Pengaruh Jenis Sumber Nitrogen Pada Pembuatan Olyhydroxybutyrate Dari Glukosa Menggunakan Bakteri Bacillus Cereus

Polyhydroxybutyrate (PHB) adalah salah satu bahan baku plastik biodegradabel. Bakteri memproduksi PHB di dalam selnya, sebagai cadangan sumber carbon dan energi untuk pertumbuhannya, pada saat pasokan nutrisi tidak seimbang. Sifat PHB mirip dengan sifat polypropylene (PP) yang merupakan bahan baku plastik berbasis petrokimia. Selain itu PHB juga bersifat renewable, ramah lingkungan dan biokompatibel. Salah satu nutrisi untuk pertumbuhan bakteri adalah Nitrogen. Penelitian ini dilakukan untuk mengetahui pengaruh jenis sumber Nitrogen terhadap pertumbuhan sel bakteri dan kadar PHB yang diperoleh.Pembuatan PHB dilakukan secara proses fermentasi. Mula-mula glukosa sebagai sumber karbon dan larutan Mineral Salt Medium (MSM), ditambah dengan sejumlah sumber nitrogen (Tripton, Pepton, Ammonium Sulfat, Ammonium Chlorida). Larutan selanjutnya disterilisasi menggunakan autocalve. Setelah medium dingin ditambahkan sejumlah 10% vol bakteri Bacillus cereus. Selanjutnya medium dilakukan proses fermentasi selama 96 jam. Setelah fermentasi selesai dilakukan pemanenan untuk pemisahan sel biomass dari filtratnya dengan cara centrifugasi. Filtrat yang diperoleh dianalisa kandungan gula reduksi, sedangkan sel biomass dianalisa kadar PHB. Hasil penelitian menunjukkan fermentasi oleh bakteri Bacillus cereus menggunakan sumber nitrogen Tripton, menghasilkan berat sel kering yang banyak, yaitu 5,391 g/L, dan produksi PHB sedikit, yaitu 11,2%. Sedangkan pada fermentasi menggunakan sumber nitrogen Pepton, menghasilkan berat sel kering sedikit (3,031g/L), tetapi produksi PHB banyak (19,6%)

Enrichment process of biogas using simultaneous Absorption - Adsorption methods

© 2017 Author(s). Removal of CO2 in biogas is an essential methods to the purification and upgrading of biogas. Natural Clinoptilolite zeolites were evaluated as sorbents for purification of biogas that produced from palm oil mill effluent (POME) by anerobic-digestion method. The absorption and adsorption experiments were conducted in a fixed-bed two column adsorption unit by simultaneous absorption-adsorption method. The Ca(OH)2 solution with concentration of 0.062 M was used as absorption method. Sorbent for removal of CO2 in biogas have been prepared by modifying of Clinoptilolite zeolites with an acid (HCl, 2M) and alkaline (NaOH, 2M), calcined at 450°C and then coated using chitosan (0.5 w/v%) in order to increase their adsorption capacity. The removal of CO2 in biogas was achieved about ∼83% using 2.5?g of sorbent zeolite (2M)/chitosan dosage for each column, breakthrough time of 30?min, and flow rate of 100?mL/min. Clinoptilolite zeolites with modifications of an acid-alkaline and chitosan (zeolite (2M)/chitosan) are promising sorbents due to the amine groups from chitosan and high surface-volume ratio are one of important factors in a simultaneous absorption-adsorption method

Pemanfaatan Sellulosa Bagas Untuk Produksi Ethanol Melalui Sakarifikasi Dan Fermentasi Serentak Dengan Enzim Xylanase

Utilization of Bagasse Cellulose for Ethanol Production through Simultaneous Saccharification andFermentation by Xylanase. Bagasse is a solid residue from sugar cane process, which is not many use it for someproduct which have more added value. Bagasse, which is a lignosellulosic material, be able to be use for alternativeenergy resources like bioethanol or biogas. With renewable energy resources a crisis of energy in Republic of Indonesiacould be solved, especially in oil and gas. This research has done the conversion of bagasse to bioethanol with xylanaseenzyme. The result show that bagasse contains of 52,7% cellulose, 20% hemicelluloses, and 24,2% lignin. Xylanaseenzyme and Saccharomyces cerevisiae was used to hydrolyse and fermentation in SSF process. Variation in thisresearch use pH (4, 4,5, and 5), for increasing ethanol quantity, SSF process was done by added chloride acid (HCl)with concentration 0.5% and 1% (v/v) and also pre-treatment with white rot fungi such as Lentinus edodes (L.edodes)as long 4 weeks. The SSF process was done with 24, 48, 72, and 96 hour's incubation time for fermentation. Variationof pH 4, 4,5, and 5 can produce ethanol with concentrations 2,357 g/L, 2,451 g/L, 2,709 g/L. The added chloride acid(HCl) with concentration 0.5% and 1% (v/v) and L. edodes can increase ethanol yield, The highest ethanolconcentration with added chloride acid (HCl) concentration 0.5% and 1% consecutively is 2,967 g/L, 3,249 g/L. Thehighest ethanol concentration with pre-treatment by L. edodes is 3,202 g/L

