摘要:

BarnetYvonneM., Daft, M.J. Stewart, W.D.P. 1984. The effect of suspended particulate material on cyanobacteria‐cyanophage interactions in liquid culture.Journal of Applied Bacteriology56, 109–115.The effect of the lytic phage LPP‐DUN 1 on the cyanobacteriumPlectonema boryanumhas been investigated in batch and in continuous cultures in the presence and absence of silt. In batch culturePlectonemawithout added phage grew normally; the presence of phage caused rapid lysis of the cyanobacterium and the addition of silt prevented lysis by the phage. In continuous culture the numbers of cyanobacterial cells and phage particles oscillated in a reciprocal manner, but the addition of silt damped down the oscillations inPlectonemabiomass without decreasing the numbers of phage particles isolated from the cultures. The presence of silt thus appears to protect the cyanobacterium from lysis by phage, although the total numbers of phage particles are relatively unaffected by the silt, at least in the short

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb04701.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Dutta, G.N. Devriese, L.A. 1984. Observations on thein vitrosensitivity and resistance of Gram positive intestinal bacteria of farm animals to growth promoting antimicrobial agents.Journal of Applied Bacteriology56, 117–123.Results of qualitativein vitrosensitivity tests made with growth promoting antimicrobial agents on clostridia, lactobacilli and enteric streptococci, isolated from caeca of pigs, cattle and poultry, are summarized. The compounds were activein vitroagainst most of the 19 bacterial species studied. However, their activity spectra differed markedly. Only four bacterial species were naturally sensitive to all agents. The natural resistances, typical for many species and compounds, could be differentiated from the acquired resistances found with all growth promotors except avoparcin. High resistance and complex patterns of cross‐resistance involving one or more of the macrolide, lincosamide and streptogramin antibiotics were detec

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb04702.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Archer, D.B. 1984. Hydrogen‐using bacteria in a methanogenic acetate enrichment culture.Journal of Applied Bacteriology56, 125–129.In a study of the anaerobic utilization of acetate, an enrichment culture of sewage sludge organisms was initiated with calcium acetate as the sole carbon and energy source. A mixed bacterial population became established from which 14 anaerobic species were isolated. Two of the isolates were methanogenic bacteria but only one of these,Methanosarcina barkeri, utilised acetate as an energy source in axenic culture. The other methanogenic isolate, aMethanobacteriumsp., utilised H2/CO2but not acetate. A third methanogen, which was morphologically identical toMethanothrix soehngenii, was detected in the enrichment but was not obtained in monoculture. 2‐Bromoethanesulphonate, a specific inhibitor of methanogenesis. completely inhibited the enrichment at a concentration of 10 μmol/1. Addition of H2formate or methanol to the enrichment did not affect the rate of methanogenesis. An H2‐utilizingDesulfovibriosp. was also isolated from the en

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb04703.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

McLoughlin, T.J. BordeleauL.M.&Dunican, L.K. 1984. Competition studies with Rhizobium trifolii in a field experiment.Journal of Applied Bacteriology56, 131–135.Competition studies were carried out in a field experiment by comparing the ability of antibiotic markedRhizobiumstrains inoculated at three inoculum levels in forming nodules against an effective indigenousRhizobiumpopulation of 1.5 times 105/g. Three inoculum strains were assessed. It was seen that by increasing the level of inoculum there was a corresponding increase in the number of nodules formed by the introduced strains. G1067 formed a high proportion (85%) at the highest level, whereas the other two inoculum strains occupied less than 50% of the nodules at the same level. Persistence of the inoculum strain was measured into the second season; G1032 could not be detected, G1006 (another ‘foreign’ strain) formed 43% and G1067 formed 97% of the nodules sampled. The indigenousRhizobiumpopulation isolated from nodules was shown to be heterogenous, and 15 different intrinsic antibiotic resistance patterns were found. Fifty per cent of the isolates fell in the same group which showed a similar pattern to that of the inoculum strain

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb04704.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Macaskie, LynneE. Sheard, A.G.M. Dainty, R.H. Henderson, P.J.F.1984. Glycerol utilization by Brochothrix thermosphacta.Journal of Applied Bacteriology56, 137–143.Growth of the meat spoilage organism,Brochothrix thermosphacta, was supported by either glucose or glycerol with acetoin production. Similar yields of bacteria were obtained at growth‐limiting concentrations of either substrate. The rate of uptake of each substrate was similar but glycerol supported higher rates of respiration than glucose. These findings are discussed in relation to metabolism of glycerol and the use of glycerol for meat stor

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb04705.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

