Recent progress in single cell protein (SCP) technology is set to revolutionise the aquafeed industry. Australian biotech MicroBioGen has developed a natural, sustainable, nutritionally enhanced yeast SCP alternative to fish meal. With the potential to turn industrial waste streams into high-quality protein for feed, MicroBioGen’s innovation solves major environmental, social and economic challenges.
Chief Executive Officer
MicroBioGen
Head of Communications
MicroBioGen
As the global demand for animal protein increases and the availability of conventional feed ingredients decreases, animal feed production is becoming a major challenge. High protein feed ingredients such as fish meal are becoming increasingly scarce and expensive, necessitating alternative sources of protein. Commercial aquafeeds often use plant-based ingredients, but they present problems such as insufficient protein content, taste issues and anti-nutritional factors.
One promising solution is single cell protein (SCP), which refers to protein derived from microorganisms such as bacteria and fungi. SCP has several advantages over conventional feed ingredients, such as fast growth rate, low land and water use and potential to utilise waste streams as substrates. However, for a microorganism to be considered suitable for SCP production, it must meet a range of criteria (Table 1).
PRODUCING SCP FOR FEED: CHOOSING THE BEST MICROBE FOR THE JOB
Among the various microorganisms that can produce SCP for animal feed, yeast has the most potential to produce premium SCP efficiently, economically and at scale. Saccharomyces cerevisiae, commonly known as brewer’s or baker’s yeast, is widely celebrated for its versatility and manufacturability in diverse industries, with applications ranging from baking and brewing to biofuels, biochemicals and animal feed.
Generally Recognised as Safe (GRAS) for both human and animal consumption, S. cerevisiae has many desirable characteristics that make it suitable as an ingredient for animal feed. Yeast is naturally rich in protein with a balanced amino acid profile, and it is a good source of fibre, vitamins and trace minerals. It is also easy to cultivate in various industrial settings, making it the ideal microorganism to use for the large-scale production of SCP. However, S. cerevisiae typically cannot grow efficiently on the components present in large industrial waste streams, nor can they achieve all the nutritional benefits required of a premium protein feed ingredient.
This is where MicroBioGen, a biotechnology company specialising in improving S. cerevisiae for industrial applications, comes in. Headquartered in Sydney, Australia, MicroBioGen leverages two decades of deep technology development to generate superior industrial yeast phenotypes – without genetic engineering.
Applying the same platform technology and library of elite non-GM yeast genetics that revolutionised the biofuels industry, MicroBioGen has succeeded in developing a natural yeast for SCP production with significantly enhanced functionality, offering a sustainable alternative to protein-rich feed ingredients such as fish meal. To validate results from their Australian laboratories (Figure 1), MicroBioGen is seeking partners for animal feed trials, with an initial focus on aquafeeds.
QUALITY AND TASTE: SUCCESSFULLY SUBSTITUTING FISH MEAL
One of the main challenges in finding an alternative protein source for aquafeed is matching – or surpassing – the nutritional quality of fish meal which contains around 65% protein and a balanced amino acid profile. MicroBioGen, uniquely capable of improving yeast using non-GM technology, has developed a yeast single-cell protein (SCP) to address this challenge. Whereas typical baker’s yeast consists of only about 45% protein, MicroBioGen’s yeast contains up to 60% protein, while the amino acid profile of MicroBioGen’s SCP aligns well with the recommended daily allowance of essential amino acids for both humans and animals (Figure 2).
Additionally, previous studies have demonstrated that S. cerevisiae is not only safe to use as a component of feed to various aquatic animals, but it also seems quite palatable. For instance, trials with Nile tilapia and Pacific white shrimp revealed no adverse effects on growth, feed conversion ratio, survival, or body composition. In fact, some metrics even improved, highlighting the potential of yeast SCP as a viable and beneficial protein source for aquafeeds. And because MicroBioGen’s yeast is completely free of genetic engineering, lengthy approval processes and market limitations associated with genetically engineered organisms can be avoided.
RECYCLING WASTE: IS YEAST UP TO THE TASK?
