Use of Yeasts as Probiotics in Fish Aquaculture

Abstract

Yeasts are unicellular eukaryotic microorganisms that are taxonomically placed within the phyla Ascomycota and Basidiomycota within the Kingdom Fungi [7]. Ascomycete yeasts comprise approximately 1,000 phylogenetically diverse species that have recently been assigned to 14 different lineages on the basis of multigene sequence analysis [8]. The other species of yeasts are classified as the basidiomycetes [9]. Some of the general characteristics and ecological properties of each phylum include the following: 1) the cell wall polysaccharide composition is dominated by chitin in the basidiomycetes and by β-glucans in the ascomycetes; 2) the guanine + cytosine (G + C) composition of the nuclear DNA tends to be higher than 50% in basidiomycetes and lower than 50% in ascomycetes; 3) ascomycetes yeasts are generally more fermentative, more copiotrophic (but at the same time nutritionally specialized), more fragrant, and mostly hyaline, while basidiomycete yeasts more often form mucoid colonies, Sustainable Aquaculture Techniques 136 Marine samples Identified yeast Identification method Reference

Dietary live yeast and increased water temperature influence the gut microbiota of rainbow trout

“…However, it was unexpected to find low abundances of D. hansenii in the present study (0–33%; Fig. ), since it is the most frequently isolated yeast from fish (Navarrete and Tovar‐Ramírez ). In addition, it was unexpected that D. hansenii was not found in the gut mucosa, since this yeast has been shown to adhere to the gut mucus in rainbow trout (Vazquez‐warez et al .…”

“…Studies have shown that feeding low inclusions rates (e.g. 10 g kg −1 ) of live yeast have a probiotic effect on gut microbiota that improves growth, feed efficiency, immune response of several fish species (Navarrete and Tovar‐Ramírez ; Hoseinifar et al . ).…”

Hypolipidaemic and antioxidant effects of functional cereal-mix produced with probiotic yeast in rats fed high cholesterol diet

“…However, the body weight increase in the other groups fed with high-cholesterol diet supplemented with cereal-based functional food could have been contributed by yeasts due to their growth promoting potentials. Yeasts are well-known for the secretion of polyamines, compounds that promote cell differentiation and maturation (Naverrete & Tovar-Ramirez, 2014). This make yeasts important feed supplements in animal husbandries to improve the growth and performance of animals (Li et al, 2006;Sharifuzzaman, Al-Harbi, & Austin, 2014).…”

Beneficial roles of feed additives as immunostimulants in aquaculture: a review

“…In addition, probiotics or beneficial bacteria are known to control pathogens through a variety of mechanisms and affect intestinal microbial communities (Kesarcodi‐Watson et al . ; Navarrete & Tovar‐Ramírez ; Newaj‐Fyzul et al . ).…”