{"title":"The influence of medium composition on the microbial secretory production of hydroxyalkanoate oligomers.","authors":"Shoji Mizuno, Tetsuo Sakurai, Mikito Nabasama, Kyouhei Kawakami, Ayaka Hiroe, Seiichi Taguchi, Takeharu Tsuge","doi":"10.2323/jgam.2020.09.002","DOIUrl":null,"url":null,"abstract":"<p><p>With the aid of a chain transfer (CT) reaction, hydroxyalkanoate (HA) oligomers can be secreted by recombinant Escherichia coli carrying the gene encoding a lactate-polymerizing enzyme (PhaC1<sub>Ps</sub>STQK) in Luria-Bertani (LB) medium supplemented with a carbon source and CT agent. In this study, HA oligomers were produced through microbial secretion using a mineral-based medium instead of LB medium, and the impact of medium composition on HA oligomer secretion was investigated. The focused targets were medium composition and NaCl concentration related to osmotic conditions. It was observed that 4.21 g/L HA oligomer was secreted by recombinant E. coli in LB medium, but the amount secreted in the mineral-based modified R (MR) medium was negligible. However, when the MR medium was supplemented with 5 g/L yeast extract, 3.75 g/L HA oligomer was secreted. This can be accounted for by the enhanced expression and activity of PhaC1<sub>Ps</sub>STQK upon supplementation with growth-activated nutrients as supplementation with yeast extract also promoted cell growth and intracellular growth-associated polymer accumulation. Furthermore, upon adding 10 g/L NaCl to the yeast extract-supplemented MR medium, HA oligomer secretion increased to 6.86 g/L, implying that NaCl-induced osmotic pressure promotes HA oligomer secretion. These findings may facilitate the secretory production of HA oligomers using an inexpensive medium.</p>","PeriodicalId":15842,"journal":{"name":"Journal of General and Applied Microbiology","volume":null,"pages":null},"PeriodicalIF":0.8000,"publicationDate":"2021-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of General and Applied Microbiology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.2323/jgam.2020.09.002","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2021/5/1 0:00:00","PubModel":"Epub","JCR":"Q4","JCRName":"BIOTECHNOLOGY & APPLIED MICROBIOLOGY","Score":null,"Total":0}
引用次数: 1
Abstract
With the aid of a chain transfer (CT) reaction, hydroxyalkanoate (HA) oligomers can be secreted by recombinant Escherichia coli carrying the gene encoding a lactate-polymerizing enzyme (PhaC1PsSTQK) in Luria-Bertani (LB) medium supplemented with a carbon source and CT agent. In this study, HA oligomers were produced through microbial secretion using a mineral-based medium instead of LB medium, and the impact of medium composition on HA oligomer secretion was investigated. The focused targets were medium composition and NaCl concentration related to osmotic conditions. It was observed that 4.21 g/L HA oligomer was secreted by recombinant E. coli in LB medium, but the amount secreted in the mineral-based modified R (MR) medium was negligible. However, when the MR medium was supplemented with 5 g/L yeast extract, 3.75 g/L HA oligomer was secreted. This can be accounted for by the enhanced expression and activity of PhaC1PsSTQK upon supplementation with growth-activated nutrients as supplementation with yeast extract also promoted cell growth and intracellular growth-associated polymer accumulation. Furthermore, upon adding 10 g/L NaCl to the yeast extract-supplemented MR medium, HA oligomer secretion increased to 6.86 g/L, implying that NaCl-induced osmotic pressure promotes HA oligomer secretion. These findings may facilitate the secretory production of HA oligomers using an inexpensive medium.
期刊介绍:
JGAM is going to publish scientific reports containing novel and significant microbiological findings, which are mainly devoted to the following categories: Antibiotics and Secondary Metabolites; Biotechnology and Metabolic Engineering; Developmental Microbiology; Environmental Microbiology and Bioremediation; Enzymology; Eukaryotic Microbiology; Evolution and Phylogenetics; Genome Integrity and Plasticity; Microalgae and Photosynthesis; Microbiology for Food; Molecular Genetics; Physiology and Cell Surface; Synthetic and Systems Microbiology.