Cloning of cellulose synthesis related genes from Acetobacter xylinum ATCC23769 and ATCC53582: comparison of cellulose synthetic ability between strains

Abstract

About 14.5 kb of DNA fragments from Acetobacter xylinum ATCC23769 and ATCC53582 were cloned, and their nucleotide sequences were determined. The sequenced DNA regions contained endo-beta-1,4-glucanase, cellulose complementing protein, cellulose synthase subunit AB, C, D and beta-glucosidase genes. The results from a homology search of deduced amino acid sequences between A. xylinum ATCC23769 and ATCC53582 showed that they were highly similar. However, the amount of cellulose production by ATCC53582 was 5 times larger than that of ATCC23769 during a 7-day incubation. In A. xylinum ATCC53582, synthesis of cellulose continued after glucose was consumed, suggesting that a metabolite of glucose, or a component of the medium other than glucose, may be a substrate of cellulose. On the other hand, cell growth of ATCC23769 was twice that of ATCC53582. Glucose is the energy source in A. xylinum as well as the substrate of cellulose synthesis, and the metabolic pathway of glucose in both strains may be different. These results suggest that the synthesis of cellulose and the growth of bacterial cells are contradictory.