Revista de Bioprocessamento e Biotécnicas

Piaractus mesopotamicus is the most produced specie in Argentinian fish culture with an annual production of 2,017 tons. The high demands of specimens generated a deficit of larvae, juveniles and sexually mature adults. The high stress conditions and the incidence of diseases had intensified this deficit. Probiotics are proven to increase survival and growth rates in aquaculture. The first step in the design of a putative probiotic is the selection of adequate microorganisms to boost fish health. Lactic Acid Bacteria and Bacillus are generally accepted as probiotics in aquaculture. In this work we obtained 522 isolates from different anatomical parts of P. mesopotamicus, with a total of 30 lactic acid bacteria (LAB) and 8 Bacillus strains submitted for the evaluation of their beneficial properties. Only eight of these strains were selected for further “in vivo” assays based on following criteria: production of inhibitory metabolites and biosurfactants, screening of antagonistic activity against foodborne and pathogenic microorganisms, ability to emulsify polar solvents and compatibility between strains. All selected microorganisms were identified by sequencing 16S RNA gene. Pure cultures of all strains herein studied are preserved in Centro de Referencia de Lactobacilos (CERELA-CONICET) and Laboratorio de Sanidad Animal of the Estación Experimental Agropecuaria Rafaela, Instituto Nacional de Tecnología Agropecuaria (INTA) culture collections.

Antrodia cinnamomea (AC) has attracted much attention recently due to its pharmacological benefits, especially for anticancer, and immunomodulation effects. Triterpenoids are the major bioactive compounds present in AC, and responsible for cancer curing ability. Oxygen supply to fermentation is a crucial environmental parameter affecting triterpenoids production. Thus, 29.6 mg/g biomass dry weight (DW) of triterpenoids was obtained by static operation (limited oxygen supply) in the second stage of monoculture of AC. In this paper, we propose a novel approach to enhancing triterpenoids production of AC through two-stage fermentation by co-culture with Saccharomyces cerevisiae in the second stage under limited oxygen supply. As a result, 38.0 mg/g DW of triterpenoids was obtained in 250 ml shake flask. Triterpenoid content was further enhanced as 46.5 mg/g DW by increasing the inoculation level of S. cerevisiae to 25%. While a scale-up study of the novel fermentation strategy was executed in a 2 L airlift bioreactor, 62.2 mg/g DW of triterpenoids was achieved, which was 110% and 64% enhancement as compared to those of monoculture of AC in the flask and airlift bioreactor, respectively. This role of S. cerevisiae and its elicitors on triterpenoids production of AC were also investigated in this study.