摘要:

AbstractYarrowia lipolytica, like other lower fungi, has a fatty acid synthetase complex (FAS) with an α6β6molecular structure. Both subunits are multifunctional proteins each with a molecular weight of more then 200000 daltons. A collection of FAS‐deficient2)Y. lipolyticamutants was isolated and characterized by both genetic complementation and enzyme activity measurements. It was found that the three acyl transferases (acetyl‐, malonyl‐ and palmityl‐transacylation) together with the enoyl reductase domain are located on subunit β and, therefore, are encoded by the gene locusFAS1. β‐Ketoacyl reductase, β‐ketoacyl synthase and acyl carrier protein functions are part of theFAS2‐encoded subunit α. Thus, the functional organization ofFAS1andFAS2is identical in both yeasts,Saccharomyces cerevisiaeandYarrowia lipolytica. Nevertheless, the two yeasts differ significantly with respect to the intragenic complementation characteristics offas1andfas2mutants. This finding is discussed in terms of a specific inter‐or intramolecular reaction mechanism within the oligomeric FAS complex. The pentafunctionalY. lipolytica FAS1gene was isolated from a λgtll expression library using polyclonal antisera against the purified FAS complex. At present, sequencing ofFAS1, which is more than 5 kilobases long, is almost completed. Available data indicate approx. 60 percent sequence homology together with an identical order of catalytic domains within subunit β of the two yeasts,Y. lip

ISSN:0233-111X    

DOI:10.1002/jobm.3620280502

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractConsidered are our own data and those found in literature on the properties of yeast mutants impaired in their ability to utilize methanol as sole carbon and energy source; hypotheses about the role of alcohol oxidase and citrate synthase in biogenesis of peroxisomes are proposed. It has been proved that formaldehyde reductase participates in the control of the formaldehyde level in the cell. Properties of mutants defective in the catabolite repression and inactivation of enzymes of methanol metabolism are described. The existence of several autonomous mechanisms of the catabolite repression of alcohol oxidase has been shown. It has been found, that the induction of glyoxysomal enzymes of C2‐metabolism is repressed by methanol in theecr1mutant ofPichia pinuswith the affected repression of alcohol oxidase by ethanol. Data are presented on the regulatory properties of the recently discovered acidification system of the medium induced by methanol. Such acidification occurs due to symport extrusion of protons and formate anions from the cell

ISSN:0233-111X    

DOI:10.1002/jobm.3620280503

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280505

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractIn recent years, yeasts other than those belonging to the speciesSaccharomyces cerevisiaeandSchizosaccharomyces pombehave become increasingly important in industrial processes. Species such asPichia stipitis, Hansenula polymorpha, Zygosaccharomyces rouxii, Saccharomyces exiguus, Torulaspora delbrueckii, Yarrowia lipolyticaand others whose perfect stage is known, can be manipulated genetically by classical methods, but those belonging to the generaCandida(C. utilis, C. tropicalis, C. bombicola, C. zeylanoides, C. boidinii, etc.),Brettanomyces, Cryptococcus, Rhodotorula, and others of the different form genera, cannot be treated in this way. Some, such asSchwanniomycesandDebaryomycesspp., which have a perfect stage, are still difficult to manipulate by conventional means. Genetic manipulation of these yeasts can be approached from two points of view; the first involving improvement of strains by cross‐breeding within one species, and the second, the introduction of desirable genes from unrelated species and even from plants or animals.Two techniques are available for construction of industrially‐useful strains from these yeasts: protoplast fusion and transformation with chimaeric plasmids containing the gene(s) it is desired to introduce into the recipient strain. The methods for the latter procedure are well known but can be laborious and time‐consuming, especially if it is desired to introduce genes from plant or animal sources for production of enzymes, hormones, vaccines and similar products. Protoplast fusion is a simple technique which can be utilized in most laboratories and used for construction of improved yeast strains for brewing, baking, ethanol production and wine‐making, either by the fusion of desirable strains of the same species which do not sporulate, or by introduction of genes from non‐Saccharomycesspecies. Methods for fusion of species from different genera and isolation of the desired hybrids have been improved considerably in recent years. We have developed a method for isolation of strains carrying the desired genes by fusing a non‐Saccharomycesspecies with an auxotrophic strain ofSaccharomces cerevisiaeand selecting hybrids having the desired characteristics on appropriate media, after which the genes are transferred to the industrial strain by rare‐mating, repeated protoplast fusion, or classical mating as required. The advantages and limitations of the method are under

ISSN:0233-111X    

DOI:10.1002/jobm.3620280506

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280507

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractFor the purpose of isolation of promoter regions which are regulated by a carbon source in the medium in ann‐alkane‐assimilating yeast,Candida maltosa, two promoter‐probe vectors were constructed. Each of them consists of theLEU2gene ofSaccharomyces cerevisiaewhose 5′‐non‐coding region was trimmed with BAL31, an autonomously replicating sequence isolated fromC. maltosagenome (the TRA region) which we have previously isolated, and the pBR322 sequence. One of them, pPLC2, having the TATA box, lacks the regulatory sequence (“sequence L”) of theLEU2gene, and the other, pPLC1, lacks both the TATA box and sequence L. Using pPLC1 as a shot‐gun cloning vector inC. maltosa, many promoter regions which were active when glucose was present in the medium as a carbon source were obtained from the genome ofC. maltosa. The sizes of the inserted fragments of two of them were determined. (In this paper, a promoter region refers to a promoter which includes a TATA box, plus a regulatory sequence such as an UAS (upstream activating sequenc

ISSN:0233-111X    

DOI:10.1002/jobm.3620280508

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractWe developed a host‐vector system for transformation and gene cloning experiments using the methylotrophic yeastHansenula polymorpha. Regeneration of protoplasts in a medium containing polyethylene glycol before plating made transformation more efficient and reproducible (2 to 3 · 104μg DNA). The frequency of transformation was significantly lower when dominant resistance marker Cup1rwas used for transformant selection. The transformation system developed was used to clone the DNA fragment which complements functionally the defect in the dihydroxyacetone kinase (DHAKAbbreviations: DHA, dihydroxyacetone; DHAK, dihydroxyacetone kinase; DHAS, dihydroxyacetone synthase; PEG, polyethylene glycol.activity of aH. polymorphamutant strain. The DNA insert isolated was shown to increase by up to ten times the activity of DHAK in transformants carrying recombinant plasmids. When recombinant plasmids were introduced intoS. cerevisiae, the transformants obtained acquired the ability to grow on the medium with dihydroxyacetone as a sole carbon source and the activity of DHAK was obser

ISSN:0233-111X    

DOI:10.1002/jobm.3620280509

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280511

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280501

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY