Bengaluru: Researchers from the Department of Inorganic and Physical Chemistry (IPC) at the Indian Institute of Science (IISc) have created an enzymatic platform capable of effectively converting readily available and affordable fatty acids into valuable hydrocarbons known as 1-alkenes. These 1-alkenes are considered promising biofuels., reports The Hindu.
Scientists are increasingly working on sustainable fuel pathways that involve hydrocarbons, seeing that fossil fuels are finite in supply and polluting in nature. According to the IISc, these hydrocarbons have huge potential for application as “drop-in” biofuels, which can be blended with existing fuels and used under existing infrastructure. Other than this, hydrocarbons find applications in polymer industries, detergent industries, and lubricant industries.
The team from IISc had earlier isolated and characterized an enzyme, UndB, residing in membranes of certain bacteria, which converted fatty acids to 1-alkenes at the fastest rate reported. However, the efficiency of the enzyme was restricted in that it became inactivated after a few cycles because the by-product H2O2 inhibited its action.
In their current work in Science Advances, the researchers overcame this issue by incorporating another enzyme called catalase into the reaction mix. The catalase degraded the formed H2O2 in the course of the reaction and strongly enhanced the activity of the enzyme—by 19 times, from 14 to 265 turnovers, a measure for the number of active cycles an enzyme passes through before the onset of inactivation.
To make matters better, the researchers engineered a fusion protein that included UndB with catalase—a carrier called plasmids, which introduced the fused genetic code into E. coli bacteria. In the best conditions, these designed E. coli whole-cell biocatalysts convert fatty acids to alkenes.
Their biocatalyst showed efficiency in reducing a variety of fatty acids with different types of carbon chains into 1-alkene compounds. They further demonstrated that the biocatalyst can make styrene, which is an important chemical and monomer in several polymer industries.
The IISc team has filed a patent for its engineered protein and whole-cell biocatalyst and is scouting for industry partners to scale up the platform to mass production mode.
The pioneering development holds great promise for the sustainable production of biofuels with potentially reduced dependence on fossil fuels and, therefore, a cleaner environment.
