高温纤维素降解菌群PN-8对小麦秸秆的降解能力及影响因素研究  

Degradation Ability and Influencing Factors of Cellulose-degradation Microbial Community PN-8 on Wheat Straw

作　　者：武凤霞[1] 孙悦 肖强[1] 张淑彬[1] 李钰飞[1] 刘建斌[1] WU Fengxia;SUN Yue;XIAO Qiang;ZHANG Shubin;LI Yufei;LIU Jianbin(Institute of Plant Nutrition,Resources and Environment,Beijing Academy of Agriculture and Forestry Sciences,Beijing 100097,China)

机构地区：[1]北京市农林科学院植物营养与资源环境研究所,北京100097

出　　处：《河南农业科学》2022年第4期77-86,共10页Journal of Henan Agricultural Sciences

基　　金：北京市农林科学院青年科研基金项目(QNJJ201908,QNJJ202004);北京市农林科学院科技创新能力建设专项(KJCX20190407,KJCX20220420)。

摘　　要：为了明确高温纤维素降解菌群PN-8的性质及关键影响因素,分析了不同化学前处理(0.5%、1.5%、10.0%的氢氧化钠,3.0%、12.0%、18.0%的盐酸,2.0%、20.0%的乙酸)及培养基中初始接种量、葡萄糖含量、pH值对PN-8降解小麦秸秆的影响,通过气质联机检测、纤维素酶活性测定及扫描电子显微镜观察等分析了PN-8降解小麦秸秆过程主要产物、不同纤维素酶活性及小麦秸秆降解特点。结果表明,小麦秸秆前处理影响PN-8的降解能力,碱(氢氧化钠)处理可以降低木质素含量从而提高PN-8的降解率,而酸(盐酸、乙酸)处理会提高木质素含量从而降低PN-8的降解率。其中,小麦秸秆经过1.5%、10.0%的氢氧化钠处理后降解率分别为71.61%、87.33%,显著高于未经化学前处理的44.33%。当初始PN-8的接种量在5.0%以下时,滤纸条分解速度和接种量呈正相关,接种量高于5.0%后其对小麦秸秆的降解率差异不显著;初始葡萄糖含量高于0.1%,或者初始pH值超出5~9时,PN-8失去对小麦秸秆的分解能力。PN-8发酵过程中甘油的质量浓度最高,发酵第1天质量浓度最高可达0.28 g/L,其次为乙酸和乙醇;PN-8降解小麦秸秆过程中羧甲基纤维素酶活性和滤纸酶活性均呈现先上升后下降的变化规律;电镜扫描结果显示,PN-8可以破坏小麦秸秆结构,分解木质纤维素。In order to clarify the characteristics and key influencing factors of thermophilic lignocellulose-degradation microbial community PN-8,we analyzed the effects of different chemical pretreatments(0. 5%,1. 5%,10. 0% sodium hydroxide,3. 0%,12. 0%,18. 0% hydrochloric acid,2. 0%,20. 0% acetic acid),initial inoculation amount,glucose content and pH on the degradation of wheat straw by PN-8. The main products of PN-8 in the process of degrading wheat straw were analyzed by GC-MSQP2010,and the degradation ability of PN-8 on wheat straw was detected by scanning electron microscope. The results showed that chemical pretreatment of wheat straw affected the degradation ability of PN-8. Alkali treatment(sodium hydroxide)could reduce lignin content and improve the degradation rate of PN-8,while acid treatment(hydrochloric acid,acetic acid)could increase lignin content and reduce the degradation rate. Among them,after 1. 5%,10. 0% sodium hydroxide treatment,the degradation rate of wheat straw reached 71. 61%,87. 33% respectively,which were significantly higher than that without chemical pretreatment(44. 33%). When the initial inoculation amount of PN-8 was less than 5. 0%,the degradation rate was positively correlated with the inoculation amount,and there was no significantly difference when the inoculation amount was higher than 5. 0%. When the initial glucose concentration was higher than 0. 1%,or the initial pH value exceeded the range of 5—9,PN-8 lost the degradation ability of wheat straw. Glycerol was the dominant fermentation product,which could reach the maximum content of 0. 28 g/L on the first day of fermentation,followed by acetic acid and ethanol. Both carboxymethyl cellulase activity and filter paper enzyme activity showed a change regular of first increasing and then decreasing during the fermentation process. The results of scanning electron microscope showed that PN-8 could destroy the structure of wheat straw and degrade lignocellulose.

关 键 词：纤维素降解菌群 纤维素酶活性 酸处理 碱处理 纤维素降解率 小麦秸秆 

分 类 号：S141.4[农业科学—肥料学] X71[农业科学—农业基础科学]