Study of Microbiome Changes during Composting and Vermicomposting of Winery Wastes

Proceedings of The 3rd World Conference on Climate Change and Global Warming

Year: 2023



Study of Microbiome Changes during Composting and Vermicomposting of Winery Wastes

Ioanna Karapantzou, Gregoria Mitropoulou, Ioanna Prapa, Dimitra Papanikolaou, Vasileios Charovas, Yiannis Kourkoutas




Annually, the wine industry produces with a high content of organic load and high acidity, and along with the presence of phytotoxic compounds, their deposition directly in the soil without pretreatment can be toxic for the environment and the agricultural cultures. Composting is the natural process of decomposing organic matter by microorganisms or earthworms under controlled conditions. This process can be achieved through microbial activity in the composting material combined with the metabolic activity of earthworms, resulting in a valuable organic biofertilizer. At the present study, winery wastes (exhausted grape marc and vine branches) were placed in a turned pile for 20 days at the start of the process, and the finished product was loaded into a vermicomposting reactor with earthworms Eisenia andrei and Eisenia fetida for 40 days. During the process, the physicochemical changes along with microbiome shifts using nextgeneration sequencing (NGS) were monitored. The compost product was stable and consistent and the C/N ratio was significantly decreased. The results showed a great diversity of bacterial and fungal genera among the samples. At the end of the process, an increased presence of Anaerolinea, Ohtaekwangia, bacteria and Aleuria, Coltricia, Mortierella, Parascedosporium, and Petriella genera were witnessed, while decreased abundances were observed for Agrobacterium, Brevundimonas, Devosia, Shinella, Sphingomonas bacteria and Galactomyces, Plectosphaerella and Trichosporon. Understanding the microbiome changes during composting is critical for controlling the process and improving the final product.

keywords: compost, earthworms, exhausted grape marc, biofertilizer, organic material, microbiome