Effect of uracil addition on proteomic profiles and 1,3-β-glucan production in Agrobacterium sp.

Uridine diphosphate (UDP)-glucose is a precursor of 1,3-β-glucan and is synthesized from glucose-1-phosphate and uridine triphosphate (UTP). Uracil was used as a precursor for UTP, which resulted in an increase in both the UDP-glucose level and the rate of 1,3-β-glucan synthesis. 1,3-β-Glucan production metabolism was reactivated after uracil addition during fermentation. 2D-PAGE was used to examine the changes in the expression level of the key metabolic enzymes in the production of 1,3-β-glucan after uracil addition. The results showed that the expression levels of UTP-glucose-1-phosphate uridylytransferase, phosphoglucomutase, and 1,3-β-glucan synthase catalytic subunit, key metabolic enzymes in the curdlan biosynthesis pathway, were increased after uracil addition by 3.5%, 30%, and 35%, respectively. Uracil phosphoribosyltransferase, which converts uracil to uridine monophosphate (UMP), was also upregulated 79% more than that without uracil addition. However, the expression levels of orotidine 5-phosphate decarboxylase, glucose-1-phosphate adenylyltransferase, and glucose-6-phosphate isomerase were decreased after uracil addition. This proteomic information is useful for predicting changes in the pathway of uracil utilization. This work provides proteomic information for the integrative analysis of bioinformatic databases, which can be used to predict and understand the metabolism of glucan synthesis at the cellular level.