ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1979.tb01196.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Strains ofLactobacillussp.,Leuconostocsp. andStreptococcussp. were preserved for 6–24 months at ambient temperature, partially dehydrated on granular pumice stone. To date, all the cultures stored by this technique have remained viable and no changes in the cultural or biochemical characteristics were observe

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1979.tb01197.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

A synthetic medium containing only low molecular weight components has been developed to growPropionibacterium acnes (P. acnes), P. avidumandP. granulosum.The medium supported the growth of 30/32 typed strains, and when solidified with agar supported the growth of these bacteria isolated directly from the skin. The mean overall efficiency of isolation on the synthetic medium was 57% that of reinforced clostridial medium (RCM).Batch culture experiments with glucose, fructose, glycerol or arginine in the medium showed that the concentrations as well as the type of carbon energy sources used could effect growth and exocellular enzyme production by these organisms.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1979.tb01198.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

A chloramphenicol resistant strain ofPediococcus acidilactici(NCIB 11432) was used in a work‐simplified, whole‐serum assay of L‐methionine. The assay compared favourably with an extraction technique and was much simpler to pe

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1979.tb01199.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

A sharply defined white line of precipitate forms in Pseudomonas Agar F (Difco) between the opaque white colonies ofPseudomonas tolaasiand translucent colonies of certain unidentified pseudomonads. This visible interaction has been utilized in a specific and reliable method for the identification ofPs. tolaasi.The white line test was positive when 113 isolates ofPs. tolaasifrom five different countries were examined, whereas 154 isolates of pseudomonads other thanPs. tolaasi, includingPs. corrugata, Ps. delphinii, Ps. fluorescens, Ps. lachrymans, Ps. marginalis, Ps. pastinaceae, Ps. phaseolicola, Ps. aeruginosa, Ps. putida, Ps. syringae, Ps. mors‐prunorum, Ps. cichorii, Ps. antirrhini, Ps. viridiflava, Ps. caryophylli, Ps. cepacia, Ps. mendocina, Ps. stutzeri, Ps. acidivorusandPs. lemoigneidid not give the white line reaction with a reacting translucent colony pseudomonad. Browning of mushrooms in host tests does not help in the identification ofPs. tolaasi, but a conspicuous pitting produced in less than 10 min at the cut surface of mushroom tissue is as specific as the white line test in detectingPs. tolaasiin suspension in distilled wate

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1979.tb01200.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Washed suspensions of the rumen ciliate protozoonEudiplodinium maggiigrownin vitroand incubated anaerobically engulfed all the bacteria tested except forBacteroides ruminicolaandKlebsiella aerogenes.There was considerable variation (160–9100 bacteria/h/protozoon at an external concentration of 1010bacteria/ml) in the rate at which the bacteria were engulfed, butEu. maggiishowed some preference for bacteria of rumen origin. Some of the bacteria were digested with the release of soluble materials into the medium. Free amino acids were incorporated from an 0.1 mM solution at rates of 0.13 to 0.84 pmol/h/protozoon. Evidence is presented thatEu. maggiicould obtain half the amino acids required for growth by the engulfment and digestion of bacteria and half by the uptake of free amino acids.Eudiplodinium maggiiincorporated uridine 5' monophosphate and also hydrolysed this to uridine and then to uracil which was reduced to dihydrouracil. These products all appeared in the medium. Ribose was incorporated by the protozoon and appeared as glucose in protozoal and bacterial polysaccharide; none was incorporated as such into protozoal nucleic aci

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1979.tb01201.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Bacteria isolated from contaminated pitching yeast, fermenting wort and beer samples from a South African lager brewery over a one‐year period were tentatively identified by an improved, rapid diagnostic procedure as pediococci (41%), homofermentative lactobacilli (5%), heterofermentative lactobacilli (9%),Acetobacterspp. (7%),Gluconobacterspp. (13%) andHafnia protea(25%). Pediococci and lactobacilli dominated samples taken from fermentation, storage and ‘bright’ beer tanks but were absent from pitched wort samples, from collection vessels and the single pitching yeast sample investigated. Acetic acid bacteria andH. proteawere widely distributed in collection vessel, fermentation and storage tank samples, andH. proteawas isolated from recycled pitching

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1979.tb01202.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

An attempt was made to develop a selective isolation medium forClostridium sporogenesand related organisms based on the ability of these organisms to obtain their energy for growth by means of coupled oxidation‐reduction reactions between appropriate pairs of amino acids (Stickland reaction). Using a semi‐defined basal medium containing various combinations of amino acids, it was found thatCl. sporogenesutilized a wider range of amino acid pairs than strains of five other species of clostridia known to carry out a Stickland‐type fermentation.With alanine and proline as the principal energy sources and the medium solidified with agar. it was shown that reference strains ofCl. sporogenesand proteolyticCl. botulinumtypes A, B and F could be recovered almost quantitatively, with or without prior heating at 80 °C for 10 min. By contrast, growth of test strains ofStreptococcus faecalis, Strep. faecium, ‘saccharolytic’Cl. botulinumtypes B, C, D, E and F and ‘proteolytic’ strains of types C and D was suppressed on this medium, as were strains of 26 other species of clostridia.Addition of 50 μg/ml of polymyxin to the agar medium had no detectable effect on the recovery ofCl. sporogenesorCl. botulinum.When samples of soil and mud were plated on the antibiotic‐containing medium, 63.1% of 225 isolates thus obtained were identified asCl. spo

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1979.tb01203.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

Joints of beef were stored in packaging films with oxygen permeabilities ranging from 0–920 ml/m224 h/atm at 25 °C and 100% r.h. The storage life of the ‘vacuum‐packaged’ meat, as assessed by discolouration and the development of putrefactive odours, was inversely related to film permeability; the best results were obtained with meat which received ‘zero oxygen’ treatment. The growth rates and final counts ofPseudomonasspp. increased with increasing film permeability; the storage life of the meat corresponded with the time taken for the counts of the organism to reachca.106/cm2for putrefactive odours to be produced. Although their growth rate was unaffected, the final counts ofBrochothrix thermosphactaalso increased with increasing film permeability. These results are discussed in terms of the influence of film permeability on the inhibitory effects ofLactobacillusspp., whose numbers were unaffected by the permeability of the film used, and the substrates in the meat available to

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1979.tb01204.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY

摘要:

The mean NH3concentration in the rumen of sheep fed whole barley (0d̀8 kg/d) by continuous feeders was increased from 6d̀1 to 13d̀4 HIM by supplementing the feed with urea (30 g/kg). This change caused a 90% increase in the rate of degradation of rolled barley, and smaller increases in the rates of degradation of protein and plant fibre in the rumen. The total viable count and numbers of pectinolytic bacteria in rumen fluid increased with the urea supplement. Enzyme studies indicated that NAD‐linked glutamate dehydrogenase was the main pathway of NH3assimilation by rumen bacteria at both NH3concentrations. Glutamate was the main free amino acid found in the rumen at low NH3but, despite the low activity of alanine dehydrogenase and glutamate‐pyruvate aminotransferase, alanine was the principal amino acid at high NH3concentrations. Hydrolytic rumen bacteria may require the higher NH3concentration either for effective NH3assimilation by an unknown mechanism involving alanine or for full expression of enzyme ac

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1979.tb01205.x

出版商:Blackwell Publishing Ltd    

年代:1979

数据来源: WILEY