A New Citrinin Derivative from the Indonesian Marine Sponge-Associated Fungus Penicillium citrinum.

Sponge-associated fungi are attractive targets for the isolation of bioactive natural products with different pharmaceutical purposes. In this investigation, 20 fungi were isolated from 10 different sponge specimens. One isolate, the fungus Penicillium citrinum strain WK-P9, showed activity against Bacillus subtilis JH642 when cultivated in malt extract medium. One new and three known citrinin derivatives were isolated from the extract of this fungus. The structures were elucidated by 1D and 2D NMR spectroscopy, as well as LC-HRMS. Their antibacterial activity against a set of common human pathogenic bacteria and fungi was tested. Compound 2 showed moderate activity against Mycobacterium smegmatis ATCC607 with a minimum inhibitory concentration (MIC) of 32 µg/mL. Compound 4 exhibited moderate growth inhibition against Bacillus subtilis JH642, B. megaterium DSM32, and M. smegmatis ATCC607 with MICs of 16, 16, and 32 µg/mL, respectively. Furthermore, weak activities of 64 µg/mL against B. subtilis DSM10 and S. aureus ATCC25923 were observed for compound 4.

The Potential of Phylogenetically Diverse Culturable Actinobacteria from Litopenaeus vannamei Pond Sediment as Extracellular Proteolytic and Lipolytic Enzyme Producers.

Enzymes are catalysts that can increase the reaction time of a biochemical process. Hydrolytic enzymes have a pivotal role in degrading organic waste in both terrestrial and aquatic environments. The aims of this study were (1) to investigate the ability of actinobacteria isolated from Litopenaeus vannamei pond sediment to produce proteolytic and lipolytic enzymes, (2) to identify promising candidates using 16S rRNA gene amplification, and (3) to construct a phylogenetic tree based on the 16S rRNA genes. A skim milk agar medium was used in the preliminary experiment of the proteolytic assay, and a Tween 20/80 medium was used in the lipolytic assay. Fifteen and 20 (out of 40) actinobacterial isolates showed great potential for proteolytic and lipolytic activities, respectively. Furthermore, four actinobacteria isolates produced both enzyme types with proteolytic and lipolytic index scores of 1-6.5. The most promising candidates were SA 2.2 (IM8), SC 2.1 (IM6), SD 1.5 (IM6) and SE 1.1 (IM8). BLAST homology results showed a high similarity between the actinobacteria isolates and Streptomyces verucosisporus, S. mangrovicola, S. barkulensis and Nocardiopsis lucentensis, respectively. Therefore, actinobacteria from Litopenaeus vannamei pond sediment are high-potential proteolytic and lipolytic enzyme producers.

Anthropogenic impact on Indonesian coastal water and ecosystems: Current status and future opportunities.

Indonesia, the world's largest archipelagic country and the fourth most populated nation, has struggled with coastal water pollution in the last decades. With the increasing population in coastal urban cities, more land-based pollutants are transported to the coastal water and adversely affected the tropical ecosystems. This paper provides an overview of anthropogenic pollutant studies in Indonesian coastal water and ecosystems from 1986 to 2021. Nutrients, heavy metals, organic pollutants, and plastic debris are the most-studied contaminants. We found that 82%, 54% and 50% of the studies exceeding nutrients, heavy metals, and organic pollutants standard limit, respectively; thus, indicating poor water quality status in part of Indonesian coastal water. The coral reef ecosystems is found to be the most sensitive to anthropogenic disturbance. The potential effect of climate change, new coastal pollution hotspots in eastern Indonesia, marine anthropogenic sources, legacy/emerging pollutants, and the need for research related to the biological contamination, are discussed for future opportunities.

Microbial community structure associated with submarine groundwater discharge in northern Java (Indonesia).

Submarine groundwater discharge (SGD) can be an important pathway for chemical or biological pollutants from land to the ocean around the world. However, studies on the microbial communities associated with SGD in Southeast Asia, which has been hypothesized as SGD hotspot, remain scarce. In this study, we examined the microbial community composition with 16S rRNA gene sequencing along the hydrological continuum of an SGD site in a tropical urban area of Indonesia. Of the observed parameters in this study, salinity and temperature were the most determinant variables explaining patterns in microbial community composition. The bacterial taxon Burkholderiaceae was predominantly found in low salinity samples, including those from terrestrial groundwater and brackish pore water, while cyanobacteria of the genus Synechococcus sp. CC9902 were indicative of saline SGD and seawater samples. The composition of microbial taxa in each sample pointed to the influence of shallow terrestrial groundwater in the beach pore water, while seawater recirculation dominated the SGD sampling points situated further offshore. We identified taxa containing fecal indicators and potential pathogens at the SGD compartments; however, while a likely explanation, we could not conclude with certainty that SGD was a conduit for these bacteria. Overall, the results from this study show that microbial community analysis can highlight hydrological processes and water quality at the SGD site; thus, they could be useful for environmental policymakers to formulate water management strategies in coastal areas.