As demand for animal protein grows and traditional feed ingredients become scarce and expensive, the aquaculture industry seeks sustainable alternatives. MicroBioGen has created an eco-friendly yeast-based protein that can be produced from industrial side streams, offering a high-quality substitute for fish meal that tackles environmental, economic and nutritional issues in aquafeed production.
Chief Executive Officer
MicroBioGen
Head of Communications
MicroBioGen
THE PROBLEM WITH FISH MEAL, AND THE SEARCH FOR A SUSTAINABLE ALTERNATIVE
As the global demand for animal protein rises, particularly in aquaculture, traditional protein sources such as fish meal are becoming increasingly unsustainable. Fish meal is rich in protein, essential fatty acids and has a balanced amino acid profile, but its limited availability and environmental impact are significant concerns. In response, the search for alternative protein sources has intensified. Plant-based ingredients are widely used in aquafeeds, but they often lack the complete nutritional profile that animal derived ingredients such as fish meal provides. This leaves a gap in the market for high-quality, cost-effective and sustainable protein sources for farmed fish and shrimp.
Single-cell protein (SCP), sourced from microorganisms including bacteria, fungi, and algae, has gained recognition as a viable alternative due to its ability to be produced with minimal land and water resources. Additionally, it has the potential to utilize industrial side streams as substrates. However, for SCP to be viable as a large-scale feed ingredient, the microorganism used must meet strict requirements, including high protein content, a well-balanced amino acid profile, non-GMO status and scalability for industrial production.
THE BREAKTHROUGH: FORTIFIED SCP THAT IS MORE SUSTAINABLE AND AFFORDABLE
Among the various edible microorganisms, yeast, specifically Saccharomyces cerevisiae (brewer’s or baker’s yeast), is a leading candidate for SCP production. Yeast offers several advantages for the production of SCP: it grows rapidly, is efficient in converting sugars into protein, and is generally recognized as safe (GRAS) for animal feed. In addition to protein, yeast is rich in fibre, vitamins, and minerals, making it a nutritionally balanced option for aquafeed. Traditional S. cerevisiae strains do not grow efficiently under the challenging conditions found in industrial side streams due to the harsh environments typically encountered. They also often lack the complete nutritional profile needed for high-quality feed formulations.
MicroBioGen has spent over two decades developing a superior yeast strain through non-GMO technologies to address these challenges while enhancing the functionality of yeast. Designed with scalability in mind, MicroBioGen’s highly advanced, natural yeast offers a sustainable, cost efficient and nutritious alternative to fish meal. The yeast can grow efficiently on industrial side streams, such as those from the food and beverage sector, which are typically discarded or underutilized. This process not only provides a high-quality protein source but also contributes to waste reduction, aligning with global sustainability goals. MicroBioGen is seeking partners for animal feed trials to validate initial lab scale results (Figure 1).
Photographs: MicroBioGen’s bioreactors can accurately represent industrial scale processes (left); A sample of live, dried MicroBioGen yeast (right)
MEETING THE DEMANDS OF AQUAFEED: IMPROVED SCP QUALITY AND TASTE
A significant challenge in substituting fish meal with alternative protein sources is achieving comparable nutritional quality. Fish meal contains approximately 65% protein and boasts a well-balanced amino acid profile, which is vital for the growth and health of farmed fish and shrimp. Although MicroBioGen yeast SCP contains slightly less protein than fish meal (up to 60%), it is considerably more protein-rich than standard baker’s yeast (~45% protein) and closely aligns with the recommended daily allowance of essential amino acids for both humans and animals (Table 1).
Furthermore, previous research has shown that S. cerevisiae is not only safe to incorporate into the feed of various aquatic species but also appears to be highly palatable. For example, trials conducted with Nile tilapia and Pacific white shrimp demonstrated no negative impacts on growth, feed conversion ratio, survival, or body composition. In fact, certain metrics even improved, underscoring the potential of yeast SCP as an effective and advantageous protein source for aquafeeds. Additionally, since MicroBioGen’s yeast SCP is entirely free from genetic engineering, it circumvents the prolonged approval processes and market restrictions typically associated with genetically engineered organisms.
