Microbes and methane combine to form sustainable omega-3 source
The method uses microorganisms to ferment methane gas into valuable nutritional supplements, the most well-known being omega-3 fish oil.
Demand for this supplement has depleted marine fish stocks worldwide to such an extent that some governments have been forced to cut yearly quotas to allow adequate recovery time.
Scientists from the University of Nottingham, biotechnology company CHAIN Biotech and industry partner Calysta, have collaborated in a year-long project entitled PUFA (polyunsaturated fatty acids).
They used the Methanococcus microbe to produce polyunsaturated fatty acids from methane gas.
Targeting the microbial cell growth in this way could provide a way to reduce dependency on fishing and also create a new use for a plentiful gas that has a harmful effect on the environment if unharnessed.
Methane is a low cost and sustainable feedstock that can be produced from a variety of renewable sources. This includes the anaerobic digestion of waste to produce biogas, of which roughly 60% is methane.
“This project will draw upon CHAIN’s expertise in Synthetic Biology to improve production characteristics by targeting both cell growth and product yield simultaneously with a focus on omega-3 fatty acids,” said Dr Basil Omar, chief commercial officer at CHAIN Biotech Ltd.
“We hope it will offer a cheaper route to a high demand product with positive environmental and social knock on effects.”
Omega-3 sources
Omega-3 fatty acids are mainly derived from fish oils, with other sources including flax seeds and plants such as the Buglossoides arvensis.
A wealth of research that highlighted the oil’s health benefits have contributed to its popularity as a nutritional supplement.
The omega-3 fish oils, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) have been positively associated in everything from foetal development, cardiovascular function through to Alzheimer’s disease.
This popularity has meant that wild fish stocks have been under pressure to meet the demand for this oil, resulting in a depletion or over-exploitation of existing fish stocks.
Back in 2014, a research review, published in Current Opinion in Biotechnology, said an increasing concern about sourcing omega-3 oils from wild fish meant the industry had to consider land-based sources including microalgae and genetically modified (GM) plants.
Stock depletion
According to the Food and Agriculture Organisation (FAO), almost 53% of marine fish stocks were close to being entirely exploited in 2008. In addition, 28% were considered over-exploited and just 1% was recovering from depletion.
More than 70% of global omega-3 supply currently comes from Peruvian anchovy fisheries, but concerns about depleted stocks led the Peruvian government to cut quotas in 2012 by 68%, to their lowest level in 25 years.
Fisheries normally adhere to best-practice guidelines that ensure there is no long-term depletion of their stocks.These practices include sonar censuses of fish stocks, determining length and quotas for the fishing season, and satellite surveillance of fishing vessels to ensure compliance.
Market research organisation Packaged Facts estimated in 2012 that the market value of products containing EPA and DHA would reach $34.7bn (€30.7bn) by 2016, representing a compound annual growth rate of 6.4% since 2011.
Despite these predictions, omega-3 suppliers have noticed a slowdown in demand over the past year.
A number of studies that have re-evaluated the potency of omega-3 fatty acids, and their supposed effects on risk of stroke, heart attack or death, may have cumulatively contributed to a shifting mindset by the consumer.
