| Congresso Brasileiro de Microbiologia 2023 | Resumo: 872-1 | ||||
Resumo:Honey and propolis from stingless bees (SB) are a potential source of antimicrobial compounds, and there is great interest in the study of the microbiota of this kind of products. In particular, the diversity of fructophilic lactic acid bacteria (FLAB) is largely unknown, and they present biotechnological potential mainly related to applications as antagonistic, starter or probiotic cultures.
In this research, fructophilic lactic acid bacteria were screened from stingless bee honey and propolis with the aim of discovering novel FLAB with beneficial properties, with focus in this step on the activity against Listeria sp. Two product samples (honey and propolis) of Jataí (Tetragonisca angustula) -without supplemental external feeding- were obtained as a kind donation from a non-commercial beekeeper from the city of Ribeirão Preto - SP, Brazil. The samples collected were immediately refrigerated and taken to the laboratory within 24 h for processing. The sample of honey (ca. 2g) was spread plated (0.1mL) in triplicate with no dilution on the surface of de Man Rogosa and Sharpe agar added 2% of fructose and 0.1% of cysteine (MRSfc agar) and MRS agar. The propolis sample (ca. 4g) was homogenized (1:1) in saline (0.9% NaCl) and it was also spread plated (0.1mL) in triplicate with no dilution on MRSfc agar and MRS agar. Incubation was carried out at 30°C for up 6 days under anaerobiosis. All the plates were checked for growth, with an estimated result of < 10 CFU/mL for the honey sample and 120 CFU/g of propolis. One of the triplicates of the propolis plates was overlaid with semi-solid Brain Heart Infusion agar (BHI broth added 0.8% bacteriological agar) seeded with 105-106 Listeria innocua per mL, to screen for antilisterial activity. Two presumptive FLAB isolates with antilisterial activity were obtained, indicating native stingless bees may be a rich source of microbial biodiversity. The FLAB were cryopreserved for further taxonomical identification and testing of the nature of inhibitory compounds. Palavras-chave: antimicrobial activity, fructophilic lactic acid bacteria, honey, propolis, Tetragonisca angustula Agência de fomento:FAPESP (Proc. 2022/16694-0), CNPq (Proc. 407025/2021-9 and 306998/2022-0). SisGen (Register number AE80FB5). We acknowledge CTA for the kind donation of samples. | |||||