摘要:

AbstractA transformation system derived from the circular plasmid pKD1 has been developed forKluyveromyces lactis. The principle is essentially equivalent to that of the 2 μ/Saccharomyces cerevisiaetransformation system. The main features of the system are presented. Using a pKD1‐based DNA bank ofK. lactis, theKEX1gene involved in the killer system was isolated by complementati

ISSN:0233-111X    

DOI:10.1002/jobm.3620280402

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractThe activities of the free and the cell‐bound lipases ofCandida rugosa, Candida guilliermondii, Candida curvata, Candida deformansandYarrowia lipolyticathat had been grown on a complex medium with various carbon and nitrogen sources were examined. The highest activities were observed with citrate and succinate as the carbon sources. In some cases olive oil was used as the efficient inducer of the cell‐bound lipases.The cells grown in the presence of the organic nitrogen sources (peptone, urea, soy flour) exhibited higher lipase levels than those cultivated in the medium containing ammonium as the nitrogen source. The extracellular enzyme was detected only in cultures grown with urea, peptone or soy flour as the nitrogen sou

ISSN:0233-111X    

DOI:10.1002/jobm.3620280403

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280404

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractMating inYarrowia lipolyticacan be induced by mixing cells of both complementary mating types (A and B) in yeast extract‐malt‐medium. By means of an inbreeding programme, strains with significantly improved mating frequencies were selected. The main events of the mating process, that have been detected so far, by means of cytological methods, are: formation of mating tubes, cell contact, cell fusion and karyogamy. During the process of conjugation, mating tubes of different lengths as and shapes are formed between haploid parental cells. Under special conditions the preformation of mating tubes was observed. Mating in the dimorphic yeastY. lipolyticahas been shown to be a distant mating and to occur between cells of a different shape and size. Cells involved in conjugation are no changed morphologically, except for the formation of special copulation structures. Several events of mating and the morphology of zygotes are different than those in the case of baker's yeasts. It is supposed that there is in this yeast also an action of diffusible factors that trigger mat

ISSN:0233-111X    

DOI:10.1002/jobm.3620280405

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractElectrophoretic karyotypes of yeasts belonging to the speciesSaccharomyces cerevisiae, Kluyveromyces marxianusandCandida macedoniensiswere established by means of OFAGE. Hybrids betweenS. cerevisiaeandK. marxianusas well as betweenK. marxianusandC. macedoniensiswere analyzed by comparing their OFAGE‐banding‐pattern with the parental banding‐patterns. Thus, evidence for exchanges of intact chromosomes and for chromosomal rearrangements could be gained on a molecular

ISSN:0233-111X    

DOI:10.1002/jobm.3620280406

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280407

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractAn acid phosphatase from derepressed cells of the yeast form ofYarrowia lipolyticawas purified 176‐fold by ammonium sulfate precipitation, chromatography on DEAE‐Sephacel and gel filtration in Biogel A 5‐M. The enzyme is a glycoprotein with a sugar content of 60%. The MICHAELISconstant of the enzyme is 5.5 × 10−4M forp‐nitrophenyl phosphate as substrate; the isoelectric point estimated by electrofocusing is around 4.6 and the optimum pH is 6.2. Phosphatase activity was destroyed by exposure of the enzyme to 40 °C for 30 min or at pH 3 for 30 min. The purified enzyme shows size heterogeneity within a linear concentration gradient of polyacrylamide (4–20%) which indicates an apparent molecular weight in the range of 90,000–200,000 in the presence of sodium dodecyl sulfate. The heterogeneity of the enzyme is due to its carbohydrate content, as can be demonstrated by gel filtration and by treatment with endoglycosidase H. The carbohydrate‐depleted protein has a molecular weight of 60,000. Aminoacid analysis revealed a high content of aspartic acid, serine, threonine, glycine and alanine. Antibodies against the protein moiety show cross reactivity with the acid phosphatase ofSacchar

ISSN:0233-111X    

DOI:10.1002/jobm.3620280408

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280409

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

摘要:

AbstractExpression of human tumor necrosis factor —α (TNF) and four different TNF analogs has been studied inPichia pastorisby utilizing the alcohol oxidase gene promoter. TNF expression level in certain transformants accounted for as much as 36% of the soluble protein. TNF expression was stably maintained during high cell density fermentation (100 g dry cell weight/liter) resulting in a TNF production level of 6–10g/liter. TNF contained inP. pastoriscell lysates was biologically active as determined by its cytotoxic effect on murine L‐929 fibroblast cells and the bioactivity was retained for at least 6 months in the lysates stored frozen at −20 °C in the presence of protease inhibitor PMSF. TNF expressed inP. pastoriswas recognized by monoclonal antibodies prepared against recombinantEscherichia coliderived TNF. TNF purified fromP. pastorishas the expected N‐terminal amino acid sequence and specific activity of 107units/mg protein. TNF analogs were also expressed at levels comparable to that of native TNF. Three of the four analogs were insoluble when produced in

ISSN:0233-111X    

DOI:10.1002/jobm.3620280410

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY

ISSN:0233-111X    

DOI:10.1002/jobm.3620280412

出版商:Wiley‐VCH    

年代:1988

数据来源: WILEY