Brno University of Technology, Faculty of Chemistry, Centre for Materials Research, Purkynova 118, 612 00 Brno, Czech Republic.
J Environ Manage. 2012 Mar;95 Suppl:S338-42. doi: 10.1016/j.jenvman.2011.06.018. Epub 2011 Jul 8.
Carotenoids are industrially significant pigments produced in many bacteria, fungi, and plants. Carotenoid biosynthesis in yeasts is involved in stress response mechanisms. Thus, controlled physiological and nutrition stress can be used for enhanced pigment production. Huge commercial demand for natural carotenoids has focused attention on developing of suitable biotechnological techniques including use of liquid waste substrates as carbon and/or nitrogen source. In this work several red yeast strains (Sporobolomyces roseus, Rhodotorula glutinis, Rhodotorula mucilaginosa) were enrolled into a comparative screening study. To increase the yield of these pigments at improved biomass production, several types of exogenous as well as nutrition stress were tested. Each strain was cultivated at optimal growth conditions and in medium with modified carbon and nitrogen sources. Synthetic media with addition of complex substrates (e.g. yeast extract) and vitamin mixtures as well as some waste materials (whey, potato extract) were used as nutrient sources. Peroxide and salt stress were applied too. The production of carotene enriched biomass was carried out in flasks as well as in laboratory fermentor. The best production of biomass was obtained in inorganic medium with yeast extract. In optimal conditions tested strains differ only slightly in biomass production. All strains were able to use most of waste substrates. Biomass and pigment production was more different according to substrate type. In laboratory fermentor better producers of enriched biomass were both Rhodotorula strains. The highest yields were obtained in R. glutinis CCY 20-2-26 cells cultivated on whey medium (cca 45 g per liter of biomass enriched by 46 mg/L of beta-carotene) and in R. mucilaginosa CCY 20-7-31 grown on potato medium and 5% salt (cca 30 g per liter of biomass enriched by 56 mg/L of beta-carotene). Such dried carotenoid-enriched red yeast biomass could be directly used in feed industry as nutrition supplement.
类胡萝卜素是许多细菌、真菌和植物中产生的具有重要工业意义的色素。酵母中的类胡萝卜素生物合成涉及应激反应机制。因此，可以利用控制的生理和营养应激来提高色素产量。对天然类胡萝卜素的巨大商业需求使人们关注开发合适的生物技术，包括使用液体废物作为碳和/或氮源。在这项工作中，研究人员对几种红酵母菌株（Sporobolomyces roseus、Rhodotorula glutinis、Rhodotorula mucilaginosa）进行了比较筛选研究。为了在提高生物量生产的同时提高这些色素的产量，研究人员测试了几种外源和营养应激。每种菌株都在最佳生长条件下和含有改良碳源和氮源的培养基中进行培养。使用添加复杂底物（如酵母提取物）和维生素混合物以及一些废物（乳清、土豆提取物）的合成培养基作为营养源。还施加了过氧化物和盐应激。在摇瓶和实验室发酵罐中进行了富含类胡萝卜素的生物量生产。在含有酵母提取物的无机培养基中获得了最佳的生物量生产。在测试的最佳条件下，菌株在生物量生产方面仅略有差异。所有菌株都能够利用大多数废物底物。根据底物类型，生物量和色素生产的差异更大。在实验室发酵罐中，两种 Rhodotorula 菌株都是富生物质的更好生产者。在 R. glutinis CCY 20-2-26 细胞在乳清培养基上培养（每升生物量富集 46mg/Lβ-胡萝卜素，产率约为 45g）和 R. mucilaginosa CCY 20-7-31 在土豆培养基和 5%盐上生长（每升生物量富集 56mg/Lβ-胡萝卜素，产率约为 30g）时，获得了最高的产量。这种富含类胡萝卜素的干燥红酵母生物质可以直接用作饲料工业的营养补充剂。
