AKTIVITAS AMILASE PENDEGRADASI PATI MENTAH DARI BAKTERI TANAH TEMPAT PEMBUANGAN AKHIR BUKIT PINANG

Raw starch-degrading amylase (RSDA) is a hydrolytic enzyme that can degrade raw starch into glucose. This study was conducted to obtain raw starch-degrading amylase-producing bacteria from the soil of the Bukit Pinang Landfill, Samarinda City. Isolation of bacteria using the spread plate method. Screening of RSDA-producing bacteria using nutrient media to contain raw starch. Isolation of bacteria obtained 10 single colonies of bacteria. The isolated bacteria were selected for their ability to produce RSDA. All single colonies of bacteria could produce RSDA and their activity was tested quantitatively using the 3,5 Dinitrosalicylic Acid (DNS) method. Bacteria with the TPA 1 colony code had the highest activity of 3.837 U/mL

ELEKTRODELOKALISASI ZAT WARNA LIMBAH CAIR SARUNG TENUN SAMARINDA MENGGUNAKAN ELEKTRODA PbO2/Cu

Electrodecolorization of Sarung Tenun Samarinda liquid waste dyestuff using PbO2/Cu electrode has been conducted. This study aims to reduce the level of dyes in Sarung Tenun Samarinda liquid waste samples by electrodecolorization method using lead dioxide (PbO2) electrode as anode and Copper (Cu) as cathode. Electrodecolorization was carried out by varying the working potential, Na2SO4 electrolyte concentration, time, and dye concentration in order to obtain optimum conditions for dye decolorization by electrolysis process. The concentration of the dye was determined by calculating the absorbance data obtained from measurements using a UV-Vis spectrophotometer. The results showed that the optimum conditions of electrodecolorization on orange dyes using PbO2/Cu electrodes were a working potential of 10.5 volts, 0.2 M Na2SO4 electrolyte concentration and a time of 20 minutes. In green dyes, the optimum conditions are working potential of 10.5 volts, electrolyte concentration of Na2SO4 0.1 M and time for 15 minutes. The percentage of decolorization of the orange Sarung Tenun Samarinda liquid waste sample using the PbO2/Cu electrode was 100% and in the green Sarung Tenun Samarinda liquid waste sample was 100%

POTENSI AKTIVITAS ANTIBAKTERI EKSTRAK DIKLOROMETANA DAN METANOL BUNGA TEROMPET EMAS (Allamanda cathartica L.) TERHADAP BAKTERI Staphylococcus aureus ATCC 25923

Potential antibacterial activity of dichloromethane and methanol extracts of the golden trumpet flower (A.cathartica L.) against S. aureus ATCC 25923 has been conducted. This study aimed to determine the values of thedichloromethane and methanol extracts of A. cathartica L. The antibacterial activity test was conducted using agardiffusion method and carried out in triplicate. The obtained results from the dichloromethane extract and methanol extractof the golden trumpet flower (A. cathartica L.) showed antibacterial activity with inhibition zone diameters of 9.66 mmfor dichloromethane extracts and 8.66 mm for methanol extracts against S. aureus ATCC 25923 bacteria.Potensi aktivitas antibakteri dari ekstrak diklorometana dan metanol bunga terompet emas (A. cathartica L.) terhadap S. aureus ATCC 25923 telah dilakukan. Penelitian ini bertujuan untuk menentukan nilai-nilai dari ekstrak diklorometana dan metanol A. cathartica L. Uji aktivitas antibakteri dilakukan menggunakan metode difusi agar dan dilakukan secara tiga kali ulangan. Hasil yang diperoleh dari ekstrak diklorometana dan ekstrak metanol bunga terompet emas (A. cathartica L.) menunjukkan aktivitas antibakteri dengan diameter zona hambatan masing-masing sebesar 9,66 mm untuk ekstrak diklorometana dan 8,66 mm untuk ekstrak metanol terhadap bakteri S. aureus ATCC 25923

