Marine-derived Bacillus strains have been proved to be a very promising source for natural product leads.However,transformation of environmental strains is much more difficult than that of domesticated strains.Here,we...Marine-derived Bacillus strains have been proved to be a very promising source for natural product leads.However,transformation of environmental strains is much more difficult than that of domesticated strains.Here,we report the development of an efficient and robust electroporation-based transformation system for marine-derived Bacillus marinus B-9987,which is a macrolactin antibiotics producer and a very promising biological control agent against fungal plant diseases.The transformation efficiency was greatly enhanced 103-fold by using unmethylated plasmid to bypass modification-restriction barrier,and using glycine betaine to protect cells from electrical damages during electroporation.Addition of HEPES and 2 mmol L?1MgCl2 further improved the efficiency by additional 2-fold,with a maximum value of 7.1×104 cfu/μg pHT3101.To demonstrate the feasibility and efficiency of the protocol,a green fluorescent protein reporter system was constructed;furthermore,phosphopantetheinyl transferase gene sfp,which is essential to the biosynthesis of polyketides and nonribosomal peptides,was overexpressed in B-9987,leading to increased production of macrolactin A by about 1.6-fold.In addition,this protocol is also applicable to marine-derived Bacillus licheniforms EI-34-6,indicating it could be a reference for other undomesticated Bacillus strains.To our knowledge,this is the first report regarding the transformation of marine-derived Bacillus strain.展开更多
Synthetic studies towards the C(3)-C(13) and C(14)-C(24) segments (3,4) of the potent antiviral and antitumor compound macrolactin A (1) are presented. Compound 3 was constructed via a convergent and facile approach, ...Synthetic studies towards the C(3)-C(13) and C(14)-C(24) segments (3,4) of the potent antiviral and antitumor compound macrolactin A (1) are presented. Compound 3 was constructed via a convergent and facile approach, exploiting Wittig olefination to generate the sensitive E, Z-diene moiety. Compound 4 was synthesized from the chiral-pool derived sulfone 39a via an α-alkylation-desulfonation reaction sequence. Cu(II)-catalyzed coupling of a Grignard reagent with an allylic bromide and Julia olefination were also investigated for the preparation of compound 4.展开更多
基金supported by grants from the National Natural Science Foundation of China (31070072,31171201)the Program for New Century Excellent Talents in University (NCET-0900717)partially supported by the National Key Technologies Research and Development Program (2011BAE06B04)
文摘Marine-derived Bacillus strains have been proved to be a very promising source for natural product leads.However,transformation of environmental strains is much more difficult than that of domesticated strains.Here,we report the development of an efficient and robust electroporation-based transformation system for marine-derived Bacillus marinus B-9987,which is a macrolactin antibiotics producer and a very promising biological control agent against fungal plant diseases.The transformation efficiency was greatly enhanced 103-fold by using unmethylated plasmid to bypass modification-restriction barrier,and using glycine betaine to protect cells from electrical damages during electroporation.Addition of HEPES and 2 mmol L?1MgCl2 further improved the efficiency by additional 2-fold,with a maximum value of 7.1×104 cfu/μg pHT3101.To demonstrate the feasibility and efficiency of the protocol,a green fluorescent protein reporter system was constructed;furthermore,phosphopantetheinyl transferase gene sfp,which is essential to the biosynthesis of polyketides and nonribosomal peptides,was overexpressed in B-9987,leading to increased production of macrolactin A by about 1.6-fold.In addition,this protocol is also applicable to marine-derived Bacillus licheniforms EI-34-6,indicating it could be a reference for other undomesticated Bacillus strains.To our knowledge,this is the first report regarding the transformation of marine-derived Bacillus strain.
基金Project supported by the National Natural Science Foundation of Chinathe State Key Laboratory of Bio-organicNatural Products Chemistry
文摘Synthetic studies towards the C(3)-C(13) and C(14)-C(24) segments (3,4) of the potent antiviral and antitumor compound macrolactin A (1) are presented. Compound 3 was constructed via a convergent and facile approach, exploiting Wittig olefination to generate the sensitive E, Z-diene moiety. Compound 4 was synthesized from the chiral-pool derived sulfone 39a via an α-alkylation-desulfonation reaction sequence. Cu(II)-catalyzed coupling of a Grignard reagent with an allylic bromide and Julia olefination were also investigated for the preparation of compound 4.
