Publicação
Indicadores de stress oxidativo em estirpes de cianobactérias e microalgas
| Resumo: | Oxidative damage and antioxidant responses induced by Cu2+ and tryptamine on cyanobacteria (Anabaena sp. and Aphanizomenon gracile) and chlorophyte (Ankistrodesmus falcatus) were analyzed to determine if these species have different efficiency for the removal of ROS. Cu2+ and tryptamine induced higher levels of MDA, a lipid-peroxidation product, and consequently more oxidative damage, in the cyanobacteria than in chlorophyte. This is probably related to the higher induction of CAT and APX in A. falcatus, which leads this isolate to a more efficient scavenging of H2O2. While no significant changes in CAT activity were detected, both cultures showed an increased in APX activity following tryptamine exposure treatments. On the other hand, A. falcatus showed a significant (p <0,05) increase in CAT and APX activity after 24 hours exposure to 50 μM Cu 2+, indicating the involvement of these enzymes in H2O2 scavenging. These results suggest that the cellular defense mechanisms triggered by A. gracile were less efficient than the ones triggered by A. falcatus for the removal of ROS. Therefore Anabaena sp. might be more stress susceptible and A. falcatus more stress-tolerant species |
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| Autores principais: | Fernandes, Alíria José Silva |
| Assunto: | cyanobacteria tryptamine oxidative damage antioxidant responses chlorophyte cianobacterias triptamina danos oxidativos resposta antioxidante Cu2+ |
| Ano: | 2009 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | português |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | Oxidative damage and antioxidant responses induced by Cu2+ and tryptamine on cyanobacteria (Anabaena sp. and Aphanizomenon gracile) and chlorophyte (Ankistrodesmus falcatus) were analyzed to determine if these species have different efficiency for the removal of ROS. Cu2+ and tryptamine induced higher levels of MDA, a lipid-peroxidation product, and consequently more oxidative damage, in the cyanobacteria than in chlorophyte. This is probably related to the higher induction of CAT and APX in A. falcatus, which leads this isolate to a more efficient scavenging of H2O2. While no significant changes in CAT activity were detected, both cultures showed an increased in APX activity following tryptamine exposure treatments. On the other hand, A. falcatus showed a significant (p <0,05) increase in CAT and APX activity after 24 hours exposure to 50 μM Cu 2+, indicating the involvement of these enzymes in H2O2 scavenging. These results suggest that the cellular defense mechanisms triggered by A. gracile were less efficient than the ones triggered by A. falcatus for the removal of ROS. Therefore Anabaena sp. might be more stress susceptible and A. falcatus more stress-tolerant species |
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