产黄青霉菌响应苯氧乙酸的Ca2+信号转导机制

Calcium-associated signals responses of Penicillium chrysogenum to phenoxyacetic acid

摘要:

【目的】研究青霉素V生产过程中—Ca2+信号转导途径参与产黄青霉菌对外源侧链前体苯氧乙酸的应答机制。【方法】考察4种不同机制的Ca2+信号干扰剂[利心平、乙二醇双(2-氨基乙基醚)四乙酸、苏拉明和硫酸新霉素]对青霉素V产量和产黄青霉菌生物量的影响。运用Fluo-3/AM荧光染料对细胞进行染色，通过荧光显微镜成像和酶标仪定量检测两种方法监测胞内Ca2+浓度的变化。【结果】苯氧乙酸添加后胞内Ca2+相对含量高于对照组49.86%，而1 mmol/L磷酸酯酶C底物抑制剂硫酸新霉素的添加使得胞内Ca2+相对含量降低了53.31%，同时青霉素V产量降低78.71%，表明产黄青霉菌可通过肌醇1,4,5-三磷酸信号途径调节胞内Ca2+浓度来响应苯氧乙酸的胁迫。【结论】首次探究了Ca2+信号转导途径在产黄青霉菌对苯氧乙酸应答中的作用，为丝状真菌中Ins(1,4,5)P3-Ca2+信号转导途径的研究提供理论依据。

Abstract:

[Objective] We studied calcium-associated signal responses of Penicillium chrysogenum to phenoxyacetic acid. [Methods] The effects of different types of Ca2+ interference agents (Nifedipine, EGTA, Suramin and Neomycin sulfate) for penicillin V production were studied. Intracellular Ca2+ concentration was measured by Olympus System microscope and SpectraMax M2 Fluorescence Microplate Reader. [Results] Levels of intracellular Ca2+ in P. chrysogenum significantly increased (49.86% higher than the control) at 25 h after treatment with phenoxyacetic acid (POA), whereas significantly reduced (53.31% lower than the control) after treatment with neomycin sulfate as an intracellular calcium inhibitor. Results indicate that cells regulated intracellular calcium level though Ins(1,4,5)P3 signaling pathways to response POA stress. [Conclusion] Understanding the effect of Ca2+ signal transduction pathway how P. chrysogenum responses to POA stress provides guidance for industrial penicillin production.