Methylococcus capsulatus is a methanotroph, a bacterium that metabolises methane. Salmon will consume pelletised protein made from these bacteria. And that could be handy for fish farmers.
Calysta, a biotechnology firm in Menlo Park, California, proposes to take advantage of the rock-bottom price of methane, a consequence of the spread of natural-gas fracking, to breed Methylococci en masse as a substitute for the fish-meal such farmers now feed to their charges.
The EU and Norway have already approved the use of Methylococcus-based fish food. Though America has yet to follow suit, this means there is a large available market for the stuff.
Calysta has concentrated on making the lives of its bacteria as comfortable as possible. The internal geometry of the reactors in which they live is designed to keep them in constant contact with enough methane to grow, enough air to respire and enough ammonia to provide the nitrogen which, along with the carbon and hydrogen in the methane, is a fundamental building block of the amino acids from which proteins are made.
FeedKind™ Protein, announced to coincide with Earth Day 2015, is expected to be introduced to the Scottish and Norwegian aquaculture sectors in 2018.
FeedKind Protein is a high quality microbial protein that provides a cost-competitive alternative to conventional fishmeal. The protein, produced with minimal land and water use, is non-GMO and approved in the EU for all fish and livestock species.
FeedKind™ protein is a premium fish feed ingredient produced from naturally occurring microbes found in soil. Using a natural fermentation process similar to making yeast, these microbes produce a nutritious, high protein feed that is a sustainable alternative to fishmeal. FeedKind protein is kind to the customer, kind to the animal, and kind to the environment.
FeedKind protein is a non-GMO product which does not compete with the human food chain
The reactors actually contain a mini ecosystem that includes other species of bacteria, known as heterotrophs, which mop up metabolic products that would otherwise slow Methylococcus’s growth. These products are mostly the result of Methylococcus consuming things other than methane (ethane, propane and so on) that are minor components of raw natural gas. Adding heterotrophs to the mix means Calysta can be less fussy about exactly which sources of natural gas it uses to feed its bugs.
At the moment, the world produces about 5 million tonnes of fish-meal a year, a number that has been constant for four decades and is limited by the size of the Earth’s fisheries. Demand, however, is growing at 6-8% a year, putting pressure on prices. This has led some fish farmers to adopt soya-based substitutes. These, though, can inflame the fishes’ guts. That, Dr Shaw says, is not a problem with Calysta’s product.
Dr Shaw seems confident Calysta’s system, which should turn out more than 8,000 tonnes of bacterial fish food a year per reactor, can do so at a cost well below the $2,000 a tonne at which fish-meal now sells
Fishmeal supply has remained flat despite sharply rising demand. This has led to a tripling of prices in the last decade with associated increases in the prices paid by consumers for farmed fish.
SOURCES – Economist, Calysta