bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment of water for aquatic bacterial growth studies
Authors: Colbourne Jennifer S. , Trew R.M. , Dennis P.J.
Published: March 2008

The composition of a water is inextricably linked to its nutrient status and hence influences the behaviour of bacteria in artificial water systems. It has not yet been possible to devise a defined liquid medium representative of the complex composition of a treated water. Instead sterilized natural or distilled waters are used to study the growth or survival of aquatic bacteria in the laboratory. This has led to conflicting data and opposing opinions when the same water has proved toxic in some laboratory studies and growth‐supporting in others. These differences may be explained by the variations in chemical composition which occur when water is collected, transported and treated or stored in the laboratory. This study describes a simple, membrane filtration method of preparing a fresh sample of water collected from the environment or a building water system such that it is both sterile and chemically unaltered. The availability of such water may enhance understanding of the behaviour of bacteria in the aquatic environment.
Counter‐immunoelectrophoresis for the detection of Brucella antigen and antibodies in the diagnosis of brucellosis in buffaloes
Authors: Chand Puran , Khanna R.N.S. , Sadana J.R.
Published: March 2008

Counter‐immunoelectrophoresis was employed for the detection of Brucella antigen in stomach contents of aborted buffalo fetuses and antibody in aborted as well as apparently healthy in contact buffaloes. Five of 16 aborted cases were serologically positive for brucellosis but isolation of Brucella abortus was successful in only two cases. By counter‐immunoelectrophoresis, Brucella antigen was detected in the fetal stomach contents of four serologically positive cases.

Of the 68 serum samples from in contact healthy buffaloes, 10 were positive with counter‐immunoelectrophoresis: more than were detected by tube agglutination, Rose Bengal plate agglutination, complement fixation and agar gel precipitation test.
An appraisal of the efficacy of pre‐enrichment for the isolation of Campylobacter jejuni from water and food
Authors: Humphrey T.J.
Published: March 2008

Cells of Campylobacter jejuni exposed to heating or freezing were progressively less able to grow at 43°C, particularly on selective media. This influenced the recovery of damaged cells from naturally and artificially contaminated samples. With broth culture the isolation rate could be increased by pre‐enrichment in basal or selective media at 37°C for 4 h. With membrane filtration or surface plating techniques the inclusion of agents that quench toxic derivatives of oxygen was more important.
A numerical taxonomic study of proteolytic and lipolytic psychrotrophs isolated from caprine milk
Authors: Cox J.M. , Rae I.C. Mac
Published: March 2008

Lipolytic and proteolytic psychrotrophs were isolated from raw and pasteurized goats’milk, which had been stored at 5°C for 7d. The 241 strains isolated and 20 reference strains were examined by 149 biochemical, physiological, and morphological tests. The results yielded 195 characters suitable for taxonomic analysis. Computer‐assisted complete linkage analysis, using the Jaccard coefficient, produced 22 phenons at 75% S. The results showed that Pseudomonas fluorescens was the predominant psychrotrophic bacterium, but that Pseudomonas fragi was dominant in some milk samples. Strains of Serratia liquefaciens and Flavobacterium balustinum were also identified.
The incidence of Listeria monocytogenes in raw milk from farm bulk tanks in North‐East Scotland
Authors: FENLON D.R. , WILSON J.
Published: March 2008

Over 180 farm bulk milk tanks were tested for the presence of Listeria monocytogenes on three separate occasions which included periods when cows were grazing and confined inside on a silage diet. The incidence of L. monocytogenes contamination was low, ranging from 3.8% in the summer samples to 1.0% in October. The level of contamination was estimated to be lower than one L. monocytogenes bacterium per ml in positive samples, as most required cold enrichment of 10–20 ml volumes before recovery. The distribution was sporadic; only one farm gave positive isolations on all three sampling occasions, one other on two, and all others were from different farms. No correlation between the presence of L. monocytogenes and hygiene standards or the feeding of silage was found.
Cell location and partial characterization of Brochothrix thermosphacta and Lactobacillus curvatus lipases
Authors: PAPON MARTINE , TALON RÉGINE
Published: March 2008

The lipases of Brochothrix thermosphacta and Lactobacillus curvatus were in the soluble fraction of the cell and not membrane‐ or wall‐bound. Their optimal activities were around pH 6mD5 and at 37°C. Enzymes were stable between 4 and 30°C and at freezing temperatures (— 20°C and —60°C). The lipase of Lact. curvatus was stable in the pH range of 4mD0 to 11mD0, whereas that of B. thermosphacta was denatured at pH lower than 5mD0 and greater than 9mD0. Among triglycerides tested, maximal activity was found with tributyrin and hydrolysis of other triglycerides decreased as the length of fatty acid increased.
Detection of β‐galactofuranosidase production by Penicillium and Aspergillus species using 4‐nitrophenyl β‐D‐galactofuranoside
Authors: COUSIN M.A. , NOTERMANS S. , HOOGERHOUT P. , VAN BOOM J.H.
Published: March 2008

An assay was developed for detecting β‐galactofuranosidase produced by Penicillium and Aspergillus spp. The substrate for the assay, 4‐nitrophenyl β‐D‐galactofura‐noside, was synthesized from penta‐O‐acetyl‐β‐D‐galactofuranose and 4‐nitrophenol by a tin chloride catalyzed reaction followed by O‐deacetylation. Aspergillus spp. produced only small quantities of β‐galactofuranosidase during 30 d at 25°C. Only the biverticillate Penicillium spp. (P. funiculosum, P. islandicum, P. rubrum and P. tardum) produced substantial β‐galactofuranosidase after 1–4 weeks at 25°C. No extracellular antigens of these four Penicillium spp. could be detected in culture filtrates by the sandwich ELISA technique when antibodies to the extracellular β‐galactofuranoside‐containing polysaccharide antigen of P. digitatum was used. Antigens to all other Penicillium and Aspergillus spp. were easily detected in their culture filtrates.
Analysis of plasmid profiling as a method for rapid differentiation of food‐associated Clostridium perfringens strains
Authors: Jones Mary K. Phillips , Iwanejko Lesley A. , Longden M. S.
Published: March 2008

