摘要
【背景】高温引起的微生物活性降低是限制园林绿化废弃物堆肥过程中木质素降解的主要因素。【目的】驯化一株木质素降解菌芽孢杆菌NO.2,提高其在高温下的微生物活性,探究其生长情况及酶学特性。【方法】采用温度梯度方法驯化菌株,以菌株生长曲线、酶活力、木质素降解率为评价指标,探究驯化前后菌株间差异,以及驯化后菌株所产木质素降解酶的酶促反应温度和pH范围。【结果】与原菌株相比,驯化后菌株在60℃培养时最大生物量间差异不显著;漆酶(laccase,Lac)、锰过氧化物酶(manganeseperoxidase,MnP)和木质素过氧化物酶(ligninperoxidase,LiP)酶活力得到进一步提高,分别提高了30.75%、35.98%和29.62%,木质素降解率提高60.52%。酶学性质研究表明,驯化后菌株所产Lac、MnP和LiP在20-60℃、pH 3.0-9.0范围内酶活力均较高,而且具有较好的稳定性,稳定性依次为Lac>LiP>MnP。【结论】温度梯度驯化方法可有效提高微生物对高温环境的适应性,扩大木质素降解酶的酶促反应温度和pH范围,在进一步自主研制专用降解园林废弃物微生物菌剂中具有应用潜能。
[Background]High temperature decreases microbial activity,thus limiting the lignin degradation in garden waste composting.[Objective]To acclimatize a lignin-degrading strain—Bacillus sp.NO.2,improve its activity at high temperature,and observe its growth status and enzymatic properties.[Methods]The temperature gradient method was used to domesticate the strain,and the growth curve,enzyme activity,and lignin degradation rate were compared before and after the domestication.Moreover,the temperature range and pH range for the enzymatic reaction of lignin-degrading enzymes generated by the strain were determined.[Results]The maximum biomass was insignificantly different between the original strain and the domesticated strain at 60℃.However,the activity of laccase(Lac),manganese peroxidase(MnP),and lignin peroxidase(LiP)was 30.75%,35.98%,and 29.62%higher,and the lignin degradation rate was 60.52%higher than those of the original strain,respectively.The Lac,MnP and LiP produced by the domesticated strain showed high activity at 20–60℃and pH 3.0–9.0,and were stable,with the stability following the order of Lac>LiP>MnP.[Conclusion]The temperature gradient method can improve the activity of Bacillus at high temperature and widen the temperature and pH ranges for enzymatic reaction of lignin-degrading enzymes.Furthermore,it has potential for developing a special microbial agent for degrading garden waste.
作者
何艳玲
孙向阳
李素艳
郝丹
HE Yanling;SUN Xiangyang;LI Suyan;HAO Dan(Key Laboratory for Silviculture and Conservation of Ministry of Education,College of Forestry,Beijing Forestry University,Beijing 100083,China)
出处
《微生物学通报》
CAS
CSCD
北大核心
2023年第1期163-174,共12页
Microbiology China
基金
北京市自然科学基金(6202021)
科技基础资源调查专项(2021FY100802)。
关键词
芽孢杆菌NO.2
温度梯度驯化
酶学性质
Bacillus sp.NO.2
acclimation by temperature gradient
enzymatic properties
