Production, purification and characterization of chitinase from Micromonospora sp. AR17

N‐acetylglucosamine (NAG) is the monomer product of chitin, which has been widely used as a bioactive com‐ pound in applications such as anti‐tumor, anti‐microbial, and antioxidant activities. In production, biological processes using enzymes are preferable to chemicals due to environmental issues. This study aims to determine the activity, purity level, and molecular weight of purified chitinase from Micromonospora sp. AR17 determines the concentration of NAG produced by purified chitinase that has been characterized. Chitinase was produced by fermentation in colloidal chitin broth at 40 °C, pH 7, for 7 days, while chitinase activity was checked every 24 h. The optimal fermentation time was used to produce chitinase for a further purification step. Enzyme purification was carried out by ultrafiltration, ammonium sulfate precipitation, ion exchange chromatography (Q Sepharose Fast Flow), and gel filtration (Sephacryl S‐300). The purified enzyme was then char‐ acterized for optimum time, pH, and temperature to produce NAG. The results suggested that the fourth day was the optimal time for chitinase production, with chitinase activity of 0.0040 U/mL and a NAG concentration of 7.62 µg/mL. The purifica‐ tion step successfully increased the purity by 6.82 times with chitinase‐specific activity at 1.4648 U/mg. Production of NAG with purified chitinase produced a NAG concentration of 32.472 µg/mL with an incubation time of 30 min at 40 °C and pH 7

Penggunaan Ekstrak Rumput Laut Padina SP. untuk Peningkatan Daya Simpan Filet Nila Merah yang Disimpan pada Suhu Dingin

Penelitian ini bertujuan untuk mengetahui pengaruh penggunaan ekstrak Padina sp. terhadap daya simpan fi let nila merah selama penyimpanan pada suhu dingin. Filet nila merah direndam selama 30 menit dalam larutan ekstrak Padina sp. dengan konsentrasi: kontrol; 0,5%; 1%; 1,5%; dan 2%, kemudian disimpan pada chilling room selama 10 hari dengan selang waktu pengamatan setiap 2 hari. Parameter yang diamati meliputi: pH, Total Plate Count (TPC), Total Volatile Base-Nitrogen (TVB-N), dan organoleptik. Hasil penelitian menunjukkan bahwa penggunaan ekstrak Padina sp. yang berbeda memberikan pengaruh nyata (P<0,05) terhadap nilai pH, kandungan bakteri total, kandungan TVB-N, dan nilai organoleptik keseluruhan fi let nila merah selama 10 hari penyimpanan pada suhu dingin. Filet nila merah yang diberi ekstrak Padina sp. masih layak dikonsumsi sampai hari ke-8. Penggunaan ekstrak Padina sp. 1% merupakan perlakuan terbaik dalam mempertahankan kesegaran fi let nila merah yang disimpan pada suhu dingin

STRUKTUR MODAL, COORPORATE GOVERNANCE DAN KINERJA PERUSAHAAN PADA PERUSAHAAN PERTAMBANGAN INDONESIA

This study aims to determine whether the capital structure (MDL) and corporate governance consisting of board size (DWN), the independent commisioner (IND), and manajerial ownership (MAN) effect on firm performance (ROA). The sample is determined by purposive sampling are 11 companies in the mining sector listed in Indonesian Stock Exchange and publish annual reports continuously in period 2011-2014. The results of this study indicate that the capital structure affect the performance of the firm, the addition of long-term debt will affect the company’s operations. Board size, manajerial ownership, and independent commisioner does not affect the performance of the firm. The three of variable does not affect the firm performance because decreased of global economic, decreased of commodity price and goverment export policy. Keywords: board size; capital structure; corporate governance; independent commissioner; manajerial ownership

GAGASAN STUDI AGAMA TERAPAN DALAM BINGKAI KAMPUS MERDEKA: PERSPSEKTIF SOSIOLOGI PENGETAHUAN

One of the big questions frequently asked by Senior High School Students who were interested in studying Religious Studies is about the career opportunity of the department’s alumni. Unlike other applied sciences that have a clear path of the alumni’s career, religious studies seem to vague in providing jobs for its alumni due to its pure/basic science characteristic. This paper proposes the possibility to develop applied religious studies to answer such a question. The author traces characteristics of religious studies from a sociology of knowledge perspective and then proposes eight fields of applied religious studies, which from a sociological perspective, meets the need for the implementation of “Freedom to Learn, Independent Campus” (Merdeka Belajar- Kampus Merdeka, MBKM), a policy from Ministry of Education and Culture, the Republic of Indonesia

Isolasi Dan Pemanfaatan Bakteri Proteolitik Untuk Memperbaiki Kualitas Limbah Cair Pengolahan Bandeng Presto (Isolation and Utilization of Proteolytic Bacteria to Improve the Quality of Milkfish Presto Processing Wastewate)