MINI REVIEW: SINTESIS DAN KARAKTERISASI NANOPARTIKEL ZnO DAN APLIKASINYA SEBAGAI FOTOKATALIS

This mini review will explore the multifunctional of ZnO nanomaterials. ZnO The multifunctional ZnO nanomaterial due to its inexpensive nature, eco-friendly, structure-dependent properties, and complete mineralization of pollutants make them more efficient semiconducting photocatalysts than other materials and good UV absorption. ZnO has many applications in everyday life such as for photocatalysts, antibacterials, edible coatings, and others. Based on the literature review, ZnO material can be synthesized using sol-gel, hydrothermal, solvothermal, precipitation and coprecipitation methods. So, this article reviews the recent developments in the degradation of Methylene Blue and Rhodamine B, which are cationic dyes, by examining operational parameters such as reaction time, initial dye concentration, and catalyst concentration.   Keywords: Nanoparticles, Nano materials, Photocatalyst

OPTIMASI PEMBENTUKAN NANOPARTIKEL PERAK DENGAN BIOREDUKTOR DARI EKSTRAK DAUN TAHONGAI ( Kleinhovia hospita Linn.)

The synthesis of Silver Nanoparticles was carried out by bottom-up method by reducing Ag+ ions to Ag0 using Tahongai leaves (Kleinhovia hospital Linn) which contain secondary metabolites such as alkaloids, flavanoids and phenolics as bioreductors that reduce AgNO3 solution as a precursor. The purpose of this study was to determine whether tahongai leaves can be used as a bioreductor in the synthesis of silver nanoparticles. The concentration variation of tahongai leaf extract bioreductor was 25 %; 50 %; and 75 %.  Changes in silver nanoparticles can be marked by changes in the color of the solution and by UV-Vis Spectrophotometer absorption. The results of this study showed a change in color of AgNO3 solution from clear to brownish yellow which indicates the formation of silver nanoparticles, and through UV-Vis Spectrophotometer analysis showed absorption at wavelengths of 420 to 430 which indicates relatively stable nanoparticles so it can be concluded that tahongai leaf extract can be used as a bioreductor for the synthesis of silver nanoparticles.Sintesis Nanopartikel Perak dengan metode bottom-up  yakni dengan mereduksi ion Ag+ menjadi Ag0, daun Tahongai (Kleinhovia hospital Linn) yang memiliki kandungan metabolit sekunder seperti alkaloid, Flavanoid dan Fenolik  sebagai bioreduktor yang mereduksi larutan AgNO3 sebagai prekursor . Tujuan dari penelitian ini adalah untuk mengetahui apakah daun tahongai dapat digunakan sebagai bioreduktor dalam sintesis nanopartikel perak. Dilakukan variasi konsentrasi dari bioreduktor ekstrak daun tahongai sebesar 25 %; 50%; dan 75%.  Perubahan Nanopartikel perak dapat  ditandai perubahan warna larutan dan dengan serapan Spektrofotometer UV-Vis. Di dapatkah hasil dari penelitian ini terjadi perubahan warna larutan AgNO3 dari bening menjadi kuning kecoklatan yang menandakan terbentuknya nanopartikel perak, dan melalui analisi  Spektrofotometer UV-Vis menunjukkan serapan pada panjang gelombang 420 hingga 430 yang menandakan nanopartikel relatif stabil sehingga dapat disimpulkan bahwa ekstrak daun tahongai dapat dijadikan sebagai bioreduktor untuk sintesis nanopartikel perak

POTENSI AKTIVITAS ANTIOKSIDAN EKSTRAK METANOL DAUN SINGKIL(Premna corymbosa Roxb & Willd.)

Antioxidant and sunscreen activity tests have been carried out on the methanol extract of singkil leaves(Premna corymbosa Roxb & Willd.) in vitro with the 1.1-diphenyl-2-picrylhydrazil (DPPH) radicalscavenging method using a spectrophotometer UV-Vis. This research aims to determine the antioxidantof singkil leaf. Based on the results of the phytochemical test, it is known that the methanol extract ofsingkil leaves contains alkaloids, flavonoids, phenolics, quinone and steroids. The IC50 value ofmethanol extract of singkil leaves, ia 50.77; in the moderate to strong antioxidant category

