Detection, purification and characterization of a lectin from freshwater green algae Spirogyra spp.

Freshwater algae are rich sources of structurally biologically active metabolites, such as fatty acids, steroids, carotenoids and polysaccharides. Among these metabolites, lectins stand out. Lectins are proteins or glycoproteins of non-immune origin which bind to carbohydrates or glycoconjugates, without changing ligand structure. Many studies have reported on the use of Spirogyra spp. as effective bioindicators of heavy metals; however, reports on Spirogyra molecular bioprospecting are quite limited. Therefore, this study aimed to detect, isolate, purify and characterize a lectin present in the freshwater green algae Spirogyra. Presence of the lectin protein in the extract was detected by hemagglutination assays. Subsequently, the protein extract was subjected to a sugar inhibition assay to identify the lectin-specific carbohydrate. Following this, the extract was applied to a guar gum column to afford the pure lectin. The lectin was inhibited by N-acetyl-glucosamine and N-acetyl-beta-D-mannose, but more strongly by D-galactose. The apparent molecular mass of the purified lectin was evaluated by Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE). Electrophoretic analysis revealed a single protein band with an apparent molecular mass of 56 kDa. Thus, it could be concluded that a lectin was purified from Spirogyra spp.

Detection, purification and characterization of a lectin from freshwater green algae Spirogyra spp

ABSTRACT Freshwater algae are rich sources of structurally biologically active metabolites, such as fatty acids, steroids, carotenoids and polysaccharides. Among these metabolites, lectins stand out. Lectins are proteins or glycoproteins of non-immune origin which bind to carbohydrates or glycoconjugates, without changing ligand structure. Many studies have reported on the use of Spirogyra spp. as effective bioindicators of heavy metals; however, reports on Spirogyra molecular bioprospecting are quite limited. Therefore, this study aimed to detect, isolate, purify and characterize a lectin present in the freshwater green algae Spirogyra. Presence of the lectin protein in the extract was detected by hemagglutination assays. Subsequently, the protein extract was subjected to a sugar inhibition assay to identify the lectin-specific carbohydrate. Following this, the extract was applied to a guar gum column to afford the pure lectin. The lectin was inhibited by N-acetyl-glucosamine and N-acetyl-beta-D-mannose, but more strongly by D-galactose. The apparent molecular mass of the purified lectin was evaluated by Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE). Electrophoretic analysis revealed a single protein band with an apparent molecular mass of 56 kDa. Thus, it could be concluded that a lectin was purified from Spirogyra spp.

Características microambientais de Spirogyra sp. em um ecossistema lótico / Environmental characteristics determining the occurrence of Spirogyra sp. in a stream

Avaliaram-se quais características ambientais determinam a abundância da macroalga bentônica Spirogyra sp. em um riacho no município de União da Vitória, Paraná. A amostragem foi feita num transecto de 10m sem vegetação marginal e alta incidência solar (550 lux). Registrou-se a abundância da macroalga ao acaso em 20 rochas. Também registraram-se as seguintes características físicoquímicas: tamanho de substratos, profundidade, pH, condutividade, velocidade da correnteza, e saturação de oxigênio. Utilizou-se uma regressão linear para testar a influência das variáveis físico/químicas na abundância (cobertura percentual) de Spirogyra sp., que variou amplamente (68,25%; 5,0% a 100,0%). As variáveis ambientais não influenciaram a abundância de Spirogyra sp. (R2=0,227; p>0,05), provavelmente devido à ampla variação dos parâmetros avaliados nas rochas em que a espécie ocorria. Portanto, essa espécie parece ser generalista. (AU)

We tested which environmental variables determine the abundance of the benthic macroalgae Spirogyra sp. in a stream in União da Vitória, Paraná, Brazil. We sampled microalgae and environmental variables in a 10m transect without marginal vegetation and high light incidence (550 lux). We recorded the abundance of the macroalgae randomly in 20 rocks inside the stream. We also recorded the following physico-chemical variables of the habitat: substrate size, depth, pH, conductivity, water velocity, and oxygen saturation. The abundance of Spirogyra sp. and abiotic variables were initially submitted to descriptive statistics. We tested the influence of physico-chemical variableson the abundance (percentage cover) of Spirogyra sp. using a linear regression. The abundance of Spirogyra sp. varied widely (68.25%;5% to 100%). The environmental variables did not influence the abundance of Spirogyra sp. (R2=0.227; p>0.05), probably due to the wide variation in environmental variables where the species is found. Therefore, the species seems to be a generalist. (AU)

Características microambientais de Spirogyra sp. em um ecossistema lótico / Environmental characteristics determining the occurrence of Spirogyra sp. in a stream

Avaliaram-se quais características ambientais determinam a abundância da macroalga bentônica Spirogyra sp. em um riacho no município de União da Vitória, Paraná. A amostragem foi feita num transecto de 10m sem vegetação marginal e alta incidência solar (550 lux). Registrou-se a abundância da macroalga ao acaso em 20 rochas. Também registraram-se as seguintes características físicoquímicas: tamanho de substratos, profundidade, pH, condutividade, velocidade da correnteza, e saturação de oxigênio. Utilizou-se uma regressão linear para testar a influência das variáveis físico/químicas na abundância (cobertura percentual) de Spirogyra sp., que variou amplamente (68,25%; 5,0% a 100,0%). As variáveis ambientais não influenciaram a abundância de Spirogyra sp. (R2=0,227; p>0,05), provavelmente devido à ampla variação dos parâmetros avaliados nas rochas em que a espécie ocorria. Portanto, essa espécie parece ser generalista.

We tested which environmental variables determine the abundance of the benthic macroalgae Spirogyra sp. in a stream in União da Vitória, Paraná, Brazil. We sampled microalgae and environmental variables in a 10m transect without marginal vegetation and high light incidence (550 lux). We recorded the abundance of the macroalgae randomly in 20 rocks inside the stream. We also recorded the following physico-chemical variables of the habitat: substrate size, depth, pH, conductivity, water velocity, and oxygen saturation. The abundance of Spirogyra sp. and abiotic variables were initially submitted to descriptive statistics. We tested the influence of physico-chemical variableson the abundance (percentage cover) of Spirogyra sp. using a linear regression. The abundance of Spirogyra sp. varied widely (68.25%;5% to 100%). The environmental variables did not influence the abundance of Spirogyra sp. (R2=0.227; p>0.05), probably due to the wide variation in environmental variables where the species is found. Therefore, the species seems to be a generalist.