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Autotransporter‐Based Surface Display of Hemicellulases on Pseudomonas putida : Whole‐Cell Biocatalysts for the Degradation of Biomass
Author(s) -
Schulte Marten F.,
Tozakidis Iasson E. P.,
Jose Joachim
Publication year - 2017
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201700577
Subject(s) - pseudomonas putida , xylan , arabinoxylan , xylose , chemistry , xylanase , pseudomonas , enzyme , bacteria , biomass (ecology) , food science , arabinose , hydrolysis , depolymerization , biochemistry , polysaccharide , fermentation , biology , organic chemistry , agronomy , genetics
The enzymatic depolymerization of xylans into their monomeric sugars by hemicellulases is of great interest from both the ecological and the economical point of view; however, the high costs of these enzymes impede their employment on industrial scales. The utilization of whole cells displaying the enzymes on their surface could reduce costs by allowing a direct employment of the cells after cultivation and their reuse in multiple reaction cycles. Here, we present the surface display of an endo ‐1,4‐ β ‐xylanase (XynA), a 1,4‐ β ‐xylosidase (XynB), and two α ‐ l ‐arabinofuranosidases (Abf2 and AbfCelf) in the gram‐negative soil bacterium Pseudomonas putida KT2440 by fusing the enzymes to the EhaA autotransporter unit from Escherichia coli . The surface display of the enzymes was verified by flow cytometry. All four enzymes retained their functionality with hydrolytic activities of 48.5 mU mL −1 for XynA towards beechwood xylan, 6 mU mL −1 for XynB towards 4‐nitrophenyl‐ β ‐ d ‐xylopyranoside, and 8.6 mU mL −1 and 6.2 mU mL −1 for the two α ‐ l ‐arabinofuranosidases Abf2 and AbfCelf towards 4‐nitrophenyl‐ α ‐ l ‐arabinofuranoside, respectively. Measurements were done with cell suspensions of an OD 578 =1. A mixture of strains displaying the three types of hemicellulases could degrade 2.5 % ( w / v ) raw arabinoxylan from rye bran to d ‐xylose with a yield of 133.5 mg L −1 cell suspension after 24 h.