The word “algae” can strike thoughts of low dissolved oxygen into the minds of limnologists and aquaculturalists alike. The most common problem-species of the autotrophic microorganisms, microcystis, have caused enough issues in the world’s waterways to earn a scummy reputation.
Still, not all algae are bad. Alltech Inc., a Nicholasville, Ky.-based company that develops natural feed supplements for agriculture and aquaculture, has put algae to work and it’s definitely for the fishes.
Inside the feed-prep room at Alltech’s aquaculture center, Vaun Cummins, a senior aquaculture technician with Alltech, holds a scoop of fine, fishy-smelling powder. The substance resembles talcum powder with its fine consistency and smooth feel. The pungent substance is Alltech’s production Schizochytrium SP1 Algae.
Cummins said the algae can be used to reduce or replace fish oil in the diet of farmed fish. Fish oil comes mainly from wild caught menhaden anchovy, a small filter feeding fish. Typically it takes two pounds of marine-caught fish to make enough fish meal and fish oil for a farmed fish to gain one pound of weight. “Aquaculture can’t rely on that for very long,” Cummins said.
Using marine-caught fish to grow farm-raised fish may become a greater problem, as aquaculture continues to advance as the fastest growing sector in world agriculture. Cummins said the average yearly growth of the global industry is around 6 percent.
The fish grow even faster. Cummins is able to raise a batch of tilapia on diets formulated with algae from fingerlings the size of a pinky finger to a harvest size of nearly two pounds in approximately eight months.
Algae are added to fish diets during trial runs. Cummins watches as the fish grow and react, while consuming different mixtures of feed. Typical trials run 9 to 12 weeks.
The trick is feeding six times per day and keeping the fish in healthy water. He keeps water quality in check with his YSI 556 handheld meter. “In aquaculture, you’re farming the water,” Cummins said. “You’re making sure those water quality parameters are where they need to be to have healthy fish and optimal growth.”
Alltech’s state-of-the-art aquaculture research center is an indoor operation, where recirculating water flows through a variety of blue tanks, ranging from 100 gallon tanks up to 1,500 gallon tanks.
In the larger 1,500-gallon tanks, fattened fish school in circles. In smaller 250-gallon tanks, catfish and bass hover near the shadowy bottom. Some tanks sit idle, awaiting the growth of fingerlings or incoming test subjects.
Northeast of the aquaculture facility, Alltech’s algae plant in Winchester towers above adjacent Kentucky Highway 64. Inside, gleaming stainless steel fermenters and dryer chambers stand four stories tall.
Kevin Welsh, operations manager for the plant, said the fermenters on site have a combined capacity of more than one million liters. A maze of piping winds throughout the plant, recirculating sterilized raw materials used in algae production. A central control room regulates and monitors the plant’s automated processes.
Here Alltech produces heterotrophic microalgae grown in a closed system. Alltech workers control the entire process ensuring traceability, sustainability and consistency.
Michelle Stevens, quality assurance manager at the plant, said her team can produce 20 tons of algae from a single 1.5 milliliter vial of algae. It takes eleven days, stepping up to larger and larger batches. “We take this (algae) and inoculate the broth and nine days later we’re harvesting the main fermenter, our biggest fermenter,” she said. “Our output from that is about 20 tons of biomass.”
The algae are only for animal consumption. Stevens said the algae can take the place of soybean meal in livestock feed or fish oil in aquaculture. The biggest difference is algae grows much faster and has more fatty acids than soybeans.
“We can still get the same growth responses,” Cummins said. “We can still get the same feed conversion ratios that we would get if we were just using a commercial diet that had fish oil in it. And not only that, this is very high in DHA (docosahexaenoic acid), the heart healthy omega-3.”
The algae then pass omega-3 fatty acids onto to the dinner table. “What we can safely say, with the research that we’ve done, is that we are able to increase that DHA level in the filet and, yes, it does make it to the consumer,” said Cummins.
Image: Alltech’s Algae Research and Production Facility in Winchester, Kentucky. (Credit: Alltech)