Wang Junqi,Liu Meijie,Mao Chengzhi,Li Sizhu,Zhou Jiabao,Fan Yaqin,Guo Lizhong,Yu Hao,Yang Xiuqing
Cyclosporine A (CsA) is a secondary cyclopeptide metabolite produced by Tolypocladium inflatum that is widely used clinically as an immunosuppressant. CsA production and mycelial growth differed when T. inflatum was cultured in different carbon source media. During early fermentation, CsA was preferred to be produced in fructose medium, while the mycelium preferred to accumulate in sucrose medium. On the sixth day, the difference was most pronounced. In this study, high-throughput comparative proteomics methods were applied to analyze differences in protein expression of mycelial samples on day 6, revealing the proteins and mechanisms that positively regulate CsA production related to carbon metabolism. The differences included small molecule acid metabolism, lipid metabolism, organic catabolism, exocrine secretion, CsA substrate Bmt synthesis, and transcriptional regulation processes. The proteins involved in the regulation of mycelial growth related to carbon metabolism were also revealed and were associated with waste reoxidation processes or coenzyme metabolism, small molecule synthesis or metabolism, the stress response, genetic information or epigenetic changes, cell component assembly, cell wall integrity, membrane metabolism, vesicle transport, intramembrane localization, and the regulation of filamentous growth. This study provides a reliable reference for CsA production from high-efficiency fermentation. This study provides key information for obtaining more CsA high-yielding strains through metabolic engineering strategies.
Qian Gui,Hai-Min Zhang,Feng Qian,Han-Yu Liu,Xiang-Xin Kong,Guo-Ying Lv,Pu Wang
Asymmetric synthesis of chiral alcohols by biocatalysts holds promising prospect. In this study, a medicinal Cordyceps fungus, namely Tolypocladium inflatum , was adopted as a novel biocatalyst for the synthesis of chiral alcohols. Among the assessed prochiral ketone substrates, T. inflatum exhibited the best catalytic activity towards 1-(4-bromophenyl)−2,2,2-trifluoroethanone (BPFO), yielding a valuable pharmaceutical intermediate ( S )−1-(4-bromophenyl)−2,2,2-trifluoroethanol (( S )-BPFL) with >99.9 % enantiomeric excesses (ee). For more efficient biosynthesis of ( S )-BPFL, cyclodextrins or surfactants were introduced to the reaction system as additives to strengthen this bioprocess. Among which methyl β-cyclodextrin (MCD) improved cell membrane permeability and alleviated product inhibition, while Triton X-100 enhanced BPFO solubility. Furthermore, synergistic promotion for BPFO bioreduction by MCD and Triton X-100 was observed. Under the optimal reaction conditions, 50 mM BPFO was converted into ( S )-BPFL with 89.1 % yield and >99.9 % ee in 12 h, showing 16-fold increase of space-time yield in the developed MCD/Triton X-100-buffer system compared to neat buffer solution. This study illustrated the potential of the enantioselective preparation of chiral alcohols mediated by Cordyceps fungus. Additionally, the biocatalytic efficiency was significantly improved in the constructed synergistic reaction system, and the underlying mechanism was also explored.