Biochemical investigation of kraft lignin degradation by Pandoraea sp. B-6 isolated from bamboo slips

Kraft lignin (KL) is the major pollutant in black liquor. The bacterial strain Pandoraea sp. B-6 was able to degrade KL without any co-substrate under high alkaline conditions. At least 38.2 % of chemical oxygen demand and 41.6 % of color were removed in 7 days at concentrations from 1 to 6 g L(-1). The optimum pH for KL degradation was 10 and the optimum temperature was 30 °C. The greatest activities of 2,249.2 U L(-1) for manganese peroxidase and 1,120.6 U L(-1) for laccase were detected on the third and fifth day at pH 10, respectively. Many small molecules, such as cinnamic acid, ferulic acid, 2-hydroxy benzyl alcohol, and vanillyl methyl ketone, were formed during the period of KL degradation based on GC-MS analysis. These results indicate that this strain has great potential for biotreatment of black liquor.