Isolation of new and potent poly(vinyl alcohol)-degrading strains and their degradation activity

Poly(vinyl alcohol) (PVA)-degrading bacteria were isolated from various sources such as activated sludge from the watercourse of textile and dyeing factories, cultivating soil and leaf mold. Acclimation of the isolated strains enhanced the PVA degradation activity by 1.3-1.7 times. Cardiobacterium sp. SB68 (SB68) and an unidentified bacterium (SB69) degraded PVA through symbiotic interactions. In contrast, Achromobacter cholinophagum SB98 (SB98) degraded PVA without any supporting bacteria. The modified Sturm test was carried out using the symbiotic strains, SB68 + SB69 and the single strain, SB98 to measure the mineralization rate of PVA into carbon dioxide (CO2). The mineralization rate was nearly independent of the degree of polymerization of PVA. The single strain, SB98, as well as the symbionts, SB68 + SB69 showed a very high activity for PVA degradation so that 75% of PVA with an initial concentration of 0.01% was mineralized during 46 days of the modified Sturm test. (C) 2003 Elsevier Science Ltd. All rights reserved.