Nitrogen-fixing bacteria are present in the root nodules of the majority of legumes, like soybeans and alfalfa.
Other “beneficial bacteria” can be found in symbiotic relationships with crop plants that promote growth, increase stress or pest resistance, or increase nutrient solubility.
Only in recent years have scientists been able to point to specific bacteria that can perform specific services for crops, and “bottled” them and sold them. But this February, the biological crop protection market was forecasted to grow at a rate of 11.33 per cent over the 2016 to 2021 period, driven by “agricultural productivity as well as increase in demand for chemical free crop protection solution [sic],” according to a Research and Markets study.
There’s clearly a future in bacteria, and science and industry are capitalizing on it.
Bacteria in the lab
At Ze-Chun Yuan’s lab in London, Ont., the Agriculture and Agri-Food Canada scientist has been working on isolating beneficial bacteria for six years. His goal is to develop viable alternatives to chemical fertilizers and crop protection products that lessen the strain on the environment — and producers’ pocketbooks.
“On the plant pathology side, you have two ways to manage plant disease. You can use a pesticide, or you can use beneficial bacteria that can protect plants and maybe also produce some nutrients in the soil,” he says. “It’s a more natural process.”
Yuan’s program has seen some important successes. His team has identified three bacteria that have potential applications for crops. Paenibacillus polymyxa CR1 was the first of these to undergo complete genome sequencing by AAFC.
This bacterium not only fixes nitrogen and produces a growth-promoting hormone, it also produces chemicals that can potentially protect plants against diseases and pests.
But it’s only one of many bacteria that Yuan and his team are examining. “We have about 2,000, almost 3,000, bacteria isolated from corn and soybean roots or legume roots. We also have a lot from wheat,” he says. “We just got a new freezer!”
The bacteria Yuan is interested in produce what are called “endospores,” extremely resilient “packages” that contain the bacteria’s genetic material and can survive under harsh conditions. For agricultural applications, this is a big advantage, says Yuan. The endospores, which are a few hundred times smaller than their “parent” bacteria, can be mixed with powder and sprayed on crops or applied as biopesticide or biofertilizer seed coatings.
This summer, Yuan intends to test both methods in field trials on soybeans, corn and tomatoes. The trials will look at P. polymyxa CR1 as well as a handful of other bacteria.
The trials will be held at AAFC’s research centre in London, but Yuan wants to collaborate with as many partners as possible, including grower groups and organizations, to expand the research to other Canadian provinces.
It might take a few years before P. polymyxa CR1, or some of the other almost 3,000 beneficial bacteria in Yuan’s freezers, hit the market in product form. But Yuan is confident that they will. “We need a year or two to figure out what the best formulation is,” he says.