Removal of Persistent Sulfamethoxazole and Carbamazepine from Water by Horseradish Peroxidase Encapsulated into Poly(vinyl chloride) Electrospun Fibers

Enzymatic conversion of pharmaceutically active ingredients (API), using immobilized enzymes should be considered as a promising industrial tool due to improved reusability and stability of the biocatalysts at harsh process conditions. Therefore, in this study horseradish peroxidase was immobilized into sodium alginate capsules and then trapped into poly(vinyl chloride) electrospun fibers to provide additional enzyme stabilization and protection against the negative effect of harsh process conditions. Due to encapsulation immobilization, 100% of immobilization yield was achieved leading to loading of 25 μg of enzyme in 1 mg of the support. Immobilized in such a way, enzyme showed over 80% activity retention. Further, only slight changes in kinetic parameters of free (Km = 1.54 mM) and immobilized horseradish peroxidase (Km = 1.83 mM) were noticed, indicating retention of high catalytic properties and high substrate affinity by encapsulated biocatalyst. Encapsulated horseradish peroxidase was tested in biodegradation of two frequently occurring in wastewater API, sulfamethoxazole (antibiotic) and carbamazepine (anticonvulsant). Over 80% of both pharmaceutics was removed by immobilized enzyme after 24 h of the process from the solution at a concentration of 1 mg/L, under optimal conditions, which were found to be pH 7, temperature 25 °C and 2 mM of H2O2. However, even from 10 mg/L solutions, it was possible to remove over 40% of both pharmaceuticals. Finally, the reusability and storage stability study of immobilized horseradish peroxidase showed retention of over 60% of initial activity after 20 days of storage at 4 °C and after 10 repeated catalytic cycles, indicating great practical application potential. By contrast, the free enzyme showed less than 20% of its initial activity after 20 days of storage and exhibited no recycling potential.

PELATIHAN PEMBUATAN KUIS EDUKATIF SEBAGAI PENUNJANG PENGUASAAN PEMBELAJARAN DARING BAGI GURU SMP DI KECAMATAN NARMADA DAN LINGSAR LOMBOK BARAT NUSA TENGGARA BARAT

ABSTRAKKompetensi dan keahlian guru dalam memanfaatkan teknologi sangat diperlukan untuk meraih keberhasilan dalam pembelajaran daring. Meski demikian tidak semua guru mampu cepat beradaptasi dalam menggunakan aplikasi-aplikasi pembelajaran. Pengabdian ini bertujuan untuk memberikan penyuluhan dan pelatihan serta bimbingan kepada guru agar memiliki kemampuan dalam melaksanakan pembelajaran dan evaluasi yang menyenangkan berbantukan aplikasi Quizziz. Metode yang digunakan dalam kegiatan ini meliputi 3 tahapan, diantaranya: kegiatan awal, kegiatan inti, dan kegiatan akhir. Kegiatan awal meliputi observasi dan FGD bersama mitra dan tim, kegiatan inti adalah pelaksanaan pelatihan, dan ketiga adalah tindak lanjut. Hasil kegiatan ini menunjukkan dimana kemampuan peserta pelatihan mengalami peningkatan yang sangat signifikan. Data awal menunjukkan pada aspek pengetahuan awal terhadap aplikasi hanya 13 % diantara mereka yang mengetahui aplikasi Quizziz dan hal tersebut meningkat menjadi 100 % setelah pelaksanaan pelatihan. Selanjutnya pada aspek pemahaman, sebelum dilaksanakan pelatihan hanya 8% peserta yang memahami aplikasi Quizziz dan setelah pelaksanaan pelatihan meningkat menjadi 70%. Dan terakhir ketertarikan dimana sebelum pelaksanaan pelatihan hanya 26% peserta yang menyatakan tertarik menggunakan aplikasi Quizziz dan setelah pelaksanaan pelatihan mengalami peningkatan menjadi 89%. Berdasarkan data tersebut dapat disimpulkan bahwa kegiatan pengabdian ini berjalan dengan baik dan berhasil meningkatkan pengetahuan, pemahaman, dan minat atau ketertarikan peserta dalam penggunaan aplikasi Quizziz pada pembelajaran. Kata kunci: pembelajaran daring; teknologi pembelajaran, aplikasi pembelajaran; quizziz . ABSTRACTThe competence and expertise of teachers in utilizing technology is needed to achieve success in online learning. However, not all teachers are able to quickly adapt in using learning applications. This service aims to provide counseling and training as well as guidance to teachers so that they have the ability to carry out fun learning and evaluations using the Quizziz application. The method used in this activity includes 3 stages, including: initial activity, core activity, and final activity. Initial activities include observation and Focus Group Discussion with partners and teams, the core activity is the implementation of training, and the third is follow-up activities. The results of this activity indicate where the ability of the training participants has increased very significantly. Preliminary data shows that in the aspect of initial knowledge only 13% of participants know the Quizziz application and eventually it increases to 100% after the training. Next on the aspect of understanding. before the training was carried out only 8% of participants understood the Quizziz application and after the training it increased to 70%. And lastly, interest, where before the training only 26% of participants expressed interest in using Quizziz and after the training increased to 89%. Based on these data, it can be concluded that this service activity went well and succeeded in increasing the knowledge, understanding, and interest of participants in using the Quizziz application for learning. Keywords: online learning; learning technology, learning applications; quizziz

