title: Alcohol-tolerant mutants of cyanobacterium Synechococcus elongatus PCC 7942 obtained by single-cell mutant screening system.
abstract: Enhancement of alcohol tolerance in microorganisms is an important strategy for improving bioalcohol productivity. Although cyanobacteria can be used as a promising biocatalyst to produce various alcohols directly from CO2, low productivity, and low tolerance against alcohols are the main issues to be resolved. Nevertheless, to date, a mutant with increasing alcohol tolerance has rarely been reported. In this study, we attempted to select isopropanol (IPA)-tolerant mutants of Synechococcus elongatus PCC 7942 using UV-C-induced random mutagenesis, followed by enrichment of the tolerant candidates in medium containing 10 g/L IPA and screening of the cells with a high growth rate in the single cell culture system in liquid medium containing 10 g/L IPA. We successfully acquired the most tolerant strain, SY1043, which maintains the ability to grow in medium containing 30 g/L IPA. The photosynthetic oxygen-evolving activities of SY1043 were almost same in cells after 72 h incubation under light with or without 10 g/L IPA, while the activity of the wild-type was remarkably decreased after the incubation with IPA. SY1043 also showed higher tolerance to ethanol, 1-butanol, isobutanol, and 1-pentanol than the wild type. These results suggest that SY1043 would be a promising candidate to improve alcohol production using cyanobacteria. Biotechnol. Bioeng. 2017;114: 1771-1778. © 2017 Wiley Periodicals, Inc.
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8603, Japan.
authors.forename: Sayuri
authors.initials: S
authors.lastname: Arai
authors.affiliation: Kobe University Research Center for Inland Seas, Awaji, Hyogo, Japan.
authors.forename: Kayoko
authors.initials: K
authors.lastname: Hayashihara
authors.affiliation: Kobe University Research Center for Inland Seas, Awaji, Hyogo, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kanamoto
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8603, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Shimizu
authors.affiliation: Laboratory for Bioinformatics, Graduate School of Systems Life Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan.
authors.forename: Yasutaka
authors.initials: Y
authors.lastname: Hirokawa
authors.affiliation: Laboratory for Bioinformatics, Graduate School of Systems Life Sciences, Kyushu University, Higashi-ku, Fukuoka, Japan.
authors.forename: Taizo
authors.initials: T
authors.lastname: Hanai
authors.affiliation: Kobe University Research Center for Inland Seas, Awaji, Hyogo, Japan.
authors.forename: Akio
authors.initials: A
authors.lastname: Murakami
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi, 464-8603, Japan.
authors.forename: Hiroyuki
authors.identifier: 0000-0002-0096-6820
authors.initials: H
authors.lastname: Honda
mesh_terms: D000438:Alcohols / Q000008:administration & dosage*; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004361:Drug Tolerance / Q000502:physiology*; D057166:High-Throughput Screening Assays / Q000379:methods*; D009154:Mutation / Q000235:genetics*; D013045:Species Specificity; D046940:Synechococcus / Q000145:classification / Q000187:drug effects* / Q000235:genetics*
chemical_list: D000438:Alcohols
keywords: alcohol-tolerance; cyanobacteria; isopropanol; photosynthesis; single cell culture system