Microbial Diversity in Composting: identification and analysis of Fungus-related and bacterial communities for enhanced organic waste recycling

Composting is an ancient and sustainable method of recycling organic waste into humus, a nutrient-rich substance that enhances soil productivity and reduces the environmental impact of waste disposal. Microorganisms, including fungi and bacteria, are essential to this process, as they drive the decomposition of organic matter.

This research aimed to identify fungal and bacterial species involved in composting and optimize their roles in decomposition. Compost samples were collected from Lusófona University's composting system after six months of processing organic waste, primarily fruit peels and vegetable scraps mixed with dry plant material. Microbiological analyses, including DNA extraction, PCR amplification, and Sanger sequencing, were used to identify the microorganisms present.

The results showed that the most abundant microorganisms were filamentous fungi, with the most predominant species being Aspergillus heyangensis, Aspergillus creber, Cladosporium asperulatum, Pestalotiopsis lespedezae, and especially Penicillium brevicompactum, which was the most prevalent. These species dominate the decomposition of the complete residue and have potential applications in industry and composting. The bacterial species identified were predominantly represented by the genera Bacillus (e.g., B. halotolerans, B. subtilis, B. amyloliquefaciens, B. mojavensis), as well as species from Sphingobacterium (S. kitahiroshimense), Serratia (S. fonticola), and Pseudomonas (P. fluorescens). The collective contribution of these microorganisms to the breakdown of organic material during composting is significant.

This study highlights the diversity and significance of fungal and bacterial communities in composting, emphasising their potential to optimize organic waste recycling processes. Understanding the microbiota involved in composting opens avenues for developing biotechnologies, such as microbial inoculants, to enhance process efficiency and sustainability. Future research should focus on optimizing environmental conditions to support beneficial microorganisms, further advancing composting practices and producing higher-quality humus.