Extracting the powers of fly larvae in South Africa
What if there was a naturally occurring, environmentally friendly material that could be used in animal feed, fertilisers, textiles, pharmaceuticals, biomedicines, water treatment and biodegradable plastics?
‘Chitin’ is not a word most people are familiar with, but it could prove to be an invaluable component in the development of many different products.
So what is it? Chitin is a naturally occurring biopolymer - a polymer produced by a living organism. Chitin can be found in the exoskeleton of insects, such as black soldier fly larvae (BSFL). The larvae are high in fats and protein and are used as a source of animal feed. South Africa has been involved in the production of larvae for animal feed for over a decade.
Improving animal feed
However, whilst the larvae are an excellent protein source for animal feed, animals find them difficult to digest, and the husks are shed by the larvae, which is where most of the chitin can be found. The larvae need to be removed from the feed as a waste product.
So can chitin be extracted from this waste to improve the quality and value of animal feed? Yes, it can. Extracting the chitin will ultimately allow for more widespread usage of the feed, reducing the need for traditional soya and fish-based feed, both of which have detrimental environment impacts. Methods of extracting chitin do exist, but they are chemical- and energy-intensive, and produce waste.
Chitin is found in the exoskeleton of insects, such as the black soldier fly
A group of researchers at the University of Warwick, led by Dr Stuart Coles, undertook a project researching less resource-intensive methods of chitin extraction, with lower chemical and energy use and a potential reduction in the scale and hazard of waste in future. The project was a collaboration between the University of Warwick and the South African waste management company Aegis Environmental.
Black soldier fly larvae – a source of chitin
Championing chitin
“The versatility of chitin makes it extremely valuable in developing countries. It could lead to opportunities for generating a new industry to bring money into the country and create jobs, improve environmental sustainability and reduce waste whilst also increasing the value of the animal feed,” explains Dr Coles.
Extracted chitin can also be used in areas such as wastewater treatment and the production of biodegradable plastics, important in areas where plastic pollution is a major problem. Examining the pros and cons of each chitin extraction method was also important.
Minimising water use when extracting chitin
So what has been the outcome of the project? “We produced an initial environmental assessment model which highlighted that the extraction of chitin, even with bacterial degradation, would be worse for the environment than landfilling the material. However, we know that the economic and social benefits that the production of chitin brings can be considerable. Therefore, we are now focusing on the water consumption of the extractions, trying to ensure that water use is minimised, as that has the largest environmental impact. This will benefit the process by optimising the consumption of critical resources, without significantly impacting the environment” says Dr Coles.
Benefits to local communities
The resulting material will be an inexpensive but valuable resource that can be used in areas such as wastewater treatment, or developed into other products.
Once extracted from black soldier fly larvae, chitin can be added to animal feed to improve its quality
Creating a new sustainable process for extracting chitin would provide jobs and income to the local economy, which supports the UN’s Sustainable Development Goals of Decent Work and Economic Growth, Responsible Consumption and Production and Clean Water and Sanitation.
