摘要:

Dent, V.E.&Williams, R.A.D. 1984.Actinomyces denticolensDent&Williams sp. nov: a new species from the dental plaque of cattle.Journal of Applied Bacteriology56, 183–192.Six strains of actinomyces isolated from the dental plaque of cattle were assigned presumptively to the genusActinomyceson the basis of Gram reaction, cellular and colony morphology and acid end‐products of metabolism. This assignment was confirmed by the peptidoglycan composition which is shared withActinomycesspecies from dental plaque. These cattle strains formed a homogeneous group on the basis of cell wall carbohydrate components, DNA base composition, polypep‐tide molecular weight distribution and physiological reactions but could not be classified with any recognised species ofActinomyces. A new taxonActinomyces denticolensis proposed for these st

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb01338.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Lowry, P.D.&Gill, C.O. 1984. Temperature and water activity minima for growth of spoilage moulds from meat.Journal of Applied Bacteriology56, 193–199.Five species of fungi were isolated from mould spoilage on meat other than black spot. ‘White spot’ colonies yieldedChrysosporium pannorumor anAcremonium sp.; ‘whiskers’ colonies yieldedThamnidium elegans or Mucor racemosus, and blue‐green colonies yieldedPenicillium corylophilum. Chrysosporium pannorumwas moderately xerotolerant with a minimum growth temperature of — 5d̀C. TheAcremoniumsp. andP. corylophilumshowed a similar level of xerotolerance but had a minimum growth temperature of — 2d̀C.Mucor racemosuswas no more xerotolerant than many spoilage bacteria and did not grow below ‐ 1d̀C, but grew rapidly at 3d̀C and above.Thamnidium elegansgrew at — 7d̀C on supercooled medium and an intrinsic minimum growth temperature of — 10d̀C was indicated. However, the low xerotolerance of this species precluded growth on frozen media below — 5d̀C. It seems therefore that — 5d̀C is the practical limiting temperature for mould growth on meat, and mould spoilage usually indicates that surfaces of freezer stored meats have appr

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb01339.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Abe, M.&Kurihara, Y. 1984. Long‐term cultivation of certain rumen protozoa in a continuous fermentation system supplemented with sponge materials.Journal of Applied Bacteriology56, 201–213.Inert polyurethane‐sponge cubes were added to an ‘artificial rumen’ fermenter. With crushed barley as protozoal substrate this system maintained a population of Ento‐dinia in both substrate bags and sponge cubes for 64 d in numbers (1 times 106/ml) comparable with those foundin vivo. This culture was more tolerant of variations in mechanical agitation and size and shape of substrate bags than a similar culture without the sponge cubes. The extent of protozoal sequestration, 2 h after feeding, on to the sponge cubes as well as on to acetone‐treated hay was evaluated. The bags of acetone‐treated hay and barley, and those of sponge cubes and barley could sequestrate the protozoa to the same extent as normal hay and barley. Based on the results of the short‐term experiments and those of the long‐term experiment with sponge cubes, a polyurethane‐sponge wall was added to the inside of the fermenter. This system maintained a varied protozoal population including large protozoa, holotrichs and Entodinia with a normal fermentation. The molar percentages of butyrate in the total volatile fatty acid (VFA) in each part of the fermenter with a sponge wall were higher than those in a fermenter without a sponge wall, suggesting that there was high protozoal activity related to the sponge wall. These results show that the introduction of the sponge wall to the fermenter produced an enlargement of the area for protozoal sequestration and a suitable micro‐habitat for the maintenance of Entodinia, large

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb01340.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Devriese, L.A. 1984. A simplified system for biotypingStaphylococcus aureusstrains isolated from different animal species.Journal of Applied Bacteriology56, 215–220.A biotyping system forStaphylococcus aureusstrains is proposed which is a simplified version of biotyping procedures described in the literature. It differentiatesStaph. aureusstrains from man and animals into host‐specific ecovars and biotypes which are not host‐specific. With the help of tests for βhaemolysin, staphylokinase, coagulation of bovine plasma and the crystal‐violet reaction, the origin of many but not allStaph. aureusstrains can be determined: 604 of 809 strains from man. poultry, cattle, pigs, goats, rabbits and foods could be alloted to four ecovars which are typically associated with man, poultry, sheep and goats and cattle. The other strains belonged to five non‐host specifi

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb01341.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Ashley, K.C. 1984. The antimicrobial properties of two commonly used antiseptic mouthwashes—Corsodyl and Oraldene.Journal of Applied Bacteriology 56>, 221–225.The antimicrobial activities of the mouthwashes Corsodyl and Oraldene against common buccal organisms were essentially similar. The concentration of the active substance in the two mouthwashes was well in excess of the minimum inhibitory concentrations determined. Also a rapid lethal effect on the bacteria was found which, when combined with the previous property, may well account for the usefulness of these products in infectious conditi

