2,909 research outputs found
Seleção de fungos produtores de β-D-frutosiltransferase por fermentação em estado sólido
A enzima β-D-frutosiltransferase é responsável pela síntese de FOS (frutooligossacarídeos) a partir de sacarose por reação de transfrutosilação é produzida por diferentes micro-organismos, principalmente por fungos filamentosos. O objetivo deste trabalho foi selecionar a melhor linhagem fúngica produtora da -D-frutosiltransferase por fermentação em estado sólido, bem como o método de extração. A fermentação em estado sólido utilizando o substrato farelo de trigo umedecido com solução de sacarose atingindo 70% de umidade na concentração de esporos de 107 no tempo de 96 horas de crescimento. Todas as linhagens manipuladas apresentaram atividade hidrolítica, no entanto apenas uma linhagem não demonstrou atividade transfrutosilação. O isolado SIS 14 que pertence ao gênero Aspergillus sp. destacou-se pelos maiores valores em atividade no método de extração utilizando água destilada, apresentando 300,90 U/mL na atividade de transfrutosilação e na atividade hidrolítica de 155,74 U/mL. Contudo, pode-se perceber que dos solventes estudados a água destilada foi melhor obtendo o valor em atividade de transfrutosilação, como também a linhagem SIS 14 é promissora para a produção da β-D-frutosiltransferase
Herbaceous Vegetation Dynamic after Cut and Burn Shrub Plants in Southern Brazil
A savanna area at Serra do Sudeste in southern Brazil, was studied during four years to evaluate the influence of cutting and burning shrub plants on dynamic of herbaceous vegetation. The cover of each species in 44 permanent quadrats (0,25 m2) and in each area (cut and burned) was evaluated. The results suggested that grasses and legumes were favored by cutting shrub plants. Burning favored forbs in the first years after disturbance and retarded the development of native forage species desirable for grazing
Next to leading order spin-orbit effects in the motion of inspiralling compact binaries
Using effective field theory (EFT) techniques we calculate the
next-to-leading order (NLO) spin-orbit contributions to the gravitational
potential of inspiralling compact binaries. We use the covariant spin
supplementarity condition (SSC), and explicitly prove the equivalence with
previous results by Faye et al. in arXiv:gr-qc/0605139. We also show that the
direct application of the Newton-Wigner SSC at the level of the action leads to
the correct dynamics using a canonical (Dirac) algebra. This paper then
completes the calculation of the necessary spin dynamics within the EFT
formalism that will be used in a separate paper to compute the spin
contributions to the energy flux and phase evolution to NLO.Comment: 25 pages, 4 figures, revtex4. v2: minor changes, refs. added. To
appear in Class. Quant. Gra
Prediction of hearing recovery in sudden deafness treated with intratympanic steroids
The present study aims to obtain a probability model allowing the prediction of the auditory recovery in patients affected by sudden sensorineural hearing loss treated exclusively with intratympanic steroids. A monocentric retrospective chart review of three-hundred eighty-one patients has been performed. A Probit model was used to investigate the correlation between the success of the treatment (marked or total recovery according to Furuashi's criteria), and the delay between the onset of disease and the beginning of therapy. The age of the patients and the audiometric curve shapes were included in the analysis. Results show that delay is negatively correlated with the variable success. Considering the entire sample, each day of delay decreases by 3% the probability of success. The prediction model shows that for every day that passes from the onset of the disease the probability of success declines in absence of the medical treatment, hence we conclude that early treatment is strongly recommended
On the exponential Diophantine equation with a prime number
In this paper we find non-negative integer solutions for exponential
Diophantine equations of the type where is a prime
number. We prove that such equation has a unique solution
if and if . We also display the infinite solution
set of that equation in the case . Finally, a brief discussion of the case
is made, where we display an equation that does not have a
non-negative integer solution and leave some open questions. The proofs are
based on the use of the properties of the modular arithmetic
Phytase production by Aspergillus niger var. phoenicis URM 4924 using cane molasses and rice brain
XI Reunião Regional Nordeste da SBBq | 4th International Symposium in Biochemistry of Macromolecules and BiotechnologyPhytase is a generic term used to describe an enzyme that hydrolyzes
phosphomonoester bonds from phytic acid, thereby liberating inorganic phosphorous,
consequently increasing the availability of phosphorous for the absorption. It is
presumed to be plant storage form of phosphate which also happens to have
considerable antinutritive effects for most animals. Phytate, a salt of phytic acid, is the
major storage form of phosphorus in typical animal feedstuffs. The aim of this study was
evaluate parameters of the medium, such as the concentrations of cane molasses and
rice brain in the production of phytase by Aspergillus niger var. phoenicis URM 4924,
using a factorial design. The experiments was carried out according to a 22 factorial
design with four center points, which were studied at three levels, cane molasses
concentration (1.0%, 1.5% and 2.0%) and the rice bran concentration (0.25%, 0.5% and
0.75%). Fermentations were carried out using 250 mL Erlenmeyer flasks, 30° C, 90 rpm,
pH 4.0, with addiction of saline solution (gL-1: KCl 0.5; MgSO4.7H2O 1.5; CaCl2.2H2O
2,0) for 72 hours of production. Phytase activity was determined by quantification of the
phosphate released from phytate during the enzymatic reaction using the method of
ammonium molybdate. The best conditions for phytase production (12.69 U/mL)
occurred using 0.75% of rice brain with 2.0% of cane molasses. These results
demonstrate the potential of cane molasses and rice brain in submerged fermentation
for the phytase production by A.CAPES and CNPqinfo:eu-repo/semantics/publishedVersio
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