摘要:

The deterioration of prepacked cod fillets in relation to the oxygen permeability of the polyethylene film was studied bacteriologically and chemically. Spoilage at 0° is not related directly to oxygen permeability (OP). The deterioration curve at higher storage temperatures (3 and 6°) is of the same form as the curve at 0°. Moreover, from the curve it can be deduced that a film withc.3600 ml/m2/24 h OP gives the best results. A maximum spoilage is observed with an OPc.1800 ml/m2/24 h. Identical results were obtained with other films. The formation of formalin bound volatile nitrogen compounds is inhibited in prepacked fish whereas the trimethylamine content increas

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1971.tb02312.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

A strain ofPolyangium luteumwas isolated from rabbit dung and grown in pure culture. This strain is described.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1971.tb02313.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

A model describing the dependence of the proportion of items contaminated (P) in a population of items on radiation dose (D) has been developed. The model was evaluated for a range of doses assuming a Poissonian distribution of micro‐organisms on items prior to and during irradiation and radiation inactivation according to ‘multiple‐hit’ kinetics; curves relatingPandDwere constructed. The influence on curve shape of changing the initial average number of micro‐organisms on items and of varying parameters of microbial sensitivity to radiation was assessed. Consideration was given to the value of using sub‐process radiation doses in microbiological quality cont

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1971.tb02314.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

A simple gas chromatograph with a katharometer detector is described to determine O2, N2, methane and CO2in gas samples of 0·01–2·0 ml. The apparatus is inexpensive, and can be modified to determine other gases. The sensitivity to oxygen is 3 × 10−6g. The use of the instrument is illustrated by a study of the growth kinetics ofMethylococcus capsulatusgrown on methane in shake flask experiments. The ratio of O2uptake to methane uptake is much lower in the stationary phase than in the growth phase of the c

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1971.tb02315.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

Twentyseven cultures of lactobacilli, isolated from 27 packs of spoiled vinegar preserves, which originated from 21 manufacturers and included 12 varieties of product, were examined according to the system of Rogosa&Sharpe and by other tests. One culture conformed to the characteristics ofLactobacillus caseivar.casei; 2 cultures to those ofL. brevis; 4 cultures to those ofL. buchneri; and 20 to those ofL. fructivorans.On the basis of the results and an examination of the literature it is suggested thatL. trichodesis a synonym ofL. fructivorans.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1971.tb02316.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

The causative organism of fire‐blight,Erwinia amylovora, survives well when contained in small airborne particles held in the laboratory at relative humidities between 40 and 90 %. Although greater loss of viability occurred when simulated aerosols were exposed to the open air, there were still significant numbers of organisms viable after 2

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1971.tb02317.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

Fentichlor is adsorbed in fairly large amounts byStaphylococcus aureusandEscherichia coliand, according to the quantity adsorbed, is either bacteriostatic or bactericidal. The observed pattern of uptake, measured under various conditions, indicates that uptake involves reversible adsorption of the neutral molecule on to the cell. The drug is taken up by the cell wall and cell membrane, the latter probably being the main site of adsorption and main site of action. Although both whole cells and cell walls ofE. colihave a higher affinity for Fentichlor than those ofStaph. aureus, the former is less susceptible to its antibacterial action. Results indicate that this may be due to the lipid‐rich nature of the cell walls ofE. coliwhich act as an adsorbing barrier preventing the access of the drug to its site of actio

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1971.tb02318.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

Fentichlor produces rapid and marked damage to cell membranes ofStaphylococcus aureusandEscherichia colicausing leakage of 260 nm material and pentose from whole cells, and lysis of spheroplasts ofE. coli.Investigations indicate that Fentichlor‐induced membrane damage is related to bactericidal activity. Bacteriostatic concentrations of 10 μg/ml or less do not stimulate leakage while at higher concentrations there is a marked relationship between loss of viability and of metabolic pool material released. Drug concentrations producing 99·99% kill within 1 h correspond closely to minimum concentrations required to produce total loss of 260 nm material from the pool. Membrane damage caused by bactericidal concentrations of drug is irreversible and under conditions optimal for enzyme activity additional leakage of 260 nm material resulting from autolytic breakdown of insoluble nucleic acids also occurs. There is no evidence that Fentichlor produces precipitation of cell cytoplasmic constitue

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1971.tb02319.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

Investigations of the effect of low concentrations of Fentichlor on the metabolic activities of Staphylococcus aurew and Escherkhk coli indicate that the bacteriostatic action of the drug results from a specific inhibition of metabolic reactions within the cell which are energy‐requiring. Bacteriostatic concentrations of Fentichlor inhibit energy dependent uptake of amino acids, assimilation of amino acids and glucose into cellular material and total protein synthesis. In contrast, energy‐independent uptake of amino acids and the uptake of glucose is little affected. These concentrations do not inhibit respiratory enzymes and selective inhibition of energy metabolism by Fentiohlor probably results from a disruption of the mechanism of energy coupling within the c

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1971.tb02320.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY

摘要:

A nalidixic acid resistant mutant ofSalmonella typhimuriumwas isolated more frequently from the Bursa of Fabricius than from the caecal contents, caecal tonsil, liver or spleen of chickens that had been given a culture of this mutant by mouth. Salmonellae were also isolated more frequently from the Bursa than from the caecal contents of naturally infected chickens.

ISSN:0021-8847    

DOI:10.1111/j.1365-2672.1971.tb02321.x

出版商:Blackwell Publishing Ltd    

年代:1971

数据来源: WILEY