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=Volume 12 - 2021

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=Thermoacidophilic Alicyclobacillus strains attract great interests as a resource of thermostable or acidic enzymes. A putative gene encoding superoxide dismutase (AaSOD) was identified in a thermoacidophilic Alicyclobacillus strain. In the growth media with manganese or iron enrichment, the activity of expressed AaSOD showed great preference to manganese, with a 16-fold activity observed in the Mn2+-enriched medium. In addition, the purified AaSOD can be reconstituted exclusively with either Fe2+ or Mn2+, with its Mn-bound protein showing 25-fold activity than that of Fe-bound form. The optimal temperature of AaSOD was 35 °C and was highly stable at high temperature. 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 and medicine additives.