title: Heterologous expression and characterization of a new heme-catalase in Bacillus subtilis 168.
abstract: Reactive oxygen species (ROS) is an inherent consequence to all aerobically living organisms that might lead to the cells being lethal and susceptible to oxidative stress. Bacillus pumilus is characterized by high-resistance oxidative stress that stimulated our interest to investigate the heterologous expression and characterization of heme-catalase as potential biocatalyst. Results indicated that recombinant enzyme significantly exhibited the high catalytic activity of 55,784 U/mg expressed in Bacillus subtilis 168 and 98.097 µmol/min/mg peroxidatic activity, the apparent K m of catalytic activity was 59.6 ± 13 mM with higher turnover rate (K cat = 322.651 × 10(3) s(-1)). The pH dependence of catalatic and peroxidatic activity was pH 7.0 and pH 4.5 respectively with temperature dependence of 40 °C and the recombinant heme-catalase exhibited a strong Fe(2+) preference. It was further revealed that catalase KatX2 improved the resistance oxidative stress of B. subtilis. These findings suggest that this B. pumilus heme-catalase can be considered among the industrially relevant biocatalysts due to its exceptional catalytic rate and high stability and it can be a potential candidate for the improvement of oxidative resistance of industrially produced strains.
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, 214122, Wuxi, Jiangsu, People's Republic of China.
authors.forename: Tuyishime
authors.initials: T
authors.lastname: Philibert
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, 214122, Wuxi, Jiangsu, People's Republic of China. raozhm@jiangnan.edu.cn.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Rao
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, 214122, Wuxi, Jiangsu, People's Republic of China.
authors.forename: Taowei
authors.initials: T
authors.lastname: Yang
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, 214122, Wuxi, Jiangsu, People's Republic of China.
authors.forename: Junping
authors.initials: J
authors.lastname: Zhou
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, 214122, Wuxi, Jiangsu, People's Republic of China.
authors.forename: Genshu
authors.initials: G
authors.lastname: Huang
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, 214122, Wuxi, Jiangsu, People's Republic of China.
authors.forename: Komera
authors.initials: K
authors.lastname: Irene
authors.affiliation: The Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, 1800 Lihu Avenue, 214122, Wuxi, Jiangsu, People's Republic of China.
authors.forename: Niyomukiza
authors.initials: N
authors.lastname: Samuel
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002374:Catalase / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D015964:Gene Expression Regulation, Bacterial; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology; D008958:Models, Molecular; D018384:Oxidative Stress; D010802:Phylogeny; D011487:Protein Conformation; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA
chemical_list: D001426:Bacterial Proteins; D012336:RNA, Ribosomal, 16S; D011994:Recombinant Proteins; D002374:Catalase
keywords: Bacillus pumilus; Characteristic; Heme-catalase; Oxidative stress