Biosorption of copper by Paenibacillus polymyxa cells and their exopolysaccharide

M. PRADO ACOSTA; E. VALDMAN; S.G.F. LEITE; F. BATTAGLINI; S.M. RUZAL

WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY

Springer

Lugar: Berlin; Año: 2005 vol. 21 p. 1157 - 1163

0959-3993

Biosorption of heavy metals by gram-positive, non-pathogenic and non-toxicogenic Paenibacillus polymyxa P13 was evaluated. Copper was chosen as a model element because it is a pollutant originated from several industries. An EPS (exopolysaccharide)-producing phenotype exhibited significant Cu(II) biosorption capacity. Under optimal assay conditions (pH 6 and 25 C), the adsorption isotherm for Cu(II) in aqueous solutions obeyed the Langmuir model. A high q value (biosorption capacity) was observed with whole cells (qmax=112 mgCu g)1). EPS production was associated with hyperosmotic stress by high salt (1 M NaCl), which led to a significant increase in the biosorption capacity of whole cells (qmax=150 mgCu g)1). Biosorption capacity for Cu(II) of the purified EPS was investigated. The maximum biosorption value (q) of 1602 mg g)1 observed with purified EPS at 0.1 mg ml)1 was particularly promising for use in field applications.