L.A. , Hernandez J.F. , Delattre J.M.
Published: March 2008

Counts of Escherichia coli, faecal streptococci and enterococci were made on faecal specimens from human and animal origin and urban raw sewage waters, with microtiter plates containing selective substances. Escherichia coli was more numerous than faecal streptococci and enterococci in 80% of the samples regardless of the origin. Consequently the use of the ratio E. coli/faecal streptococci to distinguish human from animal origin of faecal pollution is questionable. Enterococcus faecalis was predominant in human and poultry faeces, Streptococcus bovis was typical of the bovine faeces and to a lesser extent also of pig faeces whereas Enterococcus durans, Ent. hirae and Ent. faecium did not characterize any faecal source. Streptococcus bovis could be distinguished in the mictrotiter plate by its inability to reduce triphenyl tetrazolium chloride (TTC) in the medium.
Effect of growth temperature on virulence of strains of Listeria monocytogenes in the mouse: evidence for a dose dependence
Authors: Stephens J.C. , Roberts I.S. , Jones Dorothy , Andrew P.W.
Published: March 2008

Growth of Listeria monocytogenes at 4°C significantly increased its virulence for mice by the intravenous route and the effect was dose‐dependent. Virulence was apparent only at a dose of about or above 104 viable listerias. At slightly lower doses of about 103, no such effect was observed. Growth at 4°C did not increase the virulence of the strains for mice by oral‐gastric challenge when given at doses of approximately 1010.
The hydrolysis of lucerne cell‐wall monosaccharide components by monocultures or pair combinations of defined ruminal bacteria
Authors: Miron J.
Published: March 2008

The defined ruminal bacterial strains Fibrobacter succinogenes S85, Ruminococcus flavefaciens FD1, Ruminococcus albus 7, Butyrivibrio fibrisolvens D1, and Bacteroides ruminicola GA33 were grown, in monocultures or as combinations of pair strains, on isolated lucerne cell‐walls (CW) as the sole carbohydrate substrate. Fibrobacter succinogenes S85 was the dominant strain determining extent of CW hydrolysis in all combinations with S85. The hydrolysis of cellulose, xylan, hemicellulose side‐sugars, and total CW monosaccharides by pure S85 were: 58·8, 47·3, 66·9 and 57·0%, respectively. The strains combination S85 plus D1 comprised the highest complementary effect, increasing significantly the hydrolysis of cellulose and total CW monosaccharides by 16% and 13%, respectively, above the values obtained by pure S85. This complementation was expressed also in growth pattern of bacteria.

The monocultures of FD1, D1 and GA33 had very little hydrolytic effect on lucerne cellulose, but higher effects on xylan and hemicellulose side‐sugars. The combinations D1 plus GA33 and 7 plus GA33 were complementary in the hydrolysis of all CW polysaccharides. The combinations FD1 plus D1, FD1 plus GA33, and 7 plus D1 were complementary only with respect to hemicellulose hydrolysis. On the other hand, the cellulolytic combinations S85 plus FD1, S85 plus 7 and FD1 plus 7 demonstrated negative interactions in lucerne CW polysaccharides hydrolysis.

Under scanning electron microscopy (SEM), S85 comprised the most dense layer of bacterial cell mass attached to and colonized on CW particles. The cell surface topology of the cellulolytic strains S85, FD1 and 7 attached to CW particles was specified by a coat of characteristic protuberant structures.
Differentiation of dairy strains of the Bacillus cereus group by phage typing, minimum growth temperature, and fatty acid analysis
Authors: Väisänen O. M. , Mwaisumo N. J. , Salkinoja‐Salonen M. S.
Published: March 2008

A total of 130 Bacillus strains were isolated from dairy products, the dairy environment and from packaging boards and board‐producing machines. Ninety‐eight of these were members of the B. cereus group (B. cereus, B. mycoides and B. thuringiensis) as determined by whole cell fatty acid composition. Fatty acid composition did not differentiate between the three species. Of the 98 strains, which were indistinguishable by biochemical tests, 87 could be assigned into 21 different phage types (11 strains remained untypable) when tested with 12 B. cereus, B. mycoides and B. thuringiensis phages. The distribution of phage types between strains from different sources showed that the source of contamination of the dairy products was of milk origin and not from the packaging materials. Most strains isolated from the dairy products were able to grow below 10°C, whereas strains from the dairy environment and from board mills had higher minimum growth temperatures.
Induction and cultivation of a stable L‐form of Bacillus subtilis
Authors: Allan Eunice J.
Published: March 2008

The induction of L‐forms of Bacillus subtilis from protoplasts is described. The method involved the frequent subculture of the unstable L‐form on a growth medium supplemented with lysozyme and horse serum. A stable culture, which did not revert when lysozyme and horse serum were omitted from the medium, was obtained after 13 subcultures. This culture could be grown on solid and in liquid medium by routine microbiological methods. Long‐term storage of these cells was achieved by freeze drying and maintenance in glycerol at −70°C. The cultural adaptability of the L‐form is described and discussed with respect to methods of cultivation and growth.