Plasmid analysis of over 120 strains of Clostridium perfringens, isolated during food‐poisoning incidents and from animal carcasses and food constituents with no association with food poisoning, showed the potential of plasmid profiling as a means of differentiating epidemiologically related strains. On average 65% of freshly isolated strains contained one or more plasmids which could be used in the analysis. Comparison of profiles of strains from unrelated sources or unrelated strains from the same source showed a particularly wide variety of plasmid profiles. Thus the possibility that epidemiologically‐unrelated strains might possess similar profiles appears to be very low in this organism. Analysis of serologically‐related strains from the same source revealed similar plasmid profiles in all the plasmid‐bearing strains examined. A high proportion (71%) of fresh and well‐characterized food‐poisoning strains possessed plasmids of 6·2 kb in size (compared with 19% of non‐food‐poisoning strains). The possible role of these plasmids is discussed, since the structural gene encoding the enterotoxin type A was not present on any of the plasmids in the food‐poisoning strains tested.
Immunological and genetical relatedness of type‐1 and type‐2 fimbriae in salmonellas of serotypes Gallinarum, Pullorum and Typhimurium
Authors: Crichton Pamela B. , Yakubu D. E. , Old D. C. , Clegg S.
Published: March 2008

The fimbriae of 50 strains of serotype Gallinarum and 35 strains of serotype Pullorum of the genus Salmonella were compared with the type‐1 fimbriae of serotype Typhimurium strains by immune electron microscopy and dot blot hybridization tests with gene probes for type‐1 fimbriation in Typhimurium. The fimbriae of Gallinarum and Pullorum strains were coated with Typhimurium type‐1 fimbrial anti‐serum and probes hybridized strongly with DNA of Gallinarum and Pullorum strains under stringent conditions. Furthermore, when Typhimurium type‐1 fimbrial antiserum, that had been absorbed with fimbriate Gallinarum or Pullorum bacteria, was used in immune gold labelling experiments, it was shown that residual antibody recognized sites of possible adhesin incorporation at intervals along the length of Typhimurium type‐1 fimbriae. These findings suggest that the type‐2 fimbriae produced by all Gallinarum and Pullorum strains are non‐adhesive forms of adhesive, type‐1 fimbriae. This observation is of interest because type‐1 fimbriae have never been reported in naturally occurring strains of these two avian‐adapted serotypes.
A note on the physiological state of epiphytic bacteria compared with planktonic bacteria in two organically‐enriched watercourses
Authors: Al‐Hadithi S. A. , Goulder R.
Published: March 2008

Epiphytic bacteria were compared with planktonic bacteria in two watercourses enriched with sewage works effluent. Colony‐forming units as a percentage of acridine orange direct counts were higher for epiphytic bacteria in one watercourse. The percentage of cells capable of intracellular reduction of 2‐(p‐iodophenyl)‐3‐(p‐nitrophenyl)‐5‐phenyl tetrazolium chloride (INT) to INT‐formazan was higher for epiphytic bacteria in both watercourses. The greater viability of epiphytic over planktonic bacteria was less evident, however, than in previously studied non‐enriched gravel pit ponds. This suggests that the greater availability of dissolved organic nutrients in the enriched watercourses reduced stress on planktonic bacteria.
Membrane filtration differentiation ofE. colifrom coliforms in the examination of water
Authors: Mates A. , Shaffer M.
Published: March 2008

A membrane filter‐Endo agar method for enumeratingEscherichia colias distinct from other coliforms in drinking water was developed. Membranes containing coli‐form colonies are transferred to nutrient agar containing 4‐methyl umbelliferyl‐β‐d‐glucuronide (MUG) and incubated at 35°C for 4 h. The MUG is hydrolyzed by the glucuronidase ofE.coli and the fluorogenic product is visualized. The method recovered 98% ofE. coliwithout false positives and is proposed as an additional test in routine water examination for the detection of pollution.
Adherence of bacterial spores to encrusted fabrics
Authors: Ghione M. , Parrello D. , Granucci Carlotta
Published: March 2008

Adherence of Bacillus megaterium spores to fabrics depends on fabric composition and texture. Adherence to cotton terry cloth is higher than to plain cotton and cotton‐polyester fabrics. The adherence is always proportionally enhanced by the presence of organic and inorganic encrustation on the surface of fibres. These encrustations are deposited when fabrics are washed without adequate detergents. This frequently happens because of attempts to limit or banish the use of efficient ingredients (such as sodium tripolyphosphate) for ecological reasons and to use low temperature washing methods to permit energy savings. Encrustation, inadequate detergency and low temperature washing can concur to sustain a high level of bacterial contamination on the fabric surface.
Fate of salmonellas in the alimentary tract of chicks pre‐treated with a mature caecal microflora to increase colonization resistance
Authors: IMPEY C. S. , MEAD G. C.
Published: March 2008

