title: Overexpression of sigma factor SigB improves temperature and butanol tolerance of Synechocystis sp. PCC6803.
abstract: Among phenotypes of interest for an industrial cyanobacteria host are improved tolerance to temperature, salt, and solvent stress. Cellular responses to many stresses are controlled by the network of sensory receptors and downstream regulatory proteins. We applied transcription factor engineering to Synechocystis and tested mutant strains for tolerance to temperature and the biofuel 1-butanol. Histidine kinases (Hik), response regulators (Rre), and an RNA polymerase sigma factor (SigB) were overexpressed or deleted. Overexpression of SigB increased both temperature and butanol tolerance and lowered the intracellular concentration of reactive oxygen species. This report demonstrates that alteration of regulatory proteins in a cyanobacterium can be a useful tool to improve stress tolerance.
authors.affiliation: School of Biotechnology, KTH-Royal Institute of Technology, Department of Proteomics, Roslagstullsbacken 21, 10450 Stockholm, Sweden.
authors.forename: Danuta
authors.initials: D
authors.lastname: Kaczmarzyk
authors.affiliation: School of Biotechnology, KTH-Royal Institute of Technology, Department of Proteomics, Roslagstullsbacken 21, 10450 Stockholm, Sweden.
authors.forename: Josefine
authors.initials: J
authors.lastname: Anfelt
authors.affiliation: School of Biotechnology, KTH-Royal Institute of Technology, Department of Proteomics, Roslagstullsbacken 21, 10450 Stockholm, Sweden.
authors.forename: Amanda
authors.initials: A
authors.lastname: Särnegrim
authors.affiliation: School of Biotechnology, KTH-Royal Institute of Technology, Department of Proteomics, Roslagstullsbacken 21, 10450 Stockholm, Sweden. Electronic address: paul.hudson@biotech.kth.se.
authors.forename: Elton P
authors.initials: EP
authors.lastname: Hudson
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D000440:Butanols / Q000494:pharmacology*; D060847:Metabolic Engineering / Q000379:methods*; D050296:Microbial Viability / Q000235:genetics; D017382:Reactive Oxygen Species; D012808:Sigma Factor / Q000235:genetics* / Q000378:metabolism; D013312:Stress, Physiological / Q000235:genetics* / Q000502:physiology; D046939:Synechocystis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D000440:Butanols; D017382:Reactive Oxygen Species; D012808:Sigma Factor
keywords: Biofuels; Cyanobacteria; Reactive oxygen species; Tolerance; Transcription factors