ISOLATION AND CHARACTERIZATION OF ZYGOSACCHAROMYCES-ROUXII MUTANTS DEFECTIVE IN PROTON PUMPOUT ACTIVITY AND SALT TOLERANCE

Citation
S. Yoshikawa et al., ISOLATION AND CHARACTERIZATION OF ZYGOSACCHAROMYCES-ROUXII MUTANTS DEFECTIVE IN PROTON PUMPOUT ACTIVITY AND SALT TOLERANCE, Journal of fermentation and bioengineering, 79(1), 1995, pp. 6-10
Citations number
26
Categorie Soggetti
Food Science & Tenology","Biothechnology & Applied Migrobiology
ISSN journal
0922338X
Volume
79
Issue
1
Year of publication
1995
Pages
6 - 10
Database
ISI
SICI code
0922-338X(1995)79:1<6:IACOZM>2.0.ZU;2-9
Abstract
Two mutants defective in salt tolerance were identified among hygromyc in B (HygB)-resistant mutants of Zygosaccharomyces rouxii. These mutan ts showed different phenotypes in terms of sensitivity towards high co ncentrations of glucose and KCl. Recovery of salt tolerance by the add ition of KCl and CaCl2 or by lowering pH (pH 4.0) was different for th e two mutants. Moreover, both mutants showed lowered plasma membrane ( PM-) ATPase activity and proton pumpout activity. They exhibited neith er growth nor proton pumpout activity in a medium containing 5% NaCl. The proton pumpout activity was inhibited by vanadate, an inhibitor of PM-ATPase, only when cells were incubated in the presence of more tha n 1% NaCl. Damage of the proton pumpout activity seems to be the reaso n for the salt sensitivity of both mutants. We showed that it was esse ntial for Z. rouxii cells to pump out protons under a high salt enviro nment using mutants defective in this ability.