SINTESIS NANOPARTIKEL PERAK TERMODIFIKASI L-CYSTEINE SEBAGAI METODE ANALISIS: REVIEW JURNAL

Silver nanoparticles with a size of 1 to 100 nm with unique properties have many advantages that they are widely applied in the medical and industrial fields. Various methods can be carried out in synthesizing silver nanoparticles both physically, chemically and biologically.  In the chemical method, it is done by reducing Ag+ ions into silver nanoparticles so that this method depends on reducing agents and stabilizers used. The use of different reducing agents greatly affects the size of the nanoparticles produced. Based on the literature review, sodium borohydride (NaBH4) has a strong ability to reduce Ag+ ions into silver nanoparticles become a small size. In addition, referring to previous studies if modified with L-cysteine, the silver nanoparticles formed can be stable for more than 2 months at room temperature storage. L-cysteine-modified silver nanoparticles from previous studies were used for colorimetric analysis of vitamin B1 detection in food and water samples, where the color change in silver nanoparticles from yellow to colorless showed remarkable chemical sensor selectivity for detecting target analytes

AKTIVITAS ANTIOKSIDAN KOMBINASI EKSTRAK ETANOL 70% DAUN MELINJO (Gnetum gnemon L.) DAN BUAH BELIMBING WULUH (Averrhoa bilimbi L.)

Melinjo leaves (Gnetum gnemon L.) and Star Fruit (Averrhoa bilimbi L.) is a plant that can be used as traditional medicine. Melinjo leaves contain alkaloids, saponins, tannins, phenols, flavonoids, triterpenoids and steroids. Star fruit contains alkaloids, flavonoids and triterpenoids. These compounds function as antioxidants to counteract free radicals. The purpose of this study was to determine the secondary metabolites and determine the antioxidant activity of the combination of 70% ethanol extract of melinjo leaves and star fruit. The simplicia powder was extracted by maceration using 70% ethanol solvent, then a phytochemical test was carried out, after which the single antioxidant test and the combination of extracts were tested at a ratio of 1:3, 3:1, 1:1 with concentration series 5, 10, 20, 40, 80 ppm, the determination of antioxidants was carried out using DPPH (1,1-diphenyl-2-picrylhydrazyl) by measuring the absorbance of DPPH at a wavelength of 515 nm. The results of this study indicate that the value of IC50 for the ethanol extract of melinjo leaves was 7.86 μg/mL, the ethanol extract of star fruit was 33.70 μg/mL and the IC50 value from each combination of ethanol extract of melinjo leaves and star fruit at a ratio of 1:3 obtained 32.1 μg/mL, a ratio of 3:1 obtained 5.91 μg/mL and a ratio of 1:1 obtained 19.49 μg /mL. Based on the results of the study, it can be concluded that the antioxidant activity of the combination of 70% ethanol extract of melinjo leaves and star fruit in a ratio of 3:1 has an IC50 value the best was 5.91 μg/mL which was included in the very strong category.   Keywords: Antioxidants, Melinjo Leaves, Star Fruit, Phytochemicals, DPP

MINI REVIEW: SINTESIS DAN KARAKTERISASI NANOPARTIKEL CaO DARI CANGKANG TELUR MENGGUNAKAN METODE KALSINASI

This review article aims to collect, compare and analyze the latest research on the synthesis and characterization of CaO nanoparticles from eggshells. CaO is a material in the form of white crystalline solids made from thermal decomposition of limestone or shells, which contains CaCO3 which has the potential to become CaO nanoparticles to be applied in various fields. Currently, various methods have been carried out to synthesize these materials, such as precipitation methods, hydrothermal methods, sol-gel methods, and so on. One of them is the calcination method. The calcination method itself is a commonly used thermal processing method involving heating at high temperatures. The advantages of the calcination method are that it is efficient, has a high level of purity, is economical and relatively simple and others. However, the calcination method itself has disadvantages, namely the process time is quite long, must be careful and can have a negative impact on the environment. In this review, we will discuss the synthesis of CaO nanoparticles characterized using X-Ray Diffraction (XRD), Fourier Transform InfraRed (FTIR), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM). The literature results show that in XRD the main peak 2θ positions are 111 and 200 and the crystal size is 10-55 nm, in FTIR the functional groups that appear are the Ca-O stretch group and C-O stretch vibrations, in SEM and TEM the shape of the crystal.   Keywords: Synthesis, CaO nanoparticles, Calcinatio