RÉSUMÉ
In this paper, five different methods were carried out for DNA extraction directly from soil. The result shows that all five methods could generate DNA with more than 15 kb in size. They were subsequently used as templates for PCR amplification with success, using primers of the bacterial 16S rRNA gene and Shiva-1 gene encoding an antibacterial peptide. However, method 5 is more suitable for DNA extraction directly from a small amount of soil sample as it produced a good yield of DNA in high integrity with reliable reproducibility.
RÉSUMÉ
Klebsiella pneumoniae M5a1 metabolizes 3-hydroxybenzoate via gentisate to central metabolites. The plasmid pBSI encoding the full catabolic pathway endowed E.coli with the ability to grow on 3-hydroxybenzoate. We have determined the sequence of an 8-kb region spanning the mhb genes. Blast search in the GenBank revealed the mhbR was a putative transcript regulator and mhbT was a putative 3-hydroxybenzoate transporter. The E.coli strain containing the plasmid with frameshift mutantion either in mhbR or mhbT grew more slowly on 3-hydroxybenzoate than that containing the wild type clone.