Isolation and enzyme bioprospection of bacteria associated to Bruguiera cylindrica, a mangrove plant of North Sumatra, Indonesia.

Mangrove-associated bacteria are of industrial interest due to their diverse and versatile enzyme properties. This study investigates the culturable bacteria from a wide range of habitat in a Bruguiera cylindrica mangrove ecosystem in North Sumatra. Screening of extracellular hydrolytic enzymes showed multiple potential traits in amylase, cellulase, chitinase, phosphatase, protease, and urease production by bacterial isolates. Molecular identification based on 16S rDNA region of a potential strain, Vibrio alginolyticus Jme3-20 is then reported as a newly proteolytic agent. The strain also showed a stable growth under salinity (NaCl) stress with considerable phosphate solubilization activities. Protease activity was enhanced by optimizing the 0.5 % (w/v) sucrose and soy peptone in the fermentation medium. SDS-PAGE and zymogram analysis showed the presence of a 35-kDa MW protease. Hence, our study revealed important insights into the bacterial diversity and activity in mangrove ecosystems, evidencing the importance of microbial exploration in this ecosystem.

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

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.