Oral challenge with a strain of Salmonella kedougou, resistant to nalidixic acid, gave a time‐course for salmonella survival in the the alimentary tract of chicks pre‐treated with a caecal culture from an eight‐week‐old bird to increase colonization resistance. In untreated, control chicks, salmonella colonization of the caeca resulted in counts of > 106/g within 48 h and a mean generation time of 1·6 h. With treated birds, however, the salmonellas failed to multiply in the caeca and decreased to a low level over a 48‐h period, thus suggesting a mainly bacteriostatic effect. Pretreatment of chicks with the caecal culture also reduced the proportion of salmonella‐positive crop samples. Growth of the salmonella in a feed‐slurry system resembling moistened crop contents occurred rapidly at 37°C but was prevented by addition of the treatment culture, a decline in numbers coinciding with Lactobacillus populations of ca 109/g and a pH value of 5·5. Incorporation of a feed decontaminant, 1% formic acid (pH 4·0), rapidly eliminated both salmonellas and organisms added from the treatment culture.
Evidence for the pathogenic role of Rhodococcus species in pulmonary diseases
Authors: OSOAGBAKA O. U.
Published: March 2008

Three hundred expectorated sputa from patients suffering from chest disorders were examined microscopically and cultured on various media. Among other microorganisms isolated there were four strains of Rhodococcus aurantiacus (Gordona aurantiaca), one each of Rh. erythropolis, Rh. pellegrino, Rh. rubropertinctus and Rh. rhodnii. Suspensions in 5% hog gastric mucin were virulent for immuno‐suppressed white mice and the pathology of their lungs was compatible with those produced in experimental nocardial and rhodococcus infections. The in‐vitro antibiogram was similar to that of Nocardia asteroides. Two of the patients from whom Rh. aurantiacus and Rh. pellegrino were isolated responded bacteriologically and clinically to treatment with co‐trimoxazole. The frequency with which these rhodococci were isolated and the clinical conditions of the patients strongly indicated a pathogenic role for some Rhodococcus species. It is suggested that rhodococci should be sought in chronic pulmonary infections, particularly in those who are immuno‐compromised or debilitated, and their aetiologic role determined.
Studies on antagonism between porcine skin bacteria
Authors: ALLAKER R. P. , LLOYD D. H. , NOBLE W. C.
Published: March 2008

Strains of Staphylococcus warneri, Staph. epidermidis and Aerococcus viridans isolated from porcine skin were shown to produce substances that inhibited the growth of Staph. hyicus. Studies of interactions between the inhibitor‐producing bacteria and Staph. hyicus on cellulose acetate membranes demonstrated a significant reduction (P < 0.001) of the Staph. hyicus population at various stages of its growth cycle, depending on the inhibitor used. Inhibitor production profiles in batch culture showed a change in production with culture growth. Trypsin and an extracellular substance from Staph. hyicus had similar effects in reducing inhibitor production. Staphylococcus hyicus was shown to produce varying amounts of a proteolytic enzyme during growth in batch culture. Such in vitro models of bacterial interaction enable potential mechanisms of disease control using inhibitor‐producing organisms to be investigated and provide a basis for studies in vivo.
Enterotoxigenic aeromonads on retail lamb meat and offal
Authors: Majeed K. , Egan A. , Mac Rae I. C.
Published: March 2008

Enrichment in alkaline peptone water was compared with the direct plating method for the isolation of Aeromonas spp. from lamb meat and offal samples. The enrichment method significantly increased the isolation rate of aeromonads. Motile Aeromonas species (A. hydrophila, A. sobria and A. caviae) were present in all kinds of samples investigated. Seventy‐three Aeromonas strains isolated in this survey were characterized to species level and examined for their ability to produce virulence factors. Strains identified as A. sobria were the strongest producers of haemolysin and enterotoxin, whereas A. caviae strains were consistently non‐haemolytic and non‐enterotoxigenic. Thus it is likely that lamb meat and offal are potentially significant sources of virulent Aeromonas species and may play an important role in the aetiology of Aeromonas‐associated gastro‐enteritis.
A note on susceptibility of Branhamella catarrhalis to heavy metals
Authors: Riley T.V. , Taylor M.L.
Published: March 2008

The susceptibility of 56 strains of Branhamella catarrhalis and ten Neisseria spp. to arsenate, silver, nickel, mercury, lead, cadmium, chromium, manganese, iron, cobalt and molybdenum was tested with an agar dilution technique. All but two strains of B. catarrhalis were resistant to multiple metal ions. There were not sufficient differences in susceptibility, however, to allow the development of a typing scheme based on resistograms. Heavy metal resistance in Branhamella was unrelated to beta‐lactamase production. Neisseria spp. were more susceptible to metal ions than B. catarrhalis and this may form the basis of a simple diagnostic test.
Influence of nutrient‐limited growth on pathogenesis‐associated outer membrane proteins of Yersinia enterocolitica
Authors: Harakeh S. , Matin A.
Published: March 2008

From studies based on batch culture, it has been postulated that the expression of the virulence‐associated proteins of Yersinia spp. is controlled by temperature and Ca2+, such that these proteins are synthesized only at the higher temperature (37°C) and calcium‐scarce conditions of the intracellular environment. It was found, however, that in Yersinia enterocolitica one of these proteins (140 kDa) is not synthesized at submaximal growth rates under any of the relevant conditions, and that another of the implicated proteins (34 kDa), is synthesized even at 28°C during nutrient‐limited growth. Thus, temperature and Ca2+ influence the synthesis of these proteins differently under growth conditions that better approximate the natural environments than do batch cultures.
Relation between Aeromonas and faecal coliforms in fresh waters
Authors: Araujo Rosa M. , Arribas Rosa M. , Lucena Francisco , Pares Ramon
Published: March 2008

