title: Transcriptional analysis of the effect of exogenous decanoic acid stress on Streptomyces roseosporus.
abstract: BACKGROUND
  Daptomycin is an important antibiotic against infections caused by drug-resistant pathogens. Its production critically depends on the addition of decanoic acid during fermentation. Unfortunately, decanoic acid (>2.5 mM) is toxic to daptomycin producer, Streptomyces roseosporus.
  
  
  RESULTS
  To understand the mechanism underlying decanoic tolerance or toxicity, the responses of S. roseosporus was determined by a combination of phospholipid fatty acid analysis, reactive oxygen species (ROS) measurement and RNA sequencing. Assays using fluorescent dyes indicated a sharp increase in reactive oxygen species during decanoic acid stress; fatty acid analysis revealed a marked increase in the composition of branched-chain fatty acids by approximately 10%, with a corresponding decrease in straight-chain fatty acids; functional analysis indicated decanoic acid stress has components common to other stress response, including perturbation of respiratory functions (nuo and cyd operons), oxidative stress, and heat shock. Interestingly, our transcriptomic analysis revealed that genes coding for components of proteasome and related to treholase synthesis were up-regulated in the decanoic acid -treated cells.
  
  
  CONCLUSIONS
  These findings represent an important first step in understanding mechanism of decanoic acid toxicity and provide a basis for engineering microbial tolerance.
authors: Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, School of life sciences, School of Pharmaceutical Sciences Southwest University, Chongqing 400715, China.
authors: Guojian
authors: G
authors: Liao
authors: Qing
authors: Q
authors: Liu
authors: Jianping
authors: J
authors: Xie
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry / Q000494:pharmacology*; D003652:Decanoic Acids / Q000737:chemistry / Q000494:pharmacology*; D004734:Energy Metabolism / Q000187:drug effects; D005227:Fatty Acids / Q000378:metabolism; D005456:Fluorescent Dyes / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000378:metabolism; D017423:Sequence Analysis, RNA; D013302:Streptomyces / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D059467:Transcriptome / Q000187:drug effects*
chemical_list: D000935:Antifungal Agents; D003652:Decanoic Acids; D005227:Fatty Acids; D005456:Fluorescent Dyes; D017382:Reactive Oxygen Species; C031071:decanoic acid