Bisphenol A removal and degradation pathways in microorganisms with probiotic properties.

Bisphenol-A (BPA) is a constituent of polycarbonate plastics and epoxy resins, widely applied on food packaging materials. As BPA exposure results in health hazards, its efficient removal is of crucial importance. In our study five potentially probiotic microorganisms, namely Lactococcus lactis, Bacillus subtilis, Lactobacillus plantarum, Enterococcus faecalis, and Saccharomyces cerevisiae, were tested for their toxicity tolerance to BPA and their BPA removal ability. Although BPA toxicity, evident on all microorganisms, presented a correlation to both BPA addition time and its concentration, all strains exhibited BPA-removal ability with increased removal rate between 0 and 24 h of incubation. BPA degradation resulted in the formation of two dimer products in cells while the compounds Hydroquinone (HQ), 4-Hydroxyacetophenone (HAP), 4-Hydroxybenzoic acid (HBA) and 4-Isopropenylphenol (PP) were identified in the culture medium. In the proposed BPA degradation pathways BPA adducts formation appears as a common pattern, while BPA decomposition as well as the formation, and the levels of its end products present differences among microorganisms. The BPA degradation ability of the tested beneficial microorganisms demonstrates their potential application in the bioremediation of BPA contaminated foods and feeds and provides a means to suppress the adverse effects of BPA on human and animal health.

Towards Functional Insect Feeds: Agri-Food By-Products Enriched with Post-Distillation Residues of Medicinal Aromatic Plants in Tenebrio molitor (Coleoptera: Tenebrionidae) Breeding.

Sustainability, circular economy and alternative production systems are urgent imperatives for humanity and animal husbandry. Unless wasted, agri-food by-products can offer a promising source of high value. We evaluated the effect of rice bran (RB), corncob (CC), potato peels (PP), solid biogas residues (BR), and olive-oil processing residuals (OR), as alternative substrates to wheat bran (WB as control), on the growth and nutritional value of Tenebrio molitor during its breeding for animal feeds and/or human consumption. Innovation-wise, we further investigated the substrate supplementation (0, 10, 20%) with post-distillation residues of Mediterranean aromatic-medicinal plants (MAPs: lavender, Greek oregano, rosemary, olive; 1:1:1:1 ratio). Tenebrio molitor larvae (TML) were reared in all the studied substrates, and TML and diets' proximate and fatty acid compositions as well as total phenol and flavonoid content and antioxidant potential were assessed using standard procedures. After statistical analysis of correlations, we observed that CC promoted oviposition and progeny survival; larval weight and dry matter were positively affected mainly by dietary energy and fat content; number of TML and/or larval weight increased using 10% MAPs inclusion in WB, RB and OR or RB, OR, BR and PP, respectively, which did not affect protein content; TML fatty acid composition decreased the content of saturated ones and increased that of mono-unsaturated ones; MAPs residues had an apparent favorable impact on total phenolic content and antioxidant activity of each substrate, with RB displaying the highest capacity and content. These findings indicate that alternative substrates can be exploited and their enrichment with natural phenolics is able to influence T. molitor growth, offering highly beneficial and nutritional value.