Bioenergy sorghum, known for its resilience, biomass production, and soil fertility improvement, has recently been characterized by researchers at Texas A&M AgriLife Research and the Texas A&M College of Agriculture and Life Sciences for its high wax production. This discovery could potentially provide an additional profit source for growers.
Plant waxes are valuable across a wide range of commercial products, such as cosmetics, inks, candles, edible food coatings, and biofuels. Bioenergy sorghum, with its wax production of around 90-180 pounds per acre, could offer growers a new revenue stream.
The study, led by doctoral student Robert Chemelewski from the Department of Biochemistry and Biophysics and supervised by John Mullet, Ph.D., University Distinguished Professor and Perry L. Adkisson Chair in Agricultural Biology, was published in the journal Frontiers in Plant Science.
Sorghum, a drought- and heat-tolerant grass, is typically used for grain, forage, and biomass production for bioenergy. Bioenergy sorghum grows very long stems that can reach up to 18 feet in height. Its resilience allows it to remain productive even when grown on marginal land or with limited water supply. This resilience is partly due to the plant’s high wax production, which helps limit water loss and prevent excessive heat absorption by reflecting solar radiation.
Mullet explained, “Bioenergy sorghum spent 50 million years surviving in Africa, in a very hot, dry environment. To survive drought at high radiation loads, the sorghum adapted by secreting a lot of wax on the surfaces of leaves and stems.”
Researchers also suspect that the wax increases pest resistance. Mullet added, “If you mutate plants to remove waxes, they become much more susceptible to insects. Insects crawling up the stem encounter a very thick wax layer. So, we think wax helps protect the stem from insect damage.
In the future, growers of bioenergy sorghum may benefit financially from the plant’s wax in addition to income generated from the crop as a feedstock for biofuels and biopower generation. Dr. Mullet stated, “We’re always looking for ways we can extract a value-added product from the plant prior to converting it into biofuel. When harvested biomass goes to a biorefinery, you could remove the wax early in the process for later purification and sale as a valuable coproduct.”
The research team is currently exploring the market potential of bioenergy sorghum wax. Mullet said, “We keep learning things about bioenergy sorghum that are just amazing. The wax could have a lot of uses. Finding out how it can be removed and recovered economically is the next step in this type of research.”