Ottenheim, C.; Verdejo, C.; Zimmermann, W.; Wu, J. C., Hemicellulase production by Aspergillus niger DSM 26641 in hydrothermal palm oil empty fruit bunch hydrolysate and transcriptome analysis. Journal of Bioscience and Bioengineering 2014, 118, (6), p 696-701.
Abstract:
Palm oil empty fruit bunches (EFB) is an abundant and cheap lignocellulose material in Southeast Asia. Its use as the sole medium for producing lignocellulose-hydrolyzing enzymes would increase its commercial value. A newly isolated Aspergillus niger DSM 26641 was investigated for its capability of producing hemicellulases in EFB hydrolysate obtained by treatment with pressurized hot water (1–20%, w/v) at 120–180°C in a 1 L Parr reactor for 10–60 min. The optimal hydrolysate for the fungal growth and endoxylanase production was obtained when 10% (w/v) of empty fruit bunch was treated at 120°C or 150°C for 10 min, giving an endoxylanase activity of 24.5 mU ml−1 on RBB-Xylan and a saccharification activity of 5 U ml−1 on xylan (DNS assay). When the hydrolysates were produced at higher temperatures, longer treatment times or higher biomass contents, only less than 20% of the above maximal endoxylanase activity was detected, possibly due to the higher carbohydrate concentrations in the medium. Transcriptome analysis showed that 3 endoxylanases (expression levels 59–100%, the highest level was set as 100%), 2 β-xylosidases (4%), 4 side chain-cleaving arabinofuranosidases (1–95%), 1 acetyl xylan esterase (9%) and 2 ferulic acid esterases (0.3–9%) were produced together.
License type:
http://creativecommons.org/licenses/by-nc-nd/4.0/
Funding Info:
This work was funded by the Science and Engineering Research Council (SERC) of the Agency for Science, Technology and Research (A*STAR) under the Value-Added Chemicals from Lignocellulose (VACL) Program (SERC grant no. 0921590133) and Biomass to Chemicals Program (SERC grant no 1124004027) through the A*STAR Research Attachment Program (ARAP) Scholarship.