A suitable liquid chromatography quadrupole time-of-flight mass spectrometric(LC–Q-TOF–MS) method was developed for separation and characterization of related substances in bacitracin test drug. The separation was p...A suitable liquid chromatography quadrupole time-of-flight mass spectrometric(LC–Q-TOF–MS) method was developed for separation and characterization of related substances in bacitracin test drug. The separation was performed on Li Chrospher RP-18 column using methanol as mobile phase A and 0.2% ammonium acetate buffer solution as mobile phase B in gradient elution. A total of 12 related substances were detected through high resolution mass spectrometric determination in a positive electrospray ionization mode. They were identified as co-existing active components and degradation products of bacitracin through the analysis and elucidation of both the protonated parents and the product ions of all the related substances and their fragmentation pathways were also proposed.展开更多
Bacitracin consists of a mixture of several closely related polypeptide antibiotics produced from Bacillus licheniformis.The major component, Bacitracin A, is a cyclic dodecapeptide（Fig, 1）, which has strong bacteri...Bacitracin consists of a mixture of several closely related polypeptide antibiotics produced from Bacillus licheniformis.The major component, Bacitracin A, is a cyclic dodecapeptide（Fig, 1）, which has strong bacteriocidal effect on the G+ bacteria. The bacteriocidal activity requires the presence of divalent cations such as Zn;, As we know, the biological function of ploypeptides and proteins are closely related to their three-dimensional structure. Bacitracin A is very important for the demonstration of the coordination site of metal and the relationship between展开更多
Microorganisms are important sources of various natural products that have been commercialized for human medicine and animal healthcare.Bacitracin is an important antibacterial natural product predominantly pro-duced ...Microorganisms are important sources of various natural products that have been commercialized for human medicine and animal healthcare.Bacitracin is an important antibacterial natural product predominantly pro-duced by Bacillus licheniformis and Bacillus subtilis,and it is characterized by a broad antimicrobial spectrum,strong activity and low resistance,thus bacitracin is extensively applied in animal feed and veterinary medicine industries.In recent years,various strategies have been proposed to improve bacitracin production.Herein,we systematically describe the regulation of bacitracin biosynthesis in genus Bacillus and its associated mechanism,to provide a theoretical basis for bacitracin overproduction.The metabolic engineering strategies applied for bacitracin production are explored,including improving substrate utilization,using an enlarged precursor amino acid pool,increasing ATP supply and NADPH generation,and engineering transcription regulators.We also present several approaches of fermentation process optimization to facilitate the industrial large-scale production of bacitracin.Finally,the challenges and prospects associated with microbial bacitracin synthesis are discussed to facilitate the establishment of high-yield and low-cost biological factories.展开更多
Bacitracin,a new type of cyclic peptide antibiotic,is widely used as the feed additive in feed industry.Branched chain amino acids(BCAAs)are the key precursors for bacitracin synthesis.In this research,soybean meal wa...Bacitracin,a new type of cyclic peptide antibiotic,is widely used as the feed additive in feed industry.Branched chain amino acids(BCAAs)are the key precursors for bacitracin synthesis.In this research,soybean meal was served as the raw material to supply precursor amino acids for bacitracin synthesis,and enhanced production of bacitracin was attempted by engineering BCAA transporter BrnQ and its regulator Lrp in the bacitracin industrial production strain Bacillus licheniformis DW2.Firstly,our results confirmed that Lrp negatively affected bacitracin synthesis in DW2,and deletion of lrp improved intracellular BCAA accumulations,as well as the expression level of BCAA transporter BrnQ,which further led to a 14.71%increase of bacitracin yield,compared with that of DW2.On the contrary,overexpression of Lrp decreased bacitracin yield by 12.28%.Secondly,it was suggested that BrnQ acted as a BCAA importer in DW2,and overexpression of BrnQ enhanced the intracellular BCAA accumulations and 10.43%of bacitracin yield.While,the bacitracin yield decreased by 18.27%in the brnQ deletion strain DW2△brnQ.Finally,BrnQ was further overexpressed in lrp deletion strain DW2△lrp,and bacitracin yield produced by the final strain DW2△lrp::BrnQ was 965.34 U/mL,increased by 22.42%compared with that of DW2(788.48 U/mL).Collectively,this research confirmed that Lrp affected bacitracin synthesis via regulating the expression of BCAA transporter BrnQ and BCAA distributions,and provided a promising strain for industrial production of bacitracin.展开更多
基金financially supported by both the National Natural Science Foundation (NO. 81402900)the Fundamental Research Funds for the Central Universities of the Ministry of Education (NO. 2015PT043) of China
文摘A suitable liquid chromatography quadrupole time-of-flight mass spectrometric(LC–Q-TOF–MS) method was developed for separation and characterization of related substances in bacitracin test drug. The separation was performed on Li Chrospher RP-18 column using methanol as mobile phase A and 0.2% ammonium acetate buffer solution as mobile phase B in gradient elution. A total of 12 related substances were detected through high resolution mass spectrometric determination in a positive electrospray ionization mode. They were identified as co-existing active components and degradation products of bacitracin through the analysis and elucidation of both the protonated parents and the product ions of all the related substances and their fragmentation pathways were also proposed.
