title: Identification and functional characterization of an α-amylase with broad temperature and pH stability from Paenibacillus sp.
abstract: Amylases are important industrial enzymes that have been applied widely in the food, detergent, and pulp industries and fermentation processes. In the present study, a gene encoding an alpha-amylase from the genomic DNA library of Paenibacillus sp. was identified and characterized. The amylase gene designated amy1 was shown to consist of 1,980 bp and shared sequence identity towards α-amylase genes from other Bacillus sp. The deduced amino acid sequence for Amy1 indicated 80 % sequence identity with other Bacillus strains. Heterologous expression of recombinant Amy1 in Escherichia coli BL21(DE3) facilitated the recovery of this protein in soluble form. Enzyme kinetic data revealed Amy1 to have a K m of 23.83 mg/mL and K cat of 48.74 min(-1) and K cat /K m of 2 min(-1) mg(-1) mL(-1) for starch. The activity of this protein was found to be enhanced by Mn(2+), and furthermore, Amy1 remained active at a broad pH range (4-10) and temperature (30-90 °C). The ability of Amy1 to act on food waste under broad temperature and pH conditions, together with its ability to produce simple sugars, shows many advantages for further application in the food industry.
authors.affiliation: Department of Microbial Engineering, College of Engineering, Konkuk University, 1 Hwayang-dong, Gwangjin-gu, Seoul, 143-701, Korea.
authors.forename: Thangamani
authors.initials: T
authors.lastname: Rajesh
authors.forename: Yong Hyun
authors.initials: YH
authors.lastname: Kim
authors.forename: Yong-Keun
authors.initials: YK
authors.lastname: Choi
authors.forename: Jong Min
authors.initials: JM
authors.lastname: Jeon
authors.forename: Hyun Joong
authors.initials: HJ
authors.lastname: Kim
authors.forename: Sung-Hee
authors.initials: SH
authors.lastname: Park
authors.forename: Hyung-Yeon
authors.initials: HY
authors.lastname: Park
authors.forename: Kwon-Young
authors.initials: KY
authors.lastname: Choi
authors.forename: Hyungsup
authors.initials: H
authors.lastname: Kim
authors.forename: Hyung Joo
authors.initials: HJ
authors.lastname: Kim
authors.forename: Sang Hyun
authors.initials: SH
authors.lastname: Lee
authors.forename: Yung-Hun
authors.initials: YH
authors.lastname: Yang
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D004789:Enzyme Activation; D004795:Enzyme Stability; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015723:Gene Library; D005798:Genes, Bacterial; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D012275:Oryza; D056507:Paenibacillus / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification; D011134:Polysaccharides / Q000378:metabolism; D012329:RNA, Bacterial / Q000032:analysis* / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012988:Soil Microbiology; D013696:Temperature; D000516:alpha-Amylases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D011134:Polysaccharides; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D011994:Recombinant Proteins; D000516:alpha-Amylases