低温秸秆降解复合菌系分离及菌株鉴定  

Isolation of Low Temperature Straw Degraded Composite Strains and Strains Identification

作　　者：吴清云 萨如拉[1,2] 杨恒山 杨陶阳[1] 王涛 雷梓莉 WU Qingyun;SA Rula;YANG Hengshan;YANG Taoyang;WANG Tao;LEI Zili(College of Agriculture,Inner Mongolia Minzu University,Tongliao,Inner Mongolia 028000;Key Laboratory of Horqin Sandy Land Ecological Agriculture,State Ethnic Affairs Commission,Tongliao,Inner Mongolia 028000)

机构地区：[1]内蒙古民族大学农学院,内蒙古通辽028000 [2]科尔沁沙地生态农业国家民委重点实验室,内蒙古通辽028000

出　　处：《中国农学通报》2023年第21期62-67,共6页Chinese Agricultural Science Bulletin

基　　金：国家自然科学基金项目“低温秸秆降解复合菌系作用机制与途径研究”(31960383);中央引导地方科技发展资金项目“轻度盐碱地玉米大豆复合种植产量效率与地力协同提升生理生态机制”(2022ZY0032);科尔沁沙地生态农业国家民委重点实验室开放基金项目“玉米大豆轮作增产增效生理生态机制研究”(MDK2022025)。

摘　　要：为内蒙古冷凉地区秸秆促熟还田提供优良微生物菌剂,需要明确低温秸秆降解复合菌系菌种组成。以15℃实验室条件下能降解玉米秸秆的复合菌系-8号为材料,采用选择性培养基-羧甲基纤维素钠固体培养基分离获得单菌株,并从菌株形态学、生理生化特性、细菌16S rRNA、真菌ITS rDNA和?-tubulin基因序列分析方法对其进行鉴定。结果表明,8号菌系用羧甲基纤维素钠固体培养基分离到真菌8-F和细菌8-B。8-F菌落为粉白色、毡绒状、革兰氏阴性,菌丝经常缠绕成绳状,分生孢子梗呈树状或葡萄穗状分枝、直径1.5~2.0μm,分生孢子顶生或间生、倒梨状、大小2.5~4.5×2.0~3.0μm,其ITS rDNA序列与GenBank数据库中数据系统比对可知,与Geomyces sp.具有99%的同源性;根据以上特点鉴定为Geomyces pannorum。8-B菌细胞杆状、革兰氏阴性、不生孢,菌落呈浅黄色、不规则形状,能产10种酶、能利用37种碳源,其16S rDNA序列与Stenotrophomonas humi的同源性为99.71%,根据以上特点鉴定为寡养单胞菌属(Stenotrophomonas sp.)。在低温(15℃)实验室条件下能降解玉米秸秆的复合菌系优势菌种是Geomyces pannorum和Stenotrophomonas maltophilia。To provide excellent microbial agents for straw ripening and returning to the field in the cold and cool areas of Inner Mongolia,it is necessary to clarify the composition of low-temperature straw degradation complex strains.The compound strain-8,which can degrade corn straw under the laboratory condition of 15℃,was used as the material.A single strain was isolated from the selective medium-sodium carboxymethylcellulose solid medium,and identified by morphology,physiological and biochemical characteristics,16S rRNA of bacteria,ITS rDNA of fungi andß-ubulin gene sequence analysis.The results showed that fungus 8-F and bacterium 8-B were isolated from No.8 strain with sodium carboxymethylcellulose solid medium.The morphological characteristics of 8-F colony were powdery white,felt-like and gram-negative.The hyphae were often twined into ropes.The conidial peduncle was tree-like or grape-spike branched,with a diameter of 1.5-2.0μm.The conidia were terminal or intermediate,inverted pear-shaped,and(2.5-4.5)×(2.0-3.0)μm in size.The comparison of ITS rDNA sequence with the data system in GenBank database showed that it had 99%homology with Geomyces sp..According to the above characteristics,it was identified as Geomyces pannorum.The cell of 8-B strain was rod-shaped,gram-negative,non-sporogenic,and its colony was light yellow and irregular in shape.It could produce 10 enzymes and use 37 carbon sources.Its 16S rDNA sequence had 99.71%homology with Stenotrophomonas humi,and was identified as Stenotrophomonas sp.according to the above characteristics.The dominant strains of the composite strains that could degrade corn straw under low temperature(15℃)laboratory conditions were Geomycos pannorum and Stenotrophomonas maltohilia.

关 键 词：富集 驯化 Geomyces pannorum 嗜麦芽寡养单胞菌 

分 类 号：S182[农业科学—农业基础科学]