Characterization of xylanolytic bacteria Bacillus sp. EM24 from mangrove forest sediment, Kahyapu, Enggano Island

Abstract

Xylanases are extracellular enzyme that hydrolyze xylan into xylooligosaccharide and xylose. Group bacteria that have ability to hydrolyze xylan are called xylanolytic bacteria. This study aimed to characterize xylanase produced by Bacillus sp EM24 isolated from mangrove forest sediment in Kahyapu, Enggano island. The mangrove forest sediment samples were collected from Kahyapu village, Enggano island. Isolation of bacteria was done by using 0.5% xylan beechwood agar medium. The potential xylanase producing bacteria were qualitatively investigated by using 0.5% congo red solution. Colonies which produced clear zone were presumed as xylanolytic bacteria furthermore they were selected for determination of xylanase enzyme activity. The potential xylanolytic isolates was identified by Gram staining and biochemical tests. The result of isolation showed that a total number of 30 isolates were grew well on medium. Based on clear zone screening, EM24 isolate had widest clear zone. Xylanase produced by EM24 isolate had highest activity at 40th hours after incubation with the enzyme activity of 0.484 U/mL. Characterization of xylanase measurement showed that xylanase produced by EM26 isolate can optimally work at pH 6 and temperature 35 °C. Based on identification result, EM24 isolate had close relationship with Bacillus sp.