文摘Bacitracin consists of a mixture of several closely related polypeptide antibiotics produced from Bacillus licheniformis.The major component, Bacitracin A, is a cyclic dodecapeptide（Fig, 1）, which has strong bacteriocidal effect on the G+ bacteria. The bacteriocidal activity requires the presence of divalent cations such as Zn;, As we know, the biological function of ploypeptides and proteins are closely related to their three-dimensional structure. Bacitracin A is very important for the demonstration of the coordination site of metal and the relationship between
基金supported by National Key Research and Development Program of China(2022YFA0911800)Knowledge Innovation Program of Wuhan-Shuguang Project(2022020801020334)Science and Technology Project of Hubei Tobacco Company(027Y2021-023,027Y2020-013).
文摘Microorganisms are important sources of various natural products that have been commercialized for human medicine and animal healthcare.Bacitracin is an important antibacterial natural product predominantly pro-duced by Bacillus licheniformis and Bacillus subtilis,and it is characterized by a broad antimicrobial spectrum,strong activity and low resistance,thus bacitracin is extensively applied in animal feed and veterinary medicine industries.In recent years,various strategies have been proposed to improve bacitracin production.Herein,we systematically describe the regulation of bacitracin biosynthesis in genus Bacillus and its associated mechanism,to provide a theoretical basis for bacitracin overproduction.The metabolic engineering strategies applied for bacitracin production are explored,including improving substrate utilization,using an enlarged precursor amino acid pool,increasing ATP supply and NADPH generation,and engineering transcription regulators.We also present several approaches of fermentation process optimization to facilitate the industrial large-scale production of bacitracin.Finally,the challenges and prospects associated with microbial bacitracin synthesis are discussed to facilitate the establishment of high-yield and low-cost biological factories.
基金the National Program on Key Basic Research Project(973 Program,No.2015CB150505)the Technical Innovation Special Fund of Hubei Province(2018ACA149)The Key Technology Project of China National Tobacco Corporation(110201502014).
文摘Bacitracin,a new type of cyclic peptide antibiotic,is widely used as the feed additive in feed industry.Branched chain amino acids(BCAAs)are the key precursors for bacitracin synthesis.In this research,soybean meal was served as the raw material to supply precursor amino acids for bacitracin synthesis,and enhanced production of bacitracin was attempted by engineering BCAA transporter BrnQ and its regulator Lrp in the bacitracin industrial production strain Bacillus licheniformis DW2.Firstly,our results confirmed that Lrp negatively affected bacitracin synthesis in DW2,and deletion of lrp improved intracellular BCAA accumulations,as well as the expression level of BCAA transporter BrnQ,which further led to a 14.71%increase of bacitracin yield,compared with that of DW2.On the contrary,overexpression of Lrp decreased bacitracin yield by 12.28%.Secondly,it was suggested that BrnQ acted as a BCAA importer in DW2,and overexpression of BrnQ enhanced the intracellular BCAA accumulations and 10.43%of bacitracin yield.While,the bacitracin yield decreased by 18.27%in the brnQ deletion strain DW2△brnQ.Finally,BrnQ was further overexpressed in lrp deletion strain DW2△lrp,and bacitracin yield produced by the final strain DW2△lrp::BrnQ was 965.34 U/mL,increased by 22.42%compared with that of DW2(788.48 U/mL).Collectively,this research confirmed that Lrp affected bacitracin synthesis via regulating the expression of BCAA transporter BrnQ and BCAA distributions,and provided a promising strain for industrial production of bacitracin.
