scholarly journals Insertional Mutagenesis in then-Alkane-Assimilating Yeast Yarrowia lipolytica: Generation of Tagged Mutations in Genes Involved in Hydrophobic Substrate Utilization

2001 ◽  
Vol 183 (17) ◽  
pp. 5102-5109 ◽  
Author(s):  
Stephan Mauersberger ◽  
Hui-Jie Wang ◽  
Claude Gaillardin ◽  
Gerold Barth ◽  
Jean-Marc Nicaud
Keyword(s):  
Yarrowia Lipolytica ◽  
Insertional Mutagenesis ◽  
Thioredoxin Reductase ◽  
Auxotrophic Mutant ◽  
Growth Defects ◽  
Replica Plating ◽  
Dehydrogenase Gene ◽  
Reductase Gene ◽  
Alkane Chain ◽  
Chain Lengths

ABSTRACT Tagged mutants affected in the degradation of hydrophobic compounds (HC) were generated by insertion of a zeta-URA3mutagenesis cassette (MTC) into the genome of azeta-free and ura3 deletion-containing strain of Yarrowia lipolytica. MTC integration occurred predominantly at random by nonhomologous recombination. A total of 8,600 Ura+ transformants were tested by replica plating for (i) growth on minimal media with alkanes of different chain lengths (decane, dodecane, and hexadecane), oleic acid, tributyrin, or ethanol as the C source and (ii) colonial defects on different glucose-containing media (YPD, YNBD, and YNBcas). A total of 257 mutants were obtained, of which about 70 were affected in HC degradation, representing different types of non-alkane-utilizing (Alk−) mutants (phenotypic classes alkA to alkE) and tributyrin degradation mutants. Among Alk− mutants, growth defects depending on the alkane chain length were observed (alkAa to alkAc). Furthermore, mutants defective in yeast-hypha transition and ethanol utilization and selected auxotrophic mutants were isolated. Flanking borders of the integrated MTC were sequenced to identify the disrupted genes. Sequence analysis indicated that the MTC was integrated in the LEU1 locus in N083, a leucine-auxotrophic mutant, in the isocitrate dehydrogenase gene of N156 (alkE leaky), in the thioredoxin reductase gene in N040 (alkAc), and in a peroxine gene (PEX14) in N078 (alkD). This indicates that MTC integration is a powerful tool for generating and analyzing tagged mutants in Y. lipolytica.

Thioredoxin reductase gene expression and activity among human T‐cell lymphotropic virus type 1–infected patients

2018 ◽  
Author(s):  
Neda Yaghoubi ◽  
Masoud Youssefi ◽  
Seyed Isaac Hashemy ◽  
Houshang Rafat Panah ◽  
Barat Ali Mashkani ◽  
...  
Keyword(s):  
Gene Expression ◽  
T Cell ◽  
Virus Type ◽  
Thioredoxin Reductase ◽  
Human T Cell ◽  
Reductase Gene ◽  
Expression And Activity

Effects of Selenium Overexposure on Glutathione Peroxidase and Thioredoxin Reductase Gene Expressions and Activities

2002 ◽  
Vol 89 (2) ◽  
pp. 165-176 ◽  
Author(s):  
Lu Gan ◽  
Qiong Liu ◽  
Hui-Bi Xu ◽  
Yu-Shan Zhu ◽  
Xiang-Liang Yang
Keyword(s):  
Glutathione Peroxidase ◽  
Thioredoxin Reductase ◽  
Gene Expressions ◽  
Reductase Gene

scholarly journals Genetically Engineered SaccharomycesYeast Capable of Effective Cofermentation of Glucose and Xylose

1998 ◽  
Vol 64 (5) ◽  
pp. 1852-1859 ◽  
Author(s):  
Nancy W. Y. Ho ◽  
Zhengdao Chen ◽  
Adam P. Brainard
Keyword(s):  
Xylose Reductase ◽  
Pichia Stipitis ◽  
Genetically Engineered ◽  
Cellulosic Biomass ◽  
Aerobic Growth ◽  
Metabolizing Enzymes ◽  
E Coli ◽  
Dehydrogenase Gene ◽  
Reductase Gene ◽  
Recombinant Yeasts

