堆肥反应器中表面活性剂APG对牛粪堆肥酶活性的影响

利用堆肥反应器严格控制堆肥条件, 以牛粪为主要原料进行好氧堆肥, 在堆肥过程中加入表面活性剂烷基多糖苷(APG), 研究其对堆肥中微生物数量以及酶活性变化的影响。结果表明: 在好氧堆肥中添加表面活性剂APG对堆肥中的微生物无显著抑制作用, 微生物数量无显著变化(P>0.05); 但可以促进堆肥升温, 延长高温期。加入APG对堆肥中的过氧化氢酶活性几乎无影响, 最终APG处理和CK处理的酶活性值均达到1.17 mmol·g^-1左右; 加入APG后脲酶活性略有提高, 第2 d APG处理和CK处理的脲酶活性均达到峰值, 分别为32.15 mg(NH₃-N)·g^-1·24h^-1和30.17 mg(NH₃-N)·g^-1·24h^-1, 差异不显著(P>0.05), 第7 d达到最低值, 分别为0.81 mg(NH₃-N)·g^-1·24h^-1和0.38 mg(NH₃-N)·g^-1·24h^-1, 差异显著(P<0.05); APG处理对转化酶和纤维素酶活性均有明显的提高作用, 其中转化酶在第3 d加APG处理和CK处理峰值分别为18.15 mg(葡萄糖)·g^-1·24h^-1和11.77 mg(葡萄糖)·g^-1·24h^-1, 第21 d两处理峰值分别为24.09 mg(葡萄糖)·g^-1·24h^-1和20.71 mg(葡萄糖)·g^-1·24h^-1, 差异显著(P<0.05); 纤维素酶在第3 d加APG处理和CK处理峰值分别为58.77 mg·min^-1和30.62 mg·min^-1, 差异显著(P<0.05)。本试验结果表明, 添加表面活性剂APG可以提高堆肥中转化酶和纤维素酶活性, 促进堆肥中有机物质的转化, 一定程度上加快好氧堆肥进程。

Enzyme activity as affected by surfactant APG in dairy manure compost in bioreactor

Using compost bioreactors with dairy manure and mushroom residues as feed-stocks, we studied microbial population and enzyme activity as affected by surfactant APG in a 28-day composting process under controlled aerobic condition. APG was added at rate of 100 mg·kg^-1 (amended treatment on dry-weight basis) with 0.00 APG (non-amended treatment) as CK. Results show that APG addition does not inhibit microbial population in terms of total bacteria, fungi and actinomycete (P>0.05). APG addition accelerates temperature increase, with prolonged periods of high temperatures. It, however, does not affect catalase activity at approximately 1.17 mmol·g^-1 for both treatments after 28 days of composting. Urease activity under APG addition and CK reaches its peaks of respectively 32.15 mg(NH₃-N)·g^-1·24h^-1 and 30.17 mg(NH₃-N)·g^-1·24h^-1 after 2 days. There is no significant difference between the 2 treatments and both treatments respectively hit the lowests of 0.81 mg(NH₃-N)·g^-1·24h^-1 and 0.38 mg(NH₃-N)·g^-1·24h^-1 on the 7th day. APG addition significantly enhances invertase and cellulase activity. Invertase activity peaks on day 3 at 18.15 mg(glucose)·g^-1·24h^-1 for APG treatment and 11.77 mg(glucose)·g^-1·24h^-1 for CK (P<0.05), and on day 21 at 24.09 mg(glucose)·g^-1·24h^-1 and 20.71 mg(glucose)·g^-1·24h^-1 for CK respectively (P<0.05). Cellulase activity reaches its peaks of 58.77 mg·min^-1 for APG treatment and 30.62 mg·min^-1 for CK (P<0.05) on day 3. The above results suggest that APG addition enhances organic matter decomposition and therefore potentially shortens decomposition time.