Belgian institute discovers potential to produce bio-plastics from poplar trees

Bio-based products such as bio-plastics are used in the cosmetics industry by a number of leading brands in their packaging.

Johnson & Johnson Brazil launched it's Brazilian sunscreen line, Sundown, in packaging that contains sugarcane-based polyethylene; whilst Pantene started producing its shampoo and conditioner bottles made primarily from sugarcane.

The results of VIB’s field trial with genetically modified poplar trees in Zwijnaarde, Belgium, shows that the wood of lignin modified poplar trees can be converted into sugars in a more efficient way.

These sugars can serve as the starting material for producing bio-based products like bio-plastics and bio-ethanol.

Field trial​

The field trial however also showed that the suppression of the lignin biosynthesis in the trees is variable.

In some trees the suppression is stronger than in other trees, which is visible through a more pronounced red coloration of the wood beneath the bark.

The branches with the highest red coloration produce 160% more ethanol. On the whole the ethanol yield per gram of wood is 20% higher, says the study published in the online edition of PNAS.

This in itself is positive, except for the fact that the modified trees appear to grow somewhat less rapid than non-modified poplar trees.

Professor Wout Boerjan explains: "The branches with the highest red coloration give us hope that we will be able to achieve our goal in the future. The biosynthesis of lignin is very complex. We will now search for modifications that provide a strong and uniform suppression of the lignin biosynthesis.”​

“Because in the meantime we are also getting a pretty good idea of what causes the growth retardation, we immediately will start to work on poplars that grow normal, but still have a stable suppression of the lignin production. It must be possible to improve the ethanol yield per tree with 50 to 100%.”​

Suppressed enzyme​

In the poplar trees in the field trial in Zwijnaarde in Belgium the so-called ‘CCR-enzyme’ is suppressed.

This enzyme plays a key role in the biosynthesis of lignin, but its suppression apparently does not lead to a uniform lowering of the amount of lignin.

In a new field trial that VIB will start in Wetteren, in 2014, trees will be tested in which another enzyme has been suppressed: the ‘CAD-enzyme’.