Elephant dung is a source of methane gas, which the gas is the main contributor to greenhouse gas if not used as fuel. Wild elephants use grass leaves as their feed, but in Ragunan Wildlife Park, elephants are fed also with a combination of elephant grass, sweet potatoes, maize, and bananas, which aim to meet immediate nutritional needs and ensure their health. Therefore, this study examined the biogas production of elephant feces associated with the feed given. The purpose of this study is to investigate the contribution of biogas that is emitted from the elephant feces as a result of two kinds of feed, which were elephant grass and combination of elephant grass, sweet potatoes, maize, and bananas. Previously, the elephants were acclimatized for 4 days with the two types of feed. Fermentation of the feces was conducted by using simple fermenters by volume of 3.42 L for 28 days and performed measurements of temperature, pH, concentration of ammonia, concentration of volatile fatty acids, substrate degradation and production of biogas. The result showed that the composition of feed affects the physico-chemical characteristics of the feces, production of ammonia and volatile fatty acids, substrate degradation and production of biogas. The feces of Sumatran elephant fed with elephant grasses has higher potential for decomposition to mineralization into biogas and produce a higher proportion of methane gas carbon dioxide, than those fed with the combinated feed. This result needs to be a concern because with the fiber-rich feed like in their natural habitats, elephants have the potential to emit higher gas emissions. Therefore the biogas released from the elephant feces or other animals should be processed and utilized to meet the energy needs in the wildlife park itself.

The depletion of fossil fuel reserves requires advance anticipation through the search for alternative energy from renewable natural resources. Microalgae have been known as potential organisms for biodiesel feedstock. However, in order to be developed on a large scale, microalgae must have superior traits so that further development becomes more comfortable and cheaper. Tropical lakes are a source of superior microalgae adapted to moderate conditions which can later save operational costs in large-scale production. Situ Gintung and Situ Pamulang are the two largest lakes in South Tangerang, Indonesia and are potential sources of microalgae. Four microalgae isolates from both lakes have been identified, and their potential has been examined. Within an observation period of 18 days, they showed similar growth patterns reaching more than 108 cells mL−1 on day 14 and were able to resist increasing pH. The microalgae were identified through morphological observations and the sequencing of 23S rRNA genes with phylogenetic analysis. Each strain has a positive quality. Isolate G4-3, which was identified as Micractinium conductrix, and P5-4, which was identified as Monoraphidium sp., yielded biomass that exceeded 1.2 g L−1 with lipid content exceeding 60%. Likewise, G4-9, which was also identified as Micractinium conductrix, and P2-15, which was identified as Choricystis parasitica, have lipid content which accounted for 89.10% and 57.48%, respectively; although their biomass was lower. The percentage of fatty acid methyl esters of the four microalgae achieved >60–80%; thus, meeting the standard of biodiesel properties. Therefore, the microalgae isolates have great potential for being developed as biodiesel feedstock.

INTISARINutrien daun kelor (Moringa oleifera) dan jerami kacang hijau (Vigna radiata) sebagai hijauan pakan ternak cukup berkualitas sehingga perlu diproteksi untuk meningkatkan efektivitas penggunaannya di dalam rumen. Daun nangka mengandung total tanin sebesar 7,08%, sehingga potensial digunakan sebagai bahan untuk memproteksi bahan pakan sumber protein. Studi in vitro perlu dilakukan untuk mengevaluasi penggunaan tepung daun nangka untuk meningkatkan efektivitas penggunaan hijauan berupa daun kelor dan jerami kacang hijau. Tujuan dari studi yang dilakukan adalah untuk mengetahui pengaruh penambahan tepung daun nangka terhadap nilai biologis daun kelor dan jerami kacang hijau. Evaluasi produksi metana juga dilakukan untuk mengetahui efisiensi proses fermentasi. Perlakuan penelitian adalah: 1) jerami kacang hijau; 2) jerami kacang hijau + 0,7% daun nangka; 3) jerami kacang hijau + 1,4% daun nangka; 4) daun kelor; 5) daun kelor + 0,7% daun nangka; 6) daun kelor + 1,4% daun nangka. Penelitian ini menggunakan rancangan acak lengkap dengan pengulangan sebanyak tiga kali. Pengamatan dilakukan terhadap produksi gas total (inkubasi ke-0, 2, 4, 6, 8, 10, 12, dan 24 jam), konsentrasi gas metana (%), karakteristik produksi gas dan karakteristik produk fermentasi rumen. Hasil penelitian menunjukkan bahwa penambahan tepung daun nangka tidak berpengaruh terhadap produksi gas total, produksi gas maksimum dan laju degradasi kedua jenis hijauan pakan. Penambahan 0,7 dan 1,4% tepung daun nangka dapat menurunkan konsentrasi gas metana daun kelor berturut-turut sebesar 4,93% dan 3,19%. Penambahan tepung daun nangka juga mampu meningkatkan rasio CO2:CH4 substrat jerami kacang hijau masing-masing sebesar 4,42 dan 6,49%. Tepung daun nangka juga tidak memberikan efek negatif terhadap produk fermentasi rumen (pH, NH3, VFA total, dan degradasi bahan organik).(Kata kunci: In vitro, Daun kelor, Produksi gas total, Tepung daun nangka, Jerami kacang hijau) ABSTRACT Previous studies indicated kelor (Moringa oleifera) leaves and green mung beans (Vigna radiata) straws can provide good nutrient sources for ruminant. Protection of high quality nutrients from rumen microbe degradation might improve nutrient utilization for ruminants. Nutrient protection using tannins is aplicable methods to formulate rumen undegradable feed. Jackfruit (Artocarpus heterophyllus) leave contain 7.08% tannins, therefore it is potential to be used as tannin source to protect nutrient of feed, especially protein, in the rumen. The purpose of this study was to investigate the effects of tannin addition from jackfruit leaves on biological values of kelor leaves and green mung bean straws by in vitro trial.Methane production was also observed to determine the effects of jackfruit leaves addition on kelor leave and green mung bean straw. The treatments were: 1) green mung bean straw; 2) green mung bean straw + 0.7% jackfruit leaves meal; 3) green mung bean straws + 1.4% jackfruit leaves meal; 4) kelor leaves; 5) kelor leaves + 0.7% jackfruit leaves meal; and 6) kelor lea...