A possible correlation between the presence of mesophilic aeromonads and the number of faecal coliforms present in three fresh‐water habitats subject to differing levels of faecal pollution was investigated. Concentration of Aeromonas spp. between 102–109 cfu/100 ml and faecal coliforms of between 9–107 cfu/100 ml were found in the waters. In water free from faecal pollution there was no correlation but in polluted waters there was a significant relationship between the numbers of aeromonads, faecal coliform and the concentration of organic matter measured by biological oxygen demand.
Evaluation of a radiometric method for studying bacterial activity in the presence of antimicrobial agents
Authors: CUTLER R. R. , WILSON P. , CLARKE F. V.
Published: March 2008

In a study involving 2760 tests, the BACTEC semi‐automatic radiometric method which measures bacterial metabolic activity and produces a BACTEC growth index, was compared with two conventional methods commonly used for determining growth, absorbance and viable counts. In 92% of radiometry tests the suppression of growth was inversely related to the antibiotic concentration. This compared with 83% for absorbance and 63% for viable counts. The radiometric method was found to be more rapid, easier to use and more reproducible in determining the effect of antibiotics on the activity of bacteria than viable counting or absorbance methods.
The application of bacteriophage as tracers of chalk aquifer systems
Authors: SKILTON HELEN , WHEELER D.
Published: March 2008

Three tracer experiments were performed at two chalk groundwater sites. In the first experiment three bacteriophage were injected at three different depths within a chalk aquifer, 16.5 m from the pumping well. Two of the bacteriophage were recovered from the abstraction point giving a fastest migration rate of between 17 and 34.5 cm/h. One of the bacteriophage tracers, however, was not detected. In the second experiment, three bacteriophage were injected at different depths within a second chalk aquifer site, 1 km distance from the pumping well. A small percentage of original inoculum (0.055 and 0.002%) of two of the bacteriophage traversed the 1 km distance and was detected within 6 months, demonstrating a fastest migration rate of 30 and 29.5 cm/h. At the same site, two bacteriophage were injected into a different borehole, 50 m away from the pumping well. Neither of the two bacteriophage were recovered from the abstraction point. These bacteriophage tracer experiments expose several interesting hydrogeological features about each chalk aquifer system and re‐assert bacteriophage as excellent tracers at groundwater sites.
Combined effect of temperature and salt concentration/water activity on the growth rate of Halobacterium spp.
Authors: Chandler R.E. , McMeekin T.A.
Published: March 2008

Growth responses of the halophilic bacteria, Halobacterium sp. strain HB9 and Halobacterium salinarium strain CM42/12, to temperature and water activity/sodium chloride concentration were described by the square root model and Tmin (the theoretical minimum temperature for growth) was fixed. Little change in growth rate was observed in response to added NaCl at water activities below which cell lysis was avoided. Hence, growth of halobacteria on products such as salted, dried fish at water activities below 0.85 may be based on the square root temperature response without the need to incorporate a water activity term.
Purification and characterization of an extracellular polygalacturonase from Lactobacillus plantarum strain BA 11
Authors: Sakellaris G. , Nikolaropoulos S. , Evangelopoulos A. E.
Published: March 2008

Lactobacillus plantarum produced extracellular polygalacturonase in a medium containing 1.5% low methyl‐pectin (w/v) and 0.5% glucose (w/v) as inducers. The enzyme was purified (approximately 70‐fold) by ammonium sulphate fractionation, Sephadex G‐100 gel filtration and DEAE‐cellulose ion exchange chromatography. Two peaks (PG I and PG II) of enzymic activity were obtained from the DEAE‐cellulose column. The molecular mass of PG I was similar to that of PG II (32 000 Da). The Km values of PG I and PG II for sodium polypectate were calculated to be 1.63 mg/ml and 1.78 mg/ml respectively. Their isoelectric points were about pH 5.5. The pH optimum was 4.5, while the optimum temperature was 35°C for both PG I and PG II. The two purified enzymes had similar endo modes of action on polygalacturonic acid, as determined by comparison of viscosity reduction and reducing group release.
Conjugal transfer of a plasmid encoding bacteriocin production and immunity in Pediococcus acidilactici H
Authors: RAY S.K. , KIM W.J. , JOHNSON M.C. , RAY B.
Published: March 2008

Previous investigations indicated that curing of a 7.4‐Md plasmid (pSMB74) resulted in concomitant loss of bacteriocin activity and immunity in Pediococcus acidilactici H. Transfer of pSMB74 to a gentamicin‐neomycin resistant (GmrNmr) derivative of P. acidilactici LB42, which was devoid of any plasmid DNA, required cell‐to‐cell contact on a solid mating surface and converted the strain to Bac+Bacr phenotype. Gene transfer processes such as transduction and transformation were ruled out from the experiment. Treatment of donor cells with chloroform did not allow the appearance of recombinant clones, confirming that viable cells were essential for this particular mechanism of genetic transfer. Transconjugants obtained from selective agar surface were subjected to plasmid isolation and agarose gel electrophoresis. Each of them exhibited plasmid size corresponding to pSMB74 of donor strain. All results suggested this genetic transfer similar to conjugation, and provided presumptive evidence for plasmid‐encoded bacteriocin activity and immunity in P. acidilactici H.
A simple haemolytic method for quantitation of the delta endotoxin of Bacillus thuringiensis subsp. israelensis from crude samples
Authors: Majumdar M.K. , Sikdar D.P. , Sarma A.B. , Majumdar S.K.
Published: March 2008

A simple haemolytic assay method for quantitative estimation of the delta endotoxin of Bacillus thuringiensis subsp. israelensis from a crude preparation has been developed. The method has several advantages over mosquito‐larvicidal methods of assay as it is inexpensive, highly sensitive and easier to run and can be used for performing a reasonably large number of assays rapidly with high precision and with a coefficient of variation that does not exceed 1.96%.
Induction of autolysis in Enterococcus faecalis S‐47 by peptide AS‐48
Authors: Gálvez A. , Valdivia E. , Martínez‐Bueno M. , Maqueda. M.
Published: March 2008

