摘要:

Protoplasts ofTrichoderma reeseiwere fused according to the method of Zimmermann. For optimizing the fusion parameters the central composite design was used. Genetic evidence for fusion has been obtained by segregation of the auxotrophic markers in the haploid conidia. The parameters which were optimized were: pulse voltage, pulse duration and number of pulses. The optimal parameters for the fusion ofT. reeseiprotoplasts are 90 V pulse voltage, 37 μS pulse duration and six pulses at intervals of 1‐0

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1987.tb01625.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

A new method for dry rupture of bacterial spores was developed. Ammonium bicarbonate crystals, used in place of sodium chloride or glass beads, are vigorously shaken with spores. The ammonium bicarbonate is removed subsequently by sublimation, yielding uncontaminated, disrupted spores. Increased recovery of glucose dehydrogenase and protease activity fromBacillus cereusspores was obtained with the new method.

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1987.tb01626.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

The resistance ofSalmonella thompsonto heating at 54° or 60°C in tryptone soya broth, liquid whole egg, 10% or 40% reconstituted dried milk or minced beef was increased if cells were held at 48°C for 30 min before heating at the higher temperatures. Induction of thermotolerance by mild heat shock is thus not confined to cells grown and heated in broth systems. The heat shock phenomenon may therefore have implications for the safety of foods given marginal heat treatme

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1987.tb01627.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Two co‐cultures, each of a coccobacillus plus a Gram‐negative rod, were isolated from a cattle waste digester. The cultures were distinguished by production of methane from acetate only, or from either acetate or butyrate. 2‐Methylbutyrate, added initially as a growth factor, was degraded to propionate but only during growth on acetate or butyrate. Valerate and 2‐ and 3‐methyl valerate were not

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1987.tb01628.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY

摘要:

Inactivation of cefotaxime, cefoperazone and ceftazìdime by β‐lactamases from strains ofPseudomonassp. andAcinetobacter calcoaceticusisolated from freshwater of a remote environment is demonstrated. Inactivation rates showed some relation‐ship to susceptibility of the strains as a whole, but this relationship was absent for individual strains, probably because of some other resistance mechanisms. Inac‐tivation was also observed with low inocula if incubation was prolonged. These β‐lactamases seem to be coded by chromosomal genes, since no plasmids were found and they exhibited relatively high isoelect

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1987.tb01629.x

出版商:Blackwell Publishing Ltd    

年代:1987

数据来源: WILEY