SACE_5599, a putative regulatory protein, is involved in morphological differentiation and erythromycin production in Saccharopolyspora erythraea

Microbial Cell Factories

Research

Štefan Fujs¹  Jaka Horvat¹  Katarina Karničar¹  Miha Tome¹  Vasilka Magdevska¹  Marinka Horvat¹  Benjamin Kirm¹  Gregor Kosec²  Hrvoje Petković³  Robert Vidmar⁴  Marko Fonovič⁵  Boris Turk⁶  Marko Petek⁷  Špela Baebler⁷  Kristina Gruden⁷  Polona Jamnik⁸ 

[1] Acies Bio, d.o.o, Tehnološki park 21, SI-1000, Ljubljana, Slovenia;Acies Bio, d.o.o, Tehnološki park 21, SI-1000, Ljubljana, Slovenia;Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, (CIPKeBiP), Jamova cesta 39, SI-1000, Ljubljana, Slovenia;Acies Bio, d.o.o, Tehnološki park 21, SI-1000, Ljubljana, Slovenia;Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC) Universidad de Cantabria, CSIC, SODERCAN, Facultad de Medicina, Avda. Cardenal Herrera Oria s/n,, 39011, Santander, Spain;Department of Biochemistry, Jožef Stefan Institute, Molecular and Structural Biology, Jamova cesta 39, SI-1000, Ljubljana, Slovenia;Department of Biochemistry, Jožef Stefan Institute, Molecular and Structural Biology, Jamova cesta 39, SI-1000, Ljubljana, Slovenia;Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, (CIPKeBiP), Jamova cesta 39, SI-1000, Ljubljana, Slovenia;Department of Biochemistry, Jožef Stefan Institute, Molecular and Structural Biology, Jamova cesta 39, SI-1000, Ljubljana, Slovenia;Centre of Excellence for Integrated Approaches in Chemistry and Biology of Proteins, (CIPKeBiP), Jamova cesta 39, SI-1000, Ljubljana, Slovenia;Center of Excellence of Nanosciences and Nanotechnology, Jamova cesta 39, SI-1000, Ljubljana, Slovenia;Faculty of Chemistry and Chemical Technology University of Ljubljana, Aškerčeva cesta 5, SI-1000, Ljubljana, Slovenia;Department of Biotechnology and Systems Biology, National Institute of Biology, Večna pot 111, SI-1000, Ljubljana, Slovenia;Department of Food Science and Technology, University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, SI-1000, Ljubljana, Slovenia;

关键词: Saccharopolyspora erythraea;    Erythromycin;    Polyketide;    Regulator;    SACE_5599;    lmbU;    Differentiation;    Sporulation;    Strain improvement;    Metabolic engineering;   

DOI  :  10.1186/1475-2859-12-126

 received in 2013-09-08, accepted in 2013-12-10,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundErythromycin is a medically important antibiotic, biosynthesized by the actinomycete Saccharopolyspora erythraea. Genes encoding erythromycin biosynthesis are organized in a gene cluster, spanning over 60 kbp of DNA. Most often, gene clusters encoding biosynthesis of secondary metabolites contain regulatory genes. In contrast, the erythromycin gene cluster does not contain regulatory genes and regulation of its biosynthesis has therefore remained poorly understood, which has for a long time limited genetic engineering approaches for erythromycin yield improvement.ResultsWe used a comparative proteomic approach to screen for potential regulatory proteins involved in erythromycin biosynthesis. We have identified a putative regulatory protein SACE_5599 which shows significantly higher levels of expression in an erythromycin high-producing strain, compared to the wild type S. erythraea strain. SACE_5599 is a member of an uncharacterized family of putative regulatory genes, located in several actinomycete biosynthetic gene clusters. Importantly, increased expression of SACE_5599 was observed in the complex fermentation medium and at controlled bioprocess conditions, simulating a high-yield industrial fermentation process in the bioreactor. Inactivation of SACE_5599 in the high-producing strain significantly reduced erythromycin yield, in addition to drastically decreasing sporulation intensity of the SACE_5599-inactivated strains when cultivated on ABSM4 agar medium. In contrast, constitutive overexpression of SACE_5599 in the wild type NRRL23338 strain resulted in an increase of erythromycin yield by 32%. Similar yield increase was also observed when we overexpressed the bldD gene, a previously identified regulator of erythromycin biosynthesis, thereby for the first time revealing its potential for improving erythromycin biosynthesis.ConclusionsSACE_5599 is the second putative regulatory gene to be identified in S. erythraea which has positive influence on erythromycin yield. Like bldD, SACE_5599 is involved in morphological development of S. erythraea, suggesting a very close relationship between secondary metabolite biosynthesis and morphological differentiation in this organism. While the mode of action of SACE_5599 remains to be elucidated, the manipulation of this gene clearly shows potential for improvement of erythromycin production in S. erythraea in industrial setting. We have also demonstrated the applicability of the comparative proteomics approach for identifying new regulatory elements involved in biosynthesis of secondary metabolites in industrial conditions.

【 授权许可】

Unknown   
© Kirm et al.; licensee BioMed Central Ltd. 2013. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.