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The characteristic of chicken excreta has a very potential as a breeding media for flies and is known for causing odorous pollutants (NH3 emission) from undigested protein and the activities of urease microorganisms. This study is focused on extracting Maja fruit, to quantify marmelosin from different fruit conditions using HPLC, and to determine the biological activity for handling the chicken excreta problems. In this study, the Kirby-Bauer Test was used to observe the antibacterial activity of marmelosin, the NH3 trapping method was used to determine ammonia emission, and the larvae population was determined by the Fly-Grill method. Marmelosin contents in MFE from immature, mature, and fermented fruit condition were 108.65 μg/g; 65.83 μg/g, and 23.02 μg/g, respectively. The increasing level of marmelosin addition to 50, 100, 150, and 200 μg/mL caused the higher diameter of inhibition zone against E. coli (p

Methanol dehydrogenase (MDH) enzyme was purified from Bradyrhizobium japonicum USDA110 cell-free extract. The bacteria were grown in a culture medium with direct 0.5% methanol addition aimed to stimulates the MDH catalytic enzyme activation. Bradyrhizobium japonicum USDA110 MDH enzyme was purified by using 25 mM 2-(N-morpholine) ethanesulfonic acid/MES pH 5.5 buffer and 1 M sodium chloride/NaCl which separated into three columns, the first column was PD-10 for buffer exchange; the second column was HiTrap Sepharose HP to obtain unbonded fraction in the column; and the third column was Mono S 5/50 GL integrated with two pumps HPLC (high-performance liquid chromatography) to obtain pure MDH enzyme for serial changing of 1 M NaCl-25mM MES pH 5.5 with the flow rate at 1 ml/min. The protein concentration and MDH catalytic enzyme activity were observed on each purification process starting from the cell-free extract to pure MDH enzyme. The pure MDH enzyme was obtained by Mono S 5/50 GL-HPLC purification which showed a single band on SDS PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis). The MDH enzyme purification from Bradyrhizobium japonicum USDA110 showed 90-fold purification, a sub-molecular weight of 63 kDa, specific activity at 2.69 U/mg, and optimum activity at a 35oC temperature and pH 9.

This research aims to understand the effect of metal ions bioabsorption which belong on different elemental groups to the methanol dehydrogenase (MDH) enzymatic activity in nitrogen-fixing bacteria Bradyhizobium japonicum USDA 110. Ten metal ions with each have 30μM concentration were added to grow Bradyhizobium japonicum USDA 110 in 10-1 diluted nutrient medium. The MDH activity test showed a similar result between the bacteria grown in medium without metal ions addition (control) and the bacteria were grown in a calcium ion/Ca2+ added media. The highest MDH enzymatic activity was shown on the bacteria grown in a magnesium/Mg2+ added medium, which showed 0.08 (U/mg) enzymatic activities. The addition of magnesium/Mg2+ metal ion accelerates the bacterial growth by 2.6 times and MDH activity by 1.28 times compared to control. The MDH enzyme is essential, especially for bacteria which exist in the soil environment, to adapt to high methanol concentration and to support bacterial anaerobic growth capacity along with plant symbiotic process. Moreover, the MDH activity staining method could also act as pollutant indicators like metal ions and hydrocarbon derivates. This research concluded that metal ions biosorption (calcium/Ca2+ and magnesium/Mg2+) are required for bacterial cells reproduction and oxidation of single carbon chain compounds like methanol. The nitrogen-fixing symbiotic bacteria, Bradyhizobium japonicum USDA 110 showed high MDH activity after the two metal ions absorption. However, contrary results were shown on vanadium/V3+, manganese/Mn2+, iron/Fe3+, copper/Cu2+, zinc/Zn2+, and aluminum/Al3+ absorption, which showed low MDH activity and cells biomass.

Konsep kebijakan pembangunan peternakan Indonesia pada saat ini telah bergeser dari paradigma pembangunan yang sentralistik menuju pada konsep pembangunan partisipatoris. Konsep partisipatoris secara operasional formal diwujudkan dalam bentuk kelompok-kelompok ternak. Kelompok ternak merupakan perwujudan modal sosial di masyarakat yang penting dalam pembangunan masyarakat peternak khususnya dalam peningkatan kesejahteraan rumah tangga. Penelitian ini bertujuan untuk mengetahui pengaruh modal sosial terhadap tingkat kesejahteraan rumah tangga peternak. Pengambilan data melibatkan 61 rumah tangga peternak yang tergabung dalam kelompok ternak Ngudi Mulyo. Hasil penelitian menunjukkan bahwa modal sosial dan aset fisik berpengarh signifikan terhadap tingkat kesejahteraan peternak. Ini menunjukkan bahwa konsep kebijakan yang partisipatoris dalam pembangunan peternakan berkontribusi dalam peningkatan kesejahteraan rumah tangga peternak di Indonesia.

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