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"This brief discusses the impact of gold, silver, zinc oxide, and cerium oxide nanoparticles on the growth and viability of both Gram-negative and Gram-positive bacterium. Moreover, it analyses the relationship between bacterial growth inhibition, reactive oxygen species generation, the regulation of transcriptional stress genomes, and the toxicity of these materials. Finally, it reviews the specific metallic nanomaterials and highlights their modes of synthesis, reactivity at surfaces, and the importance of assay procedures in determining their toxicity levels. "

"Open mining activities result in decreased microbial biomass and negatively impacts soil fertility. Soil microbes play a role in the decomposition of soil organic matter and in nutrient cycles through the process of mineralization by the enzymes they produce. The purpose of this study was to analyse soil fertility levels in PT Bukit Asam’s various reclaimed land sites at Muara Enim Regency, South Sumatra, Indonesia, as determined by these areas’ microbial populations and soil enzyme activity. The research was conducted by using the explorative method in PT Bukit Asam’s various reclaimed land. Soil sample from 7 different reclamation age area were analysed. Our results showed that soil conditions and soil enzyme activity vary by reclamation age. At KTU, a 12-year-old reclaimed land site, urease enzyme activity had a value of 68.83 mg NH4+.g-1dm.h-1 with a microbial population of 82.64 x 104 CFU.g-1soil. The highest phosphatase enzyme activity value of 95.66 mg pNP.g-1 dm.h-1 was found on the 9-year-old SP702 reclaimed land site, with a soil pH of 5.23. Cellulase enzyme activity on the 21-year-old Udongan reclaimed site had a value of 21.51 mg GE.g-1dm.h-1 with a cellulolytic microbial population of 1.9 x 104 CFU.g-1soil, higher than on other reclamation sites. Invertase enzyme activity on the 15-year-old Tupak reclaimed land site had a value of 24.37 mg GE.g-1dm.h-1. Soil enzyme activity can be an indicator of soil quality and soil microbial activity as it relates to all forms of biochemical transformations occurring in the soil and is highly sensitive to environmental changes."

"Microbial Fuel Cel/ (IVIFC) adalan seperangkat alat yang mampu menguban energi kimia yang berasal dari metabolisme suatu mikroorganisme, menjadi energi Iistrik. |V|etabo|isme suatu mikroorganisme melibatkan transpor elektron di dalamnya, seningga dapat di manfaatkan untuk mengnasiikan listrik. Proses transpor elektron dari membran sei ke permukaan anoda dapat dibantu dengan penambanan mediator. Penelitian ini bertujuan memanfaatkan Kultur Pseudomonas aeruginosa untuk memproduksi Iistrik dalam IVIFC, tanpa penambanan mediator dari luar sistem. Pseudomonas aeruginosa adalan bakteri yang dapat mengnasilkan pigmen-pigmen berwarna knas. Salan satunya adalan pyocyanin, suatu pigmen biru nijau yang diperkirakan bersifat elektroaktif. Pyocyanin dapat dinasilkan olen P. aeruginosa pada media pertumbunan ekstrak tauge. Hasil uji voltametri siklik ternadap ekstrak pyocyanin menunjukkan banwa senyawa tersebut bersifat elektroaktif, dengan potensial oksidasi pada 0,21825 V dan potensial reduksi pada 0,147 V. Pengukuran Iistrik IVIFC dilakukan dengan menggunakan Kultur P. aeruginosa pada media ekstrak tauge dengan pyocyanin sebagai auto-mediator. Arus yang diperolen rata-rata sebesar 23 uA, serta voltase rata-rata sebesar 260 mV. Produksi Iistrik IVIFC dengan memvariasikan konsentrasi substrat glukosa sebesar 0,5 g/L; 1 g/L; 2,5 g/L; 3 glL dan 4 glL menunjukkan bahwa pengukuran berlangsung optimal penambahan glukosa sebesar 3 g/L"

"This book covers breakthroughs in sequencing methodology which offer new insight into metabolic and regulatory networks, as well as clues to the evolution of degradation pathways and to molecular adaptation strategies to changing environmental conditions. "

"The microbial desalination cell (MDC) is a modification of the microbial fuel cell (MFC) system. The microbial desalination cell is a sustainable technology to desalinate saltwater by directly utilizing the electrical power generated by bacteria during the oxidation process of organic matter. In this study, tempe wastewater will be used as a substrate. Methylene blue (MB) at concentrations of 100 ?M, 200 ?M, and 400 ?M in the anolyte is added as a redox mediator, and the effect on electricity production and desalination performance are evaluated. The average power density increases by 27.30% and 54.54% at MB concentrations of 100 ?M and 200 ?M, respectively. On the other hand, the increase of the MB concentration in the anolyte results in a decrease in the salt removal percentage. The observation made using a scanning electron microscope showed the presence of MB adsorption on the surface of the anion exchange membrane (AEM) and is suspected to be the cause of the disruption of anion transfer between MDC chambers causing a decrease in the salt removal percentage."

