Actinobacteria isolates from tin tailings and forest soil for bioremediation of heavy metals
2014
Hema T. G. | Getha K. | Tan, G. Y. A. | Lili Sahira H. | Muhd Syamil A. | Nur Fairuz M. Y.
The aim of this study was to screen actinobacteria isolated from Bidor tin tailings for heavy metal tolerance as an earlyexploration into their bioremediation capabilities. As a comparison, isolates from forest soil in Pasoh were also studied for heavy metal tolerance. At the highest test concentration, rapid metal tolerance screening showed that the numbers of Hg2+, Cd2+ and Cu2+tolerant isolates were less than 7% of the total isolatesscreened for both sites. More than 10% of total isolates screened from both sites showed tolerance to Pb2+,As 3+ and Zn2+ . The number of Ni2+tolerant isolates was significantly higher for Bidor (12.6%) compared with Pasoh (6.6%). Metal toxicity assay carried out on tolerant isolates from Bidor showed that the final metal concentrations supporting actinobacteria growth were 138.9 mmolL-1for Ni2+, 43.2 mmolL-1 for Pb2+,21.8 mmol L-1 for Cd2+, 0.8 mmol L-1 for Hg2+, 182 mmol L-1 for As3+and 14.1 mmol L-1 for Cu2+. For Pasohisolates, tolerance was observed at 21.8 mmol L-1 for Cd2+and 182 mmol L-1 for As3+. Compared with rapid metal tolerance screening, metal toxicity assay clearly showed that metal tolerant isolates from Bidor were capable of tolerating heavy metals at a higher concentration compared with Pasoh isolates. Isolates TY046-021 and TY046-078, which showed multimetal tolerance to As3+, Pb2+and Ni2+ and TY046-017, the only Hg2+ tolerant isolate from Bidor, should be further studied for heavy metal uptake and removal.
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