TY - JOUR
T1 - Lactose-inducted production of a complete lignocellulolytic enzyme system by a novel bacterium Bacillus sp. BS-5 and its application for saccharification of alkali-pretreated corn cob
AU - Xu, Jiaxing
AU - Gao, Zhen
AU - Wu, Bin
AU - He, Bingfang
N1 - Publisher Copyright:
© 2017, Springer Science+Business Media Dordrecht.
PY - 2017/5/1
Y1 - 2017/5/1
N2 - In this study, with combined carboxymethyl cellulose agar plate, xylan agar plate and filter paper hydrolysis assay, a novel cellulase and xylanase-producing strain identified as Bacillus sp. was isolated. Using lactose as the only carbon source, a complete and balanced lignocellulolytic enzyme system containing at least endoglucanase (9.6 U/ml), exoglucanase (0.8 U/ml), Fpase (1.4 U/ml), xylanase (3.8 U/ml) and β-glucosidase (1.2 U/ml) was produced. Interestingly, a zymogram of the crude culture supernatant displayed a multifunctional lignocellulolytic enzyme system including at least four bonds with both endoglucanase activity and xylanase activity at 21.2, 23.8, 28.9 and 31.2 kDa, respectively, indicating that these enzymes might be bifunctional. More gratifyingly, according to the binding affinity analysis and scanning electron microscopy, the crude enzyme complex produced by strain BS-5 was capable of hydrolyzing not only pure insoluble polysaccharides, but also agricultural residues such as corn cob. At 5% substrate concentration and 20 FPU/g enzyme loading, the reducing sugar was 350.8 mg/g of alkali-pretreated corn cob after 72 h enzymatic hydrolysis. These results suggested that this strain could be a good candidate for the development of a more cost-effective and efficient lignocellulolytic enzyme cocktail for the saccharification of lignocellulosic biomass.
AB - In this study, with combined carboxymethyl cellulose agar plate, xylan agar plate and filter paper hydrolysis assay, a novel cellulase and xylanase-producing strain identified as Bacillus sp. was isolated. Using lactose as the only carbon source, a complete and balanced lignocellulolytic enzyme system containing at least endoglucanase (9.6 U/ml), exoglucanase (0.8 U/ml), Fpase (1.4 U/ml), xylanase (3.8 U/ml) and β-glucosidase (1.2 U/ml) was produced. Interestingly, a zymogram of the crude culture supernatant displayed a multifunctional lignocellulolytic enzyme system including at least four bonds with both endoglucanase activity and xylanase activity at 21.2, 23.8, 28.9 and 31.2 kDa, respectively, indicating that these enzymes might be bifunctional. More gratifyingly, according to the binding affinity analysis and scanning electron microscopy, the crude enzyme complex produced by strain BS-5 was capable of hydrolyzing not only pure insoluble polysaccharides, but also agricultural residues such as corn cob. At 5% substrate concentration and 20 FPU/g enzyme loading, the reducing sugar was 350.8 mg/g of alkali-pretreated corn cob after 72 h enzymatic hydrolysis. These results suggested that this strain could be a good candidate for the development of a more cost-effective and efficient lignocellulolytic enzyme cocktail for the saccharification of lignocellulosic biomass.
KW - Alkali-pretreated corn cob
KW - Bacillus sp
KW - Lactose
KW - Lignocellulolytic enzyme
UR - http://www.scopus.com/inward/record.url?scp=85015639220&partnerID=8YFLogxK
U2 - 10.1007/s10570-017-1247-4
DO - 10.1007/s10570-017-1247-4
M3 - 文章
AN - SCOPUS:85015639220
SN - 0969-0239
VL - 24
SP - 2059
EP - 2070
JO - Cellulose
JF - Cellulose
IS - 5
ER -