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Ivandini Tribidasari A.
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Makara Journal of Science
Published by Universitas Indonesia
ISSN : 23391995     EISSN : 23560851     DOI : https://doi.org/10.7454/mss
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Makara Journal of Science publishes original research or theoretical papers, notes, and minireviews on new knowledge and research or research applications on current issues in basic sciences, namely: Material Sciences (including: physics, biology, and chemistry); Biochemistry, Genetics, and Molecular Biology (including: microbiology, physiology, ecology, taxonomy and evolution); and Biotechnology.
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Articles 880 Documents
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Effect of Mechanical Milling on the Total Phenolic Content and Antioxidant Activity of Garcinia mangostana Pericarp Nugroho, Dwi Wahyu; Daratika, Dyah Ayu; Kamila, Muthia; Togatorop, Lusiana; Rifada, Mohammad Aulia; Widayatno, Wahyu Bambang; Maulana, Syahrizal; Setyawati, Damai Ria; Mardliyati, Etik; Rochman, Nurul Taufiqu
Makara Journal of Science Vol. 24, No. 2
Publisher : UI Scholars Hub

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Abstract

This study aimed to identify the effect of mechanical milling on the total phenolic content and antioxidant activity of mangosteen pericarp. Mangosteen pericarp was milled under different milling times (30, 90, 150, and 210 min). The particle morphology before and after milling was observed by scanning electron microscopy (SEM), and the average particle size was obtained from SEM images and analyzed statistically. The antioxidant activity was measured through the 2,2-diphenyl-1-picrylhydrazyl method. The total phenolic content for the non-milling sample was 14.52 × 104 µg GAE/g sample, and the highest total phenol content was 17.44 × 104 µg GAE/g sample for the sample milled for 210 min. The IC50 value decreased for samples with milling 150 and 210 min, which showed strong antioxidant activity, whereas the value of gallic acid equivalent increased. SEM observations showed the presence of agglomeration in the morphology of mangosteen pericarp samples. The average particle size of the mangosteen pericarp decreased as the milling time increased (up to 4499 nm for samples milled for 210 min). Therefore, mechanical milling had a significant effect on the phenolic content and antioxidant activity, which indicated an increase in the bioavailability of mangosteen pericarp.
Indigenous Microbial Biostimulation for Microbial Enhanced Oil Recovery through Oil Degradation with Variation in Nutrent Concentrations Handaruni, Rika; Astuti, Dea Indriani; Purwasena, Isty Adhitya; Afifah, Lulu Nur
Makara Journal of Science Vol. 24, No. 2
Publisher : UI Scholars Hub

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Abstract

Oil production in Indonesia has been declining since 2002, and this decline is incompatible with the high oil consumption in Indonesia. As such oil production in Indonesia should be improved. Biostimulation in microbial enhanced oil recovery involves environmental modification to stimulate microbial growth within a reservoir by adding limiting nutrients. Variation in C, N, and P concentrations injected to reservoirs can induce different responses from indigenous microbes and increase oil recovery. In this study, molasses, urea and diammonium phosphate were used as nutrients injected to a reservoir for biostimulation. Biological, physical and chemical characteristics after biostimulation were observed and bacterial growth was monitored up to 42 days. The physical characteristics observed were pH, oil viscosity, and interfacial tension. Gas chromatography mass spectrometry was performed to determine the chemical characteristics of oil. Results showed that the addition of nutrients at various concentrations yielded different production patterns of metabolites. The addition of urea and diammonium phosphate induced biosurfactants overproduction and increase hydrocarbon degradation of by bacteria. Therefore, hydrocarbons were degraded for the first 14 days, and polymerized again on days 14 to 42.
Antibacterial and Anti-Biofilm Activities of Culture Filtrates from Schizophyllum commune, Coniothyrium sp., and Fusarium sp. Hastuty, Aerma; Mairani, Rahma; Rosada, Keukeu Kaniawati
Makara Journal of Science Vol. 24, No. 2
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Abstract

