玉米浆添加对堆肥过程中磷组分转化及微生物群落的影响

Addition of corn steep liquor affects the transformation of phosphorus fractions and microbial community during composting process

摘要:

【背景】堆肥是处理农业废弃物的一种有效方式，提高堆肥产品中磷的转化效率受到越来越多人的关注。【目的】研究玉米浆添加对双孢菇菌渣堆肥过程中磷组分转化和微生物群落的影响。【方法】设置CK (100%双孢菇菌渣)和CP (双孢菇菌渣添加0.5%玉米浆)这2个处理进行为期36 d的好氧堆肥。采用Hedley法进行磷组分测定，高通量测序技术进行微生物测定，并使用生物信息技术进行数据分析。【结果】添加玉米浆后显著提高了堆体温度，延长嗜热期，促进有机质分解，改善堆体营养状况。提高活性磷含量，促进磷的活化与积累。添加玉米浆能提高细菌和真菌的多样性和丰富度，显著提高不动杆菌属(Acinetobacter)、假单胞菌属(Pseudomonas)、霉菌属(Mycothermus)和嗜热毁丝菌属(Myceliophthora)的相对丰度。降低微生物网络的复杂程度，促进微生物之间的合作与共生。添加玉米浆改变了磷组分与部分菌属的相关性，CP中不动杆菌属、鞘氨醇杆菌属(Sphingobacterium)极大地促进了磷的活化与积累。在真菌群落中，CK的伞菌属(Agaricus)能促进磷的活化，其余菌属促进磷的积累，玉米浆添加后有更多真菌与活性磷呈正相关。【结论】添加玉米浆通过改变堆肥过程的营养方式和理化指标，进一步影响微生物群落结构与磷的转化。本研究为缓解菌渣污染问题和提高堆肥磷的有效性提供了参考。

Abstract:

[Background] Composting is an effective way of treating agricultural waste, and improving the phosphorus conversion efficiency during the composting process is receiving increasing attention. [Objective] To study the effect of corn steep liquor addition on the transformation of phosphorus fractions and microbial community in the composting process of spent mushroom substrate. [Methods] Two treatments of CK (100% spent mushroom substrate) and CP (spent mushroom substrate added with 0.5% corn steep liquor) were designed for aerobic composting for 36 d. The Hedley method was used for phosphorus fractionation. High-throughput sequencing was performed to reveal the microbial community composition, and the data were analyzed by bioinformatics tools. [Results] The addition of corn steep liquor significantly increased the temperature of the heap, prolonged the thermophilic phase, promoted the decomposition of organic matter, and improved the nutrient status of the heap by increasing active phosphorus content and promoting phosphorus activation and accumulation. The addition of corn steep liquor increased the diversity and richness of bacteria and fungi. It significantly increased the relative abundance of Acinetobacter, Pseudomonas, Mycothermus, and Myceliophthora. The addition of corn steep liquor reduced the complexity of the microbial network and promoted the cooperation and symbiosis among microorganisms. In addition, it changed the correlations between phosphorus fractions and some microbial genera. Acinetobacter and Sphingobacterium in the CP treatment greatly promoted phosphorus activation and accumulation. In the CK treatment, Agaricus promoted phosphorus activation, and the rest fungal genera promoted phosphorus accumulation. More fungi were positively correlated with active phosphorus after the addition of corn steep liquor. [Conclusion] The addition of corn steep liquor affected the microbial community structure and phosphorus transformation by changing the trophic modes and physicochemical indexes during the composting process. This study provides a reference for improving the availability of compost phosphorus.