The stems of trees and the stems of many plants usually contain a large amount of lignin that is difficult to decompose, so the efficiency of using them to extract bio-fuels will be greatly reduced. At present, people have discovered a kind of bacteria called Rhodococcus. It has the ability to decompose lignin in wood and other plants. 
Rhodococcus is easy to cultivate. At present, the gene sequencing of Rhodococcus has been completed, so Rhodococcus can be used to produce enzymes that decompose lignin on a large scale.
 it is believed that Rhodococcus can be widely used in mostly discarded stalks, thereby greatly improving the utilization rate of bio-fuels.