Bacterial infections are usually caused by biofilms that are resistant to extreme conditions. Studies have shown that fungal extracts have the potential to inhibit biofilm formation. The aim of this study was to examine the activity of several fungal culture filtrates in inhibiting bacterial growth and biofilm formation. The fungi were identified by molecular method, and the effects of different concentrations (45%, 75%, and 90%), medium pH (6, 7, and 9), temperatures (30 and 37 °C), and incubation times (24, 48, and 72 h) of the filtrates on their anti-biofilm formation properties were investigated. Anti-biofilm assay was performed using the diffusion test and microtiter assay. The parameters examined included the diameter of the inhibition zone of each well and the optical density of the filtrate solution. Molecular identification based on ITS rDNA regions showed that the fungal isolates in this study were Schizophyllum commune (strain JSB2), Coniothyrium sp. (strain JB1-3), and Fusarium sp. (strain JBB2). Antibacterial assay showed that, among the culture filtrates obtained from all fungi, that from Fusarium sp. strain JBB2 exhibits the highest inhibitory activity. Biofilm inhibition assay further revealed optimum fungal culture filtrate activities at pH 7.
Investigation of Microstructure and Magnetic Properties of Zn1-xMnxO and Zn0.98-xMnxFe0.02O (x = 0, 0.05, and 0.09) prepared by Solid-state Reaction Method Sebayang, Perdamean; Kurniawan, Candra; Lubis, Ridwan Y; Priyadi, Ignu; N, Nasruddin M; Aryanto, Didik
Makara Journal of Science Vol. 24, No. 2
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Abstract

In this study, we investigated the microstructure and magnetic properties of Zn1-xMnxO and Zn0.98-xMnxFe0.02O (x = 0, 0.05, and 0.09) powders prepared by the solid-state reaction method. The starting material, which consisted of ZnO, Mn, and Fe powders, were wet milled for 3 hours using high-energy milling. We then used an X-ray diffractometer (XRD), scanning electron microscope, and vibrating sample magnetometer to investigate the effects of doping and co-doping on the microstructure, morphology, and magnetic properties, respectively. The XRD results suggest that Mn and Fe ions had substituted into the ZnO matrix, as illustrated by the resulting single-phase polycrystalline hexagonal wurtzite structures. The diffraction intensity was observed to decrease as the Mn composition increased. The analysis showed that the lattice parameters decreased due to Mn2+ and Fe3+ ion substitution in the ZnO matrix. The co-doping of Mn-Fe ions in the ZnO structure enhanced the magnetic properties, particularly due to the Zn0.89Mn0.09Fe0.02O composition. The increase in the Mn dopant and Mn-Fe co-dopant concentrations strongly contributed to the improved morphology and magnetic properties. Therefore, we can conclude that the presence of Mn and Fe co-dopants in the ZnO system contributed to its magnetic properties, as confirmed by high-saturation magnetization.
Protein Annotation of Breast-cancer-related Proteins with Machine-learning Tools Parikesit, Arli Aditya; Agustriawan, David; Nurdiansyah, Rizky
Makara Journal of Science Vol. 24, No. 2
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Abstract

