Fish production and processing always accompany wastes that lead to a significant risk to the environment. Newfoundland and Labrador (NL) with widespread fish processing plants in its coast generated 146,960 tons of fish waste in 2001. The common way to treat fish waste in NL is disposal in the ocean which has adverse environmental impacts such as liberating methane and ammonia, decreasing phytoplankton growth, and reducing plant growth and increasing mortality.
Composting is considered to be a viable solution to the problems of waste disposal experienced by processing plants and fish farms. Utilizing fish waste in the production of compost can generate significant benefits by using the final product as a fertilizer in coastal areas, as it is rich in nutrients, particularly nitrogen and phosphorous. The produced compost can also be used as a great source of nutrient for growing biosurfactant producing bacteria and generating valuable biosurfactant products.
Biosurfactants are biologically-produced surfactants. Global biosurfactant market was worth USD 1,735.5 million in 2011 and is expected to reach USD 2,210.5 million in 2018, with a production of 476,512.2 tonnes by then. The raw materials contribute 50% of the total production cost of biosurfactants, so that the utilization of waste streams as substrate can help to significantly decrease biosurfactant production cost. Fish waste based biosurfactant production can thus be a promising strategy for the industry to increase its profitability and competitiveness.
The main purpose of this work was to create compost from fish waste, extract nutrients from the resulting compost, and use the extract as a medium in which to grow biosurfactant-producing bacteria. Two fish waste composts were generated, one using peat and one using sawdust as the bulking agents, and the chemical content and enzyme activities were monitored. Measured composition indicated that produced composts are stable and mature. Nutrients were extracted from each of the composts and used to produce biosurfactants in the lab using biosurfactant-producing bacteria. The resulting biosurfactants were then purified and characterized. Experimental results revealed fish waste compost extract can be used as a novel substrate for biosurfactant production.
The research output can help to extend technical and scientific knowledge in the field of fish waste management, solid waste composting, enzyme hydrolysis, and biosurfactant production. Using the developed methodology, fish waste in NL can be diverted into promising biosurfactant products. These products can have great market value, and thus bring short and long-term benefits for Canadian industries and the provincial government