Downscale fermentation for xylooligosaccharides production by recombinant Bacillus subtilis 3610

Supplementary material related to this article can be found, in the online version, at doi:https://doi.org/10.1016/j.carbpol.2018.09.088.
The global demand of prebiotics such as xylooligosaccharides (XOS) has been growing over the years, motivating the search for different production processes with increased efficiency. In this study, a cloned Bacillus subtilis 3610, containing the xylanase gene xyn2 of Trichoderma reesei coupled with an endogenous secretion tag, was selected for XOS production through direct fermentation of beechwood xylan. A mixture of XOS with a degree of polymerization ranging from 4-6 was obtained, presenting high stability after a static in vitro digestion (98.5±0.2%). The maximum production yield expressed as total XOS per amount of xylan (306±4mg/g) was achieved after 8h of fermentation operating under one-time impulse fed-batch. The optimal conditions found were pH 6.0 and 42.5°C, using 2.5g/L of initial concentration of xylan increased up to 5.0g/L at 3h. Xylopentaose was the major oligosaccharide produced, representing 47% of the total production yield.
CA, SCS, ACP, EC and LRR acknowledge their grants (PD/BD/ 105870/2014, SFRH/BPD/88584/2012, SFRH/BPD/ 101181/2014, SFRH/BPD/70589/2010 and SFRH/BSAB/142873/2018) from Portuguese Foundation for Science and Technology (FCT). The study received financial support from FCT under the scope of the strategic funding of UID/BIO/04469/2013 unit; COMPETE 2020 (POCI-010145-FEDER-006684); QOPNA research Unit (FCT UID/QUI/00062/ 2013), through national founds and where applicable co-financed by the FEDER, within the PT2020 Partnership Agreement; the Project MultiBiorefinery (POCI-01-0145-FEDER-016403); the Project FoSynBio (POCI-01-0145-FEDER-029549) and Lignozymes (POCI-01-0145FEDER-029773). The authors also acknowledge BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.
info:eu-repo/semantics/publishedVersion