添加木质素降解菌对堆肥中酶活性的影响

Effect of Inoculating Lignin Degradation Strains on Enzymic Activities in Composting

以奶牛粪便和稻草为堆腐材料,采用静态好氧堆肥的方式研究接种木质素降解菌对堆肥过程中的温度、pH等理化性质以及木质素降解酶活性动态变化的特征,从生物酶学角度考察人工接入外源菌剂对堆肥的影响。结果表明,接菌后的堆肥处理较CK早2 d进入高温期,并且维持时间多于CK 12 d。发酵前8 d pH值的上升幅度大且高于CK,而且接种处理比对照的C/N提前5 d达到20∶1,提早达到腐熟指标,加快堆肥腐熟化进程。堆肥中酶活分析结果表明,加入菌剂后,β-葡萄糖苷水解酶在堆置第6 d达到第一个峰值14.7μmol,较CK早6 d;羧甲基纤维素钠酶在第12 d达到峰值3 270 U,同比CK高出1 220 U;漆酶酶活峰值高达93.5U,而CK峰值只有82.8 U;锰过氧化物酶进入高温期后酶活最高为75.25 U,CK最高为54.8 U。由此可见,加入微生物菌剂后可使相关酶活性提高并提高堆体温度,加快堆肥腐熟,加速堆料中各种有机质的降解,提高微生物对底物的利用,从而提高好氧堆肥的效率。

Composting is the process under which substrate is decomposed and converted into stable and environment-friendly organic matter,therefore it is a common technology for disposing of agricultural waste at present.Agricultural waste contains large quantities of lignocellulose,which mainly consists of lignin that is difficult to be biodegraded due to its complex component and structure and leads to the insufficient transformation of humus and low quality of compost.In this sense,how to accelerate the decomposition and humification of lignin is critical to the sufficient maturity and the quality of compost.Cow dung and straw were compost under static aerobic condition and lignin degrading strains were inoculated in the pile.Changes in temperature,pH and lignin-degrading enzymes activity during composting were investigated in order to assess the influence of the inoculation on composting from the perspective of biological enzyme.The result indicated that：the inoculated compost was characterized by reaching high temperature phase 2 days earlier and keeping this period for 12 days longer than the control.In the first 8 days,pH value rose more rapidly and was higher and faster than control and C/N ratio reached 20∶1 5 days earlier than control,indicating maturity of the compost.The results of enzymatic activities analyse in composting showed that after adding inoculant,β-glucosidase enzymes reached the first peak activity 14.7 μmol on the sixth day,6 days earlier than the control and also 12.3 μmol higher than it was at the peak;Sodium carboxymethyl cellulose enzyme reached its peak（3 270 U） on the twelfth day,1 220 U higher than control;The peak activity for laccase enzyme was 93.5 U,and the peak of CK was only 82.8 U;And the manganese peroxidas enzyme activity was 75.25 U in the high temperature period,however,the highest activity of the control was only 54.8 U.Thus it could be deduced that inoculating exogenous microbes could raise the enzyme activity involved,increase the temperature,accelerate the decomposition,improve the utilization of microbial substrate,and thereby enhance the composting efficiency.