Characterisation of Lactic Acid Bacteria from Dengke Naniura of Common Carp (Cyprinus carpio) with α-Glucosidase Inhibitory Activity

Abstract

BACKGROUND: Fermented foods were favourable because of its properties in enhancing the shelf life, safety, function, sensory and nutrition. There are many fermented foods tested in vitro as an α-glucosidase enzyme inhibitor. Dengke naniura is one of Indonesia’s traditional food made using fermentation.

AIM: To identify lactic acid bacteria (LAB) strains in dengke naniura and its properties in inhibiting the α-glucosidase enzyme.

METHODS: The carp were sacrificed, and soaked with rough lemon for 6 hours then spices added to it for another 1 hour. Then the isolation of LAB conducted using a serial dilution of the samples. The selected isolates of the LAB were then characterised by its morphology under the microscope, gram staining, growth at 15°C and 45°C and biochemical identification. The isolates were then tested for its inhibiting properties against the α-glucosidase enzyme.

RESULTS: The isolates (DL-109 and DL-107) were a gram-positive, nonspore-forming and non-motile rod. The Physiological and biochemical properties of the isolates confirm its LAB properties. On the test against α-glucosidase enzyme activity inhibition, isolate DL-109 LAB (4) showed dominant activity with very low IC₅₀ compared to Acarbose (IC₅₀ = 128.06 ppm) and DL-107 (46.32 ppm) while at the lowest dosage of 25 µg/ml DL-109 showed activity as much as 54.76%.

CONCLUSION: These findings concluded that the isolates were LAB by its properties and can be used for lowering blood glucose in term of inhibition of the α-glucosidase enzyme.