Porcine intestinal yeast species, Kazachstania slooffiae, a new potential protein source with favourable amino acid composition for animals
Recently, the effect of one, two or three (oral once a day) supplementations of live K. slooffiae cells on the gut bacterial microbiota of weaning piglets was investigated in a placebo‐controlled study (Urubschurov et al., 2017). It was found that K. slooffiae was able to quickly establish in the gut of piglets, and a significant effect on the composition of the gut microbiota was observed when this yeast was supplemented twice or three times. Moreover, K. slooffiae correlated positively with short chain fatty acids, in particular n‐butyric, acetic and propionic acid and negatively with faecal pH. However, there was no effect on piglets’ growth performance parameters. The results of this experiment suggested that K. slooffiae may play an important role in digestive system of pigs and has promising probiotic properties.
Probiotic preparations, viable cells of either individual strain or a combination of strains from different micro‐organisms, have beneficial effects on host's health by influencing its intestinal microbiome (FAO/WHO, 2006). According to regulation of the European Commission (2014), only few bacterial strains belonging to genera Bacillus, Enterococcus, Lactobacillus, Pediococcus, Clostridium and some strains of the yeast Saccharomyces cerevisiae are allowed to use as a feed additives for young piglets in the European Union. Even though the effects of probiotic agents on the health of animals have been commonly studied for decades, their mode of action and effectiveness in pig production has still to be clarified (Kenny, Smidt, Mengheri, & Miller, 2011).
The recent findings of Urubschurov et al. (2017) provided new previously unknown insights into the potential role of K. slooffiae in pig intestine. However, it is still unclear how this yeast acts in the digestive tract and which substances it can use and form. Cells of other yeasts, for example S. cerevisiae, are rich source of essential amino acids, high‐quality proteins, vitamins, polysaccharides and trace elements for animal and human nutrition (Bekatorou, Psarianos, & Koutinas, 2006; Fleet, 2007). Hence, it is likely that the cells of K. slooffiae are also rich in nutritive substances, which can help to maintain or to improve the health of animals.
To get more insight into functions of K. slooffiae species in the porcine gut, the aims of this research were to characterise the cell contents of this yeast and to investigate which nitrogen sources, organic acids and alcohols may be utilised or produced by this species in vitro.