Makara Journal of Science
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Bioconversion of Glycerol to Docosahexaenoic Acid by Thraustochytrium WB-02 an Indigenous Indonesian Microalga Strain
No full textGlycerol is a by-product of the biodiesel industry, and it can be processed to produce many useful derivatives. This study is aimed at examining the bioconversion of glycerol to docosahexaenoic acid (DHA) using local microalgae. Glycerol to docosahexaenoic acid converting microalgae were obtained from the mangrove area in the coastal sea of Lampung Province. The single colony was then generated by the scratching technique in its isolation and purification process. By using 18S rDNA, a potential strain namely WB-02, was identified as Thraustochytrium sp. Gas chromatography analysis was performed to identify its product conversion. As a result, Thraustochytrium WB-02 was identified to utilize glycerol as a single carbon source and convert to DHA. A maximum DHA yield of more than 3.4 g/L was obtained when the glycerol concentration in the medium was 8%. Thraustochytrium WB-02 was regarded as a potential microalgae resource in producing DHA due to its high level of production
Bioinformatics Toxicity Assessment of RB Protein from Transgenic Potato Resistant to Phytophthora infestans
No full textThe genetically engineered potato cultivar Katahdin SP951 is resistant to late blight disease, which is caused by Phytophthora infestans. The biosafety and food safety of this cultivar should be assessed prior to its commercialization. Toxicity is one of the parameters tested in the food safety evaluation of transgenics. Toxicity testing includes the bioinformatics analysis of the homology of the RB protein of Katahdin SP951 with known proteins. Therefore, this study aimed to perform the bioinformatics analysis of Katahdin SP951 RB protein against homologous toxin proteins. Bioinformatics analysis was conducted by first translating the RB gene into an amino acid sequence by using the Emboss Transeq program from the EMBL-EBI website. The Shuffle Protein Program was then applied to obtain the randomized amino acid sequences of the RB protein. The Basic Local Alignment Search Tool (BLAST) Protein search program was utilized to identify proteins with high similarity and homology. Moreover, BLAST Suite-2 was used to analyze the homology between two or more sequence alignments. Results showed high homology between the sequences of the RB protein and those of known resistance (R) proteins with an E value of less than 0.22. This result may be attributed to the presence of numerous R proteins in plants. Further analysis indicated that the sequence of the RB protein had extremely nonsignificant homology with sequences of proteins known to be toxic in the Entrez protein database of National Center for Biotechnology Information. Therefore, the RB protein is nontoxic.  
Sterol and Triterpene Profiles of the Callus Culture of Solanum mammosum
No full textThis study aimed to compare the sterol and triterpene profiles of two types of Solanum mammosum callus cultures, i.e., compact globular structure (CGS) and normal fine (F) calluses. The CGS callus resulted from the differentiation of the F callus culture after many years of subculturing. The growth rate, microscopic characteristics, and morphologies of the two callus types were determined and compared. Sterols and triterpenes were identified through thin-layer chromatography, gas chromatography–flame ionization detection, and gas chromatography–mass spectrometry analyses. The growth rate of the CGS callus was lower than that of the F callus. Microscopic identification revealed that thick, lignin-containing cell walls formed in the CGS callus but not in the F callus. The chromatographic analysis suggested that the CGS and F callus cultures had different sterol and triterpenoid profiles. The sterols and triterpenes produced by the CGC culture were more diverse than those produced by the F callus culture
Decontamination of Ni(II) and Co(II) ions from Aqueous Medium using the Cola Lepidota Pericarp
No full textIn this study, the batch adsorption of Ni(II) and Co(II) ions was investigated by using the pericarp of Cola lepidota as the adsorbent. The pulverized sample was modified using sodium hydroxide. In addition, the effects of pH, particle size, contact time, temperature, and initial concentration on adsorption were investigated. Results revealed that maximum adsorption of metal ions are observed at pH of 6, a contact time of 60 min, and a temperature of 70 ºC. In addition, modification was to considerably impact the effectiveness of the adsorbent. The percentage removal of the metal ions on the modified (MCLR) and unmodified adsorbents (UCLR) followed increasing order of Co(II) ion on UCLR < Ni(II) ion on UCLR < Co(II) ion on the NaOH-modified adsorbent < Ni(II) ion on the NaOH-modified adsorbent. Equilibrium data were analyzed by the Langmuir and Freundlich isotherm models, and kinetic studies were carried out using pseudo-first-order and pseudo-second-order models. The adsorption data were well fitted to the Freundlich isotherm model equation, with correlation coefficient (R2) values greater than 0.950, and the pseudo-second-order kinetic model, with correlation coefficient (R2) values greater than 0.990. The monolayer adsorption capacities for modified C. lepidota residue and unmodified C. lepidota residue were 5.890 mg/g and 5.627 mg/g, respectively
CrCl3•6H2O As an Environmentally Friendly and Efficient Catalyst for One-Pot, Synthesis of 2-oxo- and 2-thio-1,2,3,4-Tetrahydropyrimidines Under Solvent-Free Conditions
No full textA one-pot, simple, and eco-friendly synthesis of 2-oxo- and 2-thio-1,2,3,4-tetrahydropyrimidines using a Biginelli condensation between β-keto esters (methyl or ethyl acetoacetate), aromatic benzaldehydes, and urea or thiourea in the presence of CrCl3·6H2O as an environmentally friendly and mild catalyst under solvent-free conditions has been performed. Based on reaction of benzaldehyde (1.0 mmol), ethyl acetoacetate (1.0 mmol), and urea (1.5 mmol), as well as 15 mol% of CrCl3·6H2O catalyst, the 82% yield was reached within 30 minute reaction time. The advantages of this methodology are solvent-free conditions, ease of handling, one-pot nature, low-cost, environmental friendliness, simple purification of products, and short reaction time