Fusion of Glutamate Dehydrogenase and Formate Dehydrogenase Yields a Bifunctional Efficient Biocatalyst for the Continuous Removal of Ammonia

A novel fusion protein has been rationally designed, combining the hexameric glutamate dehydrogenase from Clostridium symbiosum with the dimeric formate dehydrogenase from Candida boidinii. The former enzyme consumes ammonia for the reductive amination of α-ketoglutarate using NADH, while the latter biocatalyst regenerates continuously the cofactor. This enzymes fusion opens new perspectives for the detection and the removal of ammonia. The bifunctional biocatalyst has been successfully created, expressed, and then characterized. The two fused protein domains retained identical properties and catalytic activity of the individual enzymes. Additionally, the immobilization on a methacrylate resin optimized the assembly providing a reusable and stable biocatalyst. This is an example of immobilization of a fusion protein, so that efficiency and sustainability of the process are enhanced. The immobilized biocatalyst could be recycled 10 times retaining still half of the initial activity. Such preparation outperforms the co-immobilized wild-type enzymes in the conversion of 300 mM of ammonia, which could be carried out also in continuous mode.

KCl Extracted from Chlorine Bypass Dust as Activator for Plain Concrete

This study demonstrated the use of KCl separated from chlorine bypass dust (CBD) as an activator for plain concrete. The separated KCl was mixed with either ground granulated blast-furnace slag (BFS) alone, or a mixture of BFS and cement. The mixed paste of separated KCl and BFS set within 24 h, and exhibited a compressive strength of 22.6 MPa after 28 d. The separated KCl, cement, and BFS mixture exhibited a more rapid setting and a higher initial activity. Further, the compressive strength at 28 d was 57.7 MPa, which was 26.2% higher than that of the mixture without the activator. Water curing of samples with added separated KCl led to the generation of hydrocalumite, or Friedel’s salt. However, this hydrocalumite was decomposed while being cured under autoclave conditions at 180 °C. Overall, KCl was an effective activator for composite materials containing cement, and resulted in superior properties compared to mineral admixtures without an activator.

