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Wind-Driven Coastal Upwelling in the Southern Coast of Yogyakarta Rachman, Faizal; Adharini, Ratih Ida; Setiawan, Riza Yuliratno; Puspita, Indun Dewi; Triyannanto, Endy
Jurnal Perikanan Universitas Gadjah Mada Vol 20, No 1 (2018)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1389.377 KB) | DOI: 10.22146/jfs.29252

Abstract

Satellite measurement provides synoptic view of sea surface wind and can be used to study variability of coastal upwelling. Here we analyzed data of 12 years of satellite-derived sea surface wind, sea surface temperature (SST), and sea surface chlorophyll-a (Chl-a) to examine the spatial and temporal distributions of coastal upwelling off the Yogyakarta waters. Results show that upwelling occurs during the Southeast Monsoon (SEM) season. During this season, the Yogyakarta waters are dominated by strong wind speed (~7 m/s) and SST cooling (25 °C). Whereas during the Northwest Monsoon (NWM) season the low wind speed (<4 m/s) no longer favor upwelling and SST cooling. We suggest that as the Yogyakarta coastline is oriented east-west, northwesterly winds result in downwelling condition at the coast, while southeasterly winds lead to the offshore Ekman transport of surface water and subsequent upwelling.
Bioformation of N-Acetylglucosamine from Shrimp Shell Chitin by Serratia marcescens PT-6 Cultured in various pH and Temperature Sari, Bekti Wulan; Isnaini, Nurul Binti; Puspita, Indun Dewi; Husni, Amir; Ustadi, Ustadi
Jurnal Perikanan Universitas Gadjah Mada Vol 19, No 1 (2017)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jfs.25961

Abstract

The study aimed to determine the effect of pH and temperature on N-Acetylglucosamine (NAG) formation from shrimp shell chitin by Serratia marcescens PT-6 fermented in chitin broth medium. Parameters examined on NAG formation include bacteria growth, chitinase activity (U/ml), and NAG concentration in medium (mg/ ml). Bacteria growth was measured by turbidity (OD600), while chitinase activity and NAG concentration in the medium were analyzed quantitatively by colorimetric assay. The variation of initial pH examined in chitin broth medium was 5; 6; 7; 8, while temperature variation was 30°C; 37°C; dan 40°C. The results show that maximum concentration of NAG formed by Serratia marcescens PT-6 was 33.86 µg/ml on day-3 of fermentation, at pH 7 and temperature of 30°C. Chitinase activity on the same day was 0.002 U/ml, while OD600 value of the culture was 0.42 indicating the bacteria were in the log phase. This research implies that Serratia marcescens PT-6 is potential to be optimized further for the bioconversion process of NAG from shrimp shell waste through an enzymatic method by modifying its culture condition.