title: Improved production of sublancin via introduction of three characteristic promoters into operon clusters responsible for this novel distinct glycopeptide biosynthesis.
abstract: BACKGROUND
  Sublancin is a novel and distinct antimicrobial glycopeptide that can be used as an alternative to conventional antibiotics. The reported production of sublancin by Bacillus subtilis 168 is poor because transcriptional regulatory circuit of sunA, a gene that encodes presublancin, is complex and difficult to control.
  
  
  RESULTS
  A strong inducible and easy to control vegetative σA promoter of Pglv was introduced to replace that of sunA in situ in B. subtilis 1A747 [SPβc, prototroph, the derivative of B. subtilis 168 (trpC2)]. Meanwhile, other two strong promoters of P43 and PluxS were respectively placed before sunI and sunT-bdbA-sunS-bdbB, encoding five functional proteins that involved in the biosynthesis of mature sublancin. 642 mg sublancin was obtained from 1 L culture supernatant of recombinant B. subtilis 1A747 strains. Analysises of electrospray ionization mass spectrometry and circular dichroism spectrum showed that mature sublancin had a molecular weight of 3877.642 Da and displayed a α-helical conformation that are consistent with reported results. In addition, the mature sublancin was proved to be a potent antimicrobial glycopeptide with broad activity spectrum, moderate cytotoxicity and good conditional stability under high temperature, extreme pH and protease-rich environments, thus showing its potential for clinical applications.
  
  
  CONCLUSIONS
  Our present findings suggest that recombinant B. subtilis 1A747 strains can effectively and efficiently biosynthesize mature sublancin. The replacement of native promoters provides an extra method for production improvement of some other complicated peptides such as nisin and subtilin.
authors: College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, P.R. China. jzjsy1981@126.com.
authors: Shengyue
authors: S
authors: Ji
authors: College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, P.R. China. liweili524@sina.com.
authors: Weili
authors: W
authors: Li
authors: College of Veterinary Medicine, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, P.R. China. Rasheed2012@126.com.
authors: Abdul Rasheed
authors: AR
authors: Baloch
authors: College of Veterinary Medicine, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, P.R. China. wangmeng4865@126.com.
authors: Meng
authors: M
authors: Wang
authors: College of Animal Science and Technology, Northwest A&F University, 22 Xinong Road, Yangling, 712100, Shaanxi, P.R. China. jiziqing2010@163.com.
authors: Binyun
authors: B
authors: Cao
mesh_terms: D001412:Bacillus subtilis / Q000235:genetics / Q000378:metabolism; D001419:Bacteria / Q000145:classification / Q000187:drug effects / Q000254:growth & development; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D001430:Bacteriocins / Q000096:biosynthesis* / Q000737:chemistry / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D002942:Circular Dichroism; D017077:Culture Media, Conditioned / Q000378:metabolism; D006020:Glycopeptides / Q000096:biosynthesis* / Q000737:chemistry / Q000494:pharmacology; D019073:HT29 Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D060847:Metabolic Engineering / Q000379:methods; D008826:Microbial Sensitivity Tests; D008970:Molecular Weight; D009876:Operon / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics*; D055550:Protein Stability; D021241:Spectrometry, Mass, Electrospray Ionization; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D001430:Bacteriocins; D017077:Culture Media, Conditioned; D006020:Glycopeptides; C114602:sublancin 168