Isolation and characterization of a xanthan-degrading Microbacterium sp. strain XT11 from garden soil

Aims: Isolation and characterization of the xanthan-degrading Microbacterium sp. XT11. Methods and Results: The bacterial isolate XT11, capable of fragmenting xanthan, has been isolated from soil sample. Morphological and biochemical analyses, as well as 16S rRNA gene sequence comparisons, demonstrated that strain XT11 should be grouped in the genus Microbacterium, and represented a new member in this family. Xanthan could be degraded by the xanthan-degrading enzyme released from strain XT11. It has been shown that xantho-oligosaccharides fragmented from xanthan had both elicitor activity and antibacterial effect against Xanthomonas campestris pv. campestris. Conclusions: The xanthan-degrading enzyme produced by the newly isolated XT11 could fragment xanthan to form oligosaccharides. Significance and Impact of the Study: Xanthan-degrading products would be useful for potential application in the control of black rot of cruciferous plants caused by X. campestris pv. campestris and, as an oligosaccharide elicitor, in making these plants resistant to disease.