223.
A new
Aeromonas bioassay is described to assess the potential harmful effects of the glyphosate-based herbicide, Roundup
®, in the Albufera lake, a protected area near Valencia. Viability markers as membrane integrity, culturability and β-galactosidase production of
Aeromonas caviae were studied to determine the influence of the herbicide in the bacterial cells. Data from the multifactor analysis of variance test showed no significant differences (
P > 0.05) between
A. caviae counts of viability markers at the studied concentrations (0, 50 and 100 mg l
−1 of glyphosate).
The effects of Roundup® on microbial biota present in the lake were assessed by measuring the number of indigenous mesophilic Aeromonas in presence of different amounts of the herbicide at 0, 50 and 100 mg l−1 of glyphosate. In samples containing 50 and 100 mg l−1 of glyphosate a significant (P < 0.05) increase in Aeromonas spp. counts and accompanying flora was observed.
The acute toxicity of Roundup® and of Roundup® diluted with Albufera lake water to Microtox® luminescent bacterium (Vibrio fischeri) also was determined. The EC50 values obtained were 36.4 mg l−1 and 64.0 mg l−1 of glyphosate respectively. The acidity (pH 4.5) of the herbicide formulation was the responsible of the observed toxicity. 相似文献