Zhang Junying, Fan Bowen, Zhao Liqin, Zhao Changjiang, Yang Fengjun
College of Agronomy, Heilongjiang Bayi Agricultural University, Daqing, China.
Key Laboratory of Low-Carbon Green Agriculture in Northeastern China, Ministry of Agriculture and Rural Affairs, Daqing, Heilongjiang, China.
Front Microbiol. 2024 Sep 18;15:1470930. doi: 10.3389/fmicb.2024.1470930. eCollection 2024.
Humus can be formed during composting through biological pathways, nonetheless, the mechanisms through which bacterial and fungal communities govern the development of humus in compost with the addition of biochar remain uncertain.
In this study, compost with cow dung and maize stover as feedstock was employed as a control group, and compost with 10% biochar added on top of the feedstock was adopted as a treatment group to investigate the effect of bacterial and fungal communities on humus formation during biochar composting.
The results demonstrated that the humic acid content increased by 24.82 and 25.10% at the cooling and maturation stages, respectively, after adding biochar. Besides, the degree of polymerization content in the maturation stage was elevated by 90.98%, which accelerated the humification process of the compost. During the thermophilic and maturity stages, there was a respective increase of 51.34 and 31.40% in reducing sugar content, suggesting that the inclusion of biochar could furnish ample reducing sugar substrate for the Maillard reaction. The addition of biochar reduced the number of humus precursor-associated genera by 35, increased the number of genera involved in humus synthesis by two, and enhanced the stability of the cross-domain network between bacteria and fungi, which confirms that microorganisms contribute to the humification process by decreasing humus precursor consumption as well as increasing humus synthesis with the addition of biochar. Additionally, adding biochar could enhance the humification capacity of the compost pile by dominating the Maillard reaction with reducing sugars as the substrate and strengthening the function of humus synthesis-associated genera. This study enhances our comprehension of the regulatory pathways of biochar in the humification process during composting.
腐殖质可在堆肥过程中通过生物途径形成，然而，在添加生物炭的堆肥中，细菌和真菌群落控制腐殖质形成的机制仍不明确。
本研究以牛粪和玉米秸秆为原料的堆肥作为对照组，以在原料上添加10%生物炭的堆肥作为处理组，研究生物炭堆肥过程中细菌和真菌群落对腐殖质形成的影响。
结果表明，添加生物炭后，冷却阶段和成熟阶段的腐殖酸含量分别增加了24.82%和25.10%。此外，成熟阶段的聚合度含量提高了90.98%，加速了堆肥的腐殖化过程。在嗜热阶段和成熟阶段，还原糖含量分别增加了51.34%和31.40%，这表明添加生物炭可为美拉德反应提供充足的还原糖底物。添加生物炭使与腐殖质前体相关的属数量减少了35个，参与腐殖质合成的属数量增加了2个，并增强了细菌和真菌之间跨域网络的稳定性，这证实了微生物通过减少腐殖质前体消耗以及在添加生物炭的情况下增加腐殖质合成来促进腐殖化过程。此外，添加生物炭可以通过以还原糖为底物主导美拉德反应并增强与腐殖质合成相关属的功能来提高堆肥堆的腐殖化能力。本研究增进了我们对生物炭在堆肥腐殖化过程中调控途径的理解。