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb01342.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Hall, L.P. 1984. A new direct plate method for the enumeration ofEscherichia coliin frozen foods.Journal of Applied Bacteriology56, 227–235.A new method has been devised, incorporating a resuscitant stage, which allows direct isolation ofEscherichia colibiotype I, Irregular type II and Irregular type VI. Rapid indole tests on the distinctive colonies produced enable determinations ofE. colibiotype I to be made within 24 h. This method employs materials of low cost and achieves complete recovery of injured cells. It also detects not only anaerogenic strains but those which are slow in producing acid from lactose or give negative results by other methods. If required, further study of isolates can be made after the indole test. Comparisons were made between conventional methods, the new method and a similar direct plate method. The implications of the higher counts obtained by the two latter methods are discussed in relation to microbiological specifications and standards for frozen food

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb01343.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Garvie, E.I. Cole, C.B., Fuller, R.&Hewitt, D. 1984. The effect of yoghurt on some components of the gut microflora and on the metabolism of lactose in the rat.Journal of Applied Bacteriology56, 237–245Feeding yoghurt or base milk (from which the yoghurt was prepared by fermentation) to rats increased the counts of coliforms in the gut whereas the counts of lactobacilli were reduced by yoghurt but not by the base milk.Lactobacillus bulgaricussurvived in the guts of gnotobiotic and conventional rats when yoghurt was fed continuously.Streptococcus thermophilusalso survived in gnotobiotic rats but its ability to survive in conventional rats could not be examined. Both organisms failed to colonise the gut when a small inoculum of yoghurt was administered orally to germfree rats maintained on the stock diet.Streptococcus thermophilusbut notLact. bulgaricusgrew in the rat diet when testedin vitro. Two enzyme systems (β‐galactosidase and lactase) were studied using, respectively,o‐nitrophenyl‐β‐D‐galactopyranoside (ONPG) and lactose as the test substrates. Enzyme levels estimated with both substrates. increased in the gut contents when rats were fed yoghurt but an increase was only found with ONPG in the intestinal mucosa fraction. The bacterial origin of all this increased activity is discussed. The other lactose‐containing diets did not affect enzyme activity to the same degree. Feeding yoghurt changed the lactobacillus flora from one which was predominantly hetero‐fermentative (Lact. reuteri) to one which was predominantly homofermentative (

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb01344.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Nichols, W.W., Curtis, G.D.W.&Johnston, H.H. 1984. Detection of bacteriuria by bioluminescence: effect of pre‐analysis centrifugation of specimens.Journal of Applied Bacteriology56, 247–257.Three bioluminescence‐based, rapid methods of detecting significant bacteriuria were applied in parallel to 514 urine specimens. The results were compared with those of a quantitative pour plate viable count method, defined as positive if ≥ 105c.f.u./ml of urine were observed. When adjusted to yield 21% falsely positive results the three rapid methods yielded 24%, 21% and 19% falsely negative results. If specimens with evidence of urethral or vaginal contamination were excluded (237 specimens remaining) the three methods yielded respectively 14%, 8% and 13% falsely negative results. A major source of disagreement between the bioluminescence‐based methods and quantitative culture thus appeared to be contaminated urine

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb01345.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Chirife, J., Favetto, G.&FerroFontán, c.1984. Microbial growth at reduced water activities: some physicochemical properties of compatible solutes.Journal of Applied Bacteriology56, 259–268.The water activities (aw) of solutions of D‐arabitol (a major compatible solute in yeasts grown at reducedaw) and also of related polyols (L‐arabitol, xylitol and ribitol) were determined at 25d̀C. Theawof saturated solutions of L‐proline and monopotassium L‐glutamate (solutes which accumulate in bacterial cells at reducedaw) were also determined. The viscosities of L‐proline, monopotassium L‐glutamate and D‐arabitol solutions were measured at 25, 30, 35 and 40d̀C for various concentrations up to high molalities. The relative viscosity curves were described using a theoretical model for the concentration dependence of viscosity. No relationship of viscosity of the electrolytes to effectiveness as ‘compatible solutes’ were evident, neither were the compatible solutes particularly effective ‘structure makers

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb01346.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY

摘要:

Akhy, M.T., Brown, C.M.&Old, D.C. 1984. L‐Rhamnose utilisation inSalmonella typhimurium. Journal of Applied Bacteriology56, 269–274.L‐Rhamnose is degraded by strains ofSalmonella typhimuriumby isomerisation to L‐rhamnulose, phosphorylation to L‐rhamnulose‐1‐phosphate and cleavage to lac‐taldehyde and dihydroxyacetone phosphate. The enzymes involved are, respectively, rhamnose isomerase (Rhal), rhamnulokinase (RhuK) and an aldolase (Ald). Strains able to grow rapidly on L‐rhamnose contained a high‐affinity uptake system for3H‐L‐rhamnose that was induced by L‐rhamnose and repressed by D‐glucose. The synthesis of Rhal and RhuK was also induced by L‐rhamnose but was not repressed by D‐glucose. The synthesis of Ald was constitutive. Data are presented on some strains which grow very slowly on L‐rhamnose and

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1984.tb01347.x

出版商:Blackwell Publishing Ltd    

年代:1984

数据来源: WILEY