Identification and characterization of yeasts from bovine rumen for potential use as probiotics

Abstract

Aims:The aim was to isolate, identify and characterize yeasts present in rumen fluid and to select strains showing potential as probiotics. Methods and Results: Rumen fluid was sampled from 4 herds of dairy and beef cattle and 77 yeast isolates were identified. Initial screening was based on the capacity to maintain viability in a medium with different ruminal conditions. A second screening in fresh rumen fluid to assess the growth of inoculated yeasts and evaluate in vitro neutral detergent fibre digestibility (NDF-D), pH and acid accumulation was conducted. The yeast population ranged from 3Á84 to 6Á76 log 10 CFU per ml. The main species of yeast found were Pichia kudriavzevii, Candida rugosa, C. pararugosa, C. ethanolica and Magnusiomyces capitatus. Strains CCMA 933 (C. rugosa) and CCMA 970 (C. pararugosa) showed greater ability to survive in ruminal fluid and stimulated the production of acids. Isolate CCMA 967 (C. ethanolica) survived and improved the NDF-D. Conclusion: Pichia kudriavzevii was the dominant yeast found in the cattle herds. Strains CCMA 933, CCMA 970 and CCMA 967 showed properties that could be useful as potential probiotics for cattle. Significance and Impact of the Study: This study was the first to select yeasts from the rumen fluid, with the potential to be used as probiotic, based on the ruminal conditions. the contact of the cell wall with the intestinal lumen triggers an immune response (Dhama et al. 2015).Yeasts also appear to stimulate the growth and activity of fibrolytic ruminal bacteria by providing vitamins and growth factors (Moya et al. 2017). However, contradictory results are reported regarding interactions of diets, animals and environment (Chung et al. 2011). There are reports in the literature that the presence of some species Journal of Applied Microbiology 127, 845--855

Yeasts from rumen of adult Zebu cows and fermentations of lignocellulosic materials

“…These three yeast species identified in this study have also been reported in the ruminal micobiota analysis of cattle fed with tropical forages [3][4][5]. Pichia kudriavzevii was also the most frequent yeast in the rumen of cattle from South of Minas Gerais, Brazil, which may be due to its ability to better adapt to ruminal conditions.…”

“…Pichia kudriavzevii was also the most frequent yeast in the rumen of cattle from South of Minas Gerais, Brazil, which may be due to its ability to better adapt to ruminal conditions. All strains of this species showed growth in anaerobic conditions and in temperatures that predominate in the rumen [5].…”

“…The occurrence of yeast in the rumen environment is still poorly supported in the scientific literature despite their high population, especially in adult cows raised on low quality pastures [4]. Studies associated with the rumen microbiota have frequently ignored the presence of these yeast fungi in the rumen ecosystem [5]. Although the three yeast species identified in this study have also been reported in other studies of this ruminant site, the role of these microorganisms should be better elucidated in the ruminal ecosystem of animals of different categories fed with different diets.…”

“…This ecosystem comprises known species of bacteria, filamentous fungi, and protozoa [1,2]. Nevertheless, little is known about the yeast species in the rumen, that constitute up to 6.76 log of colony forming unit (CFU) per ml of ruminal fluid in healthy cattle of different ages [3][4][5].…”

Catheter-Related Sepsis by Candida pararugosa in an Adult Patient under Chemotherapy Regimen

“…Candida pararugosa are ascomycetes first isolated from human feces in 1978 [1]. Later, it was found in vegetable food [2][3][4][5] and anatomic sites of animals and humans [6,7], where it is usually a harmless commensal organism and rarely involved in infections. A persistent detection of C. pararugosa from saliva of a two-year-old girl affected by rhabdomyosarcoma and relatives, and from the oral cavity of a healthy asymptomatic subject, was reported in 2004 [8,9].…”