Effect of yeast and essential oil-enriched diets on critical determinants of health and immune function in Africanized Apis mellifera

Abstract

Nutrition is vital for health and immune function in honey bees (Apis mellifera). The effect of diets enriched with bee-associated yeasts and essential oils of Mexican oregano (Lippia graveolens) was tested on survival, food intake, accumulated fat body tissue, and gene expression of vitellogenin (Vg), prophenoloxidase (proPO) and glucose oxidase (GOx) in newly emerged worker bees. The enriched diets were provided to bees under the premise that supplementation with yeasts or essential oils can enhance health variables and the expression of genes related to immune function in worker bees. Based on a standard pollen substitute, used as a control diet, enriched diets were formulated, five with added bee-associated yeasts (Starmerella bombicola, Starmerella etchellsii, Starmerella bombicola 2, Zygosaccharomyces mellis, and the brewers’ yeast Saccharomyces cerevisiae) and three with added essential oils from L. graveolens (carvacrol, thymol, and sesquiterpenes). Groups of bees were fed one of the diets for 9 or 12 days. Survival probability was similar in the yeast and essential oils treatments in relation to the control, but median survival was lower in the carvacrol and sesquiterpenes treatments. Food intake was higher in all the yeast treatments than in the control. Fat body percentage in individual bees was slightly lower in all treatments than in the control, with significant decreases in the thymol and carvacrol treatments. Expression of the genes Vg, proPO, and GOx was minimally affected by the yeast treatments but was adversely affected by the carvacrol and thymol treatments.

Effects of spinetoram and glyphosate on physiological biomarkers and gut microbes in Bombus terrestris

“…For example, the Zygosaccharomyces abundance in the gut was reduced by the presence of glyphosate compared to that in the control bumblebees. According to a recent study ( Canche-Colli et al, 2021 ), Zygosaccharomyces is associated with the accumulation of fat bodies in bees. The researchers supplemented food with Zygosaccharomyces mellis , allowing bees to consume more food and metabolize excess nutrients, thereby increasing the accumulation of fat bodies in A. mellifera .…”

Immune and antioxidant gene expression stimulation of Apis mellifera (Hymenoptera: Apidae) larvae by Saccharomyces cerevisiae from the brewering industry

“…It has been observed in previous research that vg gene expression in honey bees fed with S. cerevisiae or other native yeasts did not show alterations (Canché-Collí et al, 2021;Tauber et al, 2019).…”

Effect of bee bread on Africanized honey bees infected with spores of Nosema spp.

“…We used real‐time quantitative PCR (qRT‐PCR) to measure the expression of Vg , proPO , and GOx genes (Canché‐Collí et al, 2021) and to identify Nosema species and their infection levels (Bourgeois et al, 2010). We sampled and dissected three bees per cage: abdomens were used for Vg , proPO , and Nosema species‐specific genes, and heads for the GOx gene.…”

“…We carried out our experiments for 7 days following the procedure of Di Pasquale et al (2013) given that, in nature, adult bees meet their protein needs within 10 days of emergence (Crailsheim et al, 1992). Moreover, Nosema infection starts to affect survival on day seven (Higes et al, 2007) and the expression of crucial enzymes and proteins related to bee health begins on day six or earlier (Canché-Collí et al, 2021).…”

“…8.05 million spores per bee). From a previous study (Canché-Collí et al, 2021), we knew that the selected colony had both Nosema species. For the infection solution, we macerated the digestive systems of an additional 10 bees from the selected colony in 1 mL of drinking water.…”