Objective: To screen, identify bacterial strains with high capability to degrade cellulose from bacteria associated with Bursaphelenchus xylophilus and to clone related genes.
Methods: First, we collected B. xylophilus samples from pine wood nematode disease areas in Nanyang, Henan province, China. Then, we obtained the bacterial strains with high cellulase activities by primarily screening according to Congo red plate methods. The bacterial strain was classified by phenotypic and genotypic characteristics. We designed degenerate primes according to the known endoglucanase gene sequences in GenBank to carry out PCR, and analyzed the cloned sequence.
Results: We obtained seven bacterial strains with high cellulase activities. Among them, the bacterial strain numbered C8 showed the highest cellulase activities. The bacterium was classified to be Enterobacter genus. The full length of a cellulase gene cDNA (1104 bp) (GenBank JQ845065) coding region was successfully cloned. The homogeneous analysis demonstrated that the deduced nucleotide and amino acid of the gene separately shared 97% and 92% with the cellulase from E. aerogenes KCTC 2190, and 82% with the endo-1,4-D-glucanase gene from Klebsiella pneumoniae, and 82% with the a cellulase gene from unculturable bacteria.
Conclusion: It was a novel cellulose gene cloned from B. xylophilus associated bacteria.