Physiological and Biochemical Responses of Fresh Water Algae, Ankistrodesmus acicularis and Anabaena flos-aquae, to Dichlobenil Exposure | Chapter 12 | Recent Advances in Biological Research Vol. 6
The herbicide dichlobenil is widely
used to control unwanted weeds in non-agricultural areas and aquatic
environment. When released into environment, it may harm the growth of algae,
which in turn might disturb the balance of aquatic ecosystem. Herein, the
physiological as well as the biochemical responses of two fresh water algae,
namely Ankistrodesmus acicularis (Chlorophyta) and Anabaena flos-aquae
(Cyanobacteria), to different concentrations of dichlobenil were assessed.
Parameters, including chlorophyll (a) Content, EC50 values, carbohydrate and
adenosine triphosphate (ATP) contents as well as the uptake by both algal
species were evaluated. We found a significant decrease in chlorophyll (a)
content of both algal species to intermediate and high concentration of
dichlobenil, whereas stimulative effect was observed for low concentration of
dichlobenil on Chl (a) content. Attainable results derived by probit analysis
revealed that the EC50 values at 5th and 7th days were approximate to each
other for both algal species. Furthermore, a drastic decrease (98%) in ATP
content was noticed at 8.0 mg/L dichlobenil treatment in case of Ankistrodesmus
acicularis. On the other hand, the activity of Anabaena flos-aquae cells was
enhanced by the application of low and intermediate concentrations of
dichlobenil (0.25-4.0 mg/L). Notably, higher concentration level (16.0 mg/L)
causes substantial decreases in ATP content. Ankistrodesmus acicularis was
found to be more sensitive than Anabaena flos-aquae. The uptake of dichlobenil
was best fit to a pseudo-first order rate kinetic. The specific uptake rate
constants of dichlobenil in case of Ankistrodesmus acicularis were considerably
lower than the corresponding rates exhibited by Anabaena flos-aquae. The half-
life time for a given concentrations of dichlobenil was at variance for both
algal species. Such variation in the uptake rates and half- life time of
dichlobenil for both algal species could have some implications on the aquatic
ecosystem.
Author(s) Details
Prof. Dr. Azza M. Abd
El-Aty
Department of Water
Pollution Research, National Research Centre, 33 El Bohouth St., Dokki, Giza
12622, Egypt.
Prof. Dr. Mohammed A.
El-Dib
Department of Water
Pollution Research, National Research Centre, 33 El Bohouth St., Dokki, Giza
12622, Egypt.
View Book: http://bp.bookpi.org/index.php/bpi/catalog/book/119
Comments
Post a Comment