In addition to its bactericidal mode of action, the peptide antibiotic AS‐48 exhibits a bacteriolytic effect on Enterococcus faecalis S‐47 that is associated with autolysin activation. Bacteriolysis induced by the antibiotic can be modulated by addition of EDTA, divalent cations and autolysin activators (trypsin) or inhibitors (cardiolipin), suggesting that topologic regulation of the autolysins is involved in the process. In addition, inhibitors of protein and RNA synthesis interfere markedly with bacteriolysis, as do ionophores and the ATPase inhibitor DCCD, suggesting the participation of an internal messenger in autolysin activation in the presence of AS‐48.
Numerical analysis of electrophoretic protein patterns of Morganella morganii strains from faeces, wound, urine and other clinical sources
Authors: Costas M. , Holmes B. , Wood A.C.
Published: March 2008

Sixty‐five strains of Morganella morganii (mainly of human origin) were characterized by one‐dimensional SDS‐PAGE of cellular proteins. The strains came from various countries; 13 were from stools (including one from a toucan), 13 from wounds, 11 from urine, five from blood (including one from a snake), five from the respiratory tract (four sputum, one lung), 12 from miscellaneous sources and six from unknown sources. The protein patterns, which contained 45 to 50 discrete bands, were highly reproducible. The patterns of 67 M. morganii cultures plus those of the type strains of seven Proteus and Providencia species were used as the basis for two numerical analyses. In the first, which included all the protein bands, the M. morganii strains formed 21 clusters at the 91% S level. In the second analysis, in which the principal protein bands (in the 31.6—43.2 kDa range) were excluded, the 67 M. morganii cultures formed a single cluster at the 80% S level distinct from the seven Proteus and Providencia reference strains. We conclude that high resolution PAGE combined with computerized analysis of protein patterns provides the basis for typing clinical strains of M. morganii. Reference strains of each of the 21 PAGE types identified are available from NCTC for inclusion in future studies.
Purification and characterization of two types of alkaline serine proteases produced by an alkalophilic actinomycete
Authors: Tsujibo Hiroshi , Miyamoto Katsushiro , Hasegawa Toru , Inamori Yoshihiko
Published: March 2008

Tsujibo, H., Miyamoto, K., Hasegawa, T. & Inamori, Y. 1990. Purification and characterization of two types of alkaline serine proteases produced by an alkalophilic actinomycete. Journal of Applied Bacteriology69, 520–529.

Two types of alkaline serine proteases were isolated from the culture filtrate of an alkalophilic actinomycete, Nocardiopsis dassonvillei OPC‐210. The enzymes (protease I and protease II) were purified by acetone precipitation, DEAE‐Sephadex A‐50, CM‐Sepharose CL‐6B, Sephadex G‐75 and phenyl‐Toyopearl 650 M column chromatography. The purified enzymes showed a single band on sodium dodecyl sulphate polyacrylamide gel electrophoresis. The molecular weights of proteases I and II were 21000 and 36000, respectively. The pIs were 6.4 (protease I) and 3.8 (protease II). The optimum pH levels for the activity of two proteases were pH 10–12 (protease I) and pH 10.5 (protease II). The optimum temperature for the activity of protease I was 70°C and that for protease II was 60°C. Protease I was stable in the range of pH 4.0–8.0 up to 60°C and protease II was stable in the range of pH 6.0–12.0 up to 50°C.
Biological control of Dutch elm disease: Bacillus thuringiensis as a potential control agent for Scolytus scolytus and S. multistriatus
Authors: Jassim Hana K. , Foster H.A. , Fairhurst C.P.
Published: March 2008

Jassim, H.K., Foster, H.A. & Fairhurst, C.P. 1990. Biological control of Dutch elm disease: Bacillus thuringiensis as a potential control agent for Scolytus scolytus and S. multistriatus. Journal of Applied Bacteriology69, 563–568.

The effects of exposing fifth instar larvae of Scolytus scolytus and S. multistriatus to spore suspensions of Bacillus spp. were investigated. Bacillus thuringiensis ser 3a, 3b increased the mortality of larvae cultured on an artificial medium from approximately 20% in control cultures to over 80% in cultures exposed to the bacteria. The mortality was dose‐dependent for S. multistriatus and the approximate LC50 value was 2.2 times 103 spores/ml. Different serotypes of B. thuringiensis caused different levels of mortality: H6 produced the highest mortality and H1 the lowest. Bacillus alvei and B. cereus were also pathogenic but B. megaterium was not. The results are discussed in relation to the mechanism of pathogenicity and the potential for the use of B. thuringiensis for the control of the vectors of Dutch elm disease.
Listeria monocytogenes contamination of crops grown on soil treated with sewage sludge cake
Authors: Al‐Ghazali M.R. , Al‐Azawi Salwa K.
Published: March 2008

Al‐Ghazali, M.R. & Al‐Azawi, S.K. 1990. Listeria monocytogenes contamination of crops grown on soil treated with sewage sludge cake. Journal of Applied Bacteriology69, 642–647.

Listeria monocytogenes was found in the sewage sludge cake which is commonly used as an agricultural fertilizer in Iraq. Soils treated with this material were contaminated with the organism. Pot and field experiment showed that crops grown on treated soil became contaminated with L. monocytogenes and when alfalfa plant was grown on farmland soil treated with sewage sludge cake, listerias were found on 10% of 50 plants sampled at harvest, but the organism was detected only in low numbers on these crops (≤ 5 cells/g). This could add to the risk to animals and man.
An investigation of indirect conductimetry for detection of some food‐borne bacteria
Authors: Bolton F.J.
Published: March 2008

Bolton, F.J. 1990. An investigation of indirect conductimetry for detection of some food‐borne bacteria. Journal of Applied Bacteriology69, 655–661.

