摘要:

AbstractAfter a short introduction on the historical background of the development ofSaccharomyces cerevisiaeas a model eukaryote, a review is given on the present state of genetics and molecular biology of copper resistance inS. cerevisiae. The gene CUP1 encodes a protein (copper metallothionein) of a molecular weight of 6570 dalton. The synthesis of this copper chelatin is induced by copper and is regulated at the level of transcription.Copper resistance (CUPr) is correlated with amplification of CUP1 and resulted in a higher copy number of this gene on chromosome VIII. Spontaneous meiotic alterations of the gene copy number have been studied.

ISSN:0233-111X    

DOI:10.1002/jobm.3620280302

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractThe development of a highly efficient integrative transformation system for the yeastYarrowia lipolyticahas permitted gene cloning by direct complementation. The main features of this system will be presented, as well as the results so far obtained on gene structure. Recent developments of these techniques now concern heterologeous gene expression and protein secretion and will be reviewed.

ISSN:0233-111X    

DOI:10.1002/jobm.3620280303

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractDuring alcoholic fermentations, the off‐flavour compound diacetyl is formed non‐enzymatically from acetolactate leaking out from the cells. Acetolactate is an intermediate in the biosynthesis of valine. In beer fermentation, the amount of diacetyl is reduced to acceptable levels during maturation. A reduction of the time needed for maturation may be achieved by the use of a brewing yeast that produces less diacetyl.Saccharomyces cerevisiaelaboratory strains with an inactiveilv2gene can not form acetolactate, whileilv5strains, blocked in the subsequent step, leak acetolactate in high amounts.Induction of recessive mutations in production strains ofSaccharomyces carlsbergensishas not yet been achieved, as the yeast is polyploid and possibly a hybrid betweenS. cerevisiaeand anotherSaccharomycesspecies. Thus, all chromosomes investigated so far are present in at least two genetically different versions. Genetic and molecular analysis has shown that the brewing yeast is structurally heterozygous forILV2andILV5.Genetic modification of brewers' yeast to reduce diacetyl formation is being carried out by mutation ofILV2. Deletion mutations in bothILV2alleles have been constructedin vitroto be used for gene replacement in the brewing strain. In addition, partial inactivation of theILV2function is carried out by selecting spontaneous dominant mutations resistant to the herbicide sulfometuron methyl. Among these mutants some produce only half the amount of diacetyl compared to the parental strain.An alternative way to reduce diacetyl production might be to increase the activity of theILV5gene product. Model experiments inS. cerevisiaeshow that the presence of theILV5gene on a 2‐micron based multi‐copy vector can reduce the diacetyl production

ISSN:0233-111X    

DOI:10.1002/jobm.3620280304

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280306

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractNumerous methods based on classical genetics have been developed for the genetic mapping of yeasts. Recombinant DNA technology and technology for electrophoretic separation of chromosomes make new approaches possible. The state‐of‐the‐art in genetic mapping ofSaccharomyces cerevisiaewill be briefly reviewed. Then the availability and application of genetic mapping methods to non‐conventional yeasts will be surveyed. Development of the genetic maps of the asexual diploidCandida albicansand of the heterothallic yeastYarrowia lipolyticawill be discussed in more

ISSN:0233-111X    

DOI:10.1002/jobm.3620280307

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractA brief review is given on the establishment of recombinant DNA technology for non‐conventional yeasts. The availability of DNA delivery systems, selectable markers for identification of transformants, and the means of replicating and amplifying the recombinant DNA are discussed. Some of the existing transformation systems among non‐conventional yeasts are explai

ISSN:0233-111X    

DOI:10.1002/jobm.3620280308

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280301

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY