通过限制培养基中氮元素含量促进香菇分泌木质素过氧化物酶  

Restricting Nitrogen Content in Culture Medium Promotes Lentinula edodes to Secrete Lignin Peroxidase

作　　者：戈永杰 尚晓冬[2] 谭琦[2] GE Yongjie;SHANG Xiaodong;TAN Qi(College of Food Science and Technology,Shanghai Ocean University,Shanghai 201200,China;Institute of Edible Fungi,Shanghai Academy of Agricultural Sciences/Key Laboratory of Edible Fungi Resources and Utilization(South),Ministry of Agriculture and Rural Affairs,P.R.China/National Engineering Research Center of Edible Fungi/Key Laboratory of Agricultural Genetics and Breeding of Shanghai,Shanghai 201403,China)

机构地区：[1]上海海洋大学食品学院,上海201200 [2]上海市农业科学院食用菌研究所,农业农村部南方食用菌资源利用重点实验室,国家食用菌工程技术研究中心,上海市农业遗传育种重点实验室,上海201403

出　　处：《食用菌学报》2022年第6期25-34,共10页Acta Edulis Fungi

基　　金：国家重点研发计划(2019YFD1001900)。

摘　　要：为考察香菇(Lentinula edodes)是否分泌木质素过氧化物酶(lignin peroxidase,LiP),采用4种(酵母麦芽浸膏、完全、基础、PDA)培养基培养香菇菌株,以赤芝(Ganoderma lucidum)为对照,通过固体显色法检测各菌株对显色底物(亮蓝、天青B)的脱色情况;以刺芹侧耳(Pleurotus eryngii)和赤芝为对照,测定各菌株液体培养后制备的粗酶液中木质纤维素降解酶的活性。以氮元素含量为0.05%胰蛋白胨(限氮培养基)培养香菇菌株,以刺芹侧耳为对照,通过固体显色法检测限氮培养基中各菌株对显色底物(亮蓝、天青B、活性黑5)的脱色情况;并以酒石酸缓冲液(pH 3.5)、天青B(底物)、藜芦醇(电子供体)、H_(2)O_(2)(活化剂)配制脱色反应体系,测定香菇菌株液体培养后制备的粗酶液中LiP的活性。结果表明:在4种培养基中培养的香菇菌株未能使亮蓝与天青B脱色,赤芝使两者均脱色;且在香菇粗酶液中未检出LiP活性。采用限氮培养基培养的香菇菌株使亮蓝与天青B脱色;采用PDA与限氮培养基培养的香菇菌株均未使活性黑5脱色,刺芹侧耳使其脱色。在实验范围内,香菇菌株于限氮培养基上培养12 d后,随着培养时间增加,所有菌株LiP活性均上升;12 d时不同菌株LiP活性无差异;22 d时菌株1504 LiP活性(39.74 U·L^(-1))较强,对天青B的脱色率在反应12 h时最高可达66.21%;菌株215、a 2 sm 99、gsm 207 LiP活性次之,分别为29.86、29.24、27.34 U·L^(-1);菌株bsm 83活性较弱为13.28 U·L^(-1)。研究结果表明通过限制培养基中氮元素的含量可以促进香菇分泌木质素过氧化物酶。To investigate whether Lentinula edodes secretes lignin peroxidase(LiP),different L.edodes strains were cultured by four kinds of media(yeast malt extract,complete,basic and PDA),and then observed for decolorization activity to chromogenic substrates(R Brilliant Blue R and azure B)on solid agar plates using Ganoderma lucidum as the positive control.Using Pleurotus eryngii and G.lucidum as controls,crude enzyme solutions of liquid cultures of different L.edodes strains were measured for lignocellulose activity.Using P.eryngii as the positive control,different L.edodes strains were cultured by a nitrogen limited medium(0.05%tryptone),and then observed for decolorization activity to chromogenic substrates(R Brilliant Blue R,azure B,and reactive black 5)on agar plates,and also measured for LiP activity in crude enzyme solution by a decolorization reaction system comprising tartaric acid buffer(pH 3.5),azure B(as the substrate),veratrol alcohol(as the electron donor)and H_(2)O_(2)(as the activator).The results showed that in four kinds of culture media with unlimited nitrogen sources,the L.edodes strains failed to decolorize R Bright Blue R and azure B,whereas G.lucidum decolorized both.No LiP activity was detected in the crude enzyme solutions of L.edodes cultured with nitrogen-unlimited media.When cultured under limited nitrogen,L.edodes decolorized R Brilliant Blue R and azure B,but failed to decolorize reactive black 5,which was decolorized by the positive control.After 12 d under limited nitrogen,the LiP activity of all L.edodes strains increased with the increase of culture time.There was no difference in LiP activity between different L.edodes strains at 12 d.Upon cultivation under limited nitrogen for 22 d,strain 1504 showed strong LiP activity(39.74 U·L^(-1)),and the decolorization rate of azure B reached 66.21%at 12 h.The LiP activities of strains 215,a 2sm99 and gsm 207 were 29.86,29.24 and 27.34 U·L^(-1),respectively.The LiP activity of strain bsm 83 was relatively weak(13.28 U·L^(-1)).These findings in

关 键 词：香菇 木质素过氧化物酶 限氮 酶活 

分 类 号：S646.12[农业科学—蔬菜学]