Biosorption of cyanide using Bacillus cereus from Salt Pan, Tuticorin, Tamilnadu – Isotherm and kinetic studies

Department of Zoology and Microbiology, Thiagarajar College, Madurai-625 009, Tamilnadu, India
Department of Chemistry, Thiagarajar College, Madurai-625 009, Tamilnadu, India
E-mail : bukanch@yahoo.co.in
Manuscript received online 14 February 2015, revised 07 June 2015, accepted 09 June 2015

In the present study, with the aim of isolating cyanide degrading organisms, four different Gram-positive,
aerobic, endospore-forming bacteria (S1 to S4) having the ability to degrade cyanide were isolated by enrichment technique from salt pan region. They were identified as Bacillus sp. and were subjected to cyanide biodegradation assay. Based on the results obtained in cyanide and ammonia estimation, the strain S3 Bacillus cereus was found to show maximum biodegradation ability. The potential isolate S3 was confirmed as Bacillus cereus and submitted in NCBI with the accession number FJ267613. The selected isolate S3 was employed for biodegradation assay in minimal medium which showed that the degradation was higher, in the medium supplemented with glucose. Thereafter optimization studies at different pH, temperature, inoculum concentration, glucose concentration were done which showed that the alkaliphilic Bacillus cereus showed their degradation potential elevated in minimal medium at pH 8, 35 ºC, 2% inoculum concentration and at 3% glucose concentration. The degradation kinetics was found to be best represented by pseudo-second order kinetic model. The Tempkin isotherm was the best fit isotherm for the degradation of cyanide under experimental conditions used in this study (R² = 0.996). Henceforth it can be concluded from the present investigation that there is a high potentiality for alkaliphilic isolate to degrade cyanide in effluent streams very effectively.