One of the primary contributors to the mortality of women is breast cancer. Several approaches are used to cure it, but recurrence occurs in 79% of the cases because the underlying mechanism of the protein molecules is not carefully ex-amined. The goal of this research was to use machine-learning tools is to elucidate conserved regions and to obtain functional annotations of breast-cancer-related proteins. The sequences of five breast-cancer-related proteins (BRCA2, BCAR1, BCAR3, BCAR4, and BRMS1) and their annotations were retrieved from the UniProt and TCGA databases, respectively. Conserved regions were extracted using CLUSTALX. We constructed a phylogenetic tree using the MEGA 7.0. SUPERFAMILY database to obtain fine-grained domain annotation. The tree revealed that the BRCA2 and BCAR4 protein sequences are located in a clade, which indicates that they have overlapping functions. Several protein domains were identified, including the SH2 and Ras GEF domains in BCAR3, the SH3 domain in BCAR1, and the BRCA2 helical domain, the nucleic-acid-binding protein, and tower domain. We found that no protein domains could be annotated for BCAR4 or BRMS1, which may indicate the presence of a disordered protein state. We suggest that each protein has distinct functionalities that are complementary in regulating the progression of breast cancer, although further study is necessary for confirmation. This protein-domain annotation project could be leveraged by the complete integration of mapping with respect to gene and disease ontology. This type of leverage is vital for obtaining biochemical insights regarding breast cancer.
Biosensor and Chemosensor Fluorophores that contain Chalcogenide Centers Yudhistira, Tesla; Lee, Woo Hyun; Churchill, David G
Makara Journal of Science Vol. 24, No. 2
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Abstract

In this timely review, we discuss the important attributes of various chalcogen-containing small-molecule probes that have been synthesized in the Molecular Logic Gate Laboratory at the Korea Advanced Institute of Science and Technology. Specifically, we discuss some of the important chemical and photophysical properties of these probes, including reversibility, responsiveness (response time), cellular localization, sensitivity to analytes, selectivity (toward a specific analyte in question), and some bioavailability criteria. Chalcogenides undergo reversible redox-type reactions with reactive oxygen species (ROS). These controlled solution reactions enable a sensible and clear response as they act to immediately affect the chemical and electronic properties of the chalcogen moiety. Often, the lone pair belongs to chalcogens, which communicate electronically with the rest of the probes. Importantly, chemically oxidized chalcogenides can revert to their original reduced (divalent) form through the addition of natural or unnatural biothiols (or other reductants). This phenomenon is considered reversibility from the standpoint of probes. It can also be called “resetability.” In this manner, a variety of fluorophore frameworks can be used to detect ROS and thiols. Further studies can help experimentally determine the lipophilicity and even the cellular localization of probes, which are important in assessing their value as diagnostic agents in biological sciences and their possible therapeutic potential.
Composition of Fatty Acids and Squalene Content of Wild Spinach (Amaranthus dubius Mart) Seed Oil Soetjipto, Hartati; Krisdayanti, Mitra; Aminu, November Rianto
Makara Journal of Science Vol. 25, No. 2
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This study aims to determine the yield of wild spinach seed oil obtained by continuous extraction methods using Soxhlet apparatus for 10.5 hours in n-hexane solvent, the physio-chemical properties, and the composition of wild spinach seed oil using the Gas Chromatography-Mass Spectrometry (GC-MS) method. Refinement of wild spinach seed oil was done by degumming and neutralization. The yield of wild spinach seed oil extraction before refinement was 4.36 ± 0.29% (w/w) while after refinement was 0.68 ± 0.033% (w/w). Physio-chemical properties of wild spinach seed oil after refinement was as follows: water content 0.37%; peroxide value 9.5 meq/kg; acid value of 0.53 mg KOH/g oil; saponification value 208.9 mg KOH/g oil. The results of GC-MS analysis showed that the wild spinach seeds were composed of 5 main components: dodecanoic acid (0.28%); tetradecanoic acid (0.08%); palmitic acid (1.31%); squalene (94.9%); and linoleic acid (3.34%).
Sensitivity Enhancement of Silicon-on-Insulator Multipath Ring Resonator using Gold Nanodisk for Sensor Application Dicky, Gabriel; Taufiqurrahman, Shidqie; Estu, Topik Teguh; Wijayanto, Yusuf Nur; Manurung, Robeth Viktoria; Mahmudin, Dadin; Anshori, Isa; Daud, Pamungkas
Makara Journal of Science Vol. 24, No. 3
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Abstract

