VALIDITAS LEMBAR KEGIATAN SISWA BERBASIS INKUIRI PADA MATERI PENCEMARAN LINGKUNGAN UNTUK MELATIHKAN LITERASI SAINS SISWA KELAS X SMA

Tingkat literasi sains siswa di Indonesia masih jauh tertinggal dengan negara-negara lainnya sehingga perlu difasilitasi bahan ajar yang dapat mendukung kegiatan literasi sains. Bahan ajar tersebut dapat berupa Lembar Kegiatan Siswa (LKS) berbasis inkuiri yang diharapkan dapat melatihkan literasi sains siswa. Penelitian yang dilakukan bertujuan untuk menghasilkan LKS dan mendeskripsikan validitas LKS berbasis inkuiri pada materi pencemaran lingkungan untuk melatihkan literasi sains siswa kelas X SMA berdasarkan penilaian 3 pakar. Terdapat dua LKS yang dikembangkan yaitu LKS 1 membahas topik pencemaran udara dan LKS 2 membahas topik pencemaran air. Model pengembangan yang digunakan dalam penelitian ini adalah model 4-D yaitu define, design, develop dan disseminate, namun tahap disseminate tidak dilaksanakan. Analisis data hasil validasi dilakukan secara teoritis dan empiris. Hasil validasi menunjukkan bahwa LKS yang dikembangkan dikategorikan sangat valid dengan perolehan persentase sebesar 93,99%. Hasil belajar siswa menunjukkan bahwa siswa mengalami peningkatan literasi sains dengan perolehan N-gain sebesar 0,71 yang tergolong kategori tinggi. Persentase jumlah siswa yang mencapai KKM (tuntas) pada saat  posttest sebesar 87,5% dengan nilai KKM 75 dan ketuntasan indikator memperoleh persentase sebesar 100% tuntas dari 13 indikator pada saat posttest.   Kata kunci: Validitas LKS, inkuiri, literasi sains, pencemaran lingkunga

VALIDITAS LEMBAR KEGIATAN SISWA BERBASIS INKUIRI PADA MATERI PENCEMARAN LINGKUNGAN UNTUK MELATIHKAN LITERASI SAINS SISWA KELAS X SMA

Tingkat literasi sains siswa di Indonesia masih jauh tertinggal dengan negara-negara lainnya sehingga perlu difasilitasi bahan ajar yang dapat mendukung kegiatan literasi sains. Bahan ajar tersebut dapat berupa Lembar Kegiatan Siswa (LKS) berbasis inkuiri yang diharapkan dapat melatihkan literasi sains siswa. Penelitian yang dilakukan bertujuan untuk menghasilkan LKS dan mendeskripsikan validitas LKS berbasis inkuiri pada materi pencemaran lingkungan untuk melatihkan literasi sains siswa kelas X SMA berdasarkan penilaian 3 pakar. Terdapat dua LKS yang dikembangkan yaitu LKS 1 membahas topik pencemaran udara dan LKS 2 membahas topik pencemaran air. Model pengembangan yang digunakan dalam penelitian ini adalah model 4-D yaitu define, design, develop dan disseminate, namun tahap disseminate tidak dilaksanakan. Analisis data hasil validasi dilakukan secara teoritis dan empiris. Hasil validasi menunjukkan bahwa LKS yang dikembangkan dikategorikan sangat valid dengan perolehan persentase sebesar 93,99%. Hasil belajar siswa menunjukkan bahwa siswa mengalami peningkatan literasi sains dengan perolehan N-gain sebesar 0,71 yang tergolong kategori tinggi. Persentase jumlah siswa yang mencapai KKM (tuntas) pada saat  posttest sebesar 87,5% dengan nilai KKM 75 dan ketuntasan indikator memperoleh persentase sebesar 100% tuntas dari 13 indikator pada saat posttest.   Kata kunci: Validitas LKS, inkuiri, literasi sains, pencemaran lingkunga

