摘要:

AbstractDuring the 1980s, a large number of typing methods for the strain differentiation ofCandida albicanswere described in the literature. Although these methods have been based on a variety of physiological and genetic markers, none is ideal. This review discusses the characteristics of an ideal typing method in terms of its typability, reproducibility, and discriminatory power. Ways of determining these characteristics are presented so that the available typing methods forCandida albicanscan be objectively compared. Available typing methods forC. albicansinclude serotyping, morphotyping, resis-totyping, biotyping, and killer yeast typing. Electrophoretic methods include immunoblotting, isoenzyme analysis, analysis of DNA restriction fragment length polymorphism, karyotyping, and the use of DNA probes. The application of these methods to epidemiological research, the investigation of outbreaks of disease, and die study of virulence is described. The potential impact of the phenomenon of phenotypic switching on the reproducibility of these typing methods is discussed. It is concluded that many of the available typing methods have not been adequately assessed by their developers and that several have only poor discriminatory power or reproducibility.

ISSN:1040-841X    

DOI:10.3109/10408419109115206

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

AbstractCellulose is the most abundant biological polymer on Earth. It is found in wood and cotton, and forms the basic structural foundation of the cell wall of almost all eukaryotic plants. Bacteria are known to secrete cellulose as part of their metabolism of glucose and other sugars. The focus of this review is upon bacterial cellulose synmesis. We emphasize recent literature directed primarily uponAcetobacter xylinumwhich has been most widely studied. Our review covers die following topics relating to cellulose synthesis: genetics, biochemistry, ultrastructure, growth conditions, and ecological considerations as they relate to the diversity of microbes capable of synthesizing this abundant, unique polymer–cellulose.

ISSN:1040-841X    

DOI:10.3109/10408419109115207

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor

摘要:

AbstractIn anaerobic ecosystems, acyl lipids are initially hydrolyzed by microbial lipases with the release of free fatty acids. Glycerol, galactose, choline, and other non-fatty acid components released during hydrolysis are fermented to volatile fatty acids by the fermentative bacteria. Fatty acids are not degraded further in the rumen or other parts of the digestive tract but are subjected to extensive biohydrogenation especially in the rumen. However, in environments such as sediments and waste digesters, which have long retention times, both long and short chain fatty acids areβ-oxidized to acetate by a special group of bacteria, the H2-producing syntrophs. Long chain fatty acids can also be degraded by a-oxidation. Biotransformation of bile acids, cholesterol, and steroids by intestinal microorganisms is extensive. Many rumen bacteria have specific growth requirements for fatty acids such asn-valeric,iso-valeric, 2-methylbutyric, andiso-butyric acids. Some species have requirements for C13to C18straight-chain saturated or monoenoic fatty acids for growth.

ISSN:1040-841X    

DOI:10.3109/10408419109115208

出版商:Taylor&Francis    

年代:1991

数据来源: Taylor