Ternary hybrid formation and Photocatalytic activity of NiO/CuO/TiO2 microstructure over textile azo dye under solar light irradiation

The photocatalytic degradation and mineralization of ReactiveOrange30 on NiO/CuO/TiO2 ternary composites has been studied using solar light irradiation. This NiO/CuO/TiO2 ternary composites were prepared by different mass ratios of NiO and CuO/TiO2(3wt% to 15wt.%) on the ethonalic dispersion and annealed at 300˚ C. SEM, UV- Vis DRS, PL, XRD and FTIR analysis has used to characterize the all photocatalysts. NiO/CuO/TiO2 ternary composites demonstrate enhanced photocatalytic activity than NiO/TiO2, CuO/TiO2and pure TiO2 due to separation of photogenerated electrons and holes charges. The NiO/CuO/TiO2ternary composites shows good photostability and the photocatalyst retain the 94% of its initial activity in the seventh cycle, respectively.

A Novel L-Asparaginase from Hyperthermophilic Archaeon Thermococcus sibiricus: Heterologous Expression and Characterization for Biotechnology Application

L-asparaginase (L-ASNase) is a vital enzyme with a broad range of applications in medicine and food industry. Drawbacks of current commercial L-ASNases stimulate the search for better-producing sources of the enzyme, and extremophiles are especially attractive in this view. In this study, a novel L-asparaginase originating from the hyperthermophilic archaeon Thermococcus sibiricus (TsA) was expressed in Escherichia coli, purified and characterized. The enzyme is optimally active at 90 °C and pH 9.0 with a specific activity of 2164 U/mg towards L-asparagine. Kinetic parameters KM and Vmax for the enzyme are 2.8 mM and 1200 µM/min, respectively. TsA is stable in urea solutions 0–6 M and displays no significant changes of the activity in the presence of metal ions Ni2+, Cu2+, Mg2+, Zn2+ and Ca2+ and EDTA added in concentrations 1 and 10 mmol/L except for Fe3+. The enzyme retains 86% of its initial activity after 20 min incubation at 90 °C, which should be enough to reduce acrylamide formation in foods processed at elevated temperatures. TsA displays strong cytotoxic activity toward cancer cell lines K562, A549 and Sk-Br-3, while normal human fibroblasts WI-38 are almost unsensitive to it. The enzyme seems to be a promising candidate for further investigation and biotechnology application.

Kompetensi Pedagogik Guru dalam Pengelolaan Pembelajaran Biologi

One of the competencies that must be possessed by a teacher is pedagogic competence. Pedagogic competence is related to the teacher's ability to carry out learning activities. The teacher is an important part in the implementation of the learning process in the classroom. Teachers have a role in preparing lesson plans as well as implementing these plans when managing learning in the classroom. Learning will take place well if the teacher has good pedagogic competence. This study aims to describe the teacher's ability to use the planned biology learning tools. Data collection in this descriptive study was carried out through observation techniques on the learning process for four face-to-face meetings. The research subject is a biology teacher at SMAN 2 Banjarbaru. The teacher is considered to have good competence in applying the biology lesson plan in the classroom seen from the implementation of the initial activity stages, core activities and final activities which show an average score of 3.89 referring to the specified rating scale.

Immobilization of Catalase on Chitosan/ZnO and Chitosan/ZnO/Fe2O3 Nanocomposites: A Comparative Study

