| 摘要: |
| 【目的】研究不同菌株组合及不同矿物元素含量对玉米秸秆降解效果的影响。【方法】以风干粉碎过2 mm筛的玉米秸秆为供试样品，以预试验筛选的降解玉米秸秆细菌菌株贝莱斯芽孢杆菌（Bacillus velezensis）和解淀粉芽孢杆菌（Bacillus amyloliquefaciens）以及真菌菌株棘孢曲霉（Aspergillus aculeatus）和黑曲霉（Aspergillus niger）为供试菌株(分别命名为HL-1、HM-6、MN-1、M1-2),根据菌株的多样性，以丰富度为依据，用4株菌株组配了15组降解组合，并通过抽样分析确定4株菌株在复合菌系中的贡献程度，以降解秸秆中粗纤维（CF）质量分数为指标来筛选最佳复合菌系。在确定最佳复合菌系的基础上，通过单因素试验和正交试验探究不同含量P、N、Ca对秸秆CF降解的影响；最后以CF质量分数为主要指标、活菌数及羧甲基纤维素酶（CMCase）和滤纸酶（FPAase）活性为辅助指标，确定最佳矿物元素含量组合。【结果】① 由菌株多样性和抽样效应分析结果可知，复合菌系J（HL-1＋HM-6＋M1-2）降解效果最好，秸秆降解后CF质量分数为31.59%，较原始玉米秸秆CF质量分数（34.65%）降低了3.06个百分点，CF降解率达到8.83%。② 单因素和正交试验结果表明，向复合菌系J中添加0.7 g/kg P、0.7 g/kg N和0.5 g/kg Ca，降解6 d后秸秆中活菌数为10.73×108 CFU/mL，CMCase和FPAase活性分别为8.12和2.51 U/g，CF质量分数为27.49%，较原始玉米秸秆下降了7.16个百分点，CF降解率达到20.66%。【结论】在该试验条件下，向筛选的最佳复合菌系J（HL-1＋HM-6＋M1-2）中添加适宜矿物元素P、N、Ca，有利于玉米秸秆的降解。 |
| 关键词: 玉米秸秆降解 贝莱斯芽孢杆菌 解淀粉芽孢杆菌 棘孢曲霉 黑曲霉 矿物元素 |
| DOI： |
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| 基金项目:国家科技部专项“国际间重点联合项目”（2017YFE0129900）；河南省重点攻关项目（212102110157）；河南省重点研发与推广专项（科技攻关）（212102110174） |
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| Effects of compound bacteria and mineral elements on corn straw degradation |
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ZHANG Junwei,LIU Xuechun,ZHANG Pengzhen,et al
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| Abstract: |
| 【Objective】This study investigated the effects of different bacterial strain combinations and different mineral element contents on the degradation effect of corn straw.【Method】Air dried corn straw after crushing and 2 mm sieving was used as the test sample,and pre-tested Bacillus velezensis and Bacillus amyloliquefaciens and fungal strains Aspergillus aculeatus and Aspergillus niger,named HL-1,HM-6,MN-1 and M1-2,were used as the test strains.According to strain diversity and richness,15 degradation combinations were assembled with 4 strains,and their contribution rates in composite strain systems were determined by sampling analysis.The mass fraction of crude fiber (CF) in degraded corn straw was used as index to select the best composite strain.With the best composite bacterial strain,the effects of different contents of P,N and Ca on CF degradation were explored by single factor tests and orthogonal test.Using the CE mass fraction as main index and the number of viable bacteria and activities of methyl cellulase (CMCase) and filter paper enzyme (FPAase) as auxiliary indexes,the optimal combination of mineral element contents was determined.【Result】① According to strain diversity and sampling effects,the degradation effect of composite strain J(HL-1+HM-6+M1-2) was the best.The mass fraction of CF after straw degradation was 31.59%,which was 3.06% lower than that of the original corn CF (34.65%),and the CF degradation rate reached 8.83%.② The single factor and orthogonal experiments showed that adding 0.7 g/kg P,0.7 g/kg N and 0.5 g/kg Ca to the composite strain J obtained live bacteria number of 10.73×108 CFU/mL after 6 days of degradation.The activities of CMCase and FPAase were 8.12 and 2.51 U/g,respectively.The mass fraction of CF was 27.49%,which was 7.16% lower than that of the original corn stalk,and the CF degradation rate reached 20.66%.【Conclusion】Under the conditions of this study,adding appropriate mineral elements of P,N,and Ca to the screened optimal composite strain J (HL-1+HM-6+M1-2) was beneficial to the degradation of corn straw. |
| Key words: degradation of corn straw Bacillus velezensis Bacillus amyloliquefaciens Aspergillus aculeatus Aspergillus niger mineral element |