Indirect conductimetry using a rapid automated bacterial impedance technique was investigated. Strains of Staphylococcus aureus, Listeria monocytogenes, Enterococcus faecalis, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Aeromonas hydrophila and Salmonella spp. grown in Whitley Impedance broth all elicited indirect conductimetric changes. These indirect conductance responses were improved by the addition of 2 g/1 glucose to the medium and resulted in maximum changes of 2340–4300 μS with associated maximum rates of change of 520–1210 μS/h. Furthermore, the indirect conductimetric assay detected growth of staphylococci, listeria and salmonella in media containing high concentrations of salts used as selective agents in culture media for the isolation of these organisms.
A note on the antibacterial properties of 3‐(3'‐isocyanocyclopent‐2'‐enylidene)propionic acid in the ovine rumen
Authors: Brewer D. , Parkinson V.O. , Taylor A.
Published: March 2008

Brewer, D., Parkinson, V.O. & Taylor, A. 1990. A note on the antibacterial properties of 3‐{3'‐isocyanocyclopent‐2'‐enylidene)propionic acid in the ovine rumen. Journal of Applied Bacteriology69, 701–704.

The concentration of 3‐(3'‐isocyanocyclopent‐2'‐enylidene)propionic acid after introduction into the ovine rumen declined by 50% during 30 min. Its antibacterial activity in the rumen could be demonstrated by the decline in numbers of cellulo‐lytic rumen bacteria from about 106/ml to about 102/ml.
Purification and characterization of an extracellular amylase from a thermophilic streptomycete
Authors: Goldberg J.D. , Edwards C.
Published: March 2008

Goldberg, J.D. & Edwards, C. 1990. Purification and characterization of an extracellular amylase from a thermophilic streptomycete. Journal of Applied Bacteriology69, 712–717.

A single extracellular alpha‐amylase (1,4‐α‐D‐glucan glucanohydrolase, EC 3.2.1.1) from Streptomyces thermoviolaceus subsp. apingens was purified to homogeneity by a starch adsorption method. SDS‐PAGE indicated that the enzyme had an apparent M, of 57 kDa and activity was optimal at a pH of 7–2 and a temperature of 55d̀C. It employed an endo‐active mechanism to liberate predominantly maltose, as well as smaller amounts of higher oligosaccharides when incubated with starch. EDTA inhibited enzyme activity, suggesting an involvement of a divalent cation in activity. The enzyme was also stabilized by divalent cations when heated and the results suggested a major role for Ca2+ ions for both activity and thermostability. The alpha‐amylase from S. thermoviolaceus displayed some similarities with commercially‐used streptomycete alpha‐amylases.
Presence of Erwinia chrysanthemi in two major river systems and their alpine sources in Australia
Authors: Cother E. J. , Gilbert R.L.
Published: March 2008

Cother, E.J. & Gilbert, R.L. 1990. Presence of Erwinia chrysanthemi in two major river systems and their alpine sources in Australia. Journal of Applied Bacteriology69, 729–738.

Erwinia chrysanthemi was isolated over three summers by filtration, with or without enrichment, of water samples from the headwaters of the Murray and Murrum‐bidgee Rivers and from several locations downstream. The bacterium could not be detected in streams rising adjacent to headwater catchments nor could it be detected in freshly voided faeces of native and domestic animals in the vicinity of the Mur‐rumbidgee headwaters. Although it survived passage through the intestinal tract of a guinea pig and fowl, it did not persist in either animal. The bacterium survived for at least 211 days at 16d̀C in sterile distilled water. The specific localities from which the bacterium was isolated and the lack of external sources of inoculum indicate that E. chrysanthemi is most likely a constituent of the sessile bacterial population on stream weeds and sediments and is not a contaminant of this alpine environment.
Thermophilic campylobacters in surface waters around Lancaster, UK: negative correlation with campylobacter infections in the community
Authors: Jones K. , Betaieb M. , Telford D.R.
Published: March 2008

Jones, K., Betaieb, M. & Telford, D.R. 1990. Thermophilic campylobacters in surface waters around Lancaster, UK: negative correlation with campylobacter infections in the community. Journal of Applied Bacteriology69, 758–764.

The incidence of campylobacter enteritis in Lancaster City Health Authority is three times the UK average for similar sizes of population and has marked seasonal peaks in May and June.

Environmental monitoring of surface waters around Lancaster showed that ther‐mophilic campylobacters were absent from drinking water from the fells and from the clean upper reaches of the River Conder but were present in the main rivers entering Morecambe Bay, the lower reaches of the River Conder, the Lancaster canal, and seawater from the Lune estuary and Morecambe Bay. AH the surface waters tested showed the same seasonality, namely, higher numbers in the winter months and low numbers or none in May, June and July. The absence of thermo‐philic campylobacters in the summer months may be due to high sunshine levels because experiments on the effects of light showed that campylobacters in sewage effluent and seawater were eliminated within 60 and 30 min of daylight respectively but survived for 24 h in darkness.

As the concentrations of campylobacters in surface waters were at their lowest precisely at the time of peak infections in the community it is unlikely that surface waters form Lancaster's reservoir of campyiobacter infection for the community.
Culture medium for Xanthomonas campestris pv. oryzae
Authors: Yuan Wuqiao
Published: March 2008

Yuan, W. 1990. Culture medium for Xanthomonas campestris pv. oryzae. Journal of Applied Bacteriology69, 798–805.