"Concerns over dwindling fossil fuel reserves and impending climate changes have focused attention worldwide on the need to discover alternative, sustainable energy sources and fuels. Biofuels, already produced on a massive industrial scale, are seen as one answer to these problems. However, very real concerns over the effects of biofuel production on food supplies, with some of the recent increases in worldwide food costs attributable to biofuel production, have lead to the realization that new, non-food substrates for biofuel production must be bought online. This book is an authoritative, comprehensive, up-to-date review of the various options under development for the production of advanced biofuels as alternative energy carriers. "

"Bakteri telah lama diketahui dapat menghasilkan listrik. Namun, pengembangan teknologi tersebut baru dilakukan beberapa tahun terakhir. MFC (Microbial Fuel Cell) adalah salah satu teknologi yang mengadaptasi prinsip kerja tersebut. MFC berpotensi sebagai penghasil energi listrik alternatif terbarukan melalui konversi limbah menjadi energi listrik. Kenyataaannya, teknologi ini masih menghasilkan listrik yang belum mencapai target nilai voltase minimum. Penelitian ini difokuskan untuk meninjau pengaruh penambahan bakteri gram positif dan negatif serta volume optimal penambahan bakteri gram dengan menggunakan tubular single chamber membranless reactor. Penambahan selektif mixed culture adalah melakukan penambahan gram bakteri masing-masing, yaitu positif dan negatif yang terdapat dalam limbah cair tempe. Gram bakteri ini telah melalui tahap isolasi dan kultur ulang terlebih dahulu sebelum dimasukkan ke dalam substrat sistem MFC. Hasil penelitian didapatkan bahwa penambahan selektif mixed culture dapat meningkatkan produksi tegangan listrik pada sistem MFC. Bakteri gram negatif mendominasi limbah cair tempe dan lebih mampu mentransferkan elektron daripada gram positif. Tegangan bertambah seiring penambahan jumlah bakteri sampai pada titik tertentu yang menyebabkan transfer elektron menurun. Penambahan bakteri gram negatif sebanyak 1 mL memberikan hasil paling optimal yang mampu meningkatkan hasil listrik mencapai 16,50 mV atau 92,14% terhadap eksperimen awal dengan tegangan rata-rata sebesar 17,91 mV. Variasi penambahan optimum ini juga memberikan hasil yang baik pada penggunaan limbah industri, yaitu tegangan dan power density listrik tertinggi sebesar 8,90 mV dan 0,02 mW/m2.

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Bacteria have long been known could produce electricity. However, the development of these new technologies carried out in recent years. MFC (Microbial Fuel Cell) is one of the technologies that adapt that working principle. MFC potential as a producer of renewable alternative electrical energy through the conversion of waste into electrical energy. The fact, this technology still produces electricity that has not reached the target value of the minimm voultage. This research is focused on reviewing the effect of the addition of gram positive and negative bacteria as well as the optimal volume additions gram using a tubular single chamber membranless reactor. The addition of selective mixed culture of bacteria is adding gram respectively, the positive and negative contained in tempe liquid waste. These gram bacteria have been through the stages of isolation and culture before incorporated into the substrate MFC system. The result showed that the addition of selective mixed culture can increase the production of electric voltage on the system MFC. Gram negative bacteria dominate liquid waste tempe and better able to transfer electrons than gram-positive. The voltage increases with increasing number of bacteria up to a point that causes the electron transfer decreases. Addition of gram-negative bacteria in 1 mL provide the most optimal results that can improve the electrical results reached 16.50 mV or 92.14% against the strart experiment with the average voltage of 17.91 mV. Variations optimum additions also give good results on the use of industrial waste, with electrical voltage and power density high of 8.90 mV and 0.02 mW/m2."