In this research, isolation of proteolytic bacteria was performed to obtain isolates with high proteolytic activity based on their ability to degrade the protein. The best isolate was examined for their growth ability and proteolytic activity in different concentrations of NaCl and degree of acidity (pH). Furthermore, the isolate ability to improve wastewater quality was observed in milkfish presto processing wastewater. Thirty-six proteolytic bacteria were isolated from fish washing wastewater of Kranggan Market, Yogyakarta. Isolate D61 has the highest proteolytic activity with activity about 20,5 mm. Isolate D61 was able to grow at a concentration of 0-10% NaCl with the highest proteolytic activity at the concentration of 0-2% NaCl. Isolate D61 was also able to live at pH 5-10 with the highest proteolytic activity at pH 7-8 and pH 10. Based on morphology and biochemical characteristics, D61 has 93.93% similarity with Bacillus soli. However, isolate D61 was not able to improve the quality of milkfish presto processing wastewater

ISOLASI DAN PEMANFAATAN BAKTERI PROTEOLITIK UNTUK MEMPERBAIKI KUALITAS LIMBAH CAIR PENGOLAHAN BANDENG PRESTO (Isolation and Utilization of Proteolytic Bacteria to Improve The Quality of Milkfish Presto Processing Wastewate)

ABSTRAKIndustri pengolahan ikan menghasilkan limbah dengan kadar protein tinggi. Penambahan bakteri proteolitik diharapkan dapat membantu mendegradasi limbah berprotein tinggi. Pada penelitian ini, isolasi bakteri proteolitik dilakukan untuk mendapatkan isolat dengan aktivitas proteolitik tinggi. Isolat terbaik diuji kemampuan hidup dan aktivitasnya pada berbagai konsentrasi NaCl dan pH. Kemampuan isolat meningkatkan kualitas limbah juga diuji pada limbah pengolahan bandeng presto. Hasil penelitian diperoleh 36 isolat bakteri proteolitik dari limbah cair pencucian ikan Pasar Kranggan Yogyakarta. Dari ke-36 isolat tersebut, isolat D61 merupakan isolat dengan aktivitas proteolitik tertinggi dengan zone diameter 20,5 mm. Isolat tersebut mampu hidup pada NaCl 0-10% dan kisaran pH 5-10, namun aktivitas proteolitik tertingginya pada NaCl 0-2% dan kisaran pH 7-8 dan pH 10. Berdasarkan karakteristik morfologi dan biokimianya, isolate D61 memiliki kemiripan 93,93% dengan Bacillus soli. Hasil ujicoba pada limbah cair pengolahan bandeng presto ternyata isolat D61 tidak mampu memperbaiki kualitas limbah tersebut.ABSTRACTIn this research, isolation of proteolytic bacteria was performed to obtain isolates with high proteolytic activity based on their ability to degrade the protein. The best isolate was examined for their growth ability and proteolytic activity in different concentrations of NaCl and degree of acidity (pH). Furthermore, the isolate ability to improve wastewater quality was observed in milkfish presto processing wastewater. Thirty-six proteolytic bacteria were isolated from fish washing wastewater of Kranggan Market, Yogyakarta. Isolate D61 has the highest proteolytic activity with activity about 20,5 mm. Isolate D61 was able to grow at a concentration of 0-10% NaCl with the highest proteolytic activity at the concentration of 0-2% NaCl. Isolate D61 was also able to live at pH 5-10 with the highest proteolytic activity at pH 7-8 and pH 10. Based on morphology and biochemical characteristics, D61 has 93.93% similarity with Bacillus soli. However, isolate D61 was not able to improve the quality of milkfish presto processing wastewater

Comparison of Formulation Methods to Produce Nano-Chitosan as Inhibitor Agent for Bacterial Growth

Chitosan is known as an antibacterial agent. The effective surface area ratio of chitosan can be increased by modification into nanoparticles. Nano-chitosan can be prepared with several simple methods, i.e. precipitation, ionic gelation, or the polyelectrolyte complex method. This study compared these three methods in terms of the targeted product characteristics, i.e. stability of the average nanoparticle size as well as the colloidal dispersion, and the antibacterial characteristics. All three methods resulted in nanoparticle formation, but in the precipitation method significant zeta potential reduction was observed due to the presence of negative ions from the alkali that neutralized the chitosan amine group. The ionic gelation method yielded higher zeta potential and higher inhibition of bacterial growth than those yielded by the polyelectrolyte complex method. Ionic gelation and the polyelectrolyte complex method resulted in much better colloidal dispersion stability than the precipitation method, where a significant particle size increase was observed after one week of storage. This result indicates that both ionic gelation and the polyelectrolyte complex method can be used for forming nano-chitosan for the purpose of food preservation. However, for fishery products it is advisable to use the polyelectrolyte complex method because the TPP usually used in ionic gelation is not allowed to be applied to fish

Pengembangan Metode Ekstraksi Alginat dari Rumput Laut Sargassum SP. sebagai Bahan Pengental

