Some ethanol makers are cheering a new biotech corn engineered strictly to produce biofuel.

Six Midwestern ethanol plants now use the hybrid called Enogen, the first corn genetically enhanced for ethanol production. Seven other ethanol makers, including Chippewa Valley Ethanol Co. in Benson, Minn., are trying it out.

“Enogen technology is truly a unique advancement in our industry,” said Mick Miller, general manager of Denco II, a farmer-owned ethanol plant in Morris, Minn., that did a trial run with the ethanol-tailored corn.

Scientists for seed giant Syngenta altered the corn to produce — within the kernel — an enzyme needed to refine biofuel. Ethanol plants using Enogen say its embedded enzyme works better than enzymes purchased separately — producing more ethanol per bushel of corn and using less energy to do it.

Jack Bernens, who heads the marketing of Enogen out of Syngenta’s regional headquarters in Minnetonka, said ethanol plants using the hybrid see a 2 to 6 percent gain in ethanol yield per bushel.

“So the plant with no additional bricks and mortar can produce more ethanol,” Bernens said.

Most of the nation’s 200 ethanol plants haven’t tried Enogen, although Syngenta is ramping up production and marketing. If the biotech corn can further boost the industry’s efficiency, it would give corn ethanol a better carbon footprint. Yet that seeming benefit is unlikely to sway environmental critics who oppose expansive corn planting as unsustainable.

“It may very well improve corn ethanol production somewhat,” said Doug Gurian-Sherman, director of sustainable agriculture at the Washington, D.C., nonprofit Center for Food Safety. “I am skeptical that it is going to be a net, significant plus.”

Enzyme companies are not idly watching as corn begins sprouting enzymes. Industry leader Novozymes reported a 19 percent boost in biofuel-related sales last year, thanks partly to its yield-enhancing Avantec enzyme introduced in 2012 and used by a third of North American ethanol plants. The Danish company says it will launch new technology this year to further increase corn-ethanol yields.

Corn strictly for fuel

Farmers in Minnesota, Iowa and other states are growing the new enzyme-exuding corn hybrid.

The appeal is a guaranteed extra payment for each bushel. In return, farmers must follow special procedures designed to keep Enogen out of the food supply. But not all farmers need to grow Enogen to serve their local ethanol plants.

Only about 15 percent of corn fed into an ethanol plant needs to be Enogen for the enzyme embedded in the kernels to do its job — breaking down starch for fermentation. Ethanol plants using this biotech corn no longer need to purchase the enzyme, called alpha amylase, from biochemical companies.

Six ethanol plants in Iowa, Kansas, Nebraska and Ohio have signed deals with Syngenta for commercial use of the corn, including a Central City, Neb., plant owned by Omaha-based Green Plains, the nation’s fourth-largest ethanol producer. Syngenta said a deal is pending with a seventh plant.

“It does work more efficiently,” said Jeff Briggs, Green Plains’ chief operating officer, who added that Enogen will be tried at two other of the company’s plants.

At the Denco plant, 160 miles northwest of Minneapolis, Enogen corn did such a good job of increasing throughput that the plant’s existing equipment couldn’t handle it, Miller said. So a modest equipment upgrade is needed before trying Enogen again, he added.

Ethanol maker Lakeview Energy has successfully tried Enogen at ethanol plants in Ohio and Iowa. Chief Operating Officer Eamonn Byrne said a midsize ethanol plant ordinarily would spend $300,000 to $350,000 a year to buy alpha amylase from an enzyme company. Yet the purchased product isn’t as efficient as the enzyme bred into Enogen corn, he said.

When ethanol plants shift to Enogen, they are in effect paying farmers instead of a chemical company for the enzyme. It’s a form of buying local that appeals to Mike Missman, an Enogen farmer and seed dealer in Woden, Iowa.

“That is a positive for our community and our environment,” Missman said. “That, to me, is a no-brainer.”

Keeping it out of food

Although federal regulators say Enogen isn’t a risk to the food supply, some critics aren’t convinced.

Syngenta acknowledges that the enzyme-laden corn, if mistakenly shipped to a food processor, could affect some foods’ texture and other properties. But the company insists there is no safety risk — and federal regulators agreed after completing reviews in 2011.

Flour mills and others in the food industry have worried that small amounts of Enogen could get mixed with corn sent to food processors. Their concern is not about food safety. But the enzyme in Enogen kernels breaks down starch, and foods like tortilla chips, for example, need starch for their texture.

“We expressed our concerns to the USDA,” said James McCarthy, CEO of the North American Millers’ Association. “Now it is sort of wait-and-see mode.”

To address such concerns, Syngenta set up an online tracking program to watch that ethanol-only corn is separately planted, harvested, stored and shipped from other corn. Farmers who grow the hybrid are obliged to follow rules to keep Enogen out of food corn.

The Center for Food Safety, a group that opposes genetically altered foods, says Enogen’s enzyme still could be a potential food allergen.

“This is an industrial product that is not intended to be in the food or feed supply,” said Gurian-Sherman, the group’s senior scientist.

Syngenta’s Bernens said the enzyme is found in human saliva, has passed tests for allergic reactions and was cleared by the U.S. Food and Drug Administration and the U.S. Agriculture Department.

Ethanol plants that use Enogen must sign contracts with Syngenta agreeing to pay farmers 40 cents per bushel more for the special corn, which can mean an extra $80 per acre. The payment also is an incentive to farmers to sell Enogen only to ethanol makers because no one else would pay that premium.

“They are really watching that you take care every step of the way,” said Kevin Lundberg, a farmer in Murdock, Minn., who grows Enogen and intends to plant 500 acres this year.

Syngenta doesn’t charge farmers extra for Enogen seed. Ethanol plants also pay nothing to Syngenta, but must pay the premium to farmers for Enogen corn. Syngenta is looking for market share. To get the extra 40 cents per bushel, Enogen farmers must plant other Syngenta seeds on additional acres.

Teeing up cellulosic ethanol?

The first ethanol plant to use Enogen, in 2013, was Quad County Corn Processors, a farmer-owned operation in Galva, Iowa.

In a coincidence that became an opportunity, the plant separately developed technology to extract ethanol from otherwise untappable parts of corn kernels like the shell. The process, trademarked Cellerate and generically known as corn fiber extraction, requires extra equipment and special yeasts to ferment sugar from fibrous parts of plants.

Quad County Corn Processors Chief Executive Delayne Johnson said Cellerate is producing 6 percent more ethanol at his plant. That is expected to climb another 5 percent after certain yeasts win regulatory approval and can be used, he said. Federal regulators have certified the extra output as low-carbon biofuel, similar to cellulosic ethanol from corn cobs.

Johnson said using Enogen and Cellerate technologies together allows both to work better. “The two combine quite well and become more efficient,” he said. So the small Iowa co-op and the giant seed company signed a deal last year.

Now Syngenta is marketing Cellerate in tandem with Enogen. So far, no other ethanol plants are using the corn fiber technology, but it has generated industry buzz. Curious ethanol executives are making pilgrimages to Galva, which is 50 miles east of Sioux City, Iowa.

“We anticipate many tours,” Johnson said.