中药渣半透膜好氧堆肥效能分析及功能微生物群落结构解析

Semipermeable membrane aerobic composting of Chinese medicine residues: performance and functional microbial community structure

摘要:

【背景】我国每年会产生大量的中药废弃物，不仅浪费药材，更会引起环境的污染。因此，利用半透膜好氧堆肥技术发酵中药渣，是一条行之有效的解决固体废弃物排放问题和实现中药废弃资源的再生价值、可持续发展的方法。【目的】探索中药渣半透膜好氧堆肥工艺和适宜的中药渣发酵的C/N，结合堆肥中的微生物群落结构变化规律，探讨功能微生物与堆肥过程的关系。【方法】以中药渣为主要堆肥原料，以牛粪为辅料，利用高通量测序技术揭示堆肥过程中的微生物群落结构动态演替规律，考察堆肥期间堆体温度、C/N、含水率、pH、NH₄⁺-N、总养分和种子发芽指数等指标变化与功能微生物之间的动态关系，验证中药渣堆肥对药用植物板蓝根和蒲公英种子萌发的有效性和安全性。【结果】C/N为25的中药渣堆肥高温期超过7 d，而且含水率显著降低，pH随着发酵时间的延长逐渐呈现出碱性特征，NH₄⁺-N含量为78.8 mg/kg (<400 mg/kg)，总养分为5.48%>5%，中药渣堆肥种子发芽指数(germination index, GI)达到161.34%，符合有机肥料标准。因此，利用半透膜堆肥技术发酵中药渣，C/N为25的中药渣堆肥效果优于C/N为20、30和35的堆肥情况，堆体高温发酵过程中细菌以赖氨酸芽孢杆菌属(Lysinibacillus)和unclassified_f__Rhizobiaceae为主要功能菌群，真菌以嗜热链球菌属(Mycothermus)和曲霉菌属(Aspergillus)为主要功能菌群，且获得的中药渣堆肥有利于板蓝根和蒲公英种子的萌发。【结论】本研究结果不仅为进一步研究微生物与不同类型中药渣堆肥的作用机制提供了理论依据，更为解决中药废弃物有效资源化的问题提供了参考，拓展了半透膜好氧堆肥工艺在环境污染治理领域的应用。

Abstract:

[Background] A large amount of Chinese medicine residues is produced every year in China, which not only wastes medicinal materials but also causes environmental pollution. Semipermeable membrane aerobic composting of Chinese medicine residues is an effective method to address the solid waste and realize the regeneration value and sustainable development of Chinese medicine waste resources. [Objective] To explore the composting process and the suitable C/N ratio of Chinese medicine residues for fermentation, and reveal the relationship between functional microorganisms and composting process based on the changes of microbial community structure during the composting process. [Methods] Chinese medicine residues were composted with cow dung as the auxiliary materials, and the 16S rRNA gene high-through sequencing was employed to disclose the succession of microbial community structure during the composting process. The temperature, C/N ratio, moisture content, pH, NH₄⁺-N, total nutrients, and seed germination index were measured, and their relationship with the changes of functional microorganisms was explored. Furthermore, the Chinese medicine residue fertilizer was applied to the seeds of the medicinal plants Isatis indigotica and dandelion, and the seed germination was examined to verify the performance and safety of the fertilizer. [Results] The high-temperature period of Chinese medicine residue composting with a C/N ratio of 25 exceeded 7 days. With the extension of fermentation time, the moisture content significantly decreased and the pH gradually increased. The obtained fertilizer showed the NH₄⁺-N content of 78.8 mg/kg (<400 mg/kg), total nutrient content of 5.48% (>5%), and the germination index (GI) reaching 161.34%, which met the standards of organic fertilizer fermentation. The composting performance of Chinese medicine residues with the C/N ratio of 25 was better than that with the C/N ratios of 20, 30, and 35. During the high-temperature fermentation of the pile, Lysinibacillus and unclassified_f__Rhizobiaceae were the dominant bacteria and Mycothermus and Aspergillus were the dominant fungi. Moreover, the obtained fertilizer promoted the seed germination of I. indigotica and dandelion. [Conclusion] The results of this study not only provide a theoretical basis for further research on the mechanism of microbial compost and different types of Chinese medicine residue compost, but also provide a reference for solving the problem of effective resource utilization of Chinese medicine waste, and expand the application of semi-permeable membrane aerobic compost process in the field of environmental pollution control.