Studies on nutrient requirements of four Chinese strains of Xanthomonas campestris pv. oryzae in a modified Watanabe's medium led to the development of a new synthetic medium containing sucrose, sodium glutamate, methionine, KH2PO4, NH4C1 and iron chelated with EDTA. The concentration of each ingredient was optimized based on the number of colonies and time required for their appearance. Various concentrations of some nutrients were compared based upon their effects on growth of the pathogen strains and 34 contaminants from rice materials. Tryp‐tone enhanced the growth of X. c. oryzae more than that of many contaminants, including Erwinia herbicola. Peptone stimulated growth of X. c. oryzae without promoting excessive contamination. When compared with other media used for X. c. oryzae, the new culture medium enriched with tryptone and peptone gave the highest recovery and earliest appearance of colonies of Chinese strains of this bacterium.
Fate of pathogenic and non‐pathogenic Escherichia coli strains in two fermented milk products
Authors: Feresu Sara , Nyati Hilda
Published: March 2008

Feresu, S. & Nyati, H. 1990. Fate of pathogenic and non‐pathogenic Escherichia coli strains in two fermented milk products. Journal of Applied Bacteriology69, 814–821.

The growth and survival of pathogenic and non‐pathogenic strains of Escherichia coli was determined in traditionally fermented pasteurized and unpasteurized milk and in Lacto, an industrially fermented milk. Each milk treatment was incubated at 20d̀C for 24 h and then stored at either 20d̀C or 5d̀C for 96 h.

Lacto inhibited all the three E. coli strains. Two strains could not be recovered and the third survived only in very low numbers after 24 h storage of Lacto at both 20d̀C and 5d̀C. All three E. coli strains survived and multiplied to maximum cell numbers in the range 107‐109/ml during traditional fermentation of unpasteurized milk. Cell numbers decreased to 103‐106 and 102‐105 during storage of the fermented product at 20d̀C and 5d̀C respectively. Higher maximum numbers, 109‐1010, of the three strains of E. coli were attained during traditional fermentation of pasteurized milk. The numbers decreased to 105‐108 and 104‐107 during storage of the fermented product at 20d̀C and 5d̀C respectively. Generally, fewer E. coli survived when the fermented milk products were stored at refrigeration temperature.
Rapid methods for differentiating Gram‐positive from Gram‐negative aerobic and facultative anaerobic bacteria
Authors: Manafi M. , Kneifel W.
Published: March 2008

Manafi, M. & Kneifel, W. 1990. Rapid methods for differentiating Gram‐positive from Gram‐negative aerobic and facultative anaerobic bacteria. Journal of Applied Bacteriology69, 822–827.

Different tests based on lysis by KOH and on reaction with fluorogenic and chromogenic substrates, L‐alanine‐4‐nitroanilide (LANA); L‐alanine‐4‐methoxy‐β‐naphthylamide (MNA); 4‐alanine‐2‐amidoacridone (AAA); L‐alanine‐7‐amido‐4‐methylcoumarin (AAMC); 8‐anilino‐l‐naphthalene‐sulphonic acid (ANS) were compared for their suitability to distinguish Gram‐positive from Gram‐negative bacteria. A concentration of 100 μg/ml was chosen for incorporating LANA, AAA, AAMC and ANS into the growth medium, based on sensitivity tests. MNA did not show any detectable reaction over a concentration range from 50 to 200 μg/ml, and led to inhibition of all bacteria at 200 μ/ml. In the examination of a total of 146 bacterial strains, including Yersinia enterocoiitica, Bacillus cereus, and B. subtilis the KOH test was not comparable with the Gram staining. A good correlation with Gram staining was found between LANA, AAA and AAMC added to plate count agar on one hand, and LANA and AAMC impregnated paper strips on the other hand, thereby utilizing the aminopeptidase activity. Agar containing ANS showed detectable fluorescence with all Gram‐negative strains, but with Staphylococcus aureus and Staph. epidermidis a weak reaction was also observed. AAMC was selected for a rapid paper strip test With this substrate a pronounced blue fluorescence was obtained with Gram‐negative colonies.
Adherence of Staphylococcus aureus to cell monolayers
Authors: Wyatt I.E. , Poston S.M. , Noble W.C.
Published: March 2008

Wyatt, J.E., Poston, S.M. & Noble, W.C. 1990. Adherence of Staphylococcus aureus to cell monolayers. Journal of Applied Bacteriology69, 834–844.

Adherence of four strains of Staphylococcus aureus to eukaryotic cell monolayers was assayed with [3H]‐thymidine labelled bacterial cells and the results were analysed by non‐parametric statistical tests. Adherence to primary (human mesothelial) and semi‐continuous (human embryonic lung) cell monolayers was significantly better than to continuous cell lines (HEp2, HeLa and Vero). HEp2 cell monolayers provided the most reliable assay substrate of the continuous cell lines tested. Variation occurred between bacterial culture batches but the assay measured significant differences between adhesion levels of the strains and distinguished between high level (RN92, 8325–4) and low level (Wood46, ISP458) adhering strains. Adherence to different batches of cell monolayers also varied but relative adherence values for strains were similar and the ranking of strains according to adhesion values ‐was unchanged.

Potential adhesion mediators have been monitored for their effect on adhesion of a highly adherent strain (RN92) to HEp2 monolayers. Fibronectin, protein A and anti‐protein A did not significantly affect adhesion. Lipoteichoic acid caused a significant inhibition of adhesion. With critical statistical analysis to accommodate inherent variations, this assay provides a useful model to study factors involved in adherence of Staph. aureus to eukaryotic cells.
Plasmid‐encoded resistance to macrolides and lincosamides in Staphylococcus hyicus
Authors: Schwarz S. , Wegener H. , Blobel H.
Published: March 2008

Schwarz, S., Wegener, H. & Blobel, H. 1990. Plasmid‐encoded resistance to macrolides and lincosamides in Staphylococcus hyicus. Journal of Applied Bacteriology69, 845–849.

