黄孢原毛平革菌抗营养阻遏产漆酶同工酶动态分析  

Dynamic Analysis of Laccase Isozyme Production by Phanerochaete chrysosporium Resisting Nutrional Repression

作　　者：郑耀通[1,2] 李文燕[2] ZHENG Yao-tong;LI Wen-yan(Coll.of Res.&Environ.,2.Inst.of Applied Microbial Technol.,Fujian Agric.&Forest.Uni.,Fuzhou 350002)

机构地区：[1]福建农林大学资源与环境学院,福建福州350002 [2]福建农林大学应用微生物技术研究所,福建福州350002

出　　处：《微生物学杂志》2020年第6期13-20,共8页Journal of Microbiology

基　　金：福建省自然科学基金资助项目(2011J05047)。

摘　　要：以选育的抗营养阻遏产木质素降解酶黄孢原毛平革菌(Phanerochaete chrysosporium)pcR5305、pcR5324为实验对象,研究了其在富氮条件下动态产漆酶同工酶的规律及其可能的营养调控机制。两菌株可在初始氨氮质量浓度达2.2 g/L的富氮环境下产漆酶,启动漆酶合成及达到产酶峰值对应的葡萄糖、氨氮浓度阀值远高于野生型,基质C/N的降低是漆酶合成启动及达到高峰的前提,其中碳浓度的降低更为重要。两菌株在不同时间可产生1~3种漆酶同工酶(分别为Lac1、Lac2和Lac3),其中Lac3产酶伴随菌体整个生长过程,其合成启动与积累无需受基质碳氮饥饿及C/N的限制;Lac2在pcR5305初生代谢阶段产生,但只能在pcR5324次生代谢阶段产生;Lac1仅在pcR5305的初生代谢或次生代谢阶段产生,基质C/N降至5.0~7.0时诱导产生Lac1的合成,并随培养时间的增加产酶量逐渐提高。显然3种同工酶的合成具有不同的调控机制。Selected Phanerochaete chrysosporium strains pcR5305 and pcR5324 producing lignin degradative enzyme and resisting nutritional repression were taken as the experimental objects,and the dynamic laccase isozyme production rule and their possible nutritional regulation mechanism under nitrogen rich conditions were studied.Both of the two strains could produce laccase in the nitrogen rich environment with initial concentration of ammonia nitrogen at 2.2 g/L.The threshold level of the concentrations of glucose and ammonia nitrogen which corresponded with the start-up of laccase synthesis and the achievement of the peak value of enzyme were much higher than that of the wild type;the reduction of C/N in substrate was the precondition of the start-up of laccase synthesis and the achievement of the peak value of enzyme and the reduction of the concentration of carbon was much more important.The two strains could produce 1-3 kinds of laccase isozyme(respectively Lac1-Lac3)at different time,among them the production of Lac3 was with the whole process of growth of their thalli,and its start-up of synthesis and accumulation needed not starvation of carbon and nitrogen in the substrate,as well as were not limited by carbon,nitrogen and C/N;Lac2 was produced during"primary metabolism"phase by pcR5305,while it was produced during"secondary metabolism"phase by pcR5324;Lac1 was only produced by pcR5305 during"primary metabolism"phase and"secondary metabolism"phase as well,but the synthesis of Lac1 was induced by the reduction of C/N to 5.0-7.0 in the substrate and the enzyme output gradually improved with the extension of cultivation time,obviously the synthesis of three isozyme had different regulation mechanisms.

关 键 词：黄孢原毛平革菌 漆酶 同工酶 营养阻遏解除 碳氮营养调控 

分 类 号：Q939.99[生物学—微生物学]