摘要:

Summary.A double layer plating technique was used for countingBdellovibrio bacteriovorusin river water and sewage samples. The optimum conditions for enumeration were provided by dilute media with 0.6 % of agar as the top layer, incubated for 6 days at 30° withAchromobactersp. as the host. Pretreatment of samples affected counts: centrifugation and membrane filtration reduced the bdellovibrio count, homogenization increased it. Protozoa in sewage samples caused large plaques that greatly hindered counting and attempts to eliminate these plaques were unsuccessful. The highest counts in sewage samples averaged 900 cells/ml

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1973.tb04066.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.An assay of pyocine based on the turbidimetric measurement of the percentage inhibition of a sensitive indicator strain ofPseudomonas aeruginosais described. The tendency of this organism to clump is circumvented in the method which is simple, rapid in performance and has good precision and reproducibility.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1973.tb04067.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.After freeze‐etching, cells ofMicrococcus denitrificansandM. halodenitrificansrevealed structures similar to those observed in ultrathin sections. Both organisms had a similar cell wall structure. The cell wall was double layered, the smooth surface of which had a delicate granular structure. The cytoplasmic membrane was in 2 parts, both covered with spherical particles 8–12 nm diam. The cytoplasmic membrane possessed rod‐shaped invaginations (100–300 × 30–50 nm). The cytoplasm of both species contained inclusions of poly‐β‐hydr

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1973.tb04068.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.The enumeration of sparse populations of clostridia by a total clostridia count technique in a fluid medium (DRCM) gives small estimates of the numbers ofClostridium welchii.This organism may be readily detected in mixed ‘presumptive total’ clostridia cultures by streaking on lactose‐egg yolk‐milk agar before pasteurizing these cultures. The results of screening poultry carcases and processing plants with this technique are presented and the incidence ofCl. welchiion 3 sites of poultry carcases (breast, vent and neck skin) are compared for 3 processing

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1973.tb04069.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.A method is described which increases the efficiency of recovery of microorganisms from solid, fibrous and polymer materials. It is suitable for routine assessment of the microbial quality of various medical products.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1973.tb04070.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.Spores of 2 strains ofBacillus megateriumproduced on a complex medium showed absorption of their coats on germination whereas those produced on a chemically defined medium emerged by rupture of the coat. Spores produced on a complex medium were the more resistant to chlorocresol.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1973.tb04071.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.A study of the range of organic compounds utilized as sole carbon source byAcinetobacter lwoffiiNCIB 10553 indicates that the organism isAcinetobacterA2 in the classification of Baumann, Doudoroff&Stanier (1968). NCIB 10553 resembles NCIB 8250 (‘Vibrio 01′, described by Fewson, 1967a,b). NCIB 10553 adapted to utilize acetylsalicylate does not grow with the lowern‐alkanes, whereas it does utilize some sugars, although after a lag, and grows readily on a number of aromatic and aliphatic carboxylic esters, including triglycerides, natural oils and fats and other compounds of pharmaceutical interest. Cell‐free extracts readily hydrolyse fatty acid esters of the mono‐ and dihydroxybenzoates and of catechol, quinol, phenol andp‐nitrophenol. They also simultaneously hydroxylate and decarboxylate salicylate, 2,3‐, 2,4‐, 2,5‐ and 2,6‐dihydroxybenzoate but only in the presence of NADH (or NADPH) and FAD. Some other aromatic acids are slowly oxidized und

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1973.tb04072.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.A series of nitro compounds studied inhibitedEscherichia coli, Staphylococcus aureusandPseudomonas aeruginosa, bronopol being the most active derivative. Bronopol causes some membrane damage. A consideration of its action on enzyme activity, reaction with cell constituents and chemical reaction with cysteine, glutathione and proteins suggests that the oxidation of thiol groups to disulphides may be its primary action.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1973.tb04073.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.The population of aerobic bacteria present in the waters of a tip‐lagoon system being used to purify a coke‐oven effluent has been investigated. Though organisms capable of degrading phenol were detected, the total bacterial population was low, mainly due to a deficiency of orthophosphate and lack of aeration. Phenols can be removed from coke‐oven effluents by allowing them to percolate through columns of material from colliery waste tips. Bacteria need not be present for this to occur though the presence of bacteria capable of degrading phenol were detected in the liquid coming from such columns. Only traces of thiocyanate are removed. If a biological filter can be developed, as on columns packed with gravel, better removal of phenols and thiocyanate occurs, but it is doubtful if bacteria play any significant role in the purification of coke‐oven waste liquors percolating through large tips of collier

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1973.tb04074.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY

摘要:

Summary.Anin vitroassociation between cells ofSaccharomyces cerevisiaeand aLeuconostocsp. has been demonstrated using the scanning electron microscope. These organisms are often naturally associated in fruit products and fermenting beverages such as apple juice and cider.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1973.tb04075.x

出版商:Blackwell Publishing Ltd    

年代:1973

数据来源: WILEY