Vol.:(0123456789) 1 3 Waste and Biomass Valorization https://doi.org/10.1007/s12649-020-01027-z ORIGINAL PAPER Selection of Microorganisms Possessing Thermostable Lignocellulolytic Enzymes and Application of the Enzymes for Saccharification of Pretreated Palm Oil Mill Wastes Wiyada Khangkhachit 1  · Wasana Suyotha 1  · Sompong O‑Thong 2  · Poonsuk Prasertsan 3 Received: 20 September 2019 / Accepted: 16 March 2020 © Springer Nature B.V. 2020 Abstract This study attempted to find potential effective thermotolerant microorganisms producing complex enzymes for use in the hydrolyzing empty fruit bunch (EFB) to reduce cost of enzyme and enhance the efficiency of saccharification. The enrich- ment process at 45 °C was employed as a strategy to obtain four effective thermotolerant microorganisms. Streptomyces thermocarboxydus ME742, Bacillus subtilis ME751 and Bacillus amyloliquefaciens ASB/TRE produced the highest activ- ity of xylanase (226.2 U/mL), CMCase (3.84 U/mL) and FPase (69.55 U/mL), respectively, while Aspergillus fumigatus A4112 exhibited the highest specific activity of xylanase (637.9 U/mg), CMCase (5.55 U/mg) and FPase (21.58 U/mg). Xylanase of isolated ME742 and A4112, CMCase of isolated ASB/TRE, FPase of isolated ME742, ME751 and ASB/TRE possessed thermostability with 80% remaining activity at 60 °C after 1 h incubation. These four strains were capable to reduce 49–78% (w/w) lignin in raw EFB with simultaneous enzyme production. The EFB residue was reused as substrate for saccharification with the highest amount of reducing sugar using the crude enzymes from S. thermocarboxydus ME742 (9.24 mg/g EFB). The sugar was 3.76 and 3.61 fold higher than that obtained from saccharification of acid- and alkaline- pretreated EFB, respectively. Moreover, the crude enzymes from A. fumigatus A4112 and B. amyloliquefaciens ASB/TRE hydrolyzed palm oil mill effluent (POME) to generate high yield of reducing sugar (61.01–64.63 mg/g TS-POME). Therefore, these selected strains were considered as the potent biological tool applicable in the bioconversion of oil palm biomass to fermentable reducing sugars. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s12649-020-01027-z) contains supplementary material, which is available to authorized users. * Wasana Suyotha wasana.suy@psu.ac.th 1 Biotechnology for Bioresource Utilization Laboratory, Department of Industrial Biotechnology, Faculty of Agro-Industry, Prince of Songkla University, Hat Yai 90112, Thailand 2 Department of Biology, Faculty of Science, Thaksin University, Phatthalung 93110, Thailand 3 Research and Development Office, Prince of Songkla University, Hat Yai 90112, Thailand