ANALISIS KELAYAKAN USAHA UNTUK PENGEMBANGAN BISNIS WEDANG WAROK

Analisis kelayakan usaha adalah analisis yang dilakukan untuk menentukan layak atau tidaknya usaha tersebut dikembangkan. Analisis ini ditinjau dari aspek finansial dan aspek nonfinansial. Aspek finansial atau keuangan berupa analisis Break Event Point (BEP) dan analisis Revenue Cost Ratio (R/C). Sedangkan aspek nonfinansial salah satunya berupa aspek pemasaran. Aspek pemasaran yang digunakan dalam penelitian ini adalah analisis SWOT. Tujuan dari penelitian ini adalah mengetahui analisis kelayakan usaha untuk pengembangan bisnis Wedang Warok. Objek penelitian ini adalah kelayakan usaha untuk pengembangan bisnis Wedang Warok. Metode yang digunakan dalam penelitian ini adalah metode deskriptif kuantitatif. Hasil dari penelitian menunjukkan bisnis Wedang Warok mengalami Break Event Point tingkat penjualan 118 unit dengan total penerimaan sebesar Rp 295.000. Dari perhitungan Revenue Cost Ratio diperoleh angka >1 yaitu 1,7. Hal itu menunjukkan bahwa bisnis Wedang Warok layak untuk dikembangkan. Analisis tersebut diperkuat dengan hasil analisis SWOT yang menunjukkan bahwa kekuatan dan peluang yang dimiliki produk sangat besar untuk pengembangan bisnis. Kata kunci : Kelayakan Usaha, BEP, R/C, Analisis SWO

Aktivitas NADP(H) Oksidoreduktase pada Kultur Sel Kina (Cinchona ledgeriana Moens) Terelisitasi

Cinchona ledgeriana Moens is an industrial plant producing secondary metabolite quinoline alkaloids. To maintain and moreover, to increase the quinoline production especially quinine, in vitro culture system through cell culture could be a potential alternative. If the use of elicitor in cell culture can increase the production of a secondary metabolite, the activity of the enzymes involved in the biosynthetic pathway of the secondary metabolite in question might be increasing. This study aimed to examine the activity of NADPH oxidoreductase in the elicitated cell culture of C. ledgeriana and to evaluate the correlation between the activity of this enzyme and the level of quinine production. The cell cultures of Cinchona were treated with abscisic acid (ABA) or paclobutrazol (PBZ), combined with sucrose, sorbitol, or mannitol in Wood Plant (WP) media, for 7 weeks on a shaker. The quinine concentration was determined using high-performance liquid chromatography (HPLC) and the enzyme activity was measured using fluorometry. The results showed that the highest enzyme activity was found in the P7M cells (PBZ 7 mg/L + mannitol 5.3 g/L + sucrose 20 g/L), followed by the A3S cells (ABA 3 mg/L + sorbitol 5.3 g/L + sucrose 20 g/L). These results correspond to their production level of the quinine alkaloids. The lowest enzyme activity was found in the cultures without elicitor. The increase of NADP(H) enzyme activity in the P7M and A3S treatments were 13.5 and 8.5%, respectively, compared to that in the control cells. Keywords: elicitation, fluorometry, NADP(H) oxidoreductase, quinoline alkaloi

PENGARUH TINGKAT KEMATANGAN BUAH TERHADAP AKTIVITAS LARVASIDA DAN SIFAT FISIKO-KIMIA MINYAK KAMANDRAH (Croton tiglium L.)