In addition to its amino acid profile, MicroBioGen’s yeast can be further tailored to enhance its nutritional value through specialized strains. For example, yeast enriched with phytase can neutralize anti-nutritional factors commonly found in plant-based feed ingredients, while lysine-rich yeast can address common amino acid deficiencies. Furthermore, yeast strains fortified with antioxidants help boost immune responses and reduce the need for antibiotics, offering a holistic solution for sustainable aquaculture.
A CIRCULAR APPROACH TO FEED PRODUCTION
Microorganisms used for SCP production typically rely on traditional food sugars for growth. However, this sugar-based approach is expensive, costing approximately US$0.40 per kilogram, with substrate costs reaching nearly US$1,000 per tonne of SCP – a significant barrier to economic viability in feed markets. In contrast, industrial side streams present a major valorisation opportunity. MicroBioGen’s yeast-based SCP technology can utilize various industrial side streams (Table 2), transforming low-value by-products into high-quality protein. This process not only reduces disposal costs and environmental impact but also aligns with circular economy principles.
By converting millions of tonnes of low and negative value industrial byproducts into protein, MicroBioGen’s technology has the potential to replace a substantial portion of today’s fish meal production. With nearly 20 million tonnes of industrial side streams available globally, this method can meet the protein demands of the growing aquaculture industry while significantly reducing reliance on wild fish stocks.
With a conservative yield of 0.42, this approach could produce nearly 10 million tonnes of SCP—enough to fully replace global fish meal production. By leveraging low-cost industrial side streams, MicroBioGen makes SCP production both more affordable and more sustainable, providing a scalable, eco-friendly alternative to fish meal and other traditional protein sources.
AN ECONOMICALLY VIABLE ALTERNATIVE PROTEIN: MICROBIOGEN YEAST SCP
Protein alone has limited economic value as a standalone product. An SCP with only high protein content may not be sufficient to replace fish meal effectively. Given the costs associated with substrates and processing, SCP producers must maximize the value per unit to ensure profitability.
MicroBioGen has developed three key protein value enhancers that significantly elevate the economic potential of its SCP:
Functional Enzyme-Enriched SCP: Improved Nutrient Absorption
Vegetable proteins, such as soy meal, are widely used in animal feed, with global production exceeding 400 million tonnes annually. However, many plant-based proteins contain anti-nutritional factors like phytic acid, which inhibits nutrient absorption, particularly in monogastric animals.
To address this, feed producers often add exogenous phytase enzymes to break down phytic acid. MicroBioGen has developed a non-GM yeast that produces over 500 times more phytase than standard yeast (Figure 2).
• Just 1–2 kg of MicroBioGen’s high-phytase yeast per tonne of vegetable meal can effectively neutralize all phytic acid present.
• This breakthrough enhances feed digestibility and could increase the value of SCP made from industrial side streams by up to US$800 per tonne.
Lysine-Enriched SCP: Amino Acid Profile Optimisation
Many vegetable proteins, including maize, wheat, barley, sorghum, and rice, are deficient in essential amino acids like lysine—a crucial component of balanced animal nutrition. Over the past decade, MicroBioGen’s scientists have successfully increased the lysine content in yeast from 2.6% to 8%. This remarkable three-fold improvement – verified by Australia’s National Measurement Institute – demonstrates the power of MicroBioGen’s proprietary technology platform. The breakthrough not only enhances the yeast’s ability to accumulate lysine but also opens the door to boosting levels of other essential amino acids.
• This lysine-enriched SCP improves the amino acid profile of plant-based compound feeds, making them more nutritionally complete.
• The innovation could increase the value of MicroBioGen’s SCP by an additional US$100–200 per tonne.
