Reduction of Cr+6 for isolated bacteria of agricultural soils in San Víctor, Corozal, Belize

Abstract

 
 
 

Biotechnology has developed techniques of bioremediation for the reduction of hexavalent chromium (Cr⁺⁶). The Cr⁺⁶ is a contaminant that affects directly to the health, for that reason, the potential reduction of Cr⁺⁶ was analyzed by applying isolated bacteria from agricultural soils in San Victor, Corozal, Belize. A pre-inoculum of isolated bacteria identified as SVCrB01, SVCrB02, SVCrB03, and SVCrB04 was carried out in nutritional broth supplemented with a concentration of 20 mg L^-1 potassium dichromate (K₂Cr₂O₇) for 24 h and absorbance of 0.6 to 0.8. Later on, it developed a minimum inhibitory concentration in nutritional broth in concentrations of 50, 100, 300, 500, 700, 900, 1100, 1300, and 1500 mg L^-1 of K₂Cr₂O₇ to verify the viability and the bacterial growth, presenting greater bacteria growth the SVCrB01 and the SVCrB02 in 48h. The reduction of Cr⁺⁶ was determined using nutritional broth added with a concentration of 50 mg L^-1 of K₂Cr₂O₇, which was incubated at 37°C and 200 rpm. The bacterial growth and reduction of Cr⁺⁶ were Evaluated taking aliquots in the intervals of 2, 4, 8, 12, 24, 36, and 48 h. The reduction of Cr⁺⁶ for the bacteria SVCrB01 was 85.08% in 48 h, while the bacteria SVCrB02 present an 86.14% reduction in 48h, where the growth kinetics show us a relationship with the bacteria stability used in the medium, therefore it can be concluded that the isolated bacteria from agricultural soils in San Victor, Corozal, Belize have the capacity to reduce Cr⁺⁶.