Identification of Drought-tolerant Local Cowpea Varieties of Southwest Maluku (Indonesia)
No full textCowpeas grown in Southwest Maluku have local potential due to their diversity and ability to adapt to drought stress conditions that otherwise cause low productivity. The purpose of this study was to identify of local cowpea varieties of Southwest Maluku that show tolerance to drought. The experimental samples were seven local varieties and three reference cultivars. The drought stress treatment was altered watering periods, i.e., every two (P0) and ten days (P1) from growth to harvest. The results of this research showed that a ten-day watering period significantly decreased plant height, number of leaves, number of root nodules, root and shoot dry weight, photosynthesis rate, stomatal conductance, transpiration rate, relative water content, media water content, chlorophyll content, and number and weight of seeds per plant. Drought stress treatment increased proline content and root length. Correlation analysis showed a significant correlation between plant height with all variables, except for root length, proline content, and weight of seeds per plant. The correlation and cluster analyses showed that the KM7 variety is a drought tolerant genotype among the local cowpea varieties from Southwest Maluku. Therefore, the KM7 variety can be used as plant material in future breeding programs
Seasonal and Diurnal Variations of Lightning Activity Over West Sumatra and Its Correlation with Precipitation Type
No full textSeasonal and diurnal variations of lightning activity over West Sumatra have been investigated using observations of Tropical Rainfall Measuring Mission–Lightning Imaging Sensor (TRMM–LIS) over a 16-year period. This study also used TRMM 3B43 and 2A25 data to observe the correlation between lightning activity with rainfall and precipitation type. Results show that lightning occurs more frequently over land than over ocean and coastal areas, in contrast to total rainfall, which is higher over ocean and coastal areas. The lightning pattern is similar to the convective rainfall (particularly deep convective) pattern, which indicates that the majority of lightning in West Sumatra is associated with deep convective rain. The lightning intensity in Indonesia during the convection period, namely, December–January–February and September–October–November, is higher than that during other periods. The diurnal cycle of lightning coincides with the diurnal cycle of cloud migration from the ocean to inland Sumatra, as reported in previous research. Lightning and deep convective precipitation are dominant during the day and evening (16.00–20.00 Local Standard Time [LST]), particularly over land. Stratiform precipitation occurs more frequently from afternoon to early morning (16.00–04.00 LST) over land and at 00.00–12.00 LST over the ocean
Optimization of pGEX System to Express and Isolate Mycobacterium tuberculosis Inclusion Body Protein in Combining with Modified Refolding Method
No full textAntigen sub units for vaccine studies are typically isolated from recombinant proteins in an expression system. However, not all protein expression systems are used to express the specific protein. In this study, we optimized the pGEX system combined with the modified protein refolding to express and isolate M. tuberculosis proteins, especially proteins that are expressed as an inclusion body. Resuscitation promoting factor B (RpfB) protein is one of the Resuscitation promoting factor (Rpf) family of proteins that has been studied for its ability to induce cellular immunity in animal tests. Silico analyses demonstrate how RpfB is included in cell wall and cell processes. The Rpf family proteins are promising antigens that can be used as a TB vaccine candidate. The polymerase chain reaction was briefly performed using specific primers to amplify the full length of the rpfB. PCR amplification products were then purified, cut by restriction endonucleases, and cloned in to pGEX 6-P1. Protein expression was done in the Escherichia coli BL21 strain, and expressed protein was isolated using the modified protein refolding and solubilization method. The complex protein expression that appeared as inclusion bodies were successfully isolated and can be detected as complex GST-RpfB through the western blotting process. Our study results indicate that this system and our modified method are suitable for M. tuberculosis inclusion body protein expression and isolation
Recovery of Gold with AgNO3 Pretreatment by Cyanidation at Heap Leaching Cijiwa Gold Ore Processing
No full textThis research was undertaken to study the effect of adding silver nitrate (AgNO3) during leaching of gold ore for Au recovery. Its focus is to obtain the weight of Au in feed and concentrate, the effect of AgNO3 on Au recovery, theconcentration of AgNO3 that led to optimum recovery, and the weight of bullion and Au content in bullion. This research was conducted using quantitative descriptive method with experimental technique and the research steps include the following: 1) rock and treatment plant preparation, 2) tests with variable AgNO3 concentrations, 3) analysis feed and concentrate samples using atomic absorption spectroscopy (AAS), 4) measurement of concentrate density, 5) burning of activated carbon to get the bullion, and 6) weighing bullion and Au content. There was increase Au recovery from 12.57% to 36.15%. On addition of 0 to 4 gram of AgNO3, whereby highest recovery was obtained on the addition of 4 g of AgNO3 concentration to 150 kg of feed
ZnSO4.7H2O Catalyzed One-pot and Facile Synthesis of Highly Substituted Dihydro-2-oxopyrroles at Room Temperature
No full textA mild and facile ZnSO4.7H2O-catalyzed procedure is developed for the convenient one-pot synthesis of highly substituted dihydro-2-oxopyrroles under mild reaction conditions. In this procedure, dihydro-2-oxopyrroles are synthesized via the four-component reactions of amines, dialkyl acetylenedicarboxylates and formaldehyde. The present procedure is an economical and mild approach that offers numerous advantages, including good to high yields, simplicity, inexpensive and readily available catalyst, and high atom economy