Currently, environmental degradation caused by heavy metals has become a serious concern of many countries. To monitor the concentration of heavy metals in the environment, an in-situ sensor that can measure in real time and has high quality, sensitivity, and flexibility is essential. We proposed a modified multipath ring resonator (MPRR) based on silicon-on-insulator technology with additional gold nanodisk (GND) on top of the ring to increase its sensitivity. To prove the effect of GND on the sensitivity of the modified MPRR, finite-difference time-domain simulations were conducted. Results showed that the average sensitivity of the modified MPRR was 675 nm/RIU, where RIU corresponds to the refractive index unit, higher than that of the unmodified MPRR (171 nm/RIU). Moreover, compared with the single ring structure, the proposed design had better sensitivity. We believe that our proposed approach for the modification of MPRR is suitable for application to optical sensor development.
Solid Waste Co-Conversion by Hydrothermal Treatment using Natural Zeolite Maleiva, Lalak Tarbiyatun Nasyin; Wahyu Purnomo, Chandra
Makara Journal of Science Vol. 24, No. 3
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Hydrothermal treatment is a thermal conversion technology for processing high-moisture-content solid waste to coal-like materials. In this research, mixtures of sawdust and polyethylene terephthalate (PET) waste were treated in a 2000 mL hydrothermal reactor to produce hydrochar and a liquid product. The effects of zeolite addition and temperature variations during the treatment on the product characteristics were investigated. During the treatment, the utilized temperatures were 180, 200, and 220 °C, and the zeolite contents in the mixture were 10 and 20 wt%; the temperature and zeolite content were varied, while the other processing parameters were fixed, i.e., a biomass-to-PET ratio of 1:1, solid mixture-to-water ratio of 1:10, and processing time of 30 minutes at the targeted temperature. The product from each hydrothermal condition was characterized in terms of solid yield; liquid pH; chemical characteristics, determined using proximate analysis; and calorific value. The result shows that the addition of zeolite could increase the solid yield, while a higher treatment temperature led to a higher calorific value of the solid product.
Removal of Pb2+ and Cd2+ from Aqueous Solutions using POCl3 Cross-linked Carboxymethyl Derivatives of Legume Starch Akinterinwa, Ayodele; Oladele, Ebun; Adebayo, Albert; Ajayi, Olubode
Makara Journal of Science Vol. 24, No. 3
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Starch was extracted from Kwakil beans and cross-linked with POCl3 (1% v/w of starch dry basis [db]). The cross-linked starch (PCS) derivative was carboxymethylated with sodium monochloroacetate (5% to 30% w/w of starch db) to obtain cross-linked carboxymethyl starch (PCCS) derivatives. The derivatives were used in the adsorption of Pb2+ and Cd2+, and the process was monitored using atomic adsorption spectrometer. Carboxymethylation enhanced adsorption of ions (Cd2+, 95% to 96%; Pb, 65% to 94%), and it was more appreciable with Pb2+ than Cd2+ as degree of substitution increased from 0.008 to 0.052. This was attributed to selective ion exchange, steric and stereochemical effects of the carboxymethyl groups. Derivatives were characterized with Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Adsorption increased with pH and adsorbent dosage but decreased when temperature and interfering ion (i.e., Na+ and Ca2+) concentrations increased. Adsorption equilibrium was reached in 5 min. Kinetic parameters of Pb2+ fitted the pseudo-second-order model (R2 = 0.9999), while Cd2+ fitted the pseudo-first-order model (R2 = 0.9978). Isotherm parameters of Pb2+ fitted Langmuir model (R2 = 0.9989), while Cd2+ fitted Freundlich model (R2 = 0.9689). These parameters inferred the involvement of different combinations of physisorption and chemisorption mechanisms in the adsorption of Pb2+ and Cd2+. However, the thermodynamic parameters indicated the dominance of the physisorption mechanism in the overall exothermic process (∆H = −15.51 and −9.79 kJ·mol−1 for Pb2+ and Cd2+, respectively). Pb2+ and Cd2+ were recovered (≈100%) in 1 M HNO3, and efficient re-adsorption (>80%) was obtained till third reuse cycle. Product was used to treat wastewater and the heavy metals were efficiently removed.

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