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Equilibrium constant and mass transfer parameters are needed for the study of amino acid separation in any process involving adsorption in fixed beds. The adsorption constants, effective diffusion coefficients, and axial dispersion coefficients for two amino acids, L-phenylalanine (Phe) and L-tyrosine (Tyr), are determined from a series of pulse tests in a fixed bed packed with PVP (poly-4-vinylpyridine) resin. Total bed voidage at different flow rates is estimated from NaCl pulse test data. The effective pore diffusivities of Phe, Tyr, and NaCl are estimated from moment analysis of pulse data. A detailed rate model is then solved numerically and adsorption constants, effective diffusion coefficients, axial dispersion coefficients are determined by moment analysis and compared with the pulse data. The advantage of this method is that the effective intraparticle diffusivities can be determined without the influence of extracolumn dispersion or intracolumn axial dispersion effects

-A laboratory-scale simulated moving bed (SMB) was designed and tested for the separation of paclitaxel, a powerful anti-cancer agent known as Taxol @ , from impurities of a plant tissue culture (PTC) broth. The innovative strategy of a pseudo-binary model, where mixtures A and B were treated as single solutes A and B, was used in the linear standing wave analysis to fix the SMB operating parameters for a multicomponent and complex system. Linear standing wave design was used to specify the zone flow rates and the switching time for the laboratory-scale SMB unit, with two steps of separation. The SMB consists of four packed columns, where each column is 12.5 cm in length and 1.5 cm in diameter. Two sequential separation steps were used to recover paclitaxel from a small feed batch (less than one liter). Placlitaxel was recovered from the complex plant tissue culture broth in 82% yield and 72% purity.

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Introduction Tacrolimus, also known as FK-506, is a drug first isolated in 1984, that has been widely used to prevent the rejection of transplanted organs, and to also treat dermatoses and eye diseases. 1-3 It is a 23 membered polyketide macrolide produced during fermentation through different Streptomyces species. The most commonly used is the Streptomyces tsukubaensis. 4 This medication is interesting to dermatology because it is rapidly absorbed by the epidermis and has less side effects than commonly used drugs. 5 Besides, as an immunosuppressant agent it is 10-100 times more potent than cyclosporine. 6 Nevertheless, the treatment cost using tacrolimus is high because of its low productivity. 7 Up to now, different strategies have been used to solve this problem, including the use of mutant bacteria, 8-11 and exogenous feeding of precursors in the biosynthesis. 12-14 Literature reports that S. tsukubaensis is capable of metabolizing different carbon sources, such as glucose, maltose, dextrin, soybean oil, cottonseed oil and groundnut oil. 14-16 Exogenous feeding of oil has played an important role in this bioprocess, since it is a complex source of nutrients which has increased the tacrolimus production. 12,14,17 The Brazil nut oil is rich in fatty acids and are broken in order to produce coenzymes (acetyl or propionyl) which are known as precursors for the polyketide production. 17 This study has investigated the influence of the Brazil nut (Bertholletia excelsa) oil on the tacrolimus production. The fermentative process was carried for 168 h using S. tsukubaensis. Materials and Methods Organism The Strain of S. tsukubaensis was acquired from the Leibniz Institute DSMZ. Culture Conditions Streptomyces tsukubaensis culture was maintained on petri dishes containing glucose 4 g.L-1 , yeast extract 1 g.L-1 , malt extract 10 g.L-1 , CaCO 3 2 g.L-1 and agar 12 g.L-1 , pH 7.2, and incubated at 28 o C. The seed culture medium and the production medium were based on Turlo et al 14 which are presented in Table 1 and Table 2, respectively. The seed culture medium was prepared, sterilized at 120 o C

Phenylalanine (Phe) and tyrosine (Tyr) are two of the twenty amino acids in proteins; they are classified as aromatic amino acids, because both have a benzene ring in their structures. These amino acids are important in the synthesis of several biologically active amines, such as beta-endorphin, a neurotransmitter. Amino acids can be separated by ion-exchange chromatography. In this case, it is important that fixed-bed adsorber design adequately predict the breakthrough curve. This work presents a mathematical model for both fluid and porous phases. In the solution proposed for this model the liquid-phase concentration inside the particles is solved analytically and is related to the liquid-phase concentration in the bed using Duhamel's theorem. The solution for liquid-phase concentration in the bed is then solved numerically instead of analytically. The basic mass transfer parameters are from the literature. The results from the model are compared with those obtained experimentally using Phe and Tyr diluted in aqueous solutions in a fixed bed of PVP (poly-4-vinylpyridine) resin

-Piper hispidinervium C.DC (Piperaceae) is popularly known as long pepper. It grows in degraded areas of natural fields in the state of Acre, Brazil. Its leaves are 3 to 4 % essential oil rich in safrole, within the range of 90 to 94 %. In the chemical industry, safrole is an important raw material, mainly due to two of its derivatives: heliotropin, which is widely used as a fragrance and flavoring agent, and piperonyl butoxide (PBO), a vital ingredient of pyrethroid insecticides. Natural pyrethrum in particular would not be an economical insecticide without the synergistic effect of PBO; therefore, its industrial future is linked to the continued availability of PBO. As a fragrance, safrole has many applications in household products such as floor waxes, polishes, soaps, detergents and cleaning agents. In this work, leaves were dried in a fixed-bed dryer using different drying-air temperatures (35, 40, 45, 50, 55 and 60 ºC) and drying times (900, 2700 and 3600 seconds). Essential oil was extracted by cohobation (meaning that the condensed water that comes out of the flask is recycled) from both raw and dried leaves. The essential oil yield and safrole content are susceptible to rapid loss of moisture by Piper hispidinervium C. DC leaves. It was observed that the essential oil yield increased twice after the drying process. However, safrole content decreased about 20 percent when temperature was above 50 ºC and drying times were more than 2700 minutes.