Microbiota associada ao intestino de abelha sem ferrão Scaptotrigona polysticta (Hymenoptera, Apidae, Meliponini)

Abstract

The diversity and relative abundance of communities of microorganisms existing in the gastrointestinal tract of bees play a leading role in complex and diverse symbiotic relationships, important for the maintenance of immune functions, in addition to acting in intestinal physiology, protection against pathogens and nutrient processing. In the intestine of stingless bees, bacteria and yeasts responsible for fermentation processes are present, where numerous enzymatic reactions occur, constituting a potential for discovering new enzymes and processes. This work aimed to identify bacteria associated with the intestine of stingless bees Scaptotrigona polysticta and verify the production of enzymes of industrial interest. Thus, stingless bees S. polysticta were collected from three meliponaries, 20 bee individuals each, and the description of the intestinal microbiota of the S. polysticta bee was carried out using culture-dependent methods, using five culture media, in three different conditions: aerobic, anaerobic and microaerophilic (5% CO2), at a temperature of 35 °C, being analyzed every 24 hours for 72 hours. A total of 110 bacteria were obtained in the first isolation, however only 76 bacteria were purified and identified. There are 27 types of bacteria found, eleven families and three bacterial phyla. Of the 76 isolates, 26 showed enzyme production, with proteases and amylases being the most produced enzymes. Of the 26 isolates producing hydrolytic enzymes, 17 bacteria with potential for enzyme production, with an enzyme index >2, were selected for the quantification of proteolytic and amylolytic enzymes. As a result, of the 17 bacteria selected, only 7 bacteria had enzyme production. Bacillus sp. C1M3D2AE 26, showed the highest production of α-amylase with 7,677 ± 0,111 U/mL, and Bacillus sp. C1M2D1MI 11, Bacillus sp. C1M3D2AE 26 and Bacillus sp. C3M1D2MI 68 had higher proteolytic activities with 11,700 ± 0,002 U/mL, 11,733 ± 0,004 U/mL and 12,067 ± 0,001 U/mL of proteases, respectively, with no statistical difference between them. The results demonstrate that stingless bees, S. polysticta, do not have a pattern or core microbiota as described for honey bees and other bee species. Furthermore, it was observed that these bacteria have properties of biotechnological interest, thus being a viable alternative for the production of amylolytic and proteolytic enzymes.