Palma Margarida, Mondo Stephen, Pereira Mariana, Vieira Érica, Grigoriev Igor V, Sá-Correia Isabel
Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
J Fungi (Basel). 2022 Mar 1;8(3):254. doi: 10.3390/jof8030254.
The ascomycetous yeast has been isolated from diverse habitats, including humans, insects, and environmental sources, exhibiting a remarkable ability to use different carbon sources that include pentoses, melibiose, and inulin. In this study, we isolated four strains from soil and investigated their potential to overproduce riboflavin. IST 626 was found to produce the highest concentrations of riboflavin. The volumetric production of this vitamin was higher when IST 626 cells were cultured in a commercial medium without iron and when xylose was the available carbon source compared to the same basal medium with glucose. Supplementation of the growth medium with 2 g/L glycine favored the metabolization of xylose, leading to biomass increase and consequent enhancement of riboflavin volumetric production that reached 120 mg/L after 216 h of cultivation. To gain new insights into the molecular basis of riboflavin production and carbon source utilization in this species, the first annotated genome sequence of is reported in this article, as well as the result of a comparative genomic analysis with other relevant yeast species. A total of 5619 genes were predicted to be present in IST 626 genome sequence (11.5 Mbp). Among them are genes involved in riboflavin biosynthesis, iron homeostasis, and sugar uptake and metabolism. This work put forward IST 626 as a riboflavin overproducer and provides valuable molecular data for future development of superior producing strains capable of using the wide range of carbon sources, which is a characteristic trait of the species.
子囊菌酵母已从包括人类、昆虫和环境来源在内的多种生境中分离出来，表现出利用不同碳源的显著能力，这些碳源包括戊糖、蜜二糖和菊粉。在本研究中，我们从土壤中分离出四株菌株，并研究了它们过量生产核黄素的潜力。发现IST 626产生的核黄素浓度最高。与含有葡萄糖的相同基础培养基相比，当IST 626细胞在不含铁的商业培养基中培养且木糖为可用碳源时，这种维生素的体积产量更高。在生长培养基中添加2 g/L甘氨酸有利于木糖的代谢，导致生物量增加，从而提高核黄素的体积产量，培养216小时后达到120 mg/L。为了深入了解该物种中核黄素生产和碳源利用的分子基础，本文报道了该物种的首个注释基因组序列，以及与其他相关酵母物种的比较基因组分析结果。预计IST 626基因组序列（11.5 Mbp）中共有5619个基因。其中包括参与核黄素生物合成、铁稳态以及糖摄取和代谢的基因。这项工作提出将IST 626作为核黄素过量生产者，并为未来开发能够利用广泛碳源的优良生产菌株提供了有价值的分子数据，这是该物种的一个特征。
