Exploring the impact of biochar supplement on the dynamics of antibiotic resistant fungi during pig manure composting

Biochar applications in microbial fermentation processes for producing non-methane products: Current status and future prospects

The objective of this review is to encourage the technical development of biochar-assisted microbial fermentation. To this end, recent advances in biochar applications for microbial fermentation processes (i.e., non-methane products of hydrogen, acids, alcohols, and biofertilizer) have been critically reviewed, including process performance, enhanced mechanisms, and current research gaps. Key findings of enhanced mechanisms by biochar applications in biochemical conversion platforms are summarized, including supportive microbial habitats due to the immobilization effect, pH buffering due to alkalinity, nutrition supply due to being rich in nutrient elements, promoting electron transfer by acting as electron carriers, and detoxification of inhibitors due to high adsorption capacity. The current technical limitations and biochar's industrial applications in microbial fermentation processes are also discussed. Finally, suggestions like exploring functionalized biochar materials, biochar's automatic addition and pilot-scale demonstration are proposed. This review would further promote biochar applications in microbial fermentation processes for the production of non-methane products.

Evaluation of fungal dynamics during sheep manure composting employing peach shell biochar

In this study, explored the influence of different proportion (0%, 2.5%, 5%, 7.5%, and 10%) peach shell biochar (PSB) with microbial agents (EM) on the carbon transformation, humification process and fungal community dynamics during sheep manure (SM) composting. And no additives were used as control. The results manifested that the CO2 and CH4 emissions were effectively reduced 8.23%∼13.10% and 17.92%∼33.71%. The degradation rate of fulvic acid increased by 17.12%∼23.08% and the humic acid contents were enhanced by 27.27%∼33.97% so that accelerated the composting. Besides, the dominant fungal phylum was Ascomycota (31.43%∼52.54%), Basidiomycota (3.12%∼13.85%), Mucoromycota (0.40%∼7.61%) and Mortierellomycota (0.97%∼2.39%). Pearson correlation analysis and network indicated that there were different correlations between physicochemical indexes and fungal community under different additive concentrations. In brief, the two modifiers application promoted the SM degradation and affected the fungal community structure.

Microbial Risks Caused by Livestock Excrement: Current Research Status and Prospects

Livestock excrement is a major pollutant yielded from husbandry and it has been constantly imported into various related environments. Livestock excrement comprises a variety of microorganisms including certain units with health risks and these microorganisms are transferred synchronically during the management and utilization processes of livestock excrement. The livestock excrement microbiome is extensively affecting the microbiome of humans and the relevant environments and it could be altered by related environmental factors as well. The zoonotic microorganisms, extremely zoonotic pathogens, and antibiotic-resistant microorganisms are posing threats to human health and environmental safety. In this review, we highlight the main feature of the microbiome of livestock excrement and elucidate the composition and structure of the repertoire of microbes, how these microbes transfer from different spots, and they then affect the microbiomes of related habitants as a whole. Overall, the environmental problems caused by the microbiome of livestock excrement and the potential risks it may cause are summarized from the microbial perspective and the strategies for prediction, prevention, and management are discussed so as to provide a reference for further studies regarding potential microbial risks of livestock excrement microbes.

Biochar preparation and evaluation of its effect in composting mechanism: A review

This article provides an overview of biochar application for organic waste co-composting and its biochemical transformation mechanism. As a composting amendment, biochar work in the adsorption of nutrients, the retention of oxygen and water, and the promotion of electron transfer. These functions serve the micro-organisms (physical support of niche) and determine changes in community structure beyond the succession of composing primary microorganisms. Biochar mediates resistance genes, mobile gene elements, and biochemical metabolic activities of organic matter degrading. The participation of biochar enriched the α-diversity of microbial communities at all stages of composting, and ultimately reflects the high γ-diversity. Finally, easy and convincing biochar preparation methods and characteristic need to be explored, in turn, the mechanism of biochar on composting microbes at the microscopic level can be studied in depth.

The dominant role of cooperation in fungal community drives the humification process of chicken manure composting under addition of regulatory factors

This study aimed to explore the action mechanism of fungal community on the enhancement of humification during chicken manure composting by regulating the core pathway of carbon metabolism - the tricarboxylic acid cycle. Regulators adenosine triphosphate (ATP) and malonic acid were added at the beginning of composting. The analysis of changes in humification parameters showed that the humification degree and stability of compost products were improved by adding regulators. Compared with CK, the humification parameters of adding regulators group increased by 10.98% on average. Meanwhile, adding regulators not only increased key nodes, but also strengthened the positive correlation between fungi, and network relationship was closer. Moreover, core fungi associated with humification parameters were identified by constructing OTU networks, and the division and cooperation mechanism of fungi were confirmed. Ultimately, the functional role of the fungal community acting on humification was confirmed by statistical means, that was, the fungal community promoting humification was the main group of composting process. And the contribution was more obvious in ATP treatment. This study was helpful to gain insight into the mechanism of regulators addition to advance the humification process, and provided new ideas for the safe, efficient and harmless disposal of organic solid waste.