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61.
JoséEdmundo Nava Saucedo Blandine Audras Sophie Jan Christophe-Eric Bazinet Jean-Noël Barbotin 《FEMS microbiology reviews》1994,14(1):93-98
Abstract: Immobilized cells can adopt different densities, distributions and growth patterns inside polysaccharide gel beads. These arrangements are closely related to both the morphological characteristics of a given cell strain and the internal structure of the gel bead. We have encountered different kinds of structural inhomogeneities (e.g. superficial crusts, radial shafts and rnicrochannels, discrete cavities, concentric ordered gel block layers, amorphous gel blocks, random fractures, etc.) in polysaccharicle gel beads while working under different experimental conditions. These supramacromolecular structure are important factors to take into account for the development of microorganisms inside the gel matrix and for the utilization of immobilized cells as biocatalysts. 相似文献
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J P Lydon B R O'Malley O Saucedo T Lee D R Headon O M Conneely 《Biochimica et biophysica acta》1992,1132(1):97-99
A cDNA encoding porcine lactoferrin (pLF) was isolated from a porcine mammary gland lambda gt11 cDNA library using human lactoferrin cDNA as the hybridization probe. Nucleotide sequence analysis indicates that pLF is 686 amino acids in length and shares 72.6%, 70.7% and 62.2% overall amino acid sequence identity with bovine, human and murine lactoferrin, respectively. 相似文献
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María Teresa Torres‐Mancera Itzamná Baqueiro‐Peña Arturo Figueroa‐Montero Gabriela Rodríguez‐Serrano Eduardo González‐Zamora Ernesto Favela‐Torres Gerardo Saucedo‐Castañeda 《Biotechnology progress》2013,29(2):337-345
The highest enzymatic extraction of covalent linked chlorogenic (36.1%) and caffeic (CA) (33%) acids from coffee pulp (CP) was achieved by solid‐state fermentation with a mixture of three enzymatic extracts produced by Aspergillus tamarii, Rhizomucor pusillus, and Trametes sp. Enzyme extracts were produced in a practical inexpensive way. Synergistic effects on the extraction yield were observed when more than one enzyme extract was used. In addition, biotransformation of chlorogenic acid (ChA) by Aspergillus niger C23308 was studied. Equimolar transformation of ChA into CA and quinic acids (QA) was observed during the first 36 h in submerged culture. Subsequently, after 36 h, equimolar transformation of CA into protocatechuic acid was observed; this pathway is being reported for the first time for A. niger. QA was used as a carbon source by A. niger C23308. This study presents the potential of using CP to produce enzymes and compounds such as ChA with biological activities. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29: 337–345, 2013 相似文献
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Filling out the Hippo pathway 总被引:4,自引:0,他引:4
How cell numbers are controlled during organ development is a problem that is still in need of answers. Recent studies in Drosophila melanogaster have delineated a novel signalling pathway, the Hippo pathway, which has an important role in restraining cell proliferation and promoting apoptosis in differentiating epithelial cells. Much like cancer cells, cells that contain mutations for components of the Hippo pathway proliferate inappropriately and have a competitive edge in genetically mosaic tissues. Although poorly characterized in mammals, several components of the Hippo pathway seem to be tumour suppressors in humans. 相似文献
68.
Jos Edmundo Nava Saucedo Jean-Noël Barbotin Daniel Thomas 《Applied microbiology》1989,55(9):2377-2384
Constraints created by immobilization conditions modified the physiological behavior and morphological characteristics of Gibberella fujikuroi mycelia in comparison with their development in free-cell conditions. G. fujikuroi mycelia were immobilized in different support matrices (polyurethane, carrageenan, and alginate) and showed a variety of reactions in response to the different microenvironmental factors encountered during and after immobilization. The best support with respect to gibberellic acid yield and biocatalyst stability was found to be an alginate with a high degree of polymerization. The most visible effects of immobilization included changes in growth development, morphological appearance, metabolite production, mycelial pigmentation, mycelial viability under starvation conditions, and induction of resting forms when previously immobilized mycelia were subcultured. 相似文献
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Gilberto Mosqueda Guido Van den Broeck Odila Saucedo Ana Maria Bailey Ariel Alvarez-Morales Luis Herrera-Estrella 《Molecular & general genetics : MGG》1990,222(2-3):461-466
Summary The gene coding for the phaseolotoxin-insensitive ornithine carbamoyltransferase (OCTase) fromPseudomonas syringae pv.phaseolicola has been cloned and sequenced. The gene has a deduced coding capacity for a polypeptide with a calculated M, of 36520 daltons. Comparison of the amino acid sequence of the OCTase enzymes encoded by theP. aeruginosa argF and theEscherichia coli argI andargF genes with the deduced sequence of the newly identified gene shows that 79 amino acid residues are strictly conserved in all four polypeptides; among these 7 out of 9 residues are involved in enzyme function. Of three amino acid regions that have been implicated in substrate binding or catalysis, two are strictly conserved, and the third involved in carbamoylphosphate binding differs. This correlates well with published data showing that phaseolotoxin competes for the carbamoylphosphate binding site in the phaseolotoxin-sensitive OCTases. We propose that the gene be namedargK. 相似文献
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R.A. Saucedo‐Tern N. Ramírez‐Baca L. Manzanares‐Papayanopoulos R. Bautista‐Margulis G.V. Nevrez‐Moorilln 《Engineering in Life Science》2004,4(2):160-164
Support materials of low‐density for fluidized bed reactors provide several operational advantages, including lower energy requirements and proper biofilm growth balance. The aim of this investigation was to study the extent of biofilm growth and bed fluidization in an experimental reactor, using polyester resin (ρpr = 1220 kg/m3) and vitrified expanded perlite (ρvep = 1710 kg/m3) as alternative support materials to conventional silica sand. A noteworthy amount of biofilm was observed to be attached to both support materials from the very beginning of the bioreactor operation. Nevertheless, there were significant variations in biofilm growth and activity over the course of the experimental trials. For both perlite and polyester beds, the highest biofilm mass and the highest total number of mesophilic bacteria were observed between the 7th and the 10th day, showing a steady state trend at the end of the experimental runs. The chemical oxygen demand (COD) removal levels were concomitant with biofilm mass and total mesophilic bacteria changes, although the polyester bed efficiency was slightly higher than that for the perlite bed. As expected, the polyester bed was fluidized at a lower re‐circulation flow compared to the perlite bed. Reactor back‐washing was not required for these support materials since biomass excess was adequately separated by means of a special internal device. The efficiencies of removal of organic matter achieved were acceptable (up to 78 %) despite the low volume of the support material (25 %) and the low hydraulic retention time (30 min). 相似文献