Technique for Immobilization of Lipase Within Membrane Pores as Nanoreactor

The objective of this study was to design of nanoscale biocatalyst system by utilizing the membrane as nanoporous media. The nanostructure was modified by two step methods: simple adsorption and continue with pressure driven filtration. Two types of polymeric membranes Mixed Cellulose Ester (MCE) and Polyethersulfone (PES) were used asmatrices for immobilization of lipase from Pseudomonas fluorescens. The lipase solution was allowed to permeate through the membrane and lipase molecule adsorbed on the inner wall of pores. The porosity and membrane matrices influenced the enzyme loading. The best result for enzyme loading inmembrane matric is 3.75 g.m-2 using PES membrane with incubation time of 18 hours. PES membrane was selected for further continuous transesterification studies. We evaluated the transesterification activity by converting triolein and methanol to methyl oleate and glycerol. The reaction was carried out in situ within the pores of membrane matric, so that its pores act kind of nanoreactor during formation of product material. The degree of triolein conversion using this kind of nanoreactor was about 80% with 30 minutes of residence time. The productivity of immobilized lipase within the pores were 40 fold higher than that of native free lipase

Kinetic Model for Triglyceride Hydrolysis Using Lipase: Review

Triglyceride hydrolysis using lipase has been proposed as a novel method to produce raw materials in food andcosmetic industries such as diacylglycerol, monoacylglycerol, glycerol and fatty acid. In order to design a reactor forutilizing this reaction on industrial scale, constructing a kinetic model is important. Since the substrates are oil andwater, the hydrolysis takes place at oil-water interface. Furthermore, the triglyceride has three ester bonds, so that thehydrolysis stepwise proceeds. Thus, the reaction mechanism is very complicated. The difference between theinterfacial and bulk concentrations of the enzyme, substrates and products, and the interfacial enzymatic reactionmechanism should be considered in the model

KINETIC MODEL FOR TRIGLYCERIDE HYDROLYSIS USING LIPASE: REVIEW

Triglyceride hydrolysis using lipase has been proposed as a novel method to produce raw materials in food andcosmetic industries such as diacylglycerol, monoacylglycerol, glycerol and fatty acid. In order to design a reactor forutilizing this reaction on industrial scale, constructing a kinetic model is important. Since the substrates are oil andwater, the hydrolysis takes place at oil-water interface. Furthermore, the triglyceride has three ester bonds, so that thehydrolysis stepwise proceeds. Thus, the reaction mechanism is very complicated. The difference between theinterfacial and bulk concentrations of the enzyme, substrates and products, and the interfacial enzymatic reactionmechanism should be considered in the model.Keywords: Lipase, kinetic model, enzymatic reaction mechanism, hydrolysis, triglycerid

KINETIC MODEL FOR TRIGLYCERIDE HYDROLYSIS USING LIPASE: REVIEW

Abstract Triglyceride hydrolysis using lipase has been proposed as a novel method to produce raw materials in food and cosmetic industries such as diacylglycerol, monoacylglycerol, glycerol and fatty acid. In order to design a reactor for utilizing this reaction on industrial scale, constructing a kinetic model is important. Since the substrates are oil and water, the hydrolysis takes place at oil-water interface. Furthermore, the triglyceride has three ester bonds, so that the hydrolysis stepwise proceeds. Thus, the reaction mechanism is very complicated. The difference between the interfacial and bulk concentrations of the enzyme, substrates and products, and the interfacial enzymatic reaction mechanism should be considered in the model

Perilaku Homoseksual: Mencari Akar Pada Faktor Genetik Prof. Dr. Ing. Ir. Misri Gozan, M.tech. Universitas Indonesia

The study based on literatures on this article presents data that is critical discourses ofhomosexuality and genetics. This article does not disclose the direction of Islam in termsof homosexuality because it is so obvious expressed in the Koran and explained by therighteous mufassir, muslim clerics and scholars. There is no strong data linking specificgenetic factors with the emergence of homosexual behavior. Research conducted by theproponents of homosexual showed no single gene that govern human behavior which is avery complex phenomena. In other words, the genes do not determine behavior ofhomosexuality in particular. Expressed genes responsible for the nature of homosexualityis also interpreted as genes responsible for other mental problems. The experts furtherrevealed that homosexual orientation is strongly affected by the events and stimuliexperienced by either of the environment with a growing degree of openness tohomosexual behavior as well as due to the availability of information, especially incyberspace. Some chemicals are suspected of causing physical changes and influence onsexual orientation. Efforts of healing through action or medical intervention are notimpossible. Some researches suggest that homosexual behavior is more aggressive thanmen hetersexual both in individual and family scale. The author sees the belief thatgenetic factors are the reason for accepting homosexual behavior has no strong scientificroots. Behavior of homosexuality thus can actually be, or should be, repaired and healed