MicroBioGen has made a significant advancement by developing a process to grow single-cell protein (SCP) using industrial waste streams (Table 2) instead of traditional food sugars. This innovation addresses sustainability concerns associated with sugar-based SCP production, which can be costly and environmentally taxing. By enabling the utilisation of carbon that would otherwise be lost in large-scale industrial waste streams, MicroBioGen’s innovation improves sustainability and significantly reduces production expenses.
Sugars are relatively expensive at approximately US$0.40/kg. Consequently, sugar-based SCP production is expensive, with substrate costs alone amounting to nearly US$1,000 per tonne of SCP. This limits the economics of producing sugar-based SCP for feed markets.
In contrast, nearly 20 million tonnes of side/waste streams are available today globally, representing a significant valorisation opportunity. With an average conservative yield of 0.42, this could produce nearly 10 million tonnes of SCP, theoretically enough to replace all fish meal produced globally today.
The ability to grow on low-cost industrial waste streams not only reduces production costs but also enhances sustainability, making it a superior alternative to fish meal, which relies on finite and declining wild fish stocks.
ECONOMICS: CREATING A COST-EFFECTIVE ALTERNATIVE PROTEIN
There is a limit to the value of protein as a standalone product. A single-cell protein (SCP) that only excels in a high protein content will be limited in its potential to serve as a fish meal substitute. Considering the expenses related to substrates and processing, the value per unit of SCP must be elevated to ensure the highest return for an SCP producer. MicroBioGen has created three distinct protein value enhancers, which are described in more detail below.
Naturally rich in beneficial enzymes
Vegetable proteins are commonly incorporated into animal feed. Soy meal, the greatest single source of vegetable protein used for animal feed, has an annual production of approximately 400 million tonnes. While soy meal is rich in protein, anti-nutritionals such as phytic acid interfere with nutrient absorption, particularly in monogastric animals. To counter this, producers often add exogenous phytase enzymes to the feed to decompose phytic acid. MicroBioGen has created a special non-GM yeast that produces over 500 times more phytase than normal yeast. Using just 1 to 2 kg of MicroBioGen’s high phytase yeast per tonne of vegetable meal can efficiently neutralise all the phytic acid present. This enhancement could raise the value of each tonne of SCP made from industrial waste by up to US$800.
A lysine-rich alternative protein
Another limitation when using vegetable proteins for animal feed is that they often lack certain essential amino acids. Maize, wheat, barley, sorghum and rice are usually lysine deficient. Over the past ten years, MicroBioGen scientists have been working on increasing the lysine content of yeast. The results have been excellent. From a starting point of 2.6% in wild type yeast, MicroBioGen’s yeast lysine levels have been increased to 8%, a more than 300% rise, as measured by Australia’s National Measurement Institute (NMI). It is estimated that this enhancement in lysine could potentially raise the value of MicroBioGen’s SCP made from waste by an additional US$100 to US$200 per tonne.
Antioxidant-rich yeast
MicroBioGen’s yeast, grown on industrial by-products, accumulates high levels of antioxidants such as glutathione. With the potential to bolster immune responses and disease resilience among marine species, antioxidants can help to reduce antibiotic dependence and ultimately foster more sustainable approaches to aquaculture.
A SINGLE CELL PROTEIN WITH DOUBLE THE VALUE
Having spent over 20 years developing advanced technology to upgrade yeast, MicroBioGen has succeeded in making it a viable alternative to unsustainable protein sources such as fish meal.
Key improvements include:
• Growth on low-cost industrial waste and side streams
• 50% higher protein content than typical wild yeast, with an excellent amino acid profile
• High levels of functional enzymes for better meal digestibility, significantly enhancing SCP value
• Potential to add antioxidants for improved health, reducing the need for antibiotics
These enhancements double the value compared to a protein-only solution, minimising costs and maximising value through high protein levels and added functionalities. This results in strong unit margins, driving future demand and investment.
In summary, MicroBioGen’s advancements in single-cell proteins (SCP) for aquaculture feed represent a significant step towards sustainable and economically viable fish farming. Their innovative yeast technology addresses protein sourcing challenges and promotes environmental sustainability. As the aquaculture industry grows, MicroBioGen’s SCP technology could play a crucial role in creating a more resilient, eco-friendly animal feed sector.
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, Bell 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. Geoff 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.
