Abstract. Fluid-flow related seafloor structures and gas seeps were detected in the North Sea in the 1970s and 1980s by acoustic sub-bottom profiling and oil rig surveys. A variety of features like pockmarks, gas vents and authigenic carbonate cements were found to be associated with sites of oil and gas exploration, indicating a link between these surface structures and underlying deep hydrocarbon reservoirs. In this study we performed acoustic surveys and videographic observation at Gullfaks, Holene Trench, Tommeliten, Witch's Hole and the giant pockmarks of the UK Block 15/25, to investigate the occurrence and distribution of cold seep ecosystems in the Northern North Sea. The most active gas seep sites, i.e. Gullfaks and Tommeliten, were investigated in detail: at both sites gas bubbles escaped continuously from small holes in the seabed to the water column, reaching the upper mixed surface layer as indicated by acoustic images of the gas flares. At Gullfaks a 0.1 km2 large gas emission site was detected on a flat sandy seabed, covered by filamentous sulfide-oxidizing bacteria. At Tommeliten we found a patchy distribution of small bacterial mats indicating sites of gas seepage. Here the seafloor consists of layers of sand and stiff clay, and gas emission was observed from small cracks in the seafloor. At both sites the anaerobic oxidation of methane (AOM) coupled to sulfate reduction is the major source of sulfide. Molecular analyses targeting specific lipid biomarkers and 16 S rRNA gene sequences identified an active microbial community dominated by sulfide-oxidizing and sulfate-reducing bacteria (SRB) as well as methanotrophic bacteria and archaea. Carbon isotope values of specific microbial fatty acids and alcohols were highly depleted, indicating that the microbial community at both gas seeps incorporates methane or its metabolites. The microbial community composition of both shallow seeps show high similarities to the deep water seeps associated with gas hydrates such as Hydrate Ridge or Eel River basin.

Abstract. Fluid flow related seafloor structures and gas seeps were detected in the North Sea in the 1970s and 1980s by acoustic sub-bottom profiling and oil rig surveys. A variety of features like pockmarks, gas vents and authigenic carbonate cements were found to be associated with sites of oil and gas exploration, indicating a link between these surface structures and the underlying, deep hydrocarbon reservoirs. In this study we performed acoustic surveys and videographic observation at Gullfaks, Holene Trench, Tommeliten, Witch's Hole and the giant pockmarks of the UK Block 15/25, to investigate the occurrence and distribution of cold seep ecosystems in the Northern North Sea. The most active gas seep sites, i.e. Gullfaks and Tommeliten, were investigated in detail. At both sites, gas bubbles escaped continuously from small holes in the seabed to the water column, reaching the upper mixed surface layer. At Gullfaks a gas emitting, flat area of 0.1 km 2 of sandy seabed covered by filamentous sulfur-oxidizing bacteria was detected. At Tommeliten, we found a patchy distribution of small bacterial mats indicating sites of gas seepage. Below the patches the seafloor consisted of sand from which gas emissions were observed. At both sites, the anaerobic oxidation of methane (AOM) coupled to sulfate reduction (SR) was the major source of sulfide. Molecular analyses targeting specific lipid biomarkers and 16S rRNA gene sequences identified an active microbial community dominated by sulfur-oxidizing and sulfate-reducing bacteria (SRB) as well as methanotrophic bacteria and archaea. Stable carbon isotope values of specific, microbial fatty acids and alcohols from both sites were highly depleted in the heavy isotope 13 C, indicating that the Correspondence to: G. Wegener (gwegener@mpi-bremen.de) microbial community incorporates methane or its metabolites. The microbial community composition of both shallow seeps shows high similarities to the deep water seeps associated with gas hydrates such as Hydrate Ridge or the Eel River basin.

Abstract. Iswanto T, Shovitri M, Altway A, Widjaja T, Kusumawati DI, Lisdiyanti P. 2019. Isolation and identification of caffeine-degrading bacteria from soil, coffee pulp waste and excreted coffee bean in Luwak feces. Biodiversitas 20: 1580-1587. The present study deals with the isolation and identification of caffeine-degrading bacteria obtained from the caffeine contaminated environment or caffeinated wastes. These bacteria are useful for various biotechnological applications especially in increasing the potential utilization of caffeinated wastes and producing the high-value chemicals. The suspected caffeine-degrading bacteria have been isolated from the soil of coffee plantation area, coffee pulp waste, and the excreted coffee bean in fresh feces of Luwak (Paradoxurus hermaphroditus or Asian Palm Civet) by growing them on the caffeinated agar medium (CAM) containing basal salt medium (M9) and caffeine as a sole source of carbon and nitrogen. CAM-supplemented with 1.5 to 10 g L-1 of caffeine has been used for screening of the potential bacteria which able to grow in high caffeine concentration. Molecular identification based on 16S rRNA gene sequence was performed to identify the selected bacteria. The result revealed that there were 11 and 3 strains of 12 selected bacteria which could grow on the CAM-supplemented with caffeine up to 7 and 10 g L-1, respectively. Based on 16S rRNA gene sequence and phylogenetic analysis, those bacteria were from 5 Gram-negative species, namely Pseudomonas japonica (4/12), Methylobacterium populi (5/12), Raoultella ornithinolytica (1/12), Klebsiella quasipneumoniae (1/12), and Stenotrophomonas chelatiphaga (1/12). Further investigations to determine their metabolic pathway, enzyme, and growth kinetics in the caffeinated medium may provide insights into its possible utilization for scientific or other applications.

Polietilen merupakan polimer penyusun plastik yang sulit didegradasi secara alami, dan berpotensi menjadi limbah lingkungan. Jamur dapat menjadi alternatif dalam mendegradasi plastik. Jamur Aspergillus terreus diketahui memiliki kemampuan dalam mendegradasi plastik. Penelitian ini bertujuan untuk mengetahui pengaruh pH 5 dan 6 serta suhu 25 0 C dan 35 0 C terhadap degradasi plastik oleh jamur A. terreus (LM 1021) selama 20 hari pada Minimal Salt Medium (MSM) dengan potongan plastik. Parameter yang digunakan dalam penelitian ini adalah berat kering biomassa, persentase degradasi (ED) dan analisis fourier transform infrared (FTIR). Hasil dari penelitian setelah 20 hari inkubasi menunjukkan bahwa biomassa tertinggi didapat pada pH 5 suhu 25 0 C yang mencapai 65 mg. Sedangkan nilai ED mencapai 3,25% pada pH 6 suhu 25 0 C. Analisis FTIR menunjukkan telah terjadi perubahan persentase transmisi peak untuk gugus CH, CH2, dan C=C yang merupakan indikasi adanya perubahan gugus fungsional atau molekul kimia.

No abstract