PDF(Pubmed)
Abstract：
Streptomycetes are known as producers of bioactive substances, particularly antibiotics. Streptomyces netropsis IMV Ac-5025 simultaneously produces different classes of antibiotics, including polyene compounds, phytohormones, and sterols, but the metabolic pathways involved in their biosynthesis are largely understudied. The aim of this work was to explore the biosynthesis of polyene antibiotics, sterols, and phytohormones when the producer is cultivated in a nutrient medium supplemented with exogenous β-sitosterol. Gas chromatography and high-performance liquid chromatography were applied to analyze the spectrum of bioactive compounds. The obtained results demonstrated not only an increase in the accumulation of biomass but also polyene antibiotics, intracellular sterols, auxins, and cytokinins, when cultivating S. netropsis IMV Ac-5025 in a liquid medium with the addition of β-sitosterol. The amount of biomass raised 1.5-2-fold, whilst the sum of polyene antibiotics increased 4.5-fold, sterols\' sum (ergosterol, cholesterol, stigmasterol, β-sitosterol, and 24-epibrassinolide) by 2.9-fold, auxins\' sum (indole-3-acetic acid, indole-3-acetic acid hydrazide, indole-3-carbinol, indole-3-butyric acid, indole-3-carboxaldehyde, and indole-3-carboxylic acid) by 6-fold, and cytokinins\' sum (zeatin, isopentyladenine, zeatin riboside, and isopentenyladenosine) by 11-fold. Thus, we put forward the hypothesis that β-sitosterol plays a regulatory role in the network of biosynthetic reactions of S. netropsis IMV Ac-5025.
摘要：
链霉菌被称为生物活性物质的生产者，尤其是抗生素。链霉菌网化IMVAc-5025同时产生不同类别的抗生素，包括多烯化合物，植物激素,和固醇，但是参与其生物合成的代谢途径在很大程度上是研究不足的。这项工作的目的是探索多烯抗生素的生物合成，固醇,和植物激素，当生产者在补充有外源β-谷甾醇的营养培养基中培养时。应用气相色谱法和高效液相色谱法对生物活性化合物进行光谱分析。获得的结果表明，不仅生物量的积累增加，而且多烯抗生素，胞内甾醇，生长素,和细胞分裂素，在添加β-谷甾醇的液体培养基中培养S.netropsisIMVAc-5025时。生物量增加了1.5-2倍，虽然多烯抗生素的总和增加了4.5倍，固醇\'sum(麦角甾醇，胆固醇,豆甾醇,β-谷甾醇，和24-表油菜素内酯)增加2.9倍，生长素总(吲哚-3-乙酸，吲哚-3-乙酸酰肼，吲哚-3-甲醇,吲哚-3-丁酸，吲哚-3-甲醛，和吲哚-3-羧酸）的6倍，和细胞分裂素（玉米素，异戊基腺嘌呤,玉米素核苷，和异戊烯基腺苷）增加11倍。因此，我们提出了β-谷甾醇在S.netropsisIMVAc-5025的生物合成反应网络中起调节作用的假设。
