摘要
试验从青藏高原高寒草甸土壤中筛选低温降解纤维素的菌株,探究酶学性质。采用刚果红染色法(水解圈法)和3,5-二硝基水杨酸(DNS)法对菌株所产纤维素酶和木聚糖酶进行酶学性质分析,采用形态学和分子生物学进行菌种鉴定。结果显示,从高寒草甸土壤样品中筛选出一株能同步产生低温纤维素酶和低温木聚糖酶的菌株FY8,经鉴定该菌株为枝孢霉菌(Cladosporium sp.)。该菌所产纤维素酶最适反应温度40℃,最适pH值7.0;在反应温度20~60℃、pH值4.0~9.0条件下,相对酶活力保持在75%以上;金属离子Mn^(2+)对纤维素酶活力具有明显激活作用。该菌所产木聚糖酶最适反应温度40℃,最适pH值5.0;在反应温度20~50℃、pH值4.0~7.0条件下,相对酶活力保持在75%以上;金属离子Fe^(2+)对木聚糖酶活力具有明显激活作用。该菌株在培养78 h后木聚糖酶活力达到最高值,培养84 h后纤维素酶活力达到最高值。研究表明,枝孢霉菌FY8能够产低温纤维素酶和低温木聚糖酶,且两种酶均有良好的温度稳定性和pH值稳定性,具有进一步开发利用的价值。
The experiment screened cold-adapted cellulose-xylanase degrading strains from the alpine meadow soil on the Qinghai-Tibet Plateau.Cellulose-xylanase hydrolyzing ring method and 3,5-Dinitrosalicylic acid(DNS)method were used to screen strains and test enzymatic characteristics,respectively.Strains were identified by morphology and molecular biological identification.A cold-adapted cellulose-xylanase degrading strain(FY8)was identified as Cladosporium sp..The optimum reaction temperature and pH value of the cellulase was 40℃ and 7.0,respectively.The relative stability of cellulase enzyme activity was over 75% under 20〜60℃ or pH 4.0〜9.0.The cellulase activity of FY8 was significantly enhanced by Mn^(2+).Meanwhile,the optimum reaction temperature and pH value of the xylanase was 40℃ and 5.0.The relative stability of xylanase enzyme activity was over 75% under 20〜50℃ or pH 4.0-7.0.The xylanase activity of FY8 was significantly enhanced by Fe^(2+).During fermentation culture,the xylanase activity of FY8 reached the optimum activity for 78 h,while the cellulase activity reached the optimum activity for 84 h.The study indicates show that Cladosporium sp.FY8 can produce low temperature cellulase and low temperature xylanase,and both enzymes have good temperature stability and pH value stability,which has the value of further development and utilization.
作者
曹慧
张会会
张腾月
苏奎源
张镯
刘真
杨迪
刘紫祎
CAO Hui;ZHANG Hui-hui;ZHANG Teng-yue;SU Kui-yuan;ZHANG Zhuo;LIU Zhen;YANG Di;LIU Zi-yi
出处
《饲料研究》
CAS
北大核心
2022年第3期85-88,共4页
Feed Research
基金
河南科技大学博士科研启动资金(项目编号:13480077)
青海省重点研发计划(项目编号:2017-NK-153、2019-NK-173、2019-SF-149)。
关键词
低温纤维素酶
低温木聚糖酶
酶学性质
高寒草甸土壤
low temperature cellulase
low temperature xylanase
enzymology characteristics
alpine meadow soil
作者简介
第一作者:曹慧,博士,讲师,研究方向为功能性微生物开发。
