MICROBE ASSISTED PHYTOREMEDIATION OF FLUORIDE BY BRACHIARIA DISTACHYA (L.), A NATIVE HYPER ACCUMULATOR OF FLUORIDE CONTAMINATED SITE, VISAKHAPATNAM
Fluoride is the most phytotoxic element among the trace elements. Fluoride pollution is a serious problem worldwide. Fluoride emissions from industries are main sources of air and soil pollution. Brachiaria distachya (L.), a native hyper accumulator (779.9 mg/kg of F) growing in the phosphate dumping site of Coromandel fertilizer factory, was studied to test the accumulating capacity of the plant in 3 different concentrations of (50 mg/kg, 75 mg/kg, 100 mg/kg NaF) in small scale pot experiments for 60 days by amending the bacteria (Bacillus cerus, Providencia vermicola) isolated from the rhizosphere soil of same plant in the contaminated site. The results show an increase in the biomass from 0.8 ± 0.3 to 5.9 ± 1.7 in bacillus treated to 3.1 ± 0.05 in P. vermicola treated. The chlorophyll increased in the bacterial amendments when compared to fluoride treated, the TF was 2.1 ± 0.03 in Bacillus treated to 1.4 ± 1.9 in P. vermicola at 100 mg/kg NaF, the BF ranges from 0.4 ± 0.2 to 3.4 ± 0.1 in different bacterial treatments when compared to fluoride treated ones. Comparative results (biomass, chlorophyll, mineral content, TF and BF) between B. cerus and P. vermicola indicated the application of Bacillus cerus significantly increased the uptake of fluoride by Brachiaria distachya (L.), which showed a good tolerance level at 100 mg.kg NaF. In conclusion the Brachiaria distachya (L.) and the bacteria both can be potentially used in fluoride removal from soil.
SRI BINDU CH, RATNA GRACE J AND SUJATHA B