Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos, 6627, MG, 30270-901, Belo Horizonte, Brazil.
Departamento de Patologia Geral, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil.
Probiotics Antimicrob Proteins. 2021 Oct;13(5):1338-1354. doi: 10.1007/s12602-021-09758-8. Epub 2021 Mar 23.
Antarctica is one of the most pristine and inhospitable regions of the planet, mostly inhabited by microorganisms that survive due to unusual metabolic pathways to adapt to its extreme conditions, which could be interesting for the selection of new probiotics. The aim of the present study was to screen in vitro and in vivo putative probiotics among 254 yeasts isolated from different habitats of Antarctica. In vitro selection evaluated functional (growth at 37 °C, resistance to simulated gastric environment, and to bile salts), safety (degradation of mucin, production of β-haemolysis and resistance to antifungal drugs), and beneficial (production of antagonistic substances and adhesion to pathogens) properties. Twelve yeasts were able to grow at 37 °C, one of which was eliminated to present β-haemolytic ability. The remained yeasts resisted to gastric simulation and bile salts, but none presented antagonism against the pathogens tested. Because of the high co-aggregation with Salmonella enterica Typhimurium and growth yield, Rhodotorula mucilaginosa UFMGCB 18377 and Saccharomyces cerevisiae UFMGCB 11120 were selected for in vivo steps using mice challenged with S. Typhimurium. Both yeasts reached high faecal population levels when daily administered, but only R. mucilaginosa UFMGCB 18377 protected mice against Salmonella infection presenting a higher survival and reduced weight loss, bacterial translocation to the liver, sIgA intestinal levels, and intestinal and hepatic MPO and EPO activities. Our in vitro and in vivo results suggest that R. mucilaginosa UFMGCB 18377 presents probiotic potential and deserve further studies as candidate of probiotic by-products. In addition, this is the first screening study of yeasts isolated from Antarctic environments and of Rhodotorula genus for probiotic use.
南极洲是地球上最原始和不宜居住的地区之一，主要由微生物居住，这些微生物通过不寻常的代谢途径生存下来，以适应其极端条件，这对于选择新的益生菌可能很有趣。本研究的目的是从南极洲不同栖息地分离的 254 株酵母中筛选出体外和体内潜在的益生菌。体外选择评估了功能（在 37°C 下生长、抵抗模拟胃环境和胆汁盐、降解粘蛋白、产生β-溶血和对抗真菌药物的抗性）、安全性（降解粘蛋白、产生β-溶血和对抗真菌药物的抗性）和有益特性（产生拮抗物质和与病原体的粘附）。有 12 株酵母能够在 37°C 下生长，其中一株因具有β溶血能力而被淘汰。其余的酵母能抵抗胃模拟和胆汁盐，但没有一种能对抗测试的病原体。由于与鼠伤寒沙门氏菌 Typhimurium 的高度共聚和生长产量，红酵母 UFMGCB 18377 和酿酒酵母 UFMGCB 11120 被选中进行体内试验，用鼠伤寒沙门氏菌感染的小鼠进行试验。这两种酵母在每天给药时都能达到高粪便群体水平，但只有红酵母 UFMGCB 18377能保护小鼠免受沙门氏菌感染，表现出更高的存活率和体重减轻减少、细菌向肝脏转移、肠道和肝脏的 sIgA 水平、以及肠道和肝脏的 MPO 和 EPO 活性降低。我们的体外和体内结果表明，红酵母 UFMGCB 18377具有益生菌潜力，值得进一步研究作为益生菌副产物的候选物。此外，这是首次对从南极环境中分离的酵母和红酵母属进行益生菌用途的筛选研究。
