Physicochemical, microbial, and microbiome dynamics in winery waste composting

Area of Science:

• Agro-industrial waste management
• Microbial ecology
• Sustainable agriculture

Background:

• Winery waste presents unique challenges for composting due to high lignin, cellulose, and polyphenol content.
• Efficient degradation requires specific microbial consortia and careful balancing to avoid inhibition.
• Composting this residue offers opportunities for sustainable vineyard waste management.

Purpose of the Study:

• To analyze winery waste composting using microbial enumeration and high-resolution microbiome profiling.
• To assess the feasibility of using composted winery waste as a substrate in grapevine cultivation.
• To evaluate the physicochemical stability and effectiveness of the produced biofertilizer.

Main Methods:

• Monitored key parameters (moisture, pH, temperature, conductivity, C/N ratio) over 60 days.
• Assessed enzymatic activity and microbial population shifts.
• Conducted microbiome profiling (bacterial and fungal phyla) and phytotoxicity tests.
• Performed a proof-of-concept study using compost in grapevine cultivation.

Main Results:

• Achieved a reduced carbon-to-nitrogen (C/N) ratio and stabilized neutral pH.
• Observed decreased dehydrogenases activity, indicating process completion.
• Identified dominant bacterial phyla (e.g., Acidobacteria, Bacteroidetes) and fungal phyla (e.g., Ascomycota, Basidiomycota).
• Compost showed no phytotoxicity and supported grapevine growth comparable to commercial substrates.

Conclusions:

• Winery waste microbial composting produces a stable biofertilizer.
• The compost is effective and safe for grapevine cultivation, closing the waste management loop.
• Composting offers a sustainable solution for the winemaking industry's waste challenges.