Application of methyltransferases in microbial synthesis of natural products / 生物工程学报

Methyltransferases (MTs) constitute a large group of enzymes that catalyze the transfer of a methyl moiety, most frequently from S-adenosyl-L-methionine, to their substrates. It plays an essential role in regulation of gene expression and synthesis of many natural compounds. Owing to its broad substrate spectrum, MTs make important contributions to diversify the spectrum of products through methylation modifications. Recently, great progress has been made in application of MTs for the biosynthesis of various natural products including phenylpropane compounds, fragrances, hormones and antibiotics, which is summarized in this review. Moreover, we highlighted the strategies of using MTs for efficient production and for expanding the diversity of these methylated natural products, and discussed the current challenges and future prospects in this area.

Isolation and identification of pathogen causing stem blight disease on Abelmoschus manihot (L.) Medic / 中国生化药物杂志

Objective To isolation and identify the pathogen of stem blight of Malvaceae.Methods The stems were collected from stem blight-diseased plants (J) and healthy ones (W) of Abelmoschus manihot (L.) Medic.in Yixing City of Jiangsu Province then cultured to isolate newborn mycelium.The pathogen isolated but unidentified were inoculated in stems of healthy plants of Abelmoschus manihot ( L.) Medic.and pathogenicity was verified.Finally, the pathogenic specie( s) was or were identified by morphological characteristic, rDNA-ITS analysis and polymerase chain reaction (PCR) method.Results The same fungus were excluded which were the same species in J and W, the three fungus of J2, J5 and J6 were acquired.J5 was preliminarily identified to have pathogenicity and it was Fusarium equiseti under the microscope.The genome DNA of J5 was amplified to a length of 524bp, and homology highly with Fusarium equiseti (100%).Conclusion The pathogen was identified as Fusarium equiseti.

Optimal Supply of Precursors for CoQ10 Production by Rhodopseudomonas Palustris / 现代生物医学进展

CoQ10 has been used not only as a medicine but also as food supplements because of its various physiological and biochemical activities. A full-factorial central composite design and response surface methodology were used for optimizing three precursors Solanesol, 4-hydroxybenzoic acid and methionine to maximize the production of CoQ10 by Rhodopseudomonas palustris J001. The optimization of the model predicted a maximum response 40.6 [(mg CoQ10)(g dried biomass)-1] CoQ10 production with 124.8 mg l-1 Solanesol, 267.7 mg l-14-hydroxybenzoic acid and 130.2 mg l-1 methionine, respectively. A new combination was prepared according to the result. The observed response was 40.5 ± 0.2 [(mg CoQ10)(g dried biomass)-1] and was 109.8%higher than in the control with no addition of the three precursors.