The strong catalytic performance, eco-friendly reaction systems, and selectivity of enzyme-based biocatalysts are extremely interesting. Immobilization has been shown to be a good way to improve enzyme stability and recyclability. Chitosan-incorporated metal oxides, among other support matrices, are an intriguing class of support matrices for the immobilization of various enzymes. Herein, the cross-linked chitosan/zinc oxide nanocomposite (CS/ZnO) was synthesized and further improved by adding iron oxide (Fe2O3) nanoparticles. The final cross-linked CS/ZnO/Fe2O3 nanocomposite was used as an immobilized support for catalase and is characterized by SEM, EDS, and FTIR. The nanocomposite CS/ZnO/Fe2O3 enhanced the biocompatibility and immobilized system properties. CS/ZnO/Fe2O3 achieved a higher immobilization yield (84.32%) than CS/ZnO (37%). After 10 repeated cycles, the remaining immobilized catalase activity of CS/ZnO and CS/ZnO/Fe2O3 was 14% and 45%, respectively. After 60 days of storage at 4 °C, the remaining activity of immobilized enzyme onto CS/ZnO and CS/ZnO/Fe2O3 was found to be 32% and 47% of its initial activity. The optimum temperature was noticed to be broad at 25–30 °C for the immobilized enzyme and 25 °C for the free enzyme. Compared with the free enzyme optimum pH (7.0), the optimum pH for the immobilized enzyme was 7.5. The Km and Vmax values for the free and immobilized enzyme on CS/ZnO, and the immobilized enzyme on CS/ZnO/Fe2O3, were found to be 91.28, 225.17, and 221.59 mM, and 10.45, 15.87, and 19.92 µmole ml−1, respectively. Catalase immobilization on CS/ZnO and CS/ZnO/Fe2O3 offers better stability than free catalase due to the enzyme’s half-life. The half-life of immobilized catalase on CS/ZnO/Fe2O3 was between 31.5 and 693.2 min.

Acid Stable Yeast Cell-Associated Tannase with High Capability in Gallated Catechin Biotransformation

Previously, nine tannin-tolerant and tannase-producing yeasts were isolated from Miang; all produced cell-associated tannase (CAT) during growth in tannin substrate. Among which, only CAT from Sporidiobolus ruineniae showed better stability than its purified form. Yet, it is of particular interest to directly characterize CATs from the latter yeasts. In this study, four CATs from yeasts, namely Cyberlindnera rhodanensis A22.3, Candida sp. A39.3, Debaryomyces hansenii A45.1, and Cy. rhodanensis A45.3 were characterized. The results indicate that all CATs were produced within the same production yield (11 mU/mL). Most CATs exhibited similar pH and temperature optima and stabilities, except for CAT from Cy. rhodanensis A22.3. This CAT was assigned as acid-stable tannase due to its unusual optimum pH of 2.0 with pH stability and half-life thermostability in the range of pH 2.0–4.0, and 70 °C, respectively. All CATs demonstrated high substrate specificity toward epigallocatechin gallate and epicatechin gallate, thus forming epigallocatechin and epicatechin, respectively. Moreover, they showed operational stability to repeated use for up to five cycles without loss of the initial activity. Therefore, CATs from these yeasts could be useful for the extraction and biotransformation of tea catechins and related applications.

The Effect of Titanium Tetra-Butoxide Catalyst on the Olefin Polymerization

The purpose of this study was to assess the ability of titanium Ti(IV) alkyloxy compounds supported by organic polymer polyvinyl chloride (PVC) to polymerize ethylene by feeding triethylaluminium (TEA) as a cocatalyst. Additionally, the impacts of the molar ratio of [Al]/[Ti] on the catalytic activities in ethylene’s polymerization and of the comonomer through utilization of diverse quantities of comonomers on a similar or identical activity were studied. The optimal molar ratio of [Al]/[Ti] was 773:1, and the prepared catalyst had an initial activity of up to 2.3 kg PE/mol Ti. h. when the copolymer was incorporated with 64 mmol of 1-octene. The average molecular weight (Mw) of the copolymer produced with the catalysts was between 97 kg/mol and 326 kg/mol. A significant decrease in the Mw was observed, and PDI broadened with increasing concentration of 1-hexene because of the comonomer’s stronger chain transfer capacity. The quick deactivation of titanium butoxide Ti(OBu)4 on the polymers was found to be associated with increasing oxidation when supported by the catalyst. The presence of Ti (III) after reduction with the aluminum alkyls cleaves the carbon-chlorine bonds of the polymer, producing an inactive polymeric Ti(IV) complex. The results show that synergistic effects play an important role in enhancing the observed rate of reaction, as illustrated by evidence from scanning electron microscopy (SEM). The diffusion of cocatalysts within catalytic precursor particles may also explain the progression of cobweb structures in the polymer particles.