ABSTRAKIndonesia terkenal kaya akan keanekaragaman hayati, termasukjenis tumbuhan yang mengandung bahan aktif insektisida. Tanamankamandrah (Croton tiglium L.) merupakan salah satu tanaman obat yangbanyak terdapat di wilayah Indonesia dan telah dimanfaatkan sebagaiinsektisida nabati. Penelitian ini bertujuan untuk mengetahui karakteristikfisiko-kimia minyak kamandrah pada berbagai tingkat kematangan sebagailarvasida nabati terhadap larva nyamuk demam berdarah dengue (A.aegypti). Penelitian dilakukan di Laboratorium Balai Penelitian TanamanRempah dan Aneka Tanaman Industri (Balittri) Sukabumi, Balai BesarLitbang  Pascapanen  Pertanian  Bogor,  Insektarium  LaboratoriumParasitologi dan Entomologi Kesehatan FKH IPB Bogor, dan Biofarmaka-LPPM IPB Bogor, mulai bulan Februari sampai Desember 2010. Minyakkamandrah diperoleh dengan ekstraksi menggunakan pengempa hidrolikpada suhu 65 o C dan tekanan 7,9 MPa pada buah kamandrah dengan tigatingkat kematangan yang berbeda: warna kulit buah hijau kecokelatan,cokelat kehijauan, dan cokelat penuh. Minyak yang diperoleh selanjutnyadianalisis bilangan asam, kadar asam lemak bebas, bilangan peroksida,indeks bias, berat jenis, dan nilai warna minyak, serta uji larvasidaterhadap larva nyamuk A. aegypti instar III. Penentuan nilai lethalconcentration (LC) dilakukan dengan metode probit analisis (FinneyMethod). Hasil penelitian menunjukkan bahwa berdasarkan nilai LC,rendemen, dan mutu minyaknya, buah kamandrah yang berwarna kulitcokelat penuh lebih berpotensi sebagai larvasida nabati terhadap larva A.aegypti. Rendemen minyak kamandrah 20,42% dan nilai LC 50 adalah132,67 ppm (24 jam) dan 70,08 ppm (48 jam). Minyak tersebut memilikibilangan asam 8,76 mg KOH/g minyak; kadar asam lemak bebas 4,36 mgKOH/g minyak; bilangan peroksida 3,59 meq O/100g minyak; indeks bias1,4783; bobot jenis 0,9466 g/ml; dan warna meliputi nilai L* 73,03; a*3,26; dan b* 64,13. Minyak kamandrah berpotensi dapat dimanfaatkansebagai larvasida nabati dalam pengendalian vektor penyakit DBD.Kata kunci : Croton tiglium L., kematangan buah, minyak kamandrah,larvasidaABSTRACTEffect of Maturity Level of Fruits on Larvicidal Activityand Physico-Chemical Properties of Kamandrah (Crotontiglium L.) OilIndonesia is famously rich in biodiversity, including species of plants thatcontain active ingredient for insecticide. Kamandrah plant (Croton tigliumL.) is one of many medicinal plants found in parts of Indonesia and it hasbeen used as an insecticidal plant. The objectives this research were todetermine the physico-chemical characteristics and larvasidal activities ofoil extracted from kamandrah seeds with varying levels of maturity asbotanical larvicide for mosquito dengue fever. The expreriments wereconducted in the Laboratory of Indonesian Spice and Industrial CropsResearch Institute (ISICRI) Sukabumi, Indonesian Center for AgriculturalPostharvest Research  and  Development (ICAPRD),  InsectariumLaboratory of Health Parasitology and Entomology, Faculty of Veterinaryof Bogor Agricultural University (IPB), and Biopharmaca IPB Bogor,from February to December 2010. The oil was obtained through extractionusing hydraulic pressurer at 65 o C temperatures and 7.9 MPa pressures ofkamandrah fruits with three different maturity levels : brownish green,greenish brown, and fully brown color of fruit skins. Oil gained was thenanalyzed its acid number, free fatty acid content, peroxides number,refractive index, specific gravity, and oil color values, as well as the oillarvasida test against mosquito larvae A. aegypti instar III. Determinationthe oil lethal concentration (LC) values was tested using probit analysismethod (Finney Method). The results showed that based on the values ofLC, content, and quality of the oil, full-brown colored kamandrah fruits aremore potential as larvivida against A. aegypti larvae. Oil content of thekamandrah was 20.42% while LC 50 values were 132.67 ppm (at 24 hours)and 70.08 ppm (at 48 hours). The acid number of the oil was 8.76 mgKOH/g oil; free fatty acid level of 4.36 mg KOH/g oil; peroxide number of3.59 meq O/100 g oil, refractive index of 1.4783; density of 0.9466 g/ml;and the color values were 73.03, 3.26, and 64.13 for L*, a*, and b*,respectively. Therefore, kamandrah oil is very potential to be used aslarvicide for controling the vector of dengue disease.Key words: Croton tiglium L., fruit maturity, kamandrah oil, larvicid

MIKROENKAPSULASI EKSTRAK FORMULA PEGAGAN-KUMIS KUCING-SAMBILOTO SEBAGAI INHIBITOR Angiotensin I Converting Enzyme SECARA In Vitro

Chitosan microencapsulation contained extract formula pegagan-kumis kucingsambiloto was resulted from ionic gelation process. Chitosan microencapsulation wasresulted by cleaning bath type of ultrasonication and homogenization methods. Optimum condition obtained at 2% of chitosan concentration (w/v) and 50 mL (v/v) of extract formula. The yields of chitosan microparticles was 64.24%. Characterization by SEM at 5000× magnification showed that the particle size of chitosan microparticles was not uniform. Chitosan microparticles without and contained extract formula had diameters between 0.40 μm-8.5 μm and 1 μm-6 μm, respectively. Each chitosan microparticles contained extract formula and extract formula had the ACE inhibitory activity of 78.41 %, and 75.73 %, respectively, while the captopryl as an positive control had ACE inhibitory activity of 75.24 %. Wave number peaks of chitosan spectrum was different with microparticles spectrum by using of FTIR analysis. Chitosan microparticles-sodium tripolyphosphate (STP) contained extract formula had absorbance bands of 1652.32 cm-1 (C=O) and 1565.63 cm-1 (C=C, aromatic group of benzene). New absorbance bands also appeared at wave numbers of 1153.82 cm-1 and 1154.66 cm-1 which showed absorbance band of P=O group from STP compound

