Physiological and thylakoid ultrastructural changes in cyanobacteria in response to toxic manganese concentrations.
Ecotoxicology
; 28(8): 1009-1021, 2019 Oct.
Article
em En
| MEDLINE
| ID: mdl-31471822
ABSTRACT
In this study, two cyanobacterial strains (morphologically identified as Microcystis novacekii BA005 and Nostoc paludosum BA033) were exposed to different Mn concentrations 7.0, 10.5, 15.7, 23.6 and 35.4 mg L-1 for BA005; and 15.0, 22.5, 33.7, 50.6, and 76.0 mg L-1 for BA033. Manganese toxicity was assessed by growth rate inhibition (EC50), chlorophyll a content, quantification of Mn accumulation in biomass and monitoring morphological and ultrastructural effects. The Mn EC50 values were 16 mg L-1 for BA005 and 39 mg L-1 for BA033, respectively. Reduction of chlorophyll a contents and ultrastructural changes were observed in cells exposed to Mn concentrations greater than 23.6 and 33.7 mg L-1 for BA005 and BA033. Damage to intrathylakoid spaces, increased amounts of polyphosphate granules and an increased number of carboxysomes were observed in both strains. In the context of the potential application of these strains in bioremediation approaches, BA005 was able to remove Mn almost completely from aqueous medium after 96 h exposure to an initial concentration of 10.5 mg L-1, and BA033 was capable of removing 38% when exposed to initial Mn concentration of 22.5 mg L-1. Our data shed light on how these cyanobacterial strains respond to Mn stress, as well as supporting their utility as organisms for monitoring Mn toxicity in industrial wastes and potential bioremediation application.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poluentes Químicos da Água
/
Microcystis
/
Nostoc
/
Manganês
Idioma:
En
Revista:
Ecotoxicology
Assunto da revista:
SAUDE AMBIENTAL
/
TOXICOLOGIA
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Brasil