| Congresso Brasileiro de Microbiologia 2023 | Resumo: 953-1 | ||||
Resumo:Cyanobacteria are autotrophic microorganisms that have been present on Earth for billions of years and have developed mechanisms to defend themselves against predators and other microorganisms, allowing them to survive in different environments, even those inhospitable to other living organisms. One defense mechanism of cyanobacteria is the production of compounds that exhibit antimicrobial, allelopathic, and antiparasitic activities, protecting the organism against attacks from other species of cyanobacteria, predators, and microorganisms in general. These compounds have been investigated due to their potential for various applications, such as the production of new drugs, agricultural products, and bioremediation. Antimicrobial peptides (AMPs) are molecules produced by various living organisms, including animals, plants, and microorganisms, aiming to inhibit the growth of invasive microorganisms and protect the organism. AMPs can combat a wide range of microorganisms, including bacteria, fungi, and viruses, making them powerful antimicrobial agents and an alternative to the use of antibiotics. Antimicrobial peptides act differently from antibiotics when combating bacteria, reducing the likelihood of these bacteria developing resistance. Consequently, AMPs are seen as a potential solution to the problem of antibiotic resistance. The objective of this study was to detect and evaluate the activity of an antimicrobial molecule present in the extract of the cyanobacteria Lyngbya sp. CACIAM 07, which we discuss to be an antimicrobial peptide. The crude extract was obtained from the dried biomass of the cyanobacteria, and its antimicrobial activity was evaluated against gram-positive bacteria (Bacillus subtilis ATCC 6633 and Enterococcus gallinarum), gram-negative bacteria (Proteus mirabilis and Klebsiella oxytoca), and yeasts (Candida jaroonii and Candida tropicalis) using the well diffusion technique. The minimum inhibitory concentration (MIC) was determined through microdilution on plates. In order to isolate and evaluate the activity of the target molecule, a fractionation by ultrafiltration and partial purification by size exclusion chromatography were performed. As a result, we obtained a crude extract capable of inhibiting B. subtilis after 48 hours of growth and the other bacteria after 92 hours, both incubated at 37 °C The minimum inhibitory concentration of the extract was 12.5 µL of diluted sample (1/4). Following the fractionation and partial purification, a low molecular weight molecule, probably an antimicrobial peptide (AMP), was obtained, and the fractions obtained were tested against Bacillus subtilis ATCC 6633. This study was able to isolate and partially characterize the activity of an AMP obtained from Lyngbya sp. CACIAM 07, a cyanobacteria isolated from the Amazon region. In the future, new assays will be performed against other pathogenic and antibiotic-resistant microorganisms, as well as the purification and characterization of the molecule and its biotechnological potential. Palavras-chave: cyanobacteria, antimicrobial , peptide, lyngbya, biotechnology Agência de fomento:CAPES | |||||