title: Identification of novel surfactin derivatives from NRPS modification of Bacillus subtilis and its antifungal activity against Fusarium moniliforme.
abstract: BACKGROUND
  Bacillus subtilis strain PB2-L1 produces the lipopeptide surfactin, a highly potent biosurfactant synthesized by a large multimodular nonribosomal peptide synthetase (NRPS). In the present study, the modules SrfA-A-Leu, SrfA-B-Asp, and SrfA-B-Leu from surfactin NRPS in B. subtilis BP2-L1 were successfully knocked-out using a temperature-sensitive plasmid, pKS2-mediated-based, homologous, recombination method.
  
  
  RESULTS
  Three novel surfactin products were produced, individually lacking amino acid Leu-3, Asp-5, or Leu-6. These surfactins were detected, isolated, and characterized by HPLC and LC-FTICR-MS/MS. In comparison with native surfactin, [∆Leu(3)]surfactin and [∆Leu(6)]surfactin showed evidence of reduced toxicity, while [∆Asp(5)]surfactin showed stronger inhibition than native surfactin against B. pumilus and Micrococcus luteus. These results showed that the minimum inhibitory concentration of [∆Leu(6)]surfactin for Fusarium moniliforme was 50 μg/mL, such that [∆Leu(6)]surfactin could lead to mycelium projection, cell damage, and leakage of nucleic acids and protein. These factors all contributed to stimulating apoptosis in F. moniliforme.
  
  
  CONCLUSIONS
  The present results revealed that [∆Leu(6)]surfactin showed a significant antifungal activity against F. moniliforme and might successfully be employed to control fungal food contamination and improve food safety.
authors.affiliation: College of Food Science and Technology, Nanjing Agricultural University, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, 1 Weigang, Nanjing, 210095, P.R. China.
authors.forename: Jian
authors.initials: J
authors.lastname: Jiang
authors.affiliation: College of Food Science and Technology, Nanjing Agricultural University, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, 1 Weigang, Nanjing, 210095, P.R. China.
authors.forename: Ling
authors.initials: L
authors.lastname: Gao
authors.affiliation: College of Food Science and Technology, Nanjing Agricultural University, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, 1 Weigang, Nanjing, 210095, P.R. China. bxm43@njau.edu.cn.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Bie
authors.affiliation: College of Food Science and Technology, Nanjing Agricultural University, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, 1 Weigang, Nanjing, 210095, P.R. China.
authors.forename: Zhaoxin
authors.initials: Z
authors.lastname: Lu
authors.affiliation: College of Food Science and Technology, Nanjing Agricultural University, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, 1 Weigang, Nanjing, 210095, P.R. China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Liu
authors.affiliation: College of Food Science and Technology, Nanjing Agricultural University, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, 1 Weigang, Nanjing, 210095, P.R. China.
authors.forename: Chong
authors.initials: C
authors.lastname: Zhang
authors.affiliation: College of Food Science and Technology, Nanjing Agricultural University, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, 1 Weigang, Nanjing, 210095, P.R. China.
authors.forename: Fengxia
authors.initials: F
authors.lastname: Lu
authors.affiliation: College of Food Science and Technology, Nanjing Agricultural University, Key Laboratory of Food Processing and Quality Control, Ministry of Agriculture of China, 1 Weigang, Nanjing, 210095, P.R. China.
authors.forename: Haizhen
authors.initials: H
authors.lastname: Zhao
mesh_terms: D000935:Antifungal Agents / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D001412:Bacillus subtilis / Q000737:chemistry* / Q000378:metabolism; D005670:Fusarium / Q000187:drug effects* / Q000254:growth & development; D055666:Lipopeptides / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D015394:Molecular Structure; D010453:Peptide Synthases / Q000737:chemistry*; D010456:Peptides, Cyclic / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D000935:Antifungal Agents; D055666:Lipopeptides; D010456:Peptides, Cyclic; C009365:surfactin peptide; D010453:Peptide Synthases; C104385:non-ribosomal peptide synthase