"Microbial Fuel Cell (MFC) merupakan sebuah perangkat elektrokimia yang memanfaatkan mikroorganisme untuk menghasilkan listrik dari hasil metabolisme dalam memecah senyawa oraganik. Limbah cair industri tempe berpotensi untuk dijadikan sebagai substrat MFC. Limbah cair industri tempe masih mengandung nutrisi yang tinggi untuk mikroba. Penelitian ini difokuskan pada sisi aspek pengolahan limbah ditentukan dari penurunan kadar COD dan BOD. Variasi dalam penelitian ini adalah variasi jenis larutan elektrolit, konsentrasi penambahan mediator, waktu pembentukan biofilm, dan penambahan bakteri gram selektif. Kinerja elektrolit yang paling bagus adalah Kalium Persulfat dibandingkan Natrium Klorida dengan penurunan COD dan BOD sebesar 23,07% dan 37,02%. Penambahan mediator dengan konsentrasi 20 g/L menghasilkan penurunan kadar COD dan BOD sebesar 25,92% dan 37,44%. Variasi berikutnya tidak menggunakan mediator ekstrak ragi karena meningkatkan kadar awal limbah secara signifikan. Waktu pembentukan biofilm optimum adalah 7 hari yang menghasilkan penurunan kadar COD dan BOD sebesar 18,2% dan 35,9%.Penambahan bakteri gram negatif sebanyak 5 mL menurunkan kadar COD dan BOD sebesar 29,32% dan 51,32%. Penelitian lebih lanjut dibutuhkan untuk menghasilkan penurunan kadar limbah yang lebih besar supaya dapat memenuhi baku mutu limbah.

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Microbial Fuel Cell (MFC) is an electrochemical device that uses microorganisms to produce electricity from the metabolism in the breakdown of organic compounds. Industrial wastewater of tempeh is potential to be a MFC substrate. Tempe industrial wastewater contains high nutrient for microbes. This study focused on the aspects of waste treatment which is determined by decreased levels of COD and BOD. Variations in this study are electrolyte solutions, the concentration of yeast extract addition as mediator, the formation time of biofilm, and the addition of selective gram. Potassium Persulphate result better performance than Sodium Chloride with COD and BOD removal amounted to 23.07% and 37.02%. The addition of a mediator with a concentration of 20 g/L decrease COD and BOD levels by 25.92% and 37.44%. The next variation will not use yeast extract mediator because it enhances the initial level of wastes significantly. Biofilm formation optimum time is 7 days which decrease COD and BOD levels by 18.2% and 35.9%. The addition of gram negative bacteria decrease COD and BOD levels by 29,32% dan 51,32%. Further research is needed in order to get a better result on decreasing levels of COD and BOD."

"Beberapa tahun kedepan Indonesia akan mengalami krisis air, mengingat kebutuhan air terus meningkat setiap tahunnya. Microbial Desalination Cell (MDC) merupakan pilihan teknologi yang baik untuk mendesalinasi air garam menjadi air bersih karena MDC dapat mendesalinasi air sekaligus menghasilkan energi listrik. Limbah cair tempe digunakan sebagai substrat dengan memanfaatkan sumber mikroorganisme didalamnya untuk efisiensi harga operasi. Selama penelitian digunakan limbah tempe model sebelum pada akhir penelitian diganti dengan limbah tempe industri. Untuk meningkatkan kinerja MDC, penelitian ini mengkaji penggunaan larutan buffer fosfat tanpa larutan elektrolit di ruang katoda dengan variasi konsentrasi 0,025 M, 0,05M, 0,1 M dan 0,15 M dan variasi pH buffer fosfat di ruang anoda dengan pH 6,6, pH 7,0, pH 7,4, dan pH 7,8. Hasil terbaik dari penelitian ini didapatkan pada penggunaan limbah tempe model, dengan buffer fosfat konsentrasi 0,1 M , dan pH 6,6 pada buffer fosfat di ruang anoda dengan besar slt removal 11,78% dan besar power density rata-rata yang dihasilkan 23,36 mW/m2.

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The next few years Indonesia will experience a water crisis, because the needs for water continues to increase every year. Microbial Desalination Cell (MDC) is a good choice of technology to desalinate salt water into fresh water because MDC can desalinate water and generating electricity. Tempe wastewater used as a substrate by using their source of microorganisms to efficiency price of operations. During experiment, model tempe wastewater was used before at the end of experiment was replaced with industrial tempe wastewater. To improve the performance of the MDC, this sexperiment examines the use of a phosphate buffer solution without the electrolyte solution in the cathode chamber with various concentration of 0.025 M, 0.05M, 0.1 M and 0.15 M phosphate buffer and the pH variation in the anode chamber with a pH of 6.6 , pH 7.0, pH 7.4 and pH 7.8. The The research shows that MDC using model tempe wastewater, with a concentration of 0.1 M phosphate buffer, pH 6.6 phosphate buffer in the anode chamber give the best performance by salt removal 11.78% and average power density 23 , 36 mW / m2.;"