Evaluation of xylose catabolism genes and their potential for the generation of bioproducts.

A xilose é um dos principais componentes dos materiais lignocelulósicos, os quais são de grande interesse para produção de bioprodutos como etanol e polihidroxialcanoatos (PHA). Visando melhorar o consumo de xilose em Burkholderia sacchari, uma grande produtora de PHA, os seguintes genes codificadores de xilose isomerase foram nela inseridos e avaliados: xylABs, xylABc, xylAPl, xylABp e xylABx, respectivamente de B. sacchari, B. cenocepacia, Photorhabdus luminescens, B. phymatum e B. xenovorans. Foi ainda sintetizado o gene de B. sacchari (xylA*) no qual foram inseridas modificações descritas na literatura como capazes de aumentar o consumo de xilose em outros organismos. As linhagens recombinantes de B. sacchari abrigando os genes xylABs e xylA* tiveram um aumento de aproximadamente 30%, e aquelas abrigando os genes xylABp e xylABx de 23%, no consumo de xilose quando comparadas com a linhagem controle. Essas quatro linhagens recombinantes foram aquelas que conseguiram produzir maior quantidade de P3HB, aproximadamente 70% a mais do que linhagem controle.Xylose is a major component of lignocellulosic materials, which are of great interest for the production of bio-products, such as ethanol and polyhydroxyalkanoates (PHA). To improve the consumption of xylose in Burkholderia sacchari, a major PHA producer, the following genes, encoding xylose isomerase, were introduced in these bacteria: xylABs, xylABc, xylAPl, xylABp and xylABx, respectively from B. sacchari, B. cenocepacia, Photorhabdus luminescens, B. phymatum e B. xenovorans. The gene of B. sacchari (xylA*) was also synthesized with several modifications described in the literature as able to increase the consumption of xylose in other organisms. Recombinant strains harboring B. sacchari xylABs and xylA* gene had an increase of approximately 30% in the xylose consumption compared to the control strain, and those harboring xylABx and xylABp gene an increase of 23%. These four recombinant strains were those that were able to produce more P3HB, approximately 70% more than the control strain