Gp-41 Protein Production By E. Coli In Unconventional Bioreactor Coupled With Magnetic Field Generator

Background: In this work recombinant gp-41 protein production by E. coli in an unconventional bioreactor coupled with a magnetic field generator was studied. The submerged fermentation process was carried out by fed-batch operation, recycling the culture medium externally through a stainless steel spiral U-shape tube inserted on the inside of a magnetic field generator. The exposure time and magnetic field induction were varied in a range from 1 to 12 h and 10 to 100 mT, respectively, according to a central composite design with centered face. Results: It was found that the inhibitory or stimulatory effect of magnetic field on cell growth and protein production depended on exposure time and magnetic field strength. The production of recombinant gp41 protein was 20% higher than the control. Conclusion: The procedure here presented could be an easy-to-use approach to improve the efficiency of recombinant protein production by E. coli. © 2007 Society of Chemical Industry.828738744Krell, T., Greco, F., Engel, O., Dubayle, J., Dubayle, J., Kennel, A., HIV-1 gp41 and gp160 are hyperthermostable proteins in a mesophilic environment (2004) Eur J Biochem, 271, pp. 1566-1579Narciandi RE, Garcia J, Motolongo J, Machado JA, Benites J, Novoa LI, et al, Producción, aislamiento y semipurificacion de la proteína transmembranica gp-41 sintetizada en Escherichia coli. Biotecnol Apl 10:36-39 (1993)Fojt, L., Strǎacak, L., Vetterl, V., Šmarda, J., Comparison of the low-frequency magnetic field effects on bacteria (2004) Escherichia coh, Ledercia adecarboxylata and Staphylococcus aureus. Bioelectrochemistry, 63, pp. 337-341Strašák, L., Verterl, V., Šmarda, J., Effects of low-frequency magnetic fields on bacteria Escherichia coli (2002) Bioelectrochemistry, 55, pp. 161-164Pichko, V.B., Povalyaeva, I.V., Microorganism productivity electromagnetic stimulation and its mechanisms (1996) Appl Biochem Microbiol, 32, pp. 468-472Tsuchiya, K., Nakamura, K., Okuno, K., Ano, T., Shoda, M., Effect of homogeneous and inhomogeneous high magnetic fields on the growth of Escherichia coli (1996) J Ferment Bioeng, 81, pp. 343-346Kropinski, A.M., Morris, W., Szewczuk, M.R., Sinusoidal 60 Hz electromagnetic fields failed to induce changes in protein synthesis in Escherichia coli (1994) Bioelectromagnetics, 15, pp. 283-291Goodman, E.M., Greenebaum, B., Marron, M.T., Altered protein synthesis in a cell-free system exposed to a sinusoidal magnetic field (1993) Biochim Biophys Acta, 1202, pp. 107-112Goodman, E.M., Greenebaum, B., Marron, M.T., Magnetic fields after translation in Escherichia coli (1994) Bioelectromagnetics, 15, pp. 77-83Moore, R.L., Biological effects of magnetic fields: Studies with microorganisms (1979) Can J Microbiol, 25, pp. 145-1151Justo, O.R., Pérez, V.H., Alvarez, D.C., Alegre, R.M., Growth of the Escherichia coli under extremely low frequency electromagnetic fields (2006) Appl Biochem Biotechnol, 134, pp. 155-164Meyer, H., Leist, C., Fiechter, A., Acetate formation in continuous culture of Escherichia coli K12 D1 on defined and complex media (1984) J Biotechnol, 1, pp. 355-358Lowry, O.H., Rosebrough, N.J., Farr, A.L., Randall, R.J., Protein measurement with the Folin phenol reagent (1951) J Biol Chem, 193, pp. 265-275Laemmli, U.K., Cleavage of structural proteins during the assembly of the head of bacteriophage T4 (1970) Nature, 277, pp. 680-685Clark, D.P., The fermentation pathways of Escherichia coli (1989) FEMS Microbiol Rev, 63, pp. 223-234Lee, S.Y., High cell-density culture of Escherichia coli (1996) Trends Biotechnol, 14, pp. 98-105Polk, C., Postow, E., (1996) Handbook of Biological Effects of Electromagnetic Field, , 2nd edn, CRC Press, New YorkAlvarez, D.C., Perez, V.H., Justo, O.R., Alegre, R.M., Effect of the extremely low frequency magnetic field on nisin production by Lactococcus lactis subsp. lactis using cheese whey permeate (2006) Process Biochem, 41, pp. 1967-1973Baureus Koch, C.L.M., Sommarin, M., Persson, B.R.R., Salford, L.G., Eberhardt, J.L., Interaction between weak low frequency magnetic fields and cell membranes (2003) Bioelectromagnetics, 24, pp. 395-402Nelder, J.A., The selection of terms in response surface models - how strong is the weak heredity principle (1998) Am Stat, 52, pp. 315-31

Especiarias como antioxidantes naturais: aplicações em alimentos e implicação na saúde Spices as natural antioxidants: their application in food and implication for health

O crescente interesse na substituição de antioxidantes sintéticos por naturais em alimentos tem fomentado a pesquisa sobre fontes vegetais, caracterização de matérias-primas e identificação de novos compostos antioxidantes. As reações de oxidação não são uma preocupação exclusiva das indústrias alimentícias, seu estudo é também amplamente necessário para evitar implicações indesejáveis na saúde humana. O objetivo desta revisão, depois de apresentar aspectos gerais sobre a oxidação, é concentrar-se nos benefícios da utilização das especiarias como antioxidantes naturais, em especial as da família Labiatae, amplamente utilizadas na culinária brasileira.<br>The growing interest in replacing synthetic antioxidants by natural antioxidants in food has stimulated research on vegetable sources, raw material characterization and identification of new antioxidant compounds. Oxidation reactions are not an exclusive preoccupation of the food industry; studies regarding this issue are widely necessary in order to prevent undesired implications for human health. The aim of this review, after presenting overall aspects about oxidation, is to concentrate on the benefits of using spices as natural antioxidants, especially those from the Labiatae family, which are widely used in the Brazilian cuisine