Indian Researchers Grow Oyster Mushrooms From Fishery Waste in Discarded Plastic Bottles
- Gauri Khanna
- 4 hours ago
- 3 min read
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Researchers at Annamalai University cultivated oyster mushrooms using fishery waste and recycled plastic bottles, addressing two environmental challenges simultaneously
Substrates incorporating fish scales, crab shells, and prawn waste produced mushrooms weighing up to 61 grammes with biological efficiency comparable to conventional methods
The technique demonstrates how aquaculture byproducts can enrich mushroom nutrition whilst reducing disposal costs for fishing industries
Coastal communities generate substantial fishery waste (fish scales, crab shells, prawn scraps) that typically requires costly disposal or contributes to environmental pollution. Simultaneously, plastic bottles accumulate in marine environments and beaches. Researchers at Annamalai University in Tamil Nadu have demonstrated a method addressing both problems: cultivating Pleurotus ostreatus (oyster mushrooms) using fishery waste as substrate within sterilised plastic bottles.
Substrate Preparation and Cultivation Method
The research team, led by Renupriya Kumar, collected fishery waste from the Annankovil landing site at Parangipettai and plastic bottles from nearby beaches including Puthupettai and Samiyarpettai. Fish scales, crab shells, and prawn shells underwent thorough washing with distilled water, shadow drying for 30 days, then microwave processing at 80°C for 30 minutes. The resulting powder was stored in airtight containers.
Plastic bottles received cleaning with detergent, sanitisation with ethanol, and UV radiation exposure for sterilisation. Researchers drilled holes through the bottle bodies and trimmed the tops to create growing chambers. Paddy straw (the conventional substrate for oyster mushroom cultivation) was chopped into 3-5 centimetre pieces, soaked overnight, boiled for 1-2 hours, then shallow dried to maintain approximately 3-4% moisture content.
The cultivation process involved layering damp paddy straw with fishery waste powder in a 3:1 ratio within the bottles, alternating with mushroom spawn between layers. Different bottles received distinct fishery waste types: fish scales, shrimp shells, crab shells, or mixed fishery waste. The filled bottles were maintained in darkness at 20-30°C with 55-70% humidity until budding occurred after approximately 14 days.
Yield and Biological Efficiency
The mixed fishery waste substrate produced mushrooms averaging 8 centimetres in length, with individual fruit bodies weighing 6 grammes and total harvest reaching 47 grammes. Fish scale substrate yielded 7-centimetre mushrooms weighing 8 grammes each, totalling 44 grammes. Shrimp shell substrate performed strongest, producing 9-centimetre mushrooms at 5 grammes each, with combined weight of 61 grammes. Crab shell substrate matched mixed waste performance at 47 grammes total yield.
These results demonstrate that fishery waste provides adequate nutrition for mushroom development. The substrates contribute proteins, chitin (the structural material in crustacean shells), vitamins, minerals, fatty acids, and antioxidants: compounds that potentially enhance the nutritional profile of harvested mushrooms beyond standard paddy straw cultivation.
Resource Utilisation and Economic Implications
The methodology addresses multiple sustainability challenges. Fishery processing generates substantial waste volumes globally, with disposal representing both environmental burden and operational cost for seafood industries. Converting these materials into mushroom substrate creates value from otherwise problematic byproducts.
Plastic bottle reuse tackles marine pollution whilst providing sterile, structured growing containers. The bottles' transparency allows growth monitoring, whilst drilled holes facilitate gas exchange necessary for fungal respiration. After harvest, spent substrate retains agricultural value as nutrient-rich compost or soil conditioner.
The research team noted that commercial oyster mushroom products often claim to contain beneficial compounds, though studies across multiple countries reveal 80-90% of such products contain non-viable spores or no spores whatsoever. Cultivation using enriched substrates like fishery waste potentially addresses quality concerns through improved nutritional content.
Scalability Considerations
Whether this approach scales beyond laboratory demonstration depends on several factors: consistent fishery waste supply, sterilisation costs, labour requirements for bottle preparation, and market acceptance of mushrooms grown on unconventional substrates. The technique suits small-scale or artisanal production particularly well, potentially benefiting coastal communities with ready access to both fishing waste and plastic pollution.
The study exemplifies how waste-to-value strategies in mycology can address environmental challenges whilst producing nutritious food. As global protein demand increases and waste management costs rise, such integrated approaches merit further development and economic analysis.
