Release Time:2019-03-11  Hits:

Indexed by: Journal Article

Date of Publication: 2017-10-30

Journal: MICROBIAL CELL FACTORIES

Included Journals: Scopus、PubMed、SCIE

Volume: 16

Issue: 1

Page Number: 181

ISSN: 1475-2859

Key Words: Lignocellulose-derived inhibitors; Tolerance; Thioredoxin; Thioredoxin reductase; Ethanol fermentation; Kluyveromyces marxianus

Abstract: Background: Multiple lignocellulose-derived inhibitors represent great challenges for bioethanol production from lignocellulosic materials. These inhibitors that are related to the levels of intracellular reactive oxidative species (ROS) make oxidoreductases a potential target for an enhanced tolerance in yeasts.
   Results: In this study, the thioredoxin and its reductase from Kluyveromyces marxianus Y179 was identified, which was subsequently achieved over-expression in Saccharomyces cerevisiae 280. In spite of the negative effects by expression of thioredoxin gene (KmTRX), the thioredoxin reductase (KmTrxR) helped to enhance tolerance to multiple lignocellulose-derived inhibitors, such as formic acid and acetic acid. In particular, compared with each gene expression, the double over-expression of KmTRX2 and KmTrxR achieved a better ethanol fermentative profiles under a mixture of formic acid, acetic acid, and furfural (FAF) with a shorter lag period. At last, the mechanism that improves the tolerance depended on a normal level of intracellular ROS for cell survival under stress.
   Conclusions: The synergistic effect of KmTrxR and KmTRX2 provided the potential possibility for ethanol production from lignocellulosic materials, and give a general insight into the possible toxicity mechanisms for further theoretical research.