Newly isolated cellulose-degrading bacterium Achromobacter xylosoxidans L2 has deinking potential

Abstract

Compared with conventional chemical deinking, enzymatic deinking is a more environmentally compatible alternative for processing recovered paper. In this study, a bacterial isolate identified as Achromobacter xylosoxidans (designated as L2) was found to be a promising candidate for a paper deinking process. It showed endoglucanase, β-glucosidase, endoxylanases, and filter paper degrading activities (FPase) with the maximal values of 2.60, 2.57, 3.08, and 24.58 U/mL, respectively. The optimal temperature and pH for FPase were determined to be 44 °C and pH 7.6. After two days of incubation with L2 at 130 rpm and 30 °C, the waste newspaper strips (0.5 cm × 5 cm) were disintegrated to debris with the average size of 3.5 mm (while that of the untreated without inoculation of L2 was 5.7 mm). The final brightness of the regenerated handsheets after incubation with L2 increased 3.7 units (31.4% ISO). The isolate and its complete lignocellulosic enzymes could be applied as deinking agents in the recycling of waste paper.