A small plasmid of 2–35 kb, isolated from a porcine Staphylococcus fcyicus‐culture, was found to be responsible for constitutive resistance to macrolide/lincosamide antibiotics. This plasmid‐encoded property could be established by interspecific transformation experiments. The plasmid from porcine Staph. hyicus was designated as pSE2. It differed on the basis of its restriction map from the macrolid/lincosamid resistance (MLR‐)‐plasmids of other staphylococcal species from infections of humans. Furthermore, the pSE2 plasmid encoded two proteins of approximately 20.5 and 30 kDa.
Effect of different carbohydrates on growth, polysaccharidase and glycosidase production by Bacteroides ovatus, in batch and continuous culture
Authors: Macfarlane G.T. , Hay S. , Macfarlane S. , Gibson G.R.
Published: March 2008

Bacteroides ovatus was grown in batch culture on 12 different carbon sources (five polysaccharides, seven monosaccharides and disaccharides). Specific growth rates were determined for each substrate together with polysaccharidase and glycosidase activities. Growth rates on polymerized carbohydrates were as fast or faster than on corresponding simple sugars, demonstrating that the rate of polysaccharide depolymerization was not a factor limiting growth. Bacteroides ovatus synthesized a large range of polymer‐degrading enzymes. These polysaccharidases and glycosidases were generally repressed during growth on simple sugars, but arabinose was required for optimal production of α‐arabinofuranosidase. Polysaccharidase and glycosidase activities were measured in continuous cultures grown with either xylan or guar gum under putative carbon limitation. With the exception of β‐xylosidase, activities of the polymer‐degrading enzymes were inversely related to growth rate. This correlated with polysaccharide utilization which was greatest at low dilution rates. These results show that Bact. ovatus is highly adapted for growth on polymerized carbohydrate in the human colon and confirm that the utilization of polysaccharides is partly regulated at the level of enzyme synthesis. and accepted 8 June 1989
Deoxyribonucleic acid relatedness of 24 xanthomonad strains representing 23 Xanthomonas campestris pathovars and Xanthomonas fragariae
Authors: Hildebrand D.C. , Palleroni N.J. , Schroth M.N.
Published: March 2008

Twenty Xanthomonas campestris pathotype strains, three non‐pathotype strains, and one strain of X. fragariae were studied by S1 DNA:DNA hybridization tests. The results of these tests do not support the retention of X. campestris as a single species. DNA reassociation values among many of the strains were low. Three clusters of closely related strains were observed, but nine strains did not cluster. Xanthomonas campestris pv. secalis was more closely related to X. fragariae than to any other X. campestris pathovar. Mapping the host family upon a three‐dimensional genomic distance matrix of the xanthomonads suggested that strains attacking the same plant family usually show some relationship, but only a distant one. Thus, pathogenicity toward members of the same host family is not a measure of the genomic relationships of xanthomonads.
The survival of streptococci and enterococci in animal feed and on straw with particular reference to Streptococcus uberis
Authors: Mackey E.T. , Hinton M.
Published: March 2008

The survival of Streptococcus uberis, Strep. bovis, Enterococcus faecalis spp. faecalis and Ent. faecium in animal feed and on wheat straw was studied for one month. Streptococcus bovis survived the best in feed and Strep. uberis the worst while on straw Ent. faecium was the most resilient species and there was little to choose between the other three. The recovery of all species, excepting Strep. bovis, on selective and non‐selective agar was comparable. The growth of Strep. bovis, on the other hand, was inhibited on both Edward's medium and inulin agar.
The implications of the loss and regain of cotton‐degrading activity for the degradation of straw by Ruminococcus flavefaciens strain 007
Authors: Stewart C.S. , Duncan Sylvia H. , McPherson Carol A. , Richardson A.J. , Flint H.J.
Published: March 2008

Cultivation of the cellulolytic anaerobe Ruminococcus flavefaciens strain 007 on a nutrient medium containing cellobiose as energy source resulted in a four‐ to five‐fold reduction in the cotton‐degrading activity of the strain after 15–18 subcultures. Two single colony re‐isolations also lost cotton‐degrading activity after repeated cultivation on cellobiose. When the form with poor cotton‐degrading activity (007S) was serially subcultured on cotton fibres, high cotton‐degrading activity was recovered after 7–13 subcultures. One (of three) single colony re‐isolations of 007S also recovered cotton‐degrading activity under these conditions. The time course of these changes in activity suggests that they resulted from mutations. The cotton degrader (007C) was slightly more active against Avicel, Sigmacell and filter paper than was 007S, but 007S and 007C showed similar activity against acid‐swollen cellulose. Strain 007C was not significantly more active than 007S in degrading barley straw (with or without ammonia treatment) or wheat straw. The property that enables strain 007C to degrade cotton appears to play at most a minor role in the degradation of straw. and accepted 5 July 1989
The effects of controlled exposure to formaldehyde vapour on spores of Bacillus globigii NCTC 10073
Authors: Cross G.L.C. , Lach V.H.
Published: March 2008

The effects of exposure of spores of Bacillus globigii NCTC 10073 to controlled levels of formaldehyde vapour under varying environmental conditions are reported. The death rate of the micro‐organism varies with the humidity and formaldehyde concentration and can be predicted for conditions within the limits of the information available. A mathematical model for the effects of formaldehyde is proposed which can be used to calculate the effects of known conditions and as the basis of a controlled formaldehyde fumigation process. Results of practical tests of such a process are described.