AUTHOR=Dong Xueqian , Wang Wei , Li Shannan , Han Hongyu , Lv Peiwen , Yang Chunyu 

TITLE=Thermoacidophilic Alicyclobacillus Superoxide Dismutase: Good Candidate as Additives in Food and Medicine

JOURNAL=Frontiers in Microbiology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2021.577001

DOI=10.3389/fmicb.2021.577001

ISSN=1664-302X

ABSTRACT=<p>Thermoacidophilic <italic>Alicyclobacillus</italic> strains attract great interests as the resource of thermostable or acidic enzymes. In this study, a putative gene encoding superoxide dismutase (<italic>Aa</italic>SOD) was identified in a thermoacidophilic <italic>Alicyclobacillus</italic> strain. With a 16-fold activity observed, the <italic>Aa</italic>SOD activity expressing in the medium of manganese enrichment was much higher than that in the iron medium. In addition, the purified <italic>Aa</italic>SOD can be reconstituted exclusively with either Fe<sup>2+</sup> or Mn<sup>2+</sup>, with its Mn-bound protein showing 25-fold activity than that of Fe-bound form. The optimal temperature for <italic>Aa</italic>SOD reaction was 35°C, and was highly stable at any certain temperature up to 80°C. Of particular interest, the enzyme is found to be very stable across a wide pH range spanning from 2.0 to 10.0, which confers its robust stability in the acidic stomach environment and implies striking potentials as food additive and for medical use.</p>