Sequential enzymatic pretreatment and Saccharomyces boulardii fermentation of cactus cladode biomass for bioactive food ingredients and cell culture serum alternatives.
TL;DR
It is demonstrated that DL + SC pretreatment of CCB combined with SB fermentation can produce bioactive food ingredients and candidate protein-rich growth supplements for cell culture applications and bioactivity and serum replacement evidence remains partial, in vitro and restricted to a single cell line.
Abstract
Novel biomass valorization technologies are critical for sustainable food production systems that prioritize health-promoting functional properties of foods. Sequential enzymatic delignification and saccharification (DL + SC) of cactus (Opuntia ficus-indica) cladode biomass (CCB), followed by Saccharomyces boulardii (SB) fermentation, was investigated for biomass processing. CCB delignification using Aspergillus laccases was optimized using a central composite design. At optimal conditions (35.95 °C, pH 5.55, 37.68 laccase Myceliophthora units/g dry CCB, 6 h 56 min reaction time), a 59.39 % reduction in acid-insoluble lignin concentration was achievable. Pretreated CCB was saccharified with Trichoderma reesei cellulase (10 FPU/g dry CCB, 50 °C, 48 h). DL + SC-pretreated CCB exhibited higher reducing sugar content than independent treatments, improving SB growth (68.11 % relative to yeast malt broth). Effects of pretreatment and fermentation of CCB on the bioactivities were evaluated in a benzo(a)pyrene-induced oxidative stress and DNA damage model of Caco-2 cells. Phenolic-rich extracts (50-100 µg/mL) of DL + SC-pretreated and fermented CCB significantly alleviated oxidative stress and mitigated DNA damage in Caco-2 cells compared to individual pretreatments. Protein isolated from DL + SC-pretreated and fermented CCB was evaluated as a candidate serum substitute and partially supported ILMC proliferation (54.65 ± 1.70 % relative to 10 % fetal bovine serum medium), compared with the fermented YM/SB control (62.18 ± 2.24 %). These findings demonstrate that DL + SC pretreatment of CCB combined with SB fermentation can produce bioactive food ingredients and candidate protein-rich growth supplements for cell culture applications. However, bioactivity and serum replacement evidence remains partial, in vitro, and restricted to a single cell line.