MIKROENKAPSULASI EKSTRAK FORMULA PEGAGAN-KUMIS KUCING-SAMBILOTO SEBAGAI INHIBITOR Angiotensin I Converting Enzyme SECARA In Vitro

Chitosan microencapsulation contained extract formula pegagan-kumis kucingsambiloto was resulted from ionic gelation process. Chitosan microencapsulation wasresulted by cleaning bath type of ultrasonication and homogenization methods. Optimum condition obtained at 2% of chitosan concentration (w/v) and 50 mL (v/v) of extract formula. The yields of chitosan microparticles was 64.24%. Characterization by SEM at 5000× magnification showed that the particle size of chitosan microparticles was not uniform. Chitosan microparticles without and contained extract formula had diameters between 0.40 μm-8.5 μm and 1 μm-6 μm, respectively. Each chitosan microparticles contained extract formula and extract formula had the ACE inhibitory activity of 78.41 %, and 75.73 %, respectively, while the captopryl as an positive control had ACE inhibitory activity of 75.24 %. Wave number peaks of chitosan spectrum was different with microparticles spectrum by using of FTIR analysis. Chitosan microparticles-sodium tripolyphosphate (STP) contained extract formula had absorbance bands of 1652.32 cm-1 (C=O) and 1565.63 cm-1 (C=C, aromatic group of benzene). New absorbance bands also appeared at wave numbers of 1153.82 cm-1 and 1154.66 cm-1 which showed absorbance band of P=O group from STP compound

Evaluation of Bacterial Biofilm as Biosensor for Detecting Phenol, Catechol, and 1,2-dihydroxynaphthalene

Monitoring of water quality from the presence of polyaromatic hydrocarbon (PAHs) compounds and its derivates are important for keeping the healthy aquatic environment. Some of those derivates are phenol and several related compounds sharing simmilar structures. This reseach aimed for the detection of those phenol and several similar compounds monitoring due to PAHs degradation. Three identified bacterial isolates of Pseudomonas aeruginosa, Staphylococcus sciuri, and Bacillus amyloliquifaciens were selected based on their phenol degradation characters. On physiological properties all three isolates were observed to degrade several hydrophobic substances such as for naphthalene and anthracene. Yet, genetic analysis indicated that the phenolic degradating oxygenase gene was detected only in the P. aeruginosa and S. sciuri. Applying those isolates for biofilm as biosensor showed a sufficient analytical performance such as their limit of detection between 0.1-0.5 μM

Uric Acid Biosensor Based on Biofilm of L. plantarum using Screen-Printed Carbon Electrode Modified by Magnetite

Biosensor based on biofilm of L. plantarum has been successfully done for determination of uric acid in human urine compared with colorimetric enzymatic produced relative error of less than 5%. L. plantarum has uricase activity to react with uric acid, to maintain the stability of bacteria forming themselves into biofilms. Magnetite is known to increase sensitivity of the biosensor. The combination of magnetite-polyethylene glycol (Fe3O4-PEG) was used to modify the surface of Screen-Printed Carbon Electrode modified (SPCE) and the resulting modified electrode (biofilm/Fe3O4/PEG/SPCE) displayed good electrocatalytic activity to the oxidation of UA. The composition of biofilms with optical density 1, magnetite 100 mgmL-1 and PEG 3% v / v were able to increase the current up to 48% in 4mM of UA. The biosensor with an optimum composition produced good linearity with a concentration range, limit of detection, limit of quantitation, sensitivity, and repeatability were found to be 0.1 - 4.3 mM, 70 µM,  234 µM, 25.392 µA mM-1, 2.38%, respectively. This biosensor stable up to 49 days of measurement with the remaining activity was 90.70% and selective for interference compounds such as salt, urea, glucose, ascorbic acid. This method has a good stability, sensitivity, and potential application in clinical analysis