title: Hemicellulase production by Aspergillus niger DSM 26641 in hydrothermal palm oil empty fruit bunch hydrolysate and transcriptome analysis.
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.
authors: Microbiology and Bioprocess Engineering, Institute of Biochemistry, Leipzig University, 04103 Leipzig, Germany; Institute of Chemical and Engineering Sciences, Agency for Sciences, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island, Singapore 627833, Singapore. Electronic address: christoph@ottenheim.net.
authors: Christoph
authors: C
authors: Ottenheim
authors: Institute of Chemical and Engineering Sciences, Agency for Sciences, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island, Singapore 627833, Singapore. Electronic address: carl.xymon.verdejo@gmail.com.
authors: Carl
authors: C
authors: Verdejo
authors: Microbiology and Bioprocess Engineering, Institute of Biochemistry, Leipzig University, 04103 Leipzig, Germany. Electronic address: wolfgang.zimmermann@uni-leipzig.de.
authors: Wolfgang
authors: W
authors: Zimmermann
authors: Institute of Chemical and Engineering Sciences, Agency for Sciences, Technology and Research (A*STAR), 1 Pesek Road, Jurong Island, Singapore 627833, Singapore. Electronic address: wu_jinchuan@ices.a-star.edu.sg.
authors: Jin Chuan
authors: JC
authors: Wu
mesh_terms: D001234:Aspergillus niger / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development; D018533:Biomass; D043364:Endo-1,4-beta Xylanases / Q000235:genetics / Q000378:metabolism; D005638:Fruit / Q000737:chemistry* / Q000382:microbiology; D020869:Gene Expression Profiling; D006026:Glycoside Hydrolases / Q000096:biosynthesis* / Q000235:genetics*; D006358:Hot Temperature; D006868:Hydrolysis; D008031:Lignin / Q000378:metabolism; D000073878:Palm Oil; D010938:Plant Oils; D012846:Singapore; D014020:Tissue Extracts / Q000737:chemistry*; D014867:Water
chemical_list: D010938:Plant Oils; D014020:Tissue Extracts; D014867:Water; C036909:lignocellulose; D000073878:Palm Oil; D008031:Lignin; D006026:Glycoside Hydrolases; C023305:hemicellulase; D043364:Endo-1,4-beta Xylanases
keywords: Empty fruit bunch; Endoxylanase; Filamentous fungi; Hemicellulase; Hydrolysate; Hydrothermal treatment; Submerged culture