Protein-rich Feed from Corn and Wheat to Replace Soy Protein

We're developing methods to produce affordable protein that replaces soy in fish and animal feed. Our process reduces capital expenses (CAPEX) and operating expenses (OPEX) by using low-temperature enzymes to convert ground corn and wheat into simple sugars while simultaneously growing yeast in a rotating drum bioreactor (RDB). Air blown through the drum enables evaporative cooling, and we add water to maintain moisture without excess wetness. We harvest partial yeast batches, recycling the remainder along with enzymes to speed up subsequent cycles.

Over 50% of yeast production costs stem from raw materials. Using corn-derived sugars is our cheapest tested option, yielding not just single-cell protein (SCP) but also converting corn oil to protein/omega-3s and incorporating corn's protein, potassium and phosphorus into the feed. Wheat is a viable alternative, with its higher protein content (132 g/kg vs. corn's 94 g/kg) adding value.

This process is made possible by using our bacterial contamination control technique. This allows solid-state fermentation in an RDB with yeast/enzyme recycling and evaporative cooling—avoiding expensive submerged fermenters, heat exchangers, centrifuges, and dryers.

We focus on cost-effective SCP technologies for healthier feed than soy. We're licensing patents, tech, and designs to clients with cheap corn and wheat access and feed markets, targeting the USA, Brazil, Russia, India, China, Argentina, and Mexico.

Our core patent blocks bacterial growth by limiting nickel (less than 1 mg/kg) and using urea as the sole nitrogen source—yeast thrives without nickel, but bacteria cannot. Use of this patent enables evaporative cooling and yeast recycling.

Our portable design fits in 20-ft shipping containers, using nickel-free corrugated High-Density Polyethylene (HDPE) rolling drums (2 m diameter, 5 m long). It's factory-assembled, stackable (up to 4 high), transportable by truck/train, and supports rapid large-scale setup.

Cost saving elements Impact Prerequisite
Granular Starch Hydrolyzing Enzymes No jet cooker or high temperatures
Simultaneous Saccharification and Fermentation Faster production of yeast
Solid-state fermentation with rolling drum No centrifuge or spray dryer
Evaporative cooling No plate heat exchanger or water chiller Bacterial contamination control
Corrugated HDPE rolling drum 1/10 cost of stainless steel Evaporative cooling
Yeast recycling Faster production of yeast Bacterial contamination control
Growing Candida utilis yeast Metabolizes corn oil to protein and/or omega-3
Containerized Mass production, easy install, stackable

Contamination Control

Bacterial contamination is the top challenge in industrial-scale ethanol fermentation or yeast growth. Our patented method prevents it by using urea as the sole nitrogen source and keeping nickel below 1 mg/kg—eliminating acid washes or antibiotics. Urea is added gradually during simultaneous saccharification and fermentation (SSF), accelerating the process without issues. It works at pH 4-7.

PCT Patent WO2024092285A2

U.S. Patent No. 12,297,423

U.S. Patent App. No. 19/202,827, filed May 8, 2025

Rotating Drum Bioreactor

Our RDB fermenter leverages our contamination control patents for year-round aerobic yeast growth on hammer-milled corn and wheat. Its core is a corrugated HDPE rolling drum, enabling large, containerized, stackable units at less than $1,000/m³—vs. more than $15,000/m³ for traditional ones (e.g., corrugated HDPE rolling drum costs less than $1,000 vs. more than $9,000 for stainless steel). Operating costs are lower than submerged fermentation.

It uses granular starch hydrolyzing enzymes (GSHE: glucoamylase + alpha-amylase), SSF at 38°C with Candida utilis yeast (aka Cyberlindnera jadinii), and yeast/enzyme recycling for speed.

Evaporative cooling skips heat exchangers, cutting CAPEX/OPEX and cleaning needs. Drums self-clean via abrasion during rotation. Drying is cheap at ~50% moisture in the slurry. Units are containerized and automated.

Healthier than Soy Protein

Our RDB fermenter yields yeast that's healthier than soy protein and competitively priced. Soy farming relies on harmful herbicides/pesticides that enter the food chain, plus soy has anti-nutritional compounds (e.g., trypsin inhibitors, lectins). Yeast offers better amino acid balance, sustainability (less land needed), and nutrition for fish/chicken. Prices for dried fodder yeast vary by region (higher in Japan/U.S.). Our low CAPEX/OPEX make this nutritious alternative cost-effective.

Yeast from Corn and Wheat

Our RDB fermenter cost-effectively produces protein-rich yeast from ground corn and wheat. Starch is hydrolyzed to glucose via GSHE (no-cook enzymes), with yeast grown simultaneously (SSF). This is the cheapest aerobic sugar source—mirroring POET's ethanol process but aerobic for yeast. Drying energy is low at ~50% moisture.