ABSTRAKGas metana dari ternak ruminansia merupakan salah satu penyumbang emisi gas rumah kaca terbesar di dunia, termasuk Indonesia. Gas metana yang bersumber dari peternakan berasal dari dua sumber emisi, yaitu pencernaan dan feses, sehingga produksinya dapat dikurangi melalui modifikasi pakan. Salah satu strategi untuk mengurangi produksi gas metana tersebut adalah dengan penambahan bakteri denitrifikasi, yang mengalihkan akseptor elektron untuk metanogenesis kepada denitrifikasi. Penelitian ini bertujuan untuk menyelidiki potensi penambahan bakteri denitrifikasi yang diinaktivasi dengan iiradiasi sinar Gamma dalam menurunkan produksi gas metana dalam cairan rumen sapi, yang diuji secara in vitro. Pada penelitian ini diuji empat perlakuan, yaitu dengan penambahan bakteri denitrifikasi aktif, bakteri denitrifikasi yang diinaktivasi dengan iradiasi Gamma Cell 1000 Gy dan bakteri denitrifikasi yang diinaktivasi menggunakan autoklaf 1,5 tekanan atmosfir, 120°C selama 15 menit, seluruhnya pada cairan rumen sapi yang diberi substrat hijauan sorgum secara in vitro. Hasil pengukuran dari masing-masing parameter berupa nilai pH, amonia, volatile fatty acids total, asetat, propionat, butirat, biomassa bakteri, biomassa protozoa, produksi gas total dan produksi gas metana pada jam ke-24 dan 48 mendukung penurunan metanogenesis akibat penambahan bakteri denitrifikasi aktif dan inaktif. Pemberian bakteri denitrifikasi inaktif lebih besar menekan produksi gas metana dibandingkan dengan bakteri aktif. Penurunan produksi gas metana dari jam ke-24 sampai 48 dari perlakuan penambahan bakteri denitrifikasi inaktif-iradiasi, dan inaktif-autoklaf berturut-turut sebesar 41,5% dan 55,3%, yang lebih tinggi daripada dari bakteri denitrifikasi aktif dengan penurunan sebesar 13,6%.Kata kunci : Bakteri denitrifikasi, gas metana, iradiasi, rumen, sapi ABSTRACT Methane gas derived from ruminants is one contributor to greenhouse gas emissions in the world, including Indonesia. The methane gas emitted from livestock comes from two sources of emissions, i.e. digestion and faeces, so that production can be reduced through modification of the feed. One strategy for reducing methane gas production is by the addition of denitrifying bacteria, which transfer the electron acceptor for denitrification instead of methanogenesis. This study aims to investigate the potential of radiation-inactive denitrification bacteria in reducing production of methane gas in cow rumen liquid, which examined in vitro. In this study four treatments were examined which was consisted of the addition of active denitrifying bacteria, denitrifying bacteria inactivated by the irradiation Gamma Cell 1000 Gy, and denitrifying bacteria inactivated by autoclaving 1.5 atmospheric pressure, 120°C for 15 minutes; all were applied to the cow rumen liquid with the forage sorghum as the substrate in vitro. Results on the measurement of some parameters which were pH, ammonia, total volatile fatty acids, acetate, propionate, butyrate, bacterial biomass, protozoa biomass, production of ...

The water quality in the interim wet storage of spent fuel (ISSF) needs to be monitored due to its function as a radiation shield. Water in ISSF pools must be free from microorganisms such as microalgae that live in a radioactive environment. Moreover, particular microalgae are capable of causing corrosion to stainless steel, which is a component of ISSF. Therefore, this study aims to determine the diversity of microalgae in the ISSF and those living in a radioactive environment, which cause corrosion. The microalgae were detected using the diversity and Palmer indices. The sampling of microalgae water was carried out by vertical filtration method at eight sites of ISSF. The results show that the diversity of microalgae (H′) was low due to radiation exposure in pool water, hence, only specific species can survive. The evenness (J′) of the microalgae was low, causing a high dominance index (C) value. Furthermore, the dominating species, namely, Chlorella sp. (Chlorophyceae), needs to be monitored because it has gamma radioresistance capabilities and can cause the corrosion of stainless steel.