摘要:

A shaken thermal gradient device providing temperatures between 8.3 and 33.5° C was used to investigate the effects of silver ion on the duration of the lag phase and on minimum apparent growth temperatures ofHyphomicrobiumspp. grown at 29 and 9°C. With 29°C‐grown inocula, at lower temperatures, an increased time was required for growth initiation in the presence of silver ion added at 5 ng ml‐1. With silver ion added at 10 or 100 ng ml‐1, growth initiation was not observed at lower temperatures. With 100 ng ml‐1added silver ion, this effect also was observed with 9°C‐grown inocula. This increased sensitivity to silver ion could limit the ability ofHyphomicrobiumspp., and possibly other microbes, to initiate growth and to contribute to microbial functioning in silver‐impacted low temperatu

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00840.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Capsanthin and capsaicin, the colouring and pungent principles of red chilliCapsicum annum, respectively, were tested against the growth and aflatoxin producing potentials ofAspergillus flavusin SMKY liquid medium. Capsanthin completely checked both the growth and toxin production at all the concentrations viz. 0.2, 0.6 and 1.0 mg ml‐1, till the fourth day of incubation. On the 10th day growth of the fungus and toxin biosynthesis were 39 and 22% of the control, respectively, at 1.0 mg ml‐1. Capsaicin showed some inhibitory efficacy only up to the fourth day of incubation. The fungus grew thereafter with a marginal inhibition in growth at the highest concentration. The amount of the toxin in the medium was also hig

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00841.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Rambach agar (Merck) was evaluated for its reliability as a selective diagnostic medium for the differentiation ofSalmonellaspecies from other Enterobacteriaceae. Twenty‐fiveSalmonellastrains were cultured on each of three agar media, Rambach (RAM), xylose lysine desoxycholate (XLD) and bismuth sulphite (BSA). Typical, easily interpreted reactions and colony morphologies were achieved for 23 strains on RAM and BSA and 17 on XLD. Of 135 other Enterobacteriaceae cultured on RAM, 134 gave characteristics which differentiated them fromSalmonella. One strain which looked likeSalmonellawas identified asCitrobacter freundii. Rambach agar has potential as a supplementary agar in testing foods forSalmonella, but as with other selective diagnostic agars, it has limitation

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00842.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Starch ampicillin agar (SA), starch glutamate ampicillin penicillin agar (SGAP) and Aeromonas medium (AM) were evaluated for enumeration ofAeromonasspp. from foods. Recovery from pure cultures ofAer. hydrophilaandAer. caviaewas excellent on all media. Recovery ofAer. sobriawas best on AM agar, where 95.5% were recovered, compared with 31.9% on SA agar and 33.3% on SGAP medium.

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00843.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Total cellular DNA was extracted from 28 isolates ofFusarium oxysporumfrom vascular wilt of banana. The DNA samples were digested with the restriction endonucleaseHaeIII, and separated in agarose gels. Two characteristic banding patterns were seen in ethidium bromide stained gels. The two patterns correlated to strains believed to be of pathogenic races 1 and 4. A minor variation to these was detected with isolates of race 1 from Tanzania, which gave a typical race 1 band pattern, with an additional band of approx. 10 kb.

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00844.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Uptake of glutamate byVibrio choleraewas investigated in media of different osmotic pressure. Accumulation was higher at high osmotic pressures and most accumulation was within the first 6 min of incubation. Greater degradation of glutamate by cells incubated at low osmolarity was insufficient to account for the difference in accumulation levels. The results suggest the glutamate uptake may be important in adaptation ofV. choleraeto high salinities such as encountered in estuarine and marine environments.

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00845.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

A new species of the genusNeisseriais proposed,Neisseria iguanaesp. nov. The organism is associated with septic lesions in the common iguana (Iguana iguana) and the rhinoceros iguana (Cyclura cornuta) but is also a commensal. It resemblesN. animalisandN. canisphenotypically but is distinguished from these by exhibiting pronounced tetrad arrangement and alpha haemolysis and by fermenting gluconate.

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00846.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

A complete inhibition in aflatoxin production byAspergillus flavuswas observed with greater than 4.5 mg ml‐1of 20 g 100 ml‐1leaf extract ofAmorphophallus campanulatus(OL). Suppression in growth was also well pronounced (81% at 8.0 mg ml‐1). The comparative efficacy of the corm of the plant was lower. Calcium oxalate, an important constituent of ‘OL’, completely checked the growth and toxin biosynthesis at 0.4 mg ml‐1co

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00847.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Dichloromethane extracts fromXanthium spinosumL. were fractionated and the fractions tested for their bactericidal and fungicidal activity. From the active fraction, a compound was isolated and identified as xanthatin (I). Xanthatin was active againstColletotrichum gloesporoides, Trichothecium roseum, Bacillus cereusandStaphylococcus aureus.

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00848.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY

摘要:

Laboratory studies were conducted on microbial leaching of non‐sulphide nickel ores not amenable to conventional mineral processing operations. The results showed that extensive low‐grade laterite domestic sources are generally amenable to bioleaching when micro‐organisms were cultivated in the presence of the ore. Nickel recoveries were as high as 60% using hydroxycarboxylic acid producing strains ofAspergillusandPenicilliumcodes A3, P2. Cobalt recovery achieved was around 50%. Losses of soluble nickel in the fungal biomass were found to be 3.5–10.8%. Chemical analysis of the leach liquors showed the presence of significant amounts of citric, oxalic and other organic acids, indicating that leaching may be ascribed to the production of these metabolic products of fungal a

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1994.tb00849.x

出版商:Blackwell Publishing Ltd    

年代:1994

数据来源: WILEY