Candida utilis is Generally Recognized As Safe (GRAS), approved globally for consumption by humans, fish and animals, is widely sold by Lallemand as Torula yeast, and has been safely used since the 1930s for human, fish and animal consumption.

We can boost the omega-3 content of Candida utilis via secreted lipase/phytase enzymes, metabolizing oil and phosphorus.

Using Dried Product in Fish and Animal Feed

Yeast is healthy for fish, chicken, pigs, and humans. Feed conversion ratios (kg feed/kg weight gain) are 1.0-2.0 for fish, 1.7-2.0 for chicken, 2.5-3.5 for pigs, and 6.0-10.0 for cattle (least efficient). Yeast's feed value dates to 1940s Germany. Global production: ~140M tons poultry, 110M tons pigs, 90M tons aquaculture yearly

Key health aspects: essential amino acids and fatty acids.

Essential Amino Acids

These must come from diet (fish/chicken/pigs/humans can't synthesize them). Nine essentials:

  1. Histidine - Growth, tissue repair, histamine.

  2. Isoleucine - Muscle metabolism, energy, hemoglobin.

  3. Leucine - Muscle synthesis, repair.

  4. Lysine - Protein synthesis, hormones, enzymes.

  5. Methionine - Detox, metabolism, sulfur compounds.

  6. Phenylalanine - Neurotransmitter precursor (tyrosine, dopamine, norepinephrine).

  7. Threonine - Collagen, elastin, immunity.

  8. Tryptophan - Serotonin/melatonin precursor (mood/sleep).

  9. Valine - Muscle growth, energy, repair.

Arginine is also essential for fish/chicken/pigs. Candida utilis provides all, plus biotin/B-vitamins (except B12). It may need methionine/lysine supplements, like soy (which has fewer B-vitamins). Synthetics (e.g., L-lysine) make this viable, reducing fishmeal/soybean reliance.

Essential Fatty Acids

Humans can't produce these:

  1. Alpha-Linolenic Acid (ALA, omega-3): Heart/brain health, anti-inflammation (in flaxseeds, chia, walnuts).

  2. Linoleic Acid (LA, omega-6): Skin/hair, growth, membranes (in vegetable oils, nuts).

The human body converts them to EPA/DHA (limited efficiency); balance prevents omega-6 excess inflammation. Candida utilis produces both, especially in oxygen-rich solid-state fermentation—desaturating oleic acid to LA, then LA to ALA using its CuFAD3 enzyme. This is how it metabolizes grain oil's LA to ALA.

Soy has omega-6 excess, no omega-3/EPA/DHA, leading to unhealthy fish/animals for humans. Yeast is better.

Anti-Nutritional Factors (ANFs) in Soy

Soy includes trypsin inhibitors, lectins, oligosaccharides, phytic acid, saponins, antigens, isoflavones, tannins—harmful for feed. Carnivorous fish (salmonids/shrimp) suffer enteritis/growth issues at more than 30% soy. Young animals (piglets/chicks/calves) face digestive problems; poultry get diarrhea/reduced growth. Yeast has no ANFs, yielding healthier fish/chicken/pigs.

Animal Recommended Inclusion Level Key Basis for Recommendation
Salmon 20% (up to 25% in some trials) No adverse growth or health effects; potential gut benefits; higher may disrupt microbiome in mixed diets.
Chicken 20% Maintains performance and carcass yield; higher worsens feed efficiency.
Pig 20-26% No negative growth or diarrhea; improves efficiency; up to 40% protein replacement.
Dog Up to 20% High palatability and digestibility, anti-inflammatory benefits; no regulatory limit, but aligned with studies.
Cat 20% High palatability and digestibility; limited by fecal quality concerns.

Using Dried Product in Food

The resulting dried product—a mixture of the processed ground corn and wheat solids and Candida utilis biomass—is palatable to humans, with a nutty, smoky, or umami flavor profile derived from the yeast, combined with the milder, grain-like taste of the corn and wheat residues. This is based on the established use of Candida utilis (commonly known as torula yeast) as a flavor enhancer in human foods, where it is valued for its savory qualities and ability to improve overall palatability in various products. It is suitable for inclusion in human foods, as both ground grain and Candida utilis are recognized as safe for consumption (with the yeast holding GRAS status from the FDA), and similar yeast-based single-cell protein products or fermented substrates are already incorporated into items like seasonings, spreads, soups, sauces, snacks, and vegetarian alternatives.

The dried product has a good balance of essential amino acids and essential fatty acids and a good balance of omega-6 and omega-3 fatty acids, making for an especially healthy addition to the human diet.

