Sample records for hydrolases
from WorldWideScience.org

Sample records 1 - 2 shown.



1

Microrganismos produtores de hidrolases envolvidos nas transformações dos compostos do carbono e do nitrogênio do solo/ Hydrolases producers microorganisms involved in the soil carbon and nitrogen cycling

Sanomiya, Luciana Terumi; Nahas, Ely
2003-10-01

Resumo em português Avaliou-se o efeito de culturas de braquiária e guandu, da adubação fosfatada e da calagem sobre bactérias e fungos amilolíticos, celulolíticos, proteolíticos e ureolíticos. A proporção das bactérias com atividade enzimática em relação ao total variou de 25 a 87% e, a dos fungos, de 2 a 36%. Os grupos de bactérias aumentaram sua população nas parcelas em que se aplicou superfosfato e calcário em relação aos outros tratamentos (exceto as ureolíticas qu (mais) e aumentaram na ausência de adubo) e os fungos prevaleceram na ausência de adubação (exceto os ureolíticos que aumentaram com superfosfato) e de calagem. No solo cultivado com braquiária, foram obtidas as maiores contagens de bactérias ureolíticas e fungos proteolíticos. Na ausência de planta, preponderaram os fungos CM-celulolíticos (CM, celulose microcristalina) e ureolíticos e na presença de guandu, os amilolíticos e CMC-celulolíticos (CMC, carboximetilcelulose). Os demais grupos de bactérias não foram influenciados pelo sistema de cultivo. A população e a habilidade enzimática dos fungos foram menores que as das bactérias, o que sugere menor participação na transformação dos nutrientes no solo. As bactérias apresentaram múltiplas atividades enzimáticas, mostrando maior versatilidade que os fungos. Resumo em inglês The effect of plant cultures, Brachiaria ruziziensis, Cajanus cajan, of the phosphate fertilizers and of the liming on amilolytic, cellulolytic, proteolytic and ureolytic bacteria and fungi were investigated. The proportion of bacteria with enzymatic activity in relation to the total varied from 25 to 87% and fungi from 2 to 36%. The groups of bacteria increased its population in plots added with superphosphate and lime in relation to the other treatments (except the ureo (mais) lytic that increased in plots not fertilized) and the fungi enhanced in the unfertilized (except the ureolytics that increased with superphosphate) and limed plots. The highest counts of ureolytic bacteria and proteolytic fungi were found in the soil cultivated with B. ruziziensis. The CM-cellulolytic (CM, cellulose microcrystalline) and ureolytic fungi enhanced in the uncultivated plots and the amilolytic and CMC-cellulolytic (CMC, carboxymethylcellulose) in the plots cultivated with C. cajan. The other groups of bacteria were not influenced by the cultivation system. The population and the enzymatic ability of the fungi groups were smaller than the bacteria, suggesting a smaller participation in the nutrients cycling in the soil. The bacteria presented multiple enzymatic activities, showing larger versatility than the fungi.

Scientific Electronic Library Online (Portuguese)

2

O emprego de lipases como agentes de resolução cinética de enantiômeros em síntese orgânica: aspectos gerais sobre a influência do solvente/ The use of lipases as agents of kinetic resolution of enantiomers in organic synthesis: general aspects of solvent's influence

Costa, Valentim Emilio Uberti; Amorim, Hermes Luís Neubauer de
1999-12-01

Resumo em inglês In organic synthesis, lipases are the most frequently used biocatalysts. They are efficient stereoselective catalysts in the kinetic resolution of a wide variety of chiral compounds. The discovery that enzymes possess catalytic activity in organic solvents has made it possible to address the question of reaction medium influence on enzymatic specificity. Perhaps the most exciting and significant development in this emerging area is the discovery that enzyme specificity, i (mais) n particular enantioselectivity, can be affected by changing from one organic solvent to another. This article discusses the scope and possible mechanistic models of this phenomenon in hydrolases, specially lipases, as well as directions of future research in the area.

Scientific Electronic Library Online (Portuguese)