Characterization of a bacterial consortium degrading the lignin model compound vanillyl-β-D-glucopyranoside

Aryl-β-D-glycosides have been described as intermediates in lignin biodegradation. The catabolism of this kind of compounds has been poorly studied. In this work, the isolation and initial characterization of a bacterial consortium degrading vanillyl-β-D-glucopyranoside is reported. The consortium is able to grow on and completely degrade the dimer vanillyl-β-D-glucopyranoside. The consortium is composed of three microorganisms; strain 2.1 is closely related to Chryseomonas lateola: strain 2.2. identified as Moraxella phenylpyruvica and strain 2.3, preliminary identified as Pseudomonas spp. Complete degradation of the glycoside required strains 2.1 and 2.2, although only strain 2.1 was able to cleave the aryl-glycoside linkage. Oxidation of vanillyl alcohol, one product of the aryl-glycoside cleaving reaction, to the respective acid was carried out by strain 2.2. Vanillic acid was used as growth substrate by strains 2.2 and 2.3. Strain 2.1 can grow on other aryl-β-glycosides, accumulating the aryl moiety in the culture. β-Glucosidase present in strain 2.1 is probably the key enzyme in the catabolism of aryl-glycosides by this consortium.