Antioxidant-Enriched SCP: Shelf-Life Extension and Health Benefits
MicroBioGen’s yeast, grown on industrial by-products, naturally accumulates high levels of antioxidants, including glutathione.
• Antioxidants may aid in extending the shelf life of compound feed products.
• Antioxidants support immune function, improve disease resilience in marine species, and reduce reliance on antibiotics for more sustainable aquaculture.
By integrating functional enzymes, enhanced amino acids, and natural antioxidants, MicroBioGen’s next-generation SCP delivers superior nutritional value while significantly increasing economic returns. This approach transforms low-cost industrial byproducts into premium feed ingredients, positioning SCP as a cost-effective, sustainable, and scalable alternative to fish meal.
DOUBLING THE VALUE OF SCP
With over 20 years of innovation in yeast enhancement, MicroBioGen has successfully developed SCP as a viable replacement for unsustainable protein sources like fish meal. Key breakthroughs, summarised in Figure 3, include:
• Utilization of low-cost industrial byproducts for sustainable production,
• 50% higher protein content than wild yeast, with a superior amino acid profile,
• High enzyme activity, improving meal digestibility and maximizing SCP’s nutritional value,
• Antioxidant-enriched yeast, reducing antibiotic dependence and supporting overall health.
These advancements double the value of SCP compared to standard protein sources, lowering costs while increasing functionality. This translates to stronger unit margins, greater market demand, and increased investment potential.
SHAPING THE FUTURE OF SUSTAINABLE AQUAFEED: PREMIUM, AFFORDABLE SCP
MicroBioGen’s yeast-based SCP marks a transformational shift towards sustainable, economically viable, and nutritionally complete aquafeeds. By creating solutions to convert industrial byproducts into high-quality protein, the company tackles environmental sustainability and food security challenges in the rapidly growing aquaculture sector. As the demand for sustainable protein sources rises, MicroBioGen’s yeast SCP technology offers a scalable, high-impact solution that benefits both the environment and the industry.
About Geoff Bell
Geoff Bell is the CEO of MicroBioGen. Over the past 17 years, Bell has facilitated MicroBioGen’s transformation from a small, pure research group into an international commercial success for bioethanol production and emerging areas including single cell protein from waste and human foods. Highly qualified, with a Bachelor of Science, a Bachelor of Economics and a Master of Applied Finance from the University of Sydney and Macquarie University, he has also gained extensive commercial experience. He was a Senior Analyst at two global investment banks, Prudential-Bache Securities and BNP Paribas Equities, and he became the Head of three BNP departments: Global Mining, Australian Research, and Company Research for the Asia Pacific Region. Geoff Bell was the top-rated analyst in his field for over a decade and he won several industry accolades for his outstanding insight and analytical work. For over seven years he also served as the Australian leader for The International Energy Alliance (IEA) Task 42, a program considering biorefining in a circular economy. Bell is now leading MicroBioGen’s drive to deliver a range of fuel and food sustainability solutions around the world.About An Grobler
An Grobler, Head of Communications at MicroBioGen, joined the company in 2015 as a research scientist to develop improved microbes for commercial applications. Using the genetic principles that govern evolution, she worked closely with MicroBioGen’s Head of Research to create microbes with specific phenotypic traits, such as those needed to convert the woody sugar xylose into more sustainable biofuel. After the successful commercialisation of MicroBioGen’s first products, Grobler has been instrumental in creating a new, public image for MicroBioGen, positioning the company as an international leader in biotech, and promoting its research breakthroughs and commercial successes. She holds several university degrees, including a Bachelor of Business Communication with Honours from Northwest University (South Africa), a Bachelor of Advanced Science with High Distinction from Macquarie University, and a Bachelor of Science with First Class Honours from the University of New South Wales. In recognition of her academic achievements, An Grobler was awarded with numerous merit-based scholarships and prizes.
