Beneficial effects of Bacillus subtilis subsp. subtilis Mori2, a honey associated strain, on honeybee colony performance

SABATÉ, DANIELA C.; CRUZ, MIRTA S; BENITEZ-AHRENDTS, MARCELO R.; AUDISIO, M. CARINA

Probiotics and Antimicrobial Proteins

Springer

Año: 2012 vol. 4 p. 39 - 46

1867-1306

Bacillus spp. strain isolated from a honey sample in Morillos (Salta, Argentina) was phylogenetically characterized as B. subtilis subsp. subtilis Mori2. The strain was administered to bee colonies as a monoculture in one litre of sugarcane syrup (125 g/L) at a final concentration of 10^5 spores/mL to evaluate the bee colony performance. The treated colony was monitored and any changes were compared with the control hives. All conditions were identical (weather, nourishment and supervision), except for the Bacillus spore supplement. The new nourishment, which was administered monthly from May to December 2010, was accepted by the bees and consumed within ca. 24-48 h. Photo-records and statistic analyses revealed significant differences in the open and operculated brood areas between the treated and control groups. The status of the colony improved after the second administration of the Bacillus spores until the end of the experiment. A higher number of bees was counted in the treated groups (26% more than the control) with respect to the initial number. Furthermore, at the time of harvest honey storage in the treated hives was 17% higher than in the control hives. In addition, spore counts of both Nosema sp. and Varroa sp. foretica in treated hives was lower than in the control hives. These results with experimental hives would indicate that B. subtilis subsp. subtilis Mori2, favoured the performance of bees firstly because the microorganism stimulated the queen’s egg laying, translating into a higher number of bees, consequently more honey. Secondly because it reduced the prevalence of two important bee diseases worldwide: nosemosis and varroosis