No abstract

Marine debris is one of the global issues and becomes a challenge for Indonesia as a maritime country. This research focuses on the characteristics of the one the estuaries in DKI Jakarta. The method used in this research by sampling the water at the mouth of the river by using the manta net at different depths and in tidal conditions. The results showed that the number of microplastic consists of 93 microplastic particles originating from the seven stations. The number of microplastic particles at low tide conditions is 112 particles. The results of microplastic counting obtained weight of 45.7 mg from the seven stations with high tide conditions on the surface. The maximum particle weight value of 16.2 mg found at station 1 in Muara Tiram. Based on the observations at each station, the size of the microplastic obtained range between 1mm to 5mm. The results of observing the characteristics of the forms in the research study have results including fragments, filaments, films, foams, and granules. The microplastics at the estuary come from the ocean and also from the river.

Bakteri coliform sudah lama dikenal sebagai bioindikator cemaran bahan organik di suatu perairan. Perairan laut merupakan muara bagi semua jenis limbah baik organik maupun anorganik yang berasal dari daratan. Foraminifera yang merupakan diatom bentik yang khas ditemukan di ekosistem terumbu karang juga dapat terkontaminasi bakteri coliform pada perairan yang mengalami kondisi pencemaran bahan organik. Penelitian ini bertujuan untuk mengetahui nilai kelimpahan bakteri coliform pada air laut, sedimen dan foraminifera jenis calcarina. Penelitian ini dilaksanakan dari bulan Maret sampai Agustus 2017 di Laboratorium Mikrobiologi dan Bioteknologi Molekuler (MICROMOL) Fakultas Perikanan dan Ilmu Kelautan (FPIK) Universitas Padjadjaran. Metode yang digunakan pada penelitian ini adalah metode Most Probable Number (MPN) yang dibandingkan dengan standar baku mutu Kep-51/MENKLH/2004. Hasil penelitian menunjukkan bahwa kelimpahan bakteri coliform pada air laut yaitu 9->1100 MPN/100 mL, pada sedimen sebesar 7-803,33 MPN/100 g dan yang ditemukan pada foraminifera jenis calcarina berkisar <3-16 MPN/100 g.

Bacteria are one of the prokaryotic microorganisms that are symbiotic with coral reefs. These microorganisms help corals in secreting mucus layers which are used as a place to live for bacteria and control the presence of pathogenic bacteria in corals. The purpose of this study was to determine the diversity of bacterial communities associated with Acropora digitifera corals in Ciletuh bay, West Java, by culture approach. Sampling was carried out at a depth of 4 meters. Morphology-based identification and molecular approach based on sequence of the small ribosomal unit (16S) rRNA gene were used to determine the bacterial species in the samples. A total of six pure isolates were identified based on morphological observation and the molecular DNA characteristics from three of them were identified with 16S rRNA gene sequences. The identification using 16S rRNA gene showed that the isolate ACD.P4.PH7.P had a close relationship with the BF strain and zb strain of Bacillus flexus (acc number MH569560.1) with a similarity of 85.44 %. While ACD.P4.PH9.P isolate has a close relationship with Bacillus sp. c234 (acc number FJ950647.1) with a similarity of 98.50 %. Additionally, ACD.P4.PH9.K isolates closely related to Bacillus sp. of strain 6RM1 (acc number MK134607.1) with a similarity of 94.78 %. This study also revealed that both microscopic identifications by morphological traits and molecular approach using 16S rRNA gene can be used in bacterial diversity assessment.

Haslea ostrearia has known as the only diatom which synthesizes a water-soluble blue pigment, marennine. It has some biological activities such as allelopathy, antioxidant, antibacterial, antiviral, and growth inhibitor. Marennine is available in two forms, intracellular which located in the apical of the cell and extracellular which released into the culture medium. This research aimed to test the bioactivity of Haslea ostrearia supernatant adapted in Indonesia as an antibacterial against pathogenic bacteria relevant to marine culture using in-vitro study. This research was using an explorative method, data analysed statistically and descriptive-comparatively observed. Observation parameters were the inhibitory zone of antibacterial activity, absorbance value of MIC test, and bacterial growth qualitatively from MBC test. Marennine concentration in the supernatant of Haslea ostrearia adapted in Indonesia is about 3.74 mg. L-1. The highest concentration supernatant of Haslea ostrearia that shown antibacterial activity is 3.5 mg. L-1 with inhibitory zone diameter is about 6.87 mm for Staphylococcus aureus and 7.14 mm for Vibrio harveyi, correspondingly. The minimum concentration that inhibits the growth of Staphylococcus aureus is 0.03 mg. L-1, while for Vibrio harveyi is 0.06 mg. L-1. Antibacterial activity of supernatant Haslea ostrearia originally adapted in Indonesia classified into bacteriostatic