ABSTRACT Xylose is one of the major fermentable sugars present in cellulosic biomass, second only to glucose. However, Saccharomycesspp., the best sugar-fermenting microorganisms, are not able to metabolize xylose. We developed recombinant plasmids that can transformSaccharomyces spp. into xylose-fermenting yeasts. These plasmids, designated pLNH31, -32, -33, and -34, are 2μm-based high-copy-number yeast-E. coli shuttle plasmids. In addition to the geneticin resistance and ampicillin resistance genes that serve as dominant selectable markers, these plasmids also contain three xylose-metabolizing genes, a xylose reductase gene, a xylitol dehydrogenase gene (both from Pichia stipitis), and a xylulokinase gene (from Saccharomyces cerevisiae). These xylose-metabolizing genes were also fused to signals controlling gene expression from S. cerevisiae glycolytic genes. Transformation of Saccharomyces sp. strain 1400 with each of these plasmids resulted in the conversion of strain 1400 from a non-xylose-metabolizing yeast to a xylose-metabolizing yeast that can effectively ferment xylose to ethanol and also effectively utilizes xylose for aerobic growth. Furthermore, the resulting recombinant yeasts also have additional extraordinary properties. For example, the synthesis of the xylose-metabolizing enzymes directed by the cloned genes in these recombinant yeasts does not require the presence of xylose for induction, nor is the synthesis repressed by the presence of glucose in the medium. These properties make the recombinant yeasts able to efficiently ferment xylose to ethanol and also able to efficiently coferment glucose and xylose present in the same medium to ethanol simultaneously.

scholarly journals n-Alkane Chain Length Alters Dietzia sp. Strain DQ12-45-1b Biosurfactant Production and Cell Surface Activity

2012 ◽  
Vol 79 (1) ◽  
pp. 400-402 ◽  
Author(s):  
Xing-Biao Wang ◽  
Yong Nie ◽  
Yue-Qin Tang ◽  
Gang Wu ◽  
Xiao-Lei Wu
Keyword(s):  
Cell Surface ◽  
Carbon Sources ◽  
Cell Surface Hydrophobicity ◽  
Surface Hydrophobicity ◽  
Biosurfactant Production ◽  
Content Type ◽  
Emulsification Activity ◽  
Negative Effect ◽  
Alkane Chain ◽  
Chain Lengths

ABSTRACTUpon growth onn-hexadecane (C16),n-tetracosane (C24), andn-hexatriacontane (C36),Dietziasp. strain DQ12-45-1b could produce different glycolipids, phospholipids, and lipopeptides. Interestingly, cultivation with C36increased cell surface hydrophobic activity, which attenuated the negative effect of the decline of the emulsification activity. These results suggest that the mechanisms of biosurfactant production and cell surface hydrophobicity are dependent upon the chain lengths of then-alkanes used as carbon sources.

scholarly journals Tagging Morphogenetic Genes by Insertional Mutagenesis in the Yeast Yarrowia lipolytica

2001 ◽  
Vol 183 (10) ◽  
pp. 3098-3107 ◽  
Author(s):  
Mathias Richard ◽  
Raymundo Rosas Quijano ◽  
Samira Bezzate ◽  
Florence Bordon-Pallier ◽  
Claude Gaillardin
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Yarrowia Lipolytica ◽  
Cell Walls ◽  
Type Strain ◽  
Insertional Mutagenesis ◽  
Wild Type Strain ◽  
Wild Type ◽  
Calcofluor White ◽  
Hyphal Formation ◽  
Yeast Yarrowia Lipolytica

ABSTRACT The yeast Yarrowia lipolytica is distantly related to Saccharomyces cerevisiae, can be genetically modified, and can grow in both haploid and diploid states in either yeast, pseudomycelial, or mycelial forms, depending on environmental conditions. Previous results have indicated that the STEand RIM pathways, which mediate cellular switching in other dimorphic yeasts, are not required for Y. lipolytica morphogenesis. To identify the pathways involved in morphogenesis, we mutagenized a wild-type strain of Y. lipolytica with a Tn3 derivative. We isolated eight tagged mutants, entirely defective in hyphal formation, from a total of 40,000 mutants and identified seven genes homologous toS. cerevisiae CDC25, RAS2, BUD6, KEX2, GPI7, SNF5, andPPH21. We analyzed their abilities to invade agar and to form pseudomycelium or hyphae under inducing conditions and their sensitivity to temperature and to Calcofluor white. Chitin staining was used to detect defects in their cell walls. Our results indicate that a functional Ras-cyclic AMP pathway is required for the formation of hyphae in Y. lipolytica and that perturbations in the processing of extracellular, possibly parietal, proteins result in morphogenetic defects.

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