Dados do Trabalho

Título

SCREENING FOR BACTERIAL HIDROLYTIC ENZYMES ISOLATED FROM LETTUCE SOLD AT STREET MARKETS

Introdução

Enzymes are proteins that possess remarkable catalytic capabilities, high selectivity, and specificity and are responsible for accelerating a range of chemical reactions. Although they have not been studied as intensely as enzymes derived from animal or plant sources, microorganisms have demonstrated significant advantages in industrial biotechnological processes. The purpose of this study was to investigate the enzymatic potential of bacteria isolated from lettuce for amylase and cellulase synthesis.

Material e Métodos

We analyzed 27 bacteria that were previously identified and isolated from lettuce. To conduct enzymatic screening, two different culture media were prepared, one containing starch and the other containing carboxymethylcellulose (CMC). Both culture media were prepared using 5 g/L polymer, 15 g/L agar, and 2.5 g/L bacteriological peptone. Four bacteria were inoculated into each Petri dish containing 20 mL of culture medium, and this process was repeated for all the bacteria in both culture media. The plates were then incubated at 35 °C for 48 h. Following incubation, the plates were stained with Lugol's reagent. Following the measurement of the colony diameter and degradation halo for each microorganism in duplicate, the arithmetic mean (ME) and standard deviation (SD) of the colony and halo diameters were calculated. The enzymatic potential was expressed using the enzymatic index (EI), which is the ratio between the halo and colony diameter.

Resultados e Discussão

Eleven bacteria were positive for enzymatic production, with EI values ranging from 1 to 6.82 (ME = 2.67; SD = 1.64), resulting in a variable enzymatic potential. The microorganism CMC14 stood out among the others, displaying the highest index with an EI of 6.82 and a halo diameter equivalent to 3.75±0.07 cm.

Conclusão

Because the vegetable source is naturally rich in the studied polymers, its microbiota consists of a potential source of promising cellulolytic and amylolytic microorganisms. Consequently, a significant number of bacteria isolated from lettuce exhibit high enzymatic potential for cellulases and amylases, both of which have significant applications in the food industry.