Cadmium biosorption by Bacillus circulans strain EB1


Yilmaz E., Ensari N.

WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY, cilt.21, sa.5, ss.777-779, 2005 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 21 Konu: 5
  • Basım Tarihi: 2005
  • Doi Numarası: 10.1007/sl1274-004-7258-y
  • Dergi Adı: WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY
  • Sayfa Sayıları: ss.777-779

Özet

A heavy metal resistant bacterium, Bacillus circulans strain EB1 showed a high cadmium biosorption capacity coupled with a high tolerance to this metal when grown in its presence. Bacillus circulans EB1 cells grown in the presence of 28.1 mg cadmium/l were capable of removing cadmium with a specific biosorption capacity of 5.8 mg Cd/g dry wt biomass in the first 8 h. When the cells were pre-conditioned with low concentrations of cadmium in pre-grown medium, the uptake was increased to 6.7 mg Cd/g dry wt biomass. The maximum uptake of cadmium was during mid-logarithmic phase of growth. The resting cells (both wet and dry) of EB1 were also able to biosorb cadmium. Specific biosorption capacities of wet and dry biomass were 9.8 and 26.5 mg Cd/g dry wt biomass, respectively. Maximum cadmium removals by both wet and dry cells were at pH 7.0. The results showed that the cadmium removal capacity of resting cells was markedly higher than that of growing cells. Since both growing and resting cells had a high biosorption capacity for cadmium, EB1 cells could serve as an excellent biosorbent for removal of cadmium from natural environments.