Effect of efficient pectinolytic bacterial isolates on retting and fibre quality of jute

Four bacterial strains with high balanced polygalacturonase (PG) and pectin lyase (PNL), and xylanase with minimal cellulase activity were used in jute retting. The 16S rDNA analysis revealed that the organisms were: Bacillus sp. L6 (GQ891097), Bacillus pumilus strain EK-17 (GQ891098), B. pumilus strain Geo-03-422 (GQ891103) and B. pumilus strain IK-MB12-518F (GQ891105). The microorganisms in different combinations of consortia showed synergistic effect resulting in increased PG (35.52–46.61 IU/g cell wet weight), PNL (39.79–72.12 U/ml), xylanase (0.705–0.840 μmol/ml/min) and little cellulase (0–0.153 μmol/ml/min) activities. The organisms in different combinations of consortia reduced the retting period from 11 to 13 days as compared to 19 days in the control. Microbial inoculation produced remarkable improvement in jute fibre strength (26.62–28.91 g/tex) and fineness (2.76–2.92 tex) over control. The pH of the post-retting water samples became acidic, and the electrical conductivity (Ec), chemical oxygen demand (COD) and hardness increased. The organisms could be adopted in industrial application for extraction of jute fibre.

► Isolation and characterization of four bacterial strains having balanced pectinolytic activities (polygalacturonase and pectin lyase) with little or no cellulolytic activity; the pectin lyase activity of the strains BA1 (71.0 U/ml) and SO7 (75.7 U/ml) higher than those previously reported. ► The strain SO14 had high balanced pectinolytic and xylanase activities without cellulase activity − ideal for a strain used in jute retting. ► Compared to individual strains, consortia of the isolates more effective in respect of enzyme activities, reduction of retting period and production of remarkably improvement of jute fibre quality. ► Compared to pre-retting water samples, physico-chemical parameters of post retting water samples markedly changed.