Scientists have now found a way to convert cellulose to starch, a process that can be used to obtain food from all kinds of plants and not just food crops.

Cellulose is found in all plant cells and is the most common carbohydrate in the world. However, humans can't use cellulose as a food source as they lack the enzymes to break it down. In fact, no vertebrate can digest cellulose directly due to the lack of necessary enzymes. However, animals like cows, sheep and goats have symbiotic bacteria in their intestinal tract that help them digest the carbohydrate.

The study, led by Y.H. Percival Zhang, an associate professor from Virginia Tech, has found a way to obtain food from plants that could reduce the burden on agriculture.

The study team produced a kind of starch from cellulose called amylase, which is a good source of dietary fiber.

"Cellulose and starch have the same chemical formula. The difference is in their chemical linkages. Our idea is to use an enzyme cascade to break up the bonds in cellulose, enabling their reconfiguration as starch," Zhang said.

In the new process, 30 percent cellulose from corn stover was converted to amylose, and hydrolyzes. The rest of the cellulose was converted to glucose. Researchers say that cellulose from any plant can be converted into a starch.

The process "simultaneous enzymatic biotransformation and microbial fermentation" can be scaled up to make starch from cellulose on an industrial scale and doesn't require any expensive equipment. Also, the key enzymes that are immobilized on nanoparticles can be re-used, according to a news release.

"Besides serving as a food source, the starch can be used in the manufacture of edible, clear films for biodegradable food packaging. It can even serve as a high-density hydrogen storage carrier that could solve problems related to hydrogen storage and distribution," Zhang said.

The study is published in the journal Proceedings of the National Academy of Sciences