园林废弃物降解菌剂的模型构建及效果探究

MODEL CONSTRUCTION AND EFFECT INVESTIGATION OF GARDEN WASTE DEGRADING BACTERIAL AGENT

探究了混料设计方法应用于复合菌剂构建以及组分优化的可行性,以解决当前园林废弃物(GW)堆肥周期长,木质纤维素转化效率低的问题。利用分离培养与拮抗实验,确定了源自GW堆肥样品中的降解菌株及其互作关系。然后,通过混料设计将无拮抗效应的菌株按照不同比例进行复合,并测定相关酶活(漆酶Lac、木质素过氧化物酶Lip、锰过氧化物酶Mnp、羧甲基纤维素酶CMCase、滤纸酶FPAase),从而建立回归模型。构建的复合菌剂由特基拉芽胞杆菌(Bacillus tequilensis)、贝莱斯芽孢杆菌(Bacillus velezensis)、稻壳芽孢杆菌(Bacillus oryzaecorticis)组成,三者间的最佳比例分别为28.95%、39.63%、31.42%。同时在GW降解实验中,其最大酶活Lac:47.25 U/L、Lip:66.67 U/L、Mnp:99.65 U/L、CMCase:90.66 U/mL、FPAase:48.44 U/mL,第18天木质素与纤维素的降解率分别可达9.73%和13.48%。基于混料设计而构建的复合菌剂,短期产酶能力与生物降解能力突出,对于GW的堆肥化应用具有重要意义。

To investigate the feasibility of the mixture design methodology applied to the construction of composite inoculum,and the optimization of components to address the current problems of long composting cycles and low wood fiber conversion efficiency of garden waste,the degrading strains from the GW compost samples and their interrelationships were identified,using isolation culture and antagonism experiments.The non-antagonistic strains were mixed in different proportions using the mixture design method and their enzyme activities were measured,after which the mathematical models between the proportions of different strains and the enzyme activities were established.The results showed the composite consisted of Bacillus tequilensis,Bacillus velezensis,and Bacillus oryzaecorticis,and their optimum ratio was 28.95%:39.63%:31.42%.Meanwhile,in the degradation experiment using GW as the carbon source,the maximum enzyme activity of laccase was 47.25 U/L,lignin peroxidase was 66.67 U/L,manganese peroxidase was 99.65 U/L,carboxymethyl cellulase was 90.66 U/mL,and filter paper activity was 48.44 U/mL.The degradation rates of cellulose and lignin on the 18th day could reach 13.48%and 9.73%,respectively.The composite inoculum constructed based on the mixture design showed superior short-term enzyme activity production and biodegradation capacity,which is conducive to the application of GW composting.