Production of Enriched Biomass by Carotenogenic Yeasts Cultivated on by-Products of Poultry Processing—A Screening Study

Abstract

Carotenogenic yeasts are a group of microorganisms producing valuable metabolites such as carotenoids, ergosterol, ubiquinone or fatty acids. Their exceptional adaptability allows them to grow in diverse conditions. Owing to their extracellular lipase activity, they are capable of processing many lipid-type waste substrates. This study discusses the processing of poultry waste, specifically fat and feathers by using carotenogenic yeasts. Poultry fat does not require any pre-treatment to be utilized by yeast, but hydrolytic pre-treatment is required for the utilization of the nitrogen contained in feathers. Glycerol was used as a supplementary substrate to support the culture in the early stages of growth. Seven yeast strains were used for the experiments, of which the strain Rhodotorula mucilaginosa CCY19-4-25 achieved exceptional results of biomass production: 29.5 g/L on poultry fat +10% glycerol at C/N ratio 25 and 28.3 g/L on media containing poultry fat +25% glycerol at C/N 50. The bioreactor cultivation of the Rhodosporidium toruloides strain in media containing glycerol and feather hydrolysate as a nitrogen substrate achieved a biomass yield of 34.92 g/L after 144 h of cultivation. The produced enriched yeast biomass can be used as a component for poultry feeding; thus, the study is performed under the biorefinery concept.

Conversion of Mixed Waste Food Substrates by Carotenogenic Yeasts of Rhodotorula sp. Genus

“…Furthermore, with the use of pretreatments, a number of lignocellulosic substrates can be processed with yeast: coffee grounds [21], straw [37] and grape pomace [38]. Furthermore, carotenogenic yeasts demonstrated high productivity and the ability to biotransform poultry industry waste (feathers and fat) into products with higher added value [39]. In the biotechnology of carotenogenic yeasts, however, we encounter a problem.…”

The Effect of Oil-Rich Food Waste Substrates, Used as an Alternative Carbon Source, on the Cultivation of Microalgae—A Pilot Study

“…The internal standard method was used for quantification via the addition of heptadecanoic acid (Sigma Aldrich, SRN) into the transesterification mixture in the concentration of 0.5 mg/mL. Chromatography data were evaluated using Chromeleon software 7.2 [ 31 ]. Based on the GC-FID analysis, representation of the fatty acids was analyzed via the Chromeleon program.…”