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Sponges have long been known as a source for isolating secondary metabolites. These natural compounds are biosynthetic products of symbiont bacteria from various phyla colonizing sponge tissue. Some symbiont bacteria are known to produce bioactive compounds that would have antibacterial activity, such as polyketide, due to competition in colonizing and obtaining nutrients from their hosts. In general, this study aims to explore the biosynthetic potential of seven sponge-symbiont bacteria by detecting the gene domain involved in the production of polyketide compounds. Sponge-symbiont bacteria isolation was carried out on one species of sponge collected from a depth of ±15 m in the Iboih area, Weh Island, Aceh Province, Indonesia. The bacteria was allowed to grow in Sea Water Complete agar medium and incubated at 28℃C for 10-14 days. The production of polyketide compounds involves the enzyme polyketide synthase (PKS). Polyketide synthase was detected by detecting the encoding gene domain involved in the production of polyketide compounds using PCR method. Five of the seven isolates of sponge symbiont bacteria were detected to contain the PKS gene domain. Furthermore, molecular identification confirm by 16S rRNA sequencing showed that the isolates belonged to the phylum Firmicutes and Actinobacteria. The result indicated that the sponge symbiont bacteria collected from Weh Island had the biosynthetic potential to produce polyketide compounds. These compounds would have antimicrobial activities that will play a major role in the medical field. Research related to screening PKS genes in marine sponge symbionts bacteria from Weh Island has never been reported before, thus adding to the novelty of this research. [ABSTRACT FROM AUTHOR]

To prevent the serious threat of textile wastewater, researchers have developed adsorption-based wastewater treatment using cheap, yet effective, adsorbent materials. Of which is natural bentonite, that has the advantages for adsorption due to its porous structure and functional groups but still suffers from its low affinity against anionic and hydrophilic azo dyes. Herein, we aimed of improving the affinity by amino acid tryptophan embedment into the locally isolated natural bentonite collected from Aceh Province, Indonesia. The prepared bentonite samples were characterized using Fourier transform infrared, X-ray diffraction, and scanning electron microscopy. Adsorptive removal was performed on naphthol blue black (NBB) in a batch system with variations of contact time, pH, and adsorbent dosage. The isotherm studies were carried out at optimum conditions (contact time=15 minutes; pH 1; adsorbent dosage=0.2 g) with several models including Langmuir, Freundlich, Sips, and Redlich-Peterson isotherm models. The characterization results revealed that the modification altered its functional group, crystallinity, and micro-surface morphology that add more benefits for adsorption. At optimum conditions, 99.2% NBB has been successfully removed from the aqueous solution. The isotherm studies suggested that the NBB adsorption onto the tryptophane-modified natural bentonite was dependent on Sips isotherm model (R2=0.999; root-meansquare-errors=1.11×10-4 mg/g). [ABSTRACT FROM AUTHOR]