Special Edition: Alternative Proteins

Sewage sludge to animal feed: single cell protein production model

© istock

A Dutch research project, Power to Protein, is evaluating the potential to upcycle ammonia nitrogen from sewage water to a high value single cell protein for use in feed. 

The novel protein production model is based on microbial biosynthesis of hydrogen, CO2 and ammonia nitrogen in a reactor system, using lithotrophic bacteria that rely on hydrogen as an energy source.

Last week saw the team behind the initiative officially open a pilot facility at the sewage water treatment plant (SWTP) in Enschede, in the eastern part of the Netherlands, to test the concept.

Willy Verstraete, emeritus professor, Department of Biochemical and Microbial Technology, University of Ghent, was the developer of the concept.

“He contacted KWR about two years as he was looking for a partner to scale up the concept,” said Frank Oesterholt, senior scientific researcher at the KWR Watercycle Research Institute, which is coordinating the protein project.

“We are still quite a distance to commercialization. Firstly, we want to see does it work. If so, we would then look to see is there an investor interested in scaling up the testing phase further."

"We built a reactor for the pilot testing phase, and applied for a patent on it," he said.  

Risk aversion was paramount in the design of that reactor system: “We had to guarantee the safety of the production process, given that it has hydrogen as an input source. We didn’t want to lose any hydrogen from the top of the reactor; we now have efficient hydrogen utilization,” he told us.

The reactor is fed with hydrogen and oxygen from water electrolysis, carbon dioxide comes from gas bottles and the ammonium from wastewater.

Dutch company, Nijhuis Water Technology, is providing the ammonia sulphate as a nutrient for the pilot, under an ammonia recovery initiative (NAR) using a sludge treatment plant’s reject water, in which high ammonium concentrations are efficiently recovered by means of air stripping at high temperature, said the researcher.

“We need to prove that this method prevents the transfer of all potential pathogens from the sewage sludge,” said Oesterholt.

Protein quality

Animal nutrition ingredient supplier, Barentz, which is a partner in the research project, along with KRW, Waternet, Waterkracht, AEB Amsterdam, Avecom, will test the quality of the protein produced at the Enschede facility.

“Barentz has access to that kind of analytical expertise. We are following the development of the biomass, which is very good at the moment, and we expect to get the first proteins from the reactor in around one to two months,” he said.

The team is hoping to generate between 0.5 to 1kg of single cell protein per day using the pilot reactor system.

Avecom already tested the concept in a 5L scale reactor, said Oesterholt. “The sequence of amino acids found in the protein generated from that reactor was comparable to that of fishmeal or soymeal.” 

Related News

© iStock/StrahilDimitrov

Bacterial single cell protein shows benefits in salmon, shrimp diets: study

© Leroy Group

Stable fishmeal prices forecast, alternative protein players could face choppy waters

'Common to all the new protein sources, though, is this issue of price; they can’t compete currently, but the research focus is on the development of these new sources to meet future feed requirements.' © istock/DanielLacy

Will blue protein plug the gap in organic pig and poultry production?

© iStock/pichet

Investors back KnipBio's alternative fish feed protein

© iStock/Wittayayut

Mealworm meal supports shrimp growth, development

Fishmeal free? Protein alternatives key to Australia’s prawn future

Fishmeal free? Protein alternatives key to Australia’s prawn future

'There isn’t really a sense of urgency about the alternative protein topic right now in the feed space. It is not a burning platform. But we want to get the conversation started.' © istock/ipopba

Project aims to find protein feeds ‘fit for the future’

The standardized ileal digestibility (SID) of crude protein, chemical makeup and amino acid levels could make starfish meal attractive for inclusion in pig feed. [pic: (c) istock.com/Bogdan CIUNGARA]

Starfish meal may offer a new protein source for pig diets

© Calysta

Scaling up of methane gas derived fishmeal alternative underway: Calysta

"It is no longer enough to find more sustainable ways of growing a crop," says Forum for the Future  © istock.com/Bombaert

Industry told to step up pace in hunt for fishmeal, soy alternatives

© istock

Forest to feed: Norway shining spotlight on yeast protein

© istock/cacaroot

Danish study 'validates' single cell protein technology: UniBio

© istock/Evgeny Sergeev

BioMar and Morrisons weighing up use of poultry derived protein in salmon feed

On farm algae production © University of Queensland

DIY protein? Duckweed and microalgae trialed on Australian cattle farms

© istock/Rawpixel

Insects, algae, yeasts: Forum set to assess the pluses and minuses of new proteins

© iStock/pichet

Fish-free feed challenge prompting industry trials

© Brian Skerry

Arctic Char can be a sustainable alternative to salmon: investors

Skretting looks to insects and algae as fishmeal alternatives

Skretting looks to insects and algae as fishmeal alternatives

© istock/phototechno

Nutreco challenge: Cheap edible aquaculture vaccines take top spot

© istock/baibaz

Danish study shows microalgae could work as fishmeal alternative

© istock/hors

Will UK consumers come out for or against poultry protein in salmon feed?

FeedKind protein has minimal land use and water requirements compared to many terrestrial based fish feed ingredients, says The Carbon Trust. Image © Calysta

Carbon Trust runs the numbers on Calysta's gas to feed protein

Danes producing fishmeal substitute

Danes producing fishmeal substitute

© istock/Vladimir Cetinski

EU: Starfish now allowed as fishmeal source for pig and poultry feed

© iStock/simazoran

ForFarmers makes some headway with soy free diets, but flags up scale restraints

Related Products

See more related products