Abstract

Burkholderia sacchari is Gram-negative bacterium that uses xylose as a carbon source through the Xylose Isomerase pathway (XI). Many genes are involved in the assimilation of xylose in this bacterium, however some of them have the information that allow other microorganism to produce the enzymes involved in the XI pathway and become able to use xylose as carbon source. Previous works of the laboratory identified and inserted genes encoding XI enzymes in the expression vector pBBR1MSC2 resulting in three constructions: pBBR1MCS2::XylE, pBBR1MCS2::XylA, pBBR1MCS2::XylAB. These constructions were inserted in two strains of Pseudomonas sp. (LFM064 and LFM461) under electroporation protocol. These two strains (LFM064 and LFM461) have the ability to produce, from glucose as sole carbon source, medium-chain-length Polyhydroxyalkanoates (PHAMCL) and copolymers of 3-hydroxybutyrate and medium-chain-length 3-hydroxyalkanoate P(3HB-co-3HAMCL), respectively. The aim of this study was to obtain strains of Pseudomonas sp. capable of producing PHAMCL and P(3HB-co-3HAMCL) utilizing xylose as sole carbon source, reducing the cost and making sustainable the production of biopolymers with different properties depending of the requirements of industry and market. The product of the transformation was cultivated in LB medium with Kanamycin (50mg/L) as selective compound, and in Minimal Medium with Xylose (7g/L) and Kanamycin (50mg/L) (MMXK), the antibiotic guarantees the grow of resistant clones in the culture and the xylose confirm the capacity of the microorganisms to grow using this subtrate as sole carbon source. Colonies grown on plates were submitted to PCR with specific primers and the presence of the genes was confirmed. Shaking flasks cultures were performed in MMXK to confirm the PHA production from xylose as sole carbon source.