Segregation of altered parental properties in fusions between Saccharomyces cerevisiae and the D-xylose fermenting yeasts Candida shehatae and Pichia stipitis

1992 ◽  
Vol 38 (12) ◽  
pp. 1233-1237 ◽  
Author(s):  
Abindra S. Gupthar
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Polyethylene Glycol ◽  
Gene Transfer ◽  
Key Words ◽  
Protoplast Fusion ◽  
Ethanol Tolerance ◽  
Pichia Stipitis ◽  
Candida Shehatae ◽  
Auxotrophic Mutants ◽  
Parental Type

A prototrophic strain of Saccharomyces cerevisiae CSIR Y190 MATa xyl−, resistant to high levels of ethanol, was hybridized with xylose-fermenting, auxotrophic mutants of Candida shehatae and Pichia stipitis through polyethylene glycol-induced protoplast fusion in an attempt to produce ethanol-tolerant, xylose-fermenting hybrids. Mononucleate fusants were obtained, but these dissociated into a mixture of parental-type segregants. Purified Candida- and Pichia-resembling segregants failed to acquire improved ethanol tolerance but expressed other novel properties of S. cerevisiae, suggesting that karyogamy was impaired after internuclear gene transfer. Key words: Pichia, Candida, Saccharomyces protoplast fusion.

scholarly journals Improvement of Ethanol Tolerance by Inactive Protoplast Fusion in Saccharomyces cerevisiae

2020 ◽  
Vol 2020 ◽  
pp. 1-10 ◽  
Author(s):  
Yi Xin ◽  
Mei Yang ◽  
Hua Yin ◽  
Jianming Yang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protoplast Fusion ◽  
Ethanol Tolerance ◽  
Assimilation Rate ◽  
Biotechnological Applications ◽  
Capital Costs ◽  
Fermentation Efficiency ◽  
N Assimilation ◽  
Beer Production ◽  
High Ethanol

Saccharomyces cerevisiae is a typical fermentation yeast in beer production. Improving ethanol tolerance of S. cerevisiae will increase fermentation efficiency, thereby reducing capital costs. Here, we found that S. cerevisiae strain L exhibited a higher ethanol tolerance (14%, v/v) than the fermentative strain Q (10%, v/v). In order to enhance the strain Q ethanol tolerance but preserve its fermentation property, protoplast fusion was performed with haploids from strain Q and L. The fusant Q/L-f2 with 14% ethanol tolerance was obtained. Meanwhile, the fermentation properties (flocculability, SO2 production, α-N assimilation rate, GSH production, etc.) of Q/L-f2 were similar to those of strain Q. Therefore, our works established a series of high ethanol-tolerant strains in beer production. Moreover, this demonstration of inactivated protoplast fusion in industrial S. cerevisiae strain opens many doors for yeast-based biotechnological applications.

Candida fennica: enhancement of protoplast formation and fusion

1992 ◽  
Vol 38 (8) ◽  
pp. 807-810 ◽  
Author(s):  
Carolina M. M. Andrade ◽  
Flavia M. Oliveira ◽  
Valter R. Linardi
Keyword(s):  
Key Words ◽  
Protoplast Fusion ◽  
Ultraviolet Light ◽  
Protoplast Regeneration ◽  
Protoplast Formation ◽  
Regeneration Frequency ◽  
Fusion Frequency ◽  
Auxotrophic Mutants ◽  
Enrichment Procedure ◽  
Dna Contents

Auxotrophic mutants were obtained by exposing Candida fennica FTPT/CCT-8903 to ultraviolet light and treating the cells with nystatin in an enrichment procedure. The mutants were used for protoplast fusion. The highest protoplast regeneration frequency was obtained when cells were treated with 10 mg NovoZym 234/mL in the presence of 0.8 M KCl for 60 min. Fusion frequency was in the range 5.84 × 10−5 to 7.2 × 10−5. Five prototrophic hybrid colonies, designated S9, S15, S17, S18, and S25, were isolated, and their DNA contents were measured. These measurements indicated that the S17 hybrid is haploid, S9 and S18 are polyploid, and S15 and S25 are both aneuploid. Key words: Candida fennica, nystatin, auxotrophic mutants, protoplast fusion.

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