The mutation rate of mitochondrial DNA (mtDNA) is 17 times higher than nuclear DNA, and these mutations can cause mitochondrial disease in 1 of 10.000 people. The T10609C mutation was identified in type 2 diabetes mellitus (T2DM) patients and the C10676G mutation in cataract patients, with both mutations occurring in the ND4L gene of mtDNA that encodes ND4L protein. ND4L protein, a subunit of complex I in the respiratory complex, has been shown to play a role in the proton translocation process. The purpose of this study was to investigate the effect of both mutations on the proton translocation mechanism. Mutation mapping showed changes in amino acids M47T (T10609C) and C69W (C10676G). The 100 ns molecular dynamics (MD) simulations performed on native and mutants of ND4L-ND6 subunits. It is revealed that the native model had a similar proton translocation pathway to that of complex I from other organisms. Interestingly, the mutant M47T and C69W showed the interruption of the translocation pathway by a hydrogen bond formation between Glu34 and Tyr157. It is observed that the mutations were restricting the passage of water molecules through the transmembrane region. These results could help to develop the computational assay for the validation of a specific genetic biomarker for T2DM and cataracts.

Proses flue gas desulohurization (FGD) dengan wet scrubber adalah suatu proses untuk menurunkan konsentrasi SOx gas buang hasil pembakaran. Proses inidapat mengatasi polusi udara dengan cara menurunkan emisi gas dan partikel debu sehingga menghasilkan gas buangan yang lebih bersih. Air limbah wet scrubber bersifat asam. Salah satu alternatif pemanfaatan air limbah wet scrubber adalah untuk budidaya mikroalga. Spirulina platensis merupakan mikroalga yang berwarna hijau kebiruan yang mempunyai nilai gizi tinggi. Penelitian ini bertujuan untuk mengetahui potensi air limbah wet scrubber sebagai medium pertumbuhan S. platensis dan untuk mengetahui konsentrasi air limbah yang optimum bagi pertumbuhan S. platensis. Metode yang digunakan adalah Rancangan Acak Lengkap (RAL) dengan 5 perlakuan dan 5 ulangan. Air limbah wet srubber dengan konsentrasi 0%, 25%, 50%, 75%, dan 100% digunakan sebagai medium pertumbuhan S. platensis. Selama kultivasi, dilakukan pengamatan pH, produksi biomassa, dan kandungan fikosianin. Hasil menunjukkan bahwa air limbah wet scrubber dapat dimanfaatkan sebagai medium pertumbuhan S. platensis. Konsentrasi optimum bagi pertumbuhan S. platensis adalah campuran dari 75% air limbah  wet scrubber dan 25% medium Zarrouk.Kata kunci : air limbah, flue gas desulphurization, wet scrubber, Spirulina platensis Utilization of Wet Scrubber Wastewater from Flue Gas Desuphurization (FGD) of Paper Industry as a Growth Medium for Spirulina platensisAbstractThe flue gas desulohurization (FGD) withwet scrubber is a process to reduce the concentration of SOx of the flue gas from combustion. This process can resolve the air pollution by reducing gas emission and the dust particles in the liquid droplets to produce cleaner flue gas. The wet scrubber wastewater is acidic. An alternative utilization of wet scrubber wastewater is for cultivation of microalgae. Spirulina platensis is bluish-green microalgae containing high nutritional value. The objective of this research is to determine the potential and the optimum concentration of wastewater from wet scrubber as growth medium of Spirulina. platensis. The research method was observation in the laboratory with a completely randomized design (CRD) with 5 treatments and 5 repetitions. The wastewater from wet scrubber with a concentration of 0 %, 25 %, 50 %, 75 %, and 100 % was used as growth medium of S. platensis. During cultivation, pH, biomass production, and pigment phycocyanin were measured. The results indicated that the wastewater of wet scrubber can be utilized as a growth medium of S. platensis. The optimum concentration for the growth of S. platensis is the mixture of 75% of the wastewater from wet scrubber and 25% of medium Zarrouk.Keywords : wastewater, flue gas desulphurization, wet scrubber, Spirulina platensis

Electrochemical biosensors are used to detect adenosine triphosphate (ATP) levels, which are involved in a variety of biological processes, such as regulating cellular metabolism and biochemical pathways. Therefore, this research aims to develop an aptamer-based electrochemical biosensor with Screen Printed Carbon Electrode/gold nanoparticles (SPCE/AuNP) and collect data as well as information related to ATP detection. The modification of SPCE with AuNP increased the analyte’s binding sensitivity and biocompatibility. The aptamer was selected based on its excellent bioreceptor characteristics. Furthermore, aptamer–SH (F1) and aptamer-NH2 (F2) were immobilized on the SPCE/AuNP surface, which had been characterized using SEM, EIS, and DPV. Also, the ATP-binding aptamers were electrochemically characterized using the K3[Fe(CN)6] redox system and Differential Pulse Voltammetry (DPV). According to the optimization results using the Box-Behnken experimental design, the ideal conditions obtained from the factors influencing the experiment were the F1 concentration and incubation time of 4 µM and 24 h, respectively, as well as F1/F2/ATP incubation time of 7.5 min. Meanwhile, for the range of 0.1 to 100 µM, the detection (LoD) and quantification (LoQ) limits were 7.43 and 24.78 µM, respectively. Therefore, this aptasensor method can be used to measure ATP levels in real samples.

Mitochondrial DNA mutations, such as A3243G, can affect changes in the structure of biomolecules, resulting in changes in the structure of Leucine transfer Ribose Nucleic Acid to form a dimer. Dimer structure modeling is needed to determine the properties of the structure. However, the lack of a structure template for the transfer of Ribose Nucleic Acid (tRNA) is challenging for the modeling of mutant structures of tRNA, especially mitochondrial tRNA that are susceptible to mutation. Therefore, this study predicted the structure of mitochondrial leucine tRNA and its stability through a knowledge-based method and molecular dynamics. Structural modeling and initial assessment were performed using RNAComposer and MolProbity, HNADOCK, and Discovery studios to form the dimer structure. Molecular dynamics simulations for stability analysis were performed using Amber and AmberTools20 software, showing that the conformational energy of the mutant leucine tRNA dimer structure was lower than the native structure. Moreover, the Root Mean Square Deviation (RMSD) of monomer native leucine tRNA was lower than the mutant, indicating that the dimer structure of mutant leucine tRNA is more stable than usual, and the normal leucine tRNA is more stable than the mutant.