The atmospheric and room-temperature plasma (ARTP) method on the dextranase activity and structure

• Published in: International journal of biological macromolecules 2014-09, Vol.70, p.284-291
• Main Authors: Wang, Xiaobei, Lu, Mingsheng, Wang, Shujun, Fang, Yaowei, Wang, Delong, Ren, Wei, Zhao, Gengmao
• Format: Article
• Language: English
• Subjects: Arthrobacter - enzymology; Arthrobacter - genetics; Arthrobacter - growth & development; ARTP; Biofilm; Biofilms; Crystal structure; Dextranase; Dextranase - chemistry; Dextranase - genetics; Dextranase - metabolism; Genomic Instability; Models, Molecular; Molecular Weight; Mutation; Protein Conformation; SEM; Structure-Activity Relationship; Temperature
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2014.07.006

A novel atmospheric and room-temperature plasma (ARTP) method was used to breed high-yielding mutations of Arthrobacter KQ11. Mutagenesis produced two mutations, 4-1 and 4-13, which increased enzyme activity by 19 and 30%, respectively. Dents on the cell envelope were observed under scanning electron microscopy (SEM). The optimal temperature and pH of the wild strain were 45°C and 5.5 and those of the mutant strains were 45°C, pH 6.0 (4-1) and 50°C, pH 6.0 (4-13). Under optimal enzyme production conditions of the wild and mutant strains, the dextranase activity of 4-13 was 50% higher than that of the wild strain. Through amino acid alignment, several nucleotides of the mutant strains were found to have changed. Experiments performed in vitro suggested that this endo-dextranase may inhibit biofilm formation by Streptococcus mutans.