Microbial xylanase and pectinase are two extremely valuable enzymes, which have captivated much attention. This can be seen from the increased demand for these enzymes by many industrial sectors. This study investigates the isolation and screening of extracellular xylanopectinolytic enzymes-producing bacteria in a submerged fermentation (SmF). Samples are collected from the compost of empty fruit bunch (EFB) at Biocompost Pilot Plant, located at Biorefinery Plant, Universiti Putra Malaysia. From the experiment, out of 20 isolates, 11 isolates show xylanase or/and pectinase activity, and only one isolate (EFB-11) shows the concurrent activities of xylanase and pectinase. These activities are selected for enzyme production under submerged fermentation (quantitative screening). At the 72nd hour of incubation, xylanase and pectinase show the highest production, which ranges about 42.33 U/mL and 62.17 U/mL (with low amount of cellulase present), supplemented with 2% (w/v) of rice bran as carbon source at incubation temperature level, which is 30°C. Meanwhile, the pH of media is shifted to 8.42, which indicates that EFB-11 isolate is alkalotolerant bacteria and identified as Bacillus subtilis ADI1. This strain proves to have potential in agroindustrial bioconversion and has a promising ability to scale up to an industrial scale.
The present work reports the biobleaching effect on OPEFB pulp upon utilisation of extracellular xylano-pectinolytic enzymes simultaneously yielded from Bacillus amyloliquefaciens ADI2. The impacts of different doses, retention times, pH, and temperatures required for the pulp biobleaching process were delineated accordingly. Here, the OPEFB pulp was subjected to pre-treatment with xylano-pectinolytic enzymes generated from the same alkalo-thermotolerant isolate that yielded those of higher quality. Remarkable enhanced outcomes were observed across varying pulp attributes: for example, enzyme-treated pulp treated to chemical bleaching sequence generated improved brightness of 11.25%. This resulted in 11.25% of less chlorine or chemical consumption required for obtaining pulp with optical attributes identical to those generated via typical chemical bleaching processes. Ultimately, the reduced consumption of chlorine would minimise the organochlorine compounds found in an effluent, resulting in a lowered environmental effect of paper-making processes overall as a consequence. This will undoubtedly facilitate such environmentally-friendly technology incorporation in the paper pulp industry of today.