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.
摘要:
产胡萝卜素酵母是一组产生有价值的代谢产物如类胡萝卜素的微生物,麦角固醇,泛醌或脂肪酸。它们特殊的适应性使它们能够在不同的条件下生长。由于它们的细胞外脂肪酶活性,它们能够处理许多脂类废物底物。这项研究讨论了家禽废物的处理,特别是脂肪和羽毛通过使用类胡萝卜素酵母。家禽脂肪不需要酵母进行任何预处理,但是,为了利用羽毛中的氮,需要进行水解预处理。甘油用作补充底物以支持生长早期阶段的培养物。实验使用了7种酵母菌株,其中RhodotorulamucilaginosaCCY19-4-25菌株取得了出色的生物量生产结果:在C/N比为25的家禽脂肪+10%甘油上为29.5g/L,在含有家禽脂肪+25%甘油的培养基上为28.3g/LC/N50。在含有甘油和羽毛水解物作为氮底物的培养基中,红孢菌菌株的生物反应器培养经过144小时的培养后,生物量产量为34.92g/L。产生的富集酵母生物质可用作家禽饲喂的组分;因此,这项研究是在生物炼制的概念下进行的。