Producción de pétidos fijadores de calcio y hierro por cepas probi óticas de bacillus subtilis, B. Clausii y B. Coagulans GBI-30

Some strains of Bacillus subtilis, B. clausii and B. coagulans are commercially used as probiotic bacteria and their proteolytic activity is well known. The aim of this work was to evaluate their capacity to produce calcium-and iron-binding peptides when grown in culture media with different nitrogen sources. The fermentation media included broths containing tryptic soy (TS), casein peptone (CP), soy peptone (SP), and a crude phycobiliprotein extract (CPE). Cell-free supernatants (CFS) were prepared from the fermented media after 24, 48 and 12 h of fermentation and, tested for degree of hydrolysis (DH). Calcium-and iron-binding activities were determined as well. When the inocula were prepared in a medium designed for the production of alkaline proteases (AP), trie degree of hydrolysis and the mineral-binding activity in the CFS were higher. The best rerults for calcium-binding activity and DH were obtained when B. subtilis and B. coagulans grew in a CPE-containing medium. Analogous results were found for the iron-binding activity; nevertheless, this bioactivity was also high for B. claufii when grown in broths containing TS-, CP-and, SP.