<p>Microbial β-galactosidases have been regarded as efficient biocatalysts in manufacturing galacto-oligosaccharides (GOS), which are widely recognized prebiotics. Salt-tolerant β-galactosidases can digest plant polysaccharides and synthesize GOS under high-salt conditions. In this study, five novel β-galactosidase-encoding genes in the genome of a new screened salt-tolerant <i>Bacillus hwajinpoensis</i> Zjut HJ2101 (16&#xa0;S rRNA GenBank No. PP601097) were identified via whole-genome sequencing. Comparative analysis of the specific activities of the five β-galactosidases (β-gal1-5) revealed that β-gal5 exhibited the highest specific activity. In addition, β-gal5 maintained &gt; 60% of its activity after being exposed to 1.25&#xa0;mol/L sodium chloride solution for one hour. Moreover, β-gal5 efficiently hydrolyzed 400&#xa0;g/L lactose to yield 36.8% GOS at 40℃ and pH7.0. The results of this study indicate that β-gal5 derived from <i>B. hwajinpoensis</i> Zjut HJ2101 can be regarded as a promising biocatalyst for GOS production, and could be used to industrial food manufacturing in high-salt environments.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Exploration of novel salt-tolerant β-galactosidases for GOS synthesis based on whole genome sequencing of Bacillus hwajinpoensis Zjut HJ2101

  • Chenggang Zhong,
  • Lihong Liu,
  • Weijian Ding,
  • Haoran Lin,
  • Jin Huang

摘要

Microbial β-galactosidases have been regarded as efficient biocatalysts in manufacturing galacto-oligosaccharides (GOS), which are widely recognized prebiotics. Salt-tolerant β-galactosidases can digest plant polysaccharides and synthesize GOS under high-salt conditions. In this study, five novel β-galactosidase-encoding genes in the genome of a new screened salt-tolerant Bacillus hwajinpoensis Zjut HJ2101 (16 S rRNA GenBank No. PP601097) were identified via whole-genome sequencing. Comparative analysis of the specific activities of the five β-galactosidases (β-gal1-5) revealed that β-gal5 exhibited the highest specific activity. In addition, β-gal5 maintained > 60% of its activity after being exposed to 1.25 mol/L sodium chloride solution for one hour. Moreover, β-gal5 efficiently hydrolyzed 400 g/L lactose to yield 36.8% GOS at 40℃ and pH7.0. The results of this study indicate that β-gal5 derived from B. hwajinpoensis Zjut HJ2101 can be regarded as a promising biocatalyst for GOS production, and could be used to industrial food manufacturing in high-salt environments.