However, for optimal use in human foods, additional processing (such as RNA reduction to mitigate potential health concerns like elevated uric acid levels from high nucleic acid content, or flavor adjustments) is recommended, and regulatory approval for the specific formulation might be needed. The process described uses food-grade enzymes and a yeast strain extensively utilized in the food industry, supporting its suitability.

Economics of Producing Yeast Protein from Ground Corn

Over 50% of yeast costs come from substrates; corn-hydrolyzed sugars are cheapest. Viability relies on RDB's low costs, cheap inputs, and high-value SCP for feed.

  • CAPEX: RDB at less than $1,000/m³ (50-80% below traditional $15,000/m³) for modular plants.

  • OPEX:

    • Substrates: 35-62% of costs; at $150/MT corn, ~$390/MT SCP (0.385 MT SCP/MT corn, from 70% starch).

    • Other: Enzymes, urea, rotation/cooling energy, drying. Evaporative/self-cleaning skips maintenance ($0.05-0.10/kg SCP saved); 50% moisture drying cheaper than 90%. Non-substrate: $200-300/MT SCP.

    • Labor/Utilities: Minimal via automation; low energy in containers.

  • Yields/Revenue: ~385 kg SCP/MT substrate (45-50% protein). Fodder yeast + DDGS: $500-1,000/MT (vs. soy meal ~$400/MT). Protein basis: SCP $800-1,000/MT vs. soy $890/MT, with superior nutrition. Revenue: $600-800/MT.

  • Profitability: Substrate $390/MT SCP; total cost $600-700/MT; break-even $550-650/MT; ROI 20-30% (5-year, 50k MT/year plant); margins 20-40% in high-demand areas. Pilot needed for commercialization.

Target Markets

We target regions with abundant cheap corn/wheat and strong fish/animal feed demand. Corn sugars are cheaper than molasses. Wheat works but requires endo-protease enzymes for gluten, offset somewhat by higher protein.

Country Corn Price Wheat Price
United States 377 MMT/y $157/MT 54 MMT/y $221/MT
China 295 MMT/y $321/MT 140 MMT/y $285/MT
Brazil 132 MMT/y $191/MT 8 MMT/y $231/MT
Argentina 50 MMT/y $174/MT 19 MMT/y $232/MT
Russia+Ukraine 41 MMT/y $175/MT 105 MMT/y $234/MT
India 43 MMT/y $315/MT 113 MMT/y $293/MT
Mexico 25 MMT/y $210/MT 3 MMT/y $262/MT

Who are we?

Hamrick Engineering was founded in 2013 by Edward B. Hamrick.

Edward (Ed) Hamrick graduated with honors from the California Institute of Technology (CalTech) with a degree in Engineering and Applied Science. He worked for three years at NASA/JPL on the International Ultraviolet Explorer and Voyager projects and worked for ten years at Boeing as a Senior Systems Engineer and Engineering Manager. Subsequently, Ed worked for five years at Convex Computer Corporation as a Systems Engineer and Systems Engineering Manager. Ed has been a successful entrepreneur for the past 25 years.

Alex Ablaev, MBA, PhD is Sr. Worldwide Business Developer. Alex previously worked for Genencor's enzymatic hydrolysis division, and is the President of the Russian Biofuels Association as well as General Manager of NanoTaiga, a company in Russia using CelloFuel technologies in Russia.

Alan Pryce, CEng is Chief Engineer. Alan is an experienced professional mechanical engineer - Chartered Engineer (CEng) – Member of the Institute of Mechanical Engineers (IMechE) - with 10+ years’ experience in the mechanical design and project management of factory automation projects in UK and European factories. He has been a Senior Design Consultant and project manager for over 30 years working for Frazer-Nash Consultancy Ltd involved with many design and build contracts in the military, rail, manufacturing, and nuclear industries.

Maria Kharina, PhD, is Sr. Microbiology Scientist. Maria has a PhD in Biotechnology and is a researcher with 10+ years of experience. Maria was a Fulbright Scholar in the USA from 2016-2017.

Beverley Nash is Director of Marketing. Beverley has run Nash Marketing for over 30 years and has extensive experience in marketing planning and development for both new and established businesses. Beverley has worked for many global corporations in the technical marketplace and has been responsible for both the planning and management of many programs dealing with all aspects of company and product growth.

Dr. Ryan P. O'Connor (www.oconnor-company.com) provides intellectual property strategy consulting and patent prosecution. Dr. O'Connor holds a degree in Chemical Engineering from University of Notre Dame and a Ph.D. in Chemical Engineering from University of Minnesota. He has filed more than 1000 U.S. and PCT applications and is admitted to the Patent Bar, United States Patent & Trademark Office.

Hamrick Engineering Patent Portfolio