title: Construction of a Genetic System for Streptomyces albulus PD-1 and Improving Poly(ε-L-lysine) Production Through Expression of Vitreoscilla Hemoglobin.
abstract: Poly(ε-L-lysine) (ε-PL) is a novel bioactive polymer secreted by filamentous bacteria. Owing to lack of a genetic system for most ε-PL-producing strains, very little research on enhancing ε-PL biosynthesis by genetic manipulation has been reported. In this study, an effective genetic system was established via intergeneric conjugal transfer for Streptomyces albulus PD-1, a famous ε-PL-producing strain. Using the established genetic system, the Vitreoscilla hemoglobin (VHb) gene was integrated into the chromosome of S. albulus PD-1 to alleviate oxygen limitation and to enhance the biosynthesis of ε-PL in submerged fermentation. Ultimately, the production of ε-PL increased from 22.7 g/l to 34.2 g/l after fed-batch culture in a 5 L bioreactor. Determination of the oxygen uptake rate, transcriptional level of ε-PL synthetase gene, and ATP level unveiled that the expression of VHb in S. albulus PD-1 enhanced ε-PL biosynthesis by improving respiration and ATP supply. To the best of our knowledge, this is the first report on enhancing ε-PL production by chromosomal integration of the VHb gene in an ε-PL-producing strain, and it will open a new avenue for ε-PL production.
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing 211816, P.R. China.|College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, P.R. China.
authors.forename: Zhaoxian
authors.initials: Z
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing 211816, P.R. China.|College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, P.R. China.
authors.forename: Changhong
authors.initials: C
authors.lastname: Cao
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing 211816, P.R. China.|College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, P.R. China.
authors.forename: Zhuzhen
authors.initials: Z
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing 211816, P.R. China.|College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, P.R. China.
authors.forename: Sha
authors.initials: S
authors.lastname: Li
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing 211816, P.R. China.|College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, P.R. China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing 211816, P.R. China.|College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, P.R. China.
authors.forename: Xiaohai
authors.initials: X
authors.lastname: Feng
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing 211816, P.R. China.|College of Food Science and Light Industry, Nanjing Tech University, Nanjing 211816, P.R. China.
authors.forename: Hong
authors.initials: H
authors.lastname: Xu
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D005285:Fermentation; D020869:Gene Expression Profiling; D060847:Metabolic Engineering; D010085:Oxidative Phosphorylation; D011107:Polylysine / Q000096:biosynthesis*; D013302:Streptomyces / Q000235:genetics / Q000378:metabolism*; D054793:Truncated Hemoglobins / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D001426:Bacterial Proteins; D054793:Truncated Hemoglobins; C082613:hemoglobin protein, Vitreoscilla; D011107:Polylysine; D000255:Adenosine Triphosphate
keywords: Dissolved oxygen; Genetic system; Poly(ε-L-lysine); Streptomyces albulus; Submerged fermentation; Vitreoscilla hemoglobin