Potential of associative bacteria isolates from seagrass ecosystem

Abstract

The seagrass ecosystem is rich in organic materials such as nitrates, carbon, and phosphates. Potential nutrient content available in water and sediments influences the presence of an associative bacterial community. This study aimed to explore associative bacteria in seagrass ecosystems which have potentially producing antibacterial activity and cellulase enzymes. Associative bacterial isolation was carried out on sediment samples and seagrass leaves Thalassia hemprichii which was found as the dominant ecosystem compiler. The antibacterial test was carried out using agar diffusion method against Staphylococcus aureus, Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli, and Vibrio parahaemolyticus. Meanwhile, assay on cellulase activity of the actinomycetes bacteria was using agar diffusion method on CMC media. Isolation of endophytic bacteria of seagrass leaves produced 12 isolates with 2 isolates which could inhibit all targeting bacteria and 3 isolates which could inhibit several targeting bacteria. ANOVA test showed that the sampling location significantly affected the antibacterial activity. Meanwhile, 5 isolates of actinomycetes bacteria were found from the sediments, with 4 isolates having cellulase activity. ANOVA test showed that cellulase activity of the actinobacteria was associated with the density of Cymodocea rotundata and T. hemprichii seagrass species with moderate to high category.

Cellulolytic activity at the low temperature of associative bacteria from a seagrass ecosystem

“…A total of 5 isolates of actinobacteria and 28 isolates of heterotrophic bacteria from litter and seagrass sediments in Pari Island waters from previous research activities [14] were used as test isolates in this study. Each bacterial isolate used was grown on specific media (actinobacteria isolates were grown on ISP-2 media at room temperature at 28°C, and heterotrophic bacteria were grown on ZoBell 2216E media at 37°C.…”

“…The bacterial isolates were obtained from previous studies [14], and derived from litter and sediment samples in seagrass ecosystems. The isolates consisted of a group of actinobacteria and heterotrophic bacteria.…”

“…Cellulase activity was influenced by the density of seagrass, T. hemprichii, and E. acoroides [14]. The density of litter-producing seagrass species can increase the supply of organic matter.…”