A study of alginate-chitosan membrane synthesize was done. The membrane was prepared by mixing alginate hydrosol and chitosan hydrosol at mass ratio of 1:1 and pH of 5.28 approximately. Then it was applied for matrix immobilization of urease and bromothymol blue (BTB) by entrapment technique. The physical, chemical, thermal properties of alginate–chitosan membrane and their impact on immobilized urease activity were investigated. The polymer products were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy (SEM). It’s showed that alginate-chitosan membrane was formed by electrostatic interaction.  The obtained membran has better mechanical properties than original alginat and chitosan membranes. The immobilization urease into alginate-chitosan membrane retained the catalytic activity of the enzyme, as confirmed by color change of BTB indicator after membrane was immersed in substrate solution (urea). Therefore, alginate-chitosan membrane has good characteristics as matrix of enzyme immobilization.

Desa Lembuak adalah salah satu desa di Kecamatan Narmada. Desa ini, terdiri dari 8 dusun dengan jumlah penduduk 5209 jiwa dan luas 118 ha/m2. Lebih dari 70% penduduk terkonsentrasi dalam 3 dusun yaitu Lembuak Timur, Lembuak Barat dan Lembuak Kebon (Profil Desa Lembuak, 2016). Hal ini menjadikan ketiga dusun tersebut terbentuk menjadi perkampungan yang sangat padat. Permasalahan utama di 3 dusun terpadat adalah sampah yang mencemari lingkungan. Limbah-limbah organik rumah tangga memenuhi selokan saluran air, menimbulkan bau dan menjadi sarang penyakit. Limbah ini dapat diolah dengan proses fermentasi dengan EM4 menjadi pupuk organik. Pupuk organik yang dihasilkan dapat dijadikan sebagai media tanam untuk pengembangan pertanian organik lahan sempit di Desa Lembuak Kecamatan Narmada. Melalui pengabdian ini diharapkan dapat meningkatkan ketahanan pangan dan kesehatan keluarga melalui pengolahan limbah organik dan aplikasi hasil pada pengembangan berbagai tanaman sayuran di pekarangan.

PEC of the alginate-chitosan membrane as supporting material for immobilizing urease was produced. This study aimed to develop a supporting material for enzyme immobilization that has high stability, a fast response time and an easy and relatively inexpensive preparation procedure. An alginatechitosan PEC membrane was produced by reacting alginate hydrosol and chitosan (1:1 in mass) at pH 5.28, followed by mixing and drying at room temperature. The FTIR spectra, XRD patterns and SEM assay confirmed that alginate-chitosan PEC was obtained. The color change of the BTB indicator proved that urease was trapped in the cavities of the alginate-chitosan PEC membrane while the immobilized urease still showed catalytic activity. Thus, the membrane of alginate-chitosan PEC has good characteristics as a matrix for urease immobilization.

The synthesis of polyelectrolyte complexes (PEC) based on chitosan and determination of their antibacterial properties had been conducted. The microstructure of PECs obtained were described by SEM analysis, while inhibition activity of PECs against S. aureus and E. coli was determined by measuring inhibitory zone diameter. Characteristics of chitosan, alginate and κ-carrageenan as natural polymers which non-toxic, biodagradable and safe to eat meet the edible film criteria. Chitosan as a polycationic interacts with alginate and κ-carrageenan as polyanionic under the appropriate conditions to form PEC film. Based on FTIR spectra, it was found that interaction of chitosan and alginate as well as chitosan and κ-carrageenan was an electrostatic interaction. Microstructure study using SEM found that PECs have irregular and fibrous surface structure. Based on their inhibitory activity against S. aureus and E. coli, PECs have the strongest antibacterial activity compared to their original polymer. Therefore, PECs film could be excellent edible film for food coating that protect product from bacterial contamination.

Abstrak: Pemenuhan kebutuhan air bersih yang aman dan layak dikonsumsi belum dapat dirasakan oleh semua lapisan masyarakat Lombok Tengah akibat tingginya angka kemiskinan dan rendahnya tingkat pendidikan masyarakat. Selain itu dengan tingginya aktivitas sektor pertanian yang menggunakan pupuk dan pestisida, dimungkinkan bahan kimia dan hasil peruraianya akibat proses  leaching terbawa aliran air kemudian meresap  ke dalam tanah dan masuk ke dalam sumber air tak terlindungi. Hal ini diindikasikan dengan hasil pengukuran kadar nitrit dan ammonia di beberapa sungai yang mengaliri desa. Salah satu solusi yang akan diterapkan dalam kegiatan ini adalah penerapan teknologi tepat guna tentang proses pengelolaan air siap minum dengan membuat unit pengolahan air irigasi menjadi air siap minum dengan menggunakan metode filtrasi-adsorpsi (kombinasi oleh pasir silika, karbon aktif dan membran) dan penyinaran lampu UV untuk desinfikasi. Sosialisasi kepada kelompok – kelompok tani Desa Jago dilakukan sebagai sarana alih teknologi tentang pengolahan air siap minum dan sebagai upaya mengedukasi masyarakat mengenai perilaku hidup bersih dan sehat serta pemanfaatan air secara bijak dan efektif. Keberlanjutan program dilakukan melalui pengelolaan mandiri oleh P3A dengan dukungan dari masyarakat sekitar dan pengawasan dari Perangkat Desa Jago. Kata kunci: air siap minum, filtrasi, adsorpsi, uv radiasi, Desa Jago.