Open AccessButyric acid fermentation from pretreated and hydrolysed wheat straw by an adapted C lostridium tyrobutyricum strain
Author(s) -
Baroi G. N.,
Baumann I.,
Westermann P.,
Gavala H. N.
Publication year - 2015
Publication title -
microbial biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.287
H-Index - 74
ISSN - 1751-7915
DOI - 10.1111/1751-7915.12304
Subject(s) - butyric acid , xylose , fermentation , food science , chemistry , hydrolysis , sugar , strain (injury) , yield (engineering) , straw , yeast , biochemistry , biology , materials science , inorganic chemistry , metallurgy , anatomy
Summary Butyric acid is a valuable building‐block for the production of chemicals and materials and nowadays it is produced exclusively from petroleum. The aim of this study was to develop a suitable and robust strain of C lostridium tyrobutyricum that produces butyric acid at a high yield and selectivity from lignocellulosic biomasses. Pretreated (by wet explosion) and enzymatically hydrolysed wheat straw ( PHWS ), rich in C6 and C5 sugars (71.6 and 55.4 g l −1 of glucose and xylose respectively), was used as substrate. After one year of serial selections, an adapted strain of C . tyrobutyricum was developed. The adapted strain was able to grow in 80% (v v −1 ) PHWS without addition of yeast extract compared with an initial tolerance to less than 10% PHWS and was able to ferment both glucose and xylose. It is noticeable that the adapted C . tyrobutyricum strain was characterized by a high yield and selectivity to butyric acid. Specifically, the butyric acid yield at 60–80% PHWS lie between 0.37 and 0.46 g g −1 of sugar, while the selectivity for butyric acid was as high as 0.9–1.0 g g −1 of acid. Moreover, the strain exhibited a robust response in regards to growth and product profile at pH 6 and 7.