RESUMO
In order to evaluate the function of sludge aerobic/anoxic digestibility by ultrasonic pretreatment. The SS, VSS and hydrolytic enzyme activities (amylase, glucosidase, protease, phosphatase) were measured before and after ultrasonic pretreatment (28 kHz, 0.15 kW x L(-1), 10 min). The results showed that the performances of aerobic/anoxic were greatly improved after ultrasonic pretreatment, the removal efficiency of VSS went to 44.3%, 7.8% better than of traditional aerobic/anoxic digestion. The variational trend of sludge hydrolytic enzyme activities increased firstly and then fell off during 13d digestion, the maximum of amylase activity and glucosidase activity in ultrasonic sludge, appeared in the 5 d, amylase activity was 0.104 micromol x g(-1) and glucosidase activity was 0.637 (micromol x g(-1). The maximum of intracellular protease activity and extracellular proteases activity in ultrasonic sludge, appeared in the 7 d, intracellular protease activity was 23.68 micromol x g(-1), higher than extracellular proteases activity, and it was playing a leading role in sludge digestion. The acid phosphatase activity of ultrasonic sludge was higher than the control sludge, and the alkaline phosphatase was sensitive to environment. So the alkaline phosphatase activity reduced when the internal properties of sludge was changed.
Assuntos
Esgotos/química , Ultrassom , Eliminação de Resíduos Líquidos/métodos , Aerobiose , Amilases/metabolismo , Amilases/efeitos da radiação , Anaerobiose , Reatores Biológicos , Glucosidases/metabolismo , Glucosidases/efeitos da radiação , Hidrólise , Peptídeo Hidrolases/metabolismo , Peptídeo Hidrolases/efeitos da radiação , Monoéster Fosfórico Hidrolases/metabolismo , Monoéster Fosfórico Hidrolases/efeitos da radiaçãoAssuntos
Glucosidases/efeitos da radiação , Glicogênio Hepático/metabolismo , Fígado/efeitos da radiação , Efeitos da Radiação , Amilases/efeitos da radiação , Animais , Ativação Enzimática , Jejum , Feminino , Glucosiltransferases/efeitos da radiação , Glicosídeo Hidrolases/efeitos da radiação , Fígado/citologia , Fígado/enzimologia , Glicogênio Hepático/efeitos da radiação , Açúcares de Nucleosídeo Difosfato , Fosforilases/efeitos da radiação , Polissacarídeos , Ratos , Nucleotídeos de UracilaRESUMO
This paper focuses on the radiation-damage effects when applying the same total X-ray dose to protein crystals at different dose rates. These experiments have been performed on both a selenomethionated protein and on bovine trypsin using dose rates that span nearly two orders of magnitude. The results show no clear dose-rate effect on the global indicators of radiation damage, but a small measurable dose-rate effect could be found when studying specific radiation damage. It is hypothesized that this observed dose-rate effect relates to differences in the steady-state free-radical concentration.
Assuntos
Cristalografia por Raios X , Deinococcus/enzimologia , Glucosidases/química , Glucosidases/efeitos da radiação , Tripsina/química , Tripsina/efeitos da radiação , Raios X/efeitos adversos , Animais , Bovinos , Cisteína/química , Cisteína/metabolismo , Coleta de Dados , Relação Dose-Resposta à Radiação , Modelos Moleculares , Conformação Proteica , Desnaturação Proteica/efeitos da radiação , Selenometionina/química , Selenometionina/metabolismo , SíncrotronsRESUMO
Functional groups of glucoamylase and alpha-amylase from Asp. awamori, alpha-amylase from Asp. oryzae and alpha- and beta-amylases from barley malt are identified. Kinetic curves of the activity dependency on pH, values of ionization heats and photooxidative inactivation draw to the conclusion that carboxyl-imidazole system enters into the active site of the enzymes. A hypothetic mechanism of hydrolysis of alpha-1,4-glucoside bond in starch molecule by alpha- and beta-amylases and of alpha-1,4- and alpha-1,6-glucoside bonds by glucoamylase is given. A theory of induced correspondence of enzyme and substrate satisfactorily explains the specificity of the enzyme action and the cause of complete starch convertion into glucose under glucoamylase action and of terminal starch hydrolysis by alpha- and beta-amylases.