摘要:

A rapid extraction and purification procedure is described for the preparation of toxic peptides from freshwater blooms and laboratory isolates ofMicrocystis aeruginosa. Extraction with methanol/butanol, followed by C18cartridge concentration; gel filtration and high performance liquid chromatography yields discrete toxin peaks. Elution profiles for the laboratory isolates and bloom extracts are compared and the applicability of the method for detecting cyanobacterial toxins in natural waters is discussed.

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1986.tb01502.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

The faecal enterococcal population of chickens, fed a ration containing no coc‐cidiostat or growth‐promoting antibiotic, was monitored during the first 23 d after purchase as day‐old birds. The proportion ofEnterococcus faecalis, the majority of which were resistant to streptomycin (60μg/ml) and tetracycline (30 μg/ml), fell during the first week while there was a corresponding increase in the proportion ofEnt. gallinarum. Enterococcus faecium, half of which were resistant to cephalothin (30 μg/ml), increased during the first week but thereafter rarely exceeded a quarter of the enterococcal isolates. The changes in the relative proportion of these three bacterial species was reflected by changes in the incidence of resistance to these antibiotics in the enterococcal population as

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1986.tb01503.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

The production of patulin byP. expansumLink ex Gray growing in apple juice was determined over a range of pH. Patulin was found to be produced in large quantities over a narrow range of pH from 3‐2 to 3–8. The biomass produced increased with increasing pH. The changes in pH due to growth of the organism were found to be sm

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1986.tb01504.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

An Antimicrobial Removal Device (ARD) is proposed as an alternative to membrane filtration in the sterility testing of antibiotics. The device consists of a glass vial containing adsorbent resins which completely removed the antibacterial activity of a range of antibiotics without affecting the recovery of contaminating bacteria. The method is simple to use and has several advantages compared to membrane filtration including easier aseptic handling and lack of antibiotic carry‐over to subculture media. A problem with resin turbidity in subculture media was overcome by the use of an indicator medium or by subculture into fresh mediu

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1986.tb01505.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY

摘要:

Introduction of the ColV,I‐K94 plasmid into any of four strains ofEscherichia coligave derivatives which grew less well than the parent at alkaline pH. The alkali sensitivity of the 1829 derivative resulted from the presence of the plasmid rather than from its introduction into a less alkali tolerant variant. Of two other ColV plasmids tested, one (ColV‐K30) conferred substantial alkali sensitivity whereas the other (ColV‐41) had little effect. Of several other plasmids examined, R124‐F2 (which confers derepressed transfer properties) resembled ColV,I‐K94 in its effect on alkali sensitivity and ColV‐K98 produced a marked effect. The other plasmids (Flac, R124 itself, R1 and R483ColIa) had only a small effect. For ColV plasmids, it appears to be the presence of transfer and colicin components together which leads to the reduced tolerance to a

ISSN:0266-8254    

DOI:10.1111/j.1472-765X.1986.tb01506.x

出版商:Blackwell Publishing Ltd    

年代:1986

数据来源: WILEY