On hydrolysis of cellulose and nitrocellulose under sulfate-reducing conditions

Hydrolysis of cellulose and nitrocellulose in the presence of sulfate-reducing bacterium Desulfovibrio vulgaris 1388 was studied. The cellulolytic activity was found in culture medium after D. vulgaris growth (1.45 +/- 0.04 nmol/mg protein/min). In the presence of cellulose or nitrocellulose the activity accounted for 4.82 +/- 0.23 and 2.35 +/- 0.11 nmol/mg protein/min, respectively. The initial rates of cellulose decomposition were measured using toluene to inhibit the microbial uptake of hydrolysis product-glucose. It was established that 7.6% of initially added cellulose was hydrolyzed in 3 weeks. The highest rate of glucose accumulation was observed on day 10 (2.13 mu mol glucose/g dry-wt cellulose/h). At the same time only 3.3% of nitrocellulose was hydrolyzed, since nitro-groups of polymer exerted negative influence on the hydrolysis process. It is supposed that nonspecific extracellular hydrolases participate in the polymers hydrolysis.