McWalter, P.W. 1984. Determination of susceptibility ofStaphylococcus aureusto methicillin by luciferin‐luciferase assay of bacterial adenosine triphosphate.Journal of Applied Bacteriology,56, 145–150.Susceptibility of 50 strains ofStaphylococcus aureusto methicillin was determined by disc diffusion, minimum inhibitory concentration (MIC) test and luciferin‐luciferase assay of bacterial adenosine triphosphate (ATP). ATP concentration time curves calculated on eight strains (four sensitive, four resistant) incubated at 30d̀C indicated 2.5 h as the optimum time for determination of methicillin susceptibility. The ATP concentration and relative light unit (RLU) value of each test broth (antibiotic‐containing), expressed as a percentage of its own control broth (antibiotic‐free) indicated values of<30% for ATP and<40% for RLU to be indicative of methicillin sensitivity. Single time point ATP assays carried out on the 50 strains after 2.5 h at 30d̀C correlated exactly with disc diffusion and MIC. Luciferin‐luciferase assay of bacterial ATP appeared to be a reliable, rapid technique for determining the susceptibility ofStaph. aureust

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb04706.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Bolton, F.J. CoatesD.&Hutchinson, D.N. 1984. The ability of campylobacter media supplements to neutralize photochemically induced toxicity and hydrogen peroxide.Journal of Applied Bacteriology56, 151–157.Nutrient agar plates stored in light and air for 48 h became inhibitory forCampylobacter jejuni, C. coliand nalidixic acid‐resistant, therrnophilic campylobacter (NARTC) strains. All five campylobacter test strains showed>5 log reduction in counts on media which had been stored in light and air. Media stored in the dark and/or in a reduced atmosphere did not become inhibitory and supported the growth of campylobacters. Ferrous sulphate, sodium pyruvate, blood, charcoal or sodium metabisulphite, compounds frequently used as supplements in campylobacter media, were added to nutrient agar prior to storage of media in light and air. All additives except sodium metabisulphite prevented the accumulation of photochemically generated toxic oxygen derivatives and allowed growth of test strains. In qualitative tests to determine the ability of supplements to neutralize hydrogen peroxide, blood was the most active, charcoal and sodium pyruvate slightly less active and ferrous sulphate and sodium metabisulphite the least active. The results of this study confirm that supplements in campylobacter media act as quenching or detoxifying agents and not as enrichment fact

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb04707.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

A. Baumgartner, J. Nicolet&M. Eggimann1984. Plasmid profiles ofStaphylococcus aureuscausing bovine mastitis.Journal of Applied Bacteriology56, 159–163.Plasmid profiles ofStaphylococcus aureus, isolated from herds affected with chronic bovine mastitis, are heterogeneous, as shown by the study of 85 strains from 18 different farms. The strains isolated within a herd sometimes show related plasmid patterns, although even strains isolated from different quarters of the same udder may show variations in their plasmid content. Strains without antibiotic resistance are frequently free of plasmids. Therefore, the existence of mastitis Staph. aureus virulence plasmids is unlikely.Staphylococcus aureus, resistant to penicillin and streptomycin from 9 different farms show related plasmid patterns. This result confirms a geographic spread of certain mastitis Staph. aureus strain

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb04708.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Calcott, P.H. Oliver, J.D. Dickey, K.&CalcottKatherine, 1984. Cryosensitivity ofEscherichia coliand the involvement of cyclopropane fatty acids.Journal of Applied Bacteriology56, 165–172.Strains ofEscherichia coliproficient and deficient in cylopropane fatty acid synthesis were compared for fatty acid content, cryosensitivity, presence of freeze‐thaw‐induced wall and membrane damage, resistance to detergent‐stimulated lysis and tolerance to salt and detergents during growth. The mutant populations synthesized much less cyclopropane fatty acids and were more resistant than the wild type to freezing and thawing in saline only, exhibiting less viability loss and less wall and membrane damage. While the resistance of the mutants to NaCl was unaltered, their detergent resistance was decreased under both growth and non‐growth conditions. Although these physiological changes were associated with a lower cyclopropane fatty acid content in the mutant strains, it is proposed that the responses were due to the altered membrane fluidity of the mutants due to changes in their unsaturated fatty aci

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb04709.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

ZlotnikovK.M. ChatuevB.M.khmelnitsky, M.I. 1984. A note on the isolation of auxotrophic mutants ofRhizobium japonicum. Journal of Applied Bacteriology56, 173–174.Several different stable auxotrophic mutants ofRhizobium japonicumwere isolated following NG mutagenesis. It was found that NG mutagenesis of the rhizobia was most efficient at pH 7

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb04710.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY