Transforming <i>Rhodotorula</i> sp. Biomass to Active Biologic Compounds for Poultry Nutrition

In broiler chick-rearing, the color is usually acquired by synthetic carotenoids in addition to broiler diets (25–80 mg/kg feed), often represented by β-apo-8′-carotenal. In the past fifteen years, the demand for organic food products originating from free-range reared chicks started to grow, with a more directed awareness of the quality of meat and egg. Various investigations have been reporting microorganisms, such as the oleaginous red yeasts genus Rhodotorula sp., as fast-growing unicellular eukaryotes able to synthesize natural pigments. Rhodotorula sp. represents a perfect choice as a natural resource due to the capacity to adapt easily to the environment valuing low-cost sources of nutrients for their metabolism and growth. The biodiversity and the ecology effects establish novel boundaries regarding Rhodotorula sp. productivity enhancement and control of biological risks. It is, therefore, necessary to review the current knowledge on the carotenoid synthesis of Rhodotorula sp. In this paper, we aimed to address the pathways of obtaining valuable yeast carotenoids in different conditions, discussing yeast biosynthesis, bioengineering fermentative evaluation, carotenoid extraction, and the techno-economic implication of valuable pigment additives on poultry nutrition. Finally, the pro-existent gaps in research are highlighted, which may clear the air on future studies for bio-carotenoid engineering

The Antioxidant and Prebiotic Activities of Mixtures Honey/Biomimetic NaDES and Polyphenols Show Differences between Honeysuckle and Raspberry Extracts

In our previous research, we demonstrated that honey and its biomimetic natural deep eutectic solvent (NaDES) modulate the antioxidant activity (AOA) of the raspberry extract (RE). In this study, we evaluated the AOA behaviour of the mixture honey/NaDES–honeysuckle (Lonicera caprifolium, LFL) extract and compared it with the mixture honey/NaDES–RE. These two extracts have similar major flavonoids and hydroxycinnamic acid compounds but differ in their total content and the presence of anthocyanins in RE. Therefore, it was of interest to see if the modulation of the LFL polyphenols by honey/NaDES was similar to that of RE. We also evaluated the prebiotic activity of these mixtures and individual components on Limosilactobacillus reuteri DSM 20016. Although honey/NaDES modulated the AOA of both extracts, from synergism to antagonism, the modulation was different between the two extracts for some AOA activities. Honey/NaDES mixtures enriched with LFL and RE did not show significant differences in bacterial growth stimulation. However, at a concentration of 45 mg/mL, the honey -LFL mixture exhibited a higher effect compared to the honey–RE mixture. The antioxidant and prebiotic properties of mixtures between honey and polyphenol-rich extracts are determined by multiple interactions in complex chemical systems