Enzymology and Fungal Biotechnology Lab (EFBL), Botany and Microbiology Department, Faculty of Science, Zagazig University, Zagazig, 44519, Egypt.
Agricultural Genetic Engineering Research Institute (AGERI), Agriculture Research Center, Cairo, Egypt.
Environ Sci Pollut Res Int. 2021 Aug;28(29):39866-39881. doi: 10.1007/s11356-021-13533-1. Epub 2021 Mar 25.
Attenuating the Taxol biosynthesis by fungi with storage and subculturing is the major challenge that limits their further industrial applications. Aspergillus flavipes has been reported as a potent Taxol producer, with plausible increasing to its Taxol yield upon coculturing with the microbiome of Podocarpus gracilior (El-Sayed et al., Process Biochemistry 76:55-67, 2019a; Scientific Reports 9, 2019b; Enzyme and Microbial Technology 131, 2019c); however, the identity of these microbial inducers remains ambiguous. Thus, this study was to assess the potency of individual microbes to trigger the Taxol biosynthesis by A. flavipes and to unravel the differentially expressed protein in response to bacterial interaction. Among the 25 bacterial endophytes of P. gracilior, Bacillus subtilis was the potent isolate enhancing the Taxol yield of A. flavipes by ~1.6-fold. Strikingly, this bacterial elicitor displayed a reliable inhibition to the growth of A. flavipes, so the released antifungal compound by B. subtilis could be the same signals for triggering the expression of A. flavipes Taxol synthesis. The highest Taxol yield by A. flavipes was obtained with the viable cells of B. subtilis, ensuring the pivotality of physical intimate bacterial-fungal interaction. Differential proteome of the cocultures A. flavipes and B. subtilis as well as the axenic A. flavipes was conducted by LC-MS/MS. From the total of 106 identified proteins, 50 proteins were significantly expressed, 47 were upregulated ones, and 59 were downregulated ones for the cocultures normalizing to the axenic one. From the Gene Ontology (GO) and KEGG enrichment analyses, the cellular process, primary metabolic process, and nitrogen compound metabolic process were significantly changed in the coculture normalizing to monoculture of A. flavipes. The molecular function terms (histones H2B, H2A, peptidyl-prolyl cis-trans isomerase, and nucleoside-diphosphate kinase (NDPK)) were the highly significantly expressed proteins of A. flavipes in response to B. subtilis, with strong correlation to triggering of Taxol biosynthesis. The intimate interaction of A. flavipes with B. subtilis strongly modulates the Taxol biosynthetic machinery of A. flavipes by modulating the chromatin remodeling.
通过真菌的储存和传代来减弱紫杉醇的生物合成是限制其进一步工业应用的主要挑战。黄曲霉已被报道为一种有效的紫杉醇生产者，通过与罗汉松内生微生物群落共培养，其紫杉醇产量有望增加（El-Sayed 等人，《过程生物化学》76:55-67，2019a；《科学报告》9，2019b；《酶和微生物技术》131，2019c）；然而，这些微生物诱导物的身份仍然不清楚。因此，本研究旨在评估单个微生物触发黄曲霉紫杉醇生物合成的能力，并揭示细菌相互作用下差异表达的蛋白质。在罗汉松的 25 种内生细菌中，枯草芽孢杆菌是一种有效的分离株，可将黄曲霉的紫杉醇产量提高约 1.6 倍。引人注目的是，这种细菌诱导物对黄曲霉的生长有可靠的抑制作用，因此枯草芽孢杆菌释放的抗真菌化合物可能是触发黄曲霉紫杉醇合成表达的相同信号。黄曲霉获得的最高紫杉醇产量来自枯草芽孢杆菌的活细胞，这确保了细菌-真菌物理亲密相互作用的关键作用。通过 LC-MS/MS 对黄曲霉与枯草芽孢杆菌的共培养物以及黄曲霉的无菌培养物进行了差异蛋白质组学分析。在总共鉴定的 106 种蛋白质中，50 种蛋白质的表达显著，47 种上调，59 种下调，与无菌培养物相比，共培养物归一化为无菌培养物。从基因本体（GO）和 KEGG 富集分析来看，在共培养物中，细胞过程、初级代谢过程和含氮化合物代谢过程与黄曲霉的单核培养物相比发生了显著变化。分子功能术语（组蛋白 H2B、H2A、肽基脯氨酰顺反异构酶和核苷二磷酸激酶（NDPK））是黄曲霉对枯草芽孢杆菌反应的高度显著表达蛋白，与紫杉醇生物合成的触发有很强的相关性。黄曲霉与枯草芽孢杆菌的紧密相互作用通过调节染色质重塑强烈调节黄曲霉的紫杉醇生物合成机制。