Indonesia mempunyai banyak rumput laut yang berpotensi tinggi sebagai penghasil alginate, namun metode ekstraksinya belum sesuai yang diharapkan. Penelitian ini bertujuan untuk mengembangkan metode ekstraksi natrium alginat dari rumput laut Sargassum melalui jalur kalsium alginat. Dalam penelitian ini digunakan berbagai variasi konsentrasi kalsium klorida yang digunakan pada pemisahan alginat dari filtrat hasil ekstraksinya. Konsentrasi kalsium klorida yang digunakan divariasi 0,5; 0,75 dan 1 M. Sebagai kontrol dilakukan ekstraksi alginat melalui jalur asam alginat yang dikembangkan di Balai Besar Riset Pengolahan Produk dan Bioteknologi Kelautan dan Perikanan, Jakarta. Parameter kualitas alginat yang diamati meliputi rendemen alginat, kenampakan produk, viskositas dan kekuatan gel yang dihasilkan. Hasil pengamatan menunjukkan bahwa rendemen alginat yang dihasilkan berturut-turut sebesar 32,67; 44,67 dan 53,33 % dan untuk kontrol 31,67 %. Secara kenampakan, konsentrasi kalsium klorida tidak terlalu mempengaruhi kenampakan produk alginat yang dihasilkan, tetapi lebih gelap jika dibandingkan dengan produk hasil ekstraksi melalui jalur asam alginat. Viskositas alginat yang dihasilkan berturut-turut 149, 131 dan 144 cP, sementara untuk kontrol 304 cP. Secara umum kekuatan gel alginat yang dihasilkan dari jalur kalsium alginat lebih rendah dibandingkan dengan yang diekstrak melalui jalur asam alginat

KARAKTERISASI EDIBLE FILM DARI GELATIN KULIT NILA MERAH DENGAN PENAMBAHAN PLASTICIZER SORBITOL DAN ASAM PALMITAT

Penelitian ini bertujuan untuk mengembangkan gelatin edible film menggunakan kombinasi campuran sorbitol dan asam palmitat sebagai plasticizer. Gelatin diperoleh dari kulit kering nila merah (Oreochromis niloticus) dengan perendaman dalam larutan CH3COOH 0,1 N, pH 3 selama 24 jam lalu diekstraksi pada suhu 80oC selama 3 jam. Analisis proksimat gelatin menunjukkan kadar air 5,06%, kadar abu 0,45%, lemak 7,84%, kadar protein 85,703%, rendemen 29,76%, kekuatan gel gelatin nila merah bernilai 301,6 bloom, dan viskositas 6,97 cPs. Gelatin edible film dibuat dengan melarutkan 3 g gelatin dalam 100 ml aquades pada suhu 60oC lalu ditambahkan 2 jenis plasticizer dengan konsentrasi yang berbeda. Plasticizer yang ditambahkan pertama kali untuk membuat edible film adalah sorbitol, penambahan sorbitol (0-37,5% dari berat gelatin) bertujuan memperoleh sifat fisik edible film yang cocok sebagai pembungkus. Hasil observasi karakteristik terbaik edible film sebagai pembungkus diberikan oleh konsentrasi sorbitol 37,5%, dengan nilai ketebalan 0,1203x10-3m, renggang putus 13,1598 Mpa, dan perpanjangan 4,864%. Formula edible film penambahan plasticizer sorbitol 37,5% dikombinasi dengan asam palmitat (0-1,5% dari berat gelatin) yang bertujuan meningkatkan sifat hidrofobik edible film. Penambahan asam palmitat efektif menurunkan nilai kelarutan edible film (P<0,05) namun tidak efektif dalam mengurangi nilai transfer uap air (P<0,05)

Peningkatan Semangat Kerja Guru Melalui Supervisi Komunikasi Administrasi Guru SMP Negeri 3 Gempol Satu Atap Kabupaten Pasuruan

Tercapainya tujuan organisasi merupakan suatu hal yang penting bagi&nbsp; pimpinan. Begitu juga dalam lembaga pendidikan, tercapainya tujuan lembaga pendidikan menjadi tolok ukur bagi peneliti dalam menilai keberhasilan pimpinan yakni guru di dalam memimpin para guru. Namun demikian sering dijumpai adanya guru yang kurang bersemangat dalam bekerja meskipun kebutuhan hidupnya, yang berupa gaji yang tinggi sudah dipenuhi. Hal ini disebabkan karena pihak sekolah kurang memperhatikan kebutuhan sosial psikologis para guru. Hasil dari pelaksanaan supervisi komunikasi administrasi ini ditengarai menjadikan situasi sekolah menjadi lebih kondusif apalagi jika didukung adanya lingkungan kerja yang memadai. Penelitian ini merupakan penelitian tindakan sekolah yang dilaksanakan dalam 3 siklus. Tiap siklus melalui penatahapan perencanaan, tindakan, observasi dan refleksi. Tujuan penelitian ini adalah meningkatkan semangat kerja guru SMP Negeri 3 Gempol Satu Atap Kabupaten Pasuruan melalui Supervisi Komunikasi Administrasi pada Semester II Tahun Pelajaran 2016/2017. Kenyataan membuktikan bahwa penggunaan komunikasi administrasi dapat meningkatkan semangat kerja guru, karena komunikasi administrasi mampu memperjelas tugas guru dalam melaksanakan manajemen sekolah yang akan selalu dikembangkan guru dalam melaksanakan tugas profesinya