摘要:

J.A. HUDSON, C.A.M. MACKENZIE AND K.N. JOBLIN. 1996. ASelenomonassp., isolated from the ovine rumen, was characterized with regard to its ability to hydrate oleic acid to 10‐hydroxystearic acid. Hydration occurred only in stationary phase in a medium containing 0.1%, 0.5% (w/v) galactose or 0.5% (w/v) glucose, but not in a medium containing 1% galactose. Growth under a hydrogen headspace did not result in the production of stearic acid, the biohydrogenated product of oleic acid. Linoleic and linolenic acids (0.1% v/v) were not hydrated. It is concluded that the growing bacterium is unlikely to contribute to oleic acid hydration in the rume

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb00048.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

G.D. WARD, I.A. WATSON, D.E.S. STEWART‐TULL, A.C. WARDLAW AND C.R. CHATWIN. 1996. Near infrared light from a high‐powered, 1064 nm, Neodymium : Yttrium Aluminium Garnet (Nd : YAG) laser killed a variety of Gram‐positive and Gramnegative bacteria and two yeasts, lawned on nutrient agar plates. A beam (crosssectional area, 1.65 cm2) of laser light was delivered in 10 J, 8 ms pulses at 10 Hz, in a series of exposure times. For each microbial species, a dose/response curve was obtained of area of inactivation vs energy density (J cm−2). The energy density that gave an inactivation area (IA) equal to 50% of the beam area was designated the IA50‐value and was plotted together with its 95% confidence limits. Average IA50‐values were all within a threefold range and varied from 1768 J cm−2forSerratia marcescensto 4489 J cm−2for vegetative cells ofBacillus stearothermophilus.There were no systematic differences in sensitivity attributable to cell shape, size, pigmentation or Gram reaction. At the lowest energy densities where inactivation was achieved for the majority of organisms (around 2000 J cm−2), no effect was observed on the nutrient agar surface, but as the energy density was increased, a depression in the agar surface was formed, followed by localized me

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb00049.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

B. MANNA, A. GAMBHIR AND P. GHOSH. 1996.Sphingomonas paucimobiliswas used for the synthesis of the microbial polysaccharide gellan. In a 60 h fermentation, polysaccharide yield and productivity obtained were 0.45 g gellan per g glucose consumed and 0.21 g I−1h−1respectively. The broth showed pseudoplastic behaviour with yield stress. The requirement of the solvent propanol to precipitate gellan from the broth depended on the volume of the broth rather than on gellan concentration. The addition of salt to the broth reduced the propanol requirement. Attempts to separate cells from the highly viscous broth by microfiltration were not successful. Ultrafiltration reduced the propanol requirement but appreciable membrane fouling and loss of gellan was obser

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb00050.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

P.H. DAMGAARD, H.D. LARSEN, B.M. HANSEN, J. BRESCIANI AND K. JØRGENSEN. 1996. Strains ofBacillus thuringiensiswere isolated from various food items (pasta, pitta bread and milk) and were found to belong to either H‐serotype kurstaki or neoleonensis. The strains were bioassayed againstPieris brassicaeand insecticidal activity of strains was found to correspond to the presence of thecry1.A‐gene. All strains, except one, were found to express cytotoxic effects on Vero cells as an indicator of enterotoxin activity. Further, theB. thuringiensisstrains HD‐1 (serotypekurstuki), NB‐125 (serotypetenebrionis) and HD‐567 (serotypeisruelensis) which are used commercially for insect pest management, were also found to have cytotoxic effects on

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb00051.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

T. UMEMOTO, Y. NAITO, M. LI, I. SUZUKI AND I. NAMIKAWA. 1996. Agar diffusion analysis demonstrated that rat cystatin S, a cysteine proteinase inhibitor, inhibited the growth of all tested strains of a human oral, Gram‐negative anaerobic periodontopathogenPorphyromonas gingivalis.Its specific inhibitory activity against this tissue‐invasive bacterium but not against other tested oral bacterial species emphasized the importance of specific cysteine proteinases for growth of P. gingiva

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb00052.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

M.J. ALMEIDA AND C.S. PAIS. 1996. Yeasts were isolated from a variety of home‐made bread doughs and identified. A pure culture ofSaccharomyces cerevisiaewas found in 18% of the doughs. The same species predominated in 80% of the doughs examined whereasIssatchenkia orientalis, Pichia membranaefaciensandTorulaspora delbrueckiiwere present in about 40% of the samples. About one quarter of the isolates displayed killer activity, strains ofP. anomalashowing the broadest spectra. Two isolates ofS. cerevisiaeand three ofT. delbrueckiigave biomass values in sucrose medium similar to or higher than those obtained with commercial compressed baker's yeast strain

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb00053.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

D.J. JACKSON, V.A. SAUNDERS AND A.M. HUMPHREYS. 1996. Microsomal chitinase from yeast and hyphal cells ofCandida albicanswas activated endogenously by incubation at 30°C and exogenously by trypsin. The putative activating factor of yeast cells was separated from chitinase activity by fractionation of lysed protoplasts on an Iodixanol density gradient. The vacuole fraction contained no significant chitinase activity, but was enriched in chitinase activating factor. Activity of microsomal chitinase increased upon incubation with this, but no other gradient factor. Results suggest that the regulatory system governing microsomal chitinase activity, like that governing chitin synthase, involves a ‘vacuolar’activating factor inCandida albi

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb00054.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

P. IRIARTE AND R. J. OWEN. 1996. Forty‐seven strains ofCampylobacter jejuniwere examined by PCR‐RFLP analysis of 23S rRNA genes. Seven different molecular profiles were detected by a combination ofHpaII AluI and DdeIdigest analysis. Most (83%) strains, including those with different Penner serotypes and from different hosts, had the same molecular profiles. The high level of conservation apparent within the 23S rDNA sequences confirmed their value as targets in species‐specific PCR identification assays but not for subtypic discrimination withinCamp. j

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb00055.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

摘要:

R.H. MADDEN, L. MORAN AND P. SCATES. 1996. Based on a 10‐mer primer (5′‐ CCTGTTAGCC‐3′), a random amplified polymorphic DNA (RAPD) method for typingCampylobacter coliisolated from pigs was developed. The method proved effective with a high discrimination and good reproducibility. In contrast with serotyping no untypable strains were found out of a total of 269 isolates (veterinary, food and clinical) examined. The method was also successfully applied to typingCampylobacter jejunifrom a similar range o

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb00056.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1996.tb00057.x

出版商:Blackwell Publishing Ltd    

年代:1996

数据来源: WILEY