Predominance of lead resistant and lead processing bacteria in industrial and sewage wastes
1997
Riaz-ul-Haq | Mahmood, A. | Rehman, A. | Ali, S.S. | Shakoori, A.R. (Punjab Univ., Lahore (Pakistan). Cell and Molecular Biology Lab.)
Twenty six samples from industrial wastes and sewage waste were collected and checked for the presence of lead resistance bacteria. Nineteen lead resistant bacterial strains were isolated. Most of the bacteria showed resistance against lead up to a concentration of 1 mg/ml, of the medium. Seven bacterial strains were selected to determine their lead processing ability. The bacteria showed efficient capability to process lead. The mechanism for lead processing is proposed to be lead accumulation or lead sorption. Variation in the lead processing ability of the bacteria was observed. Most of the isolates showed an initial speedy processing of lead during 24 hours and a slower relatively constant processing during next 48 hours. One of the isolates showed a slow processing during first 24 hours and a more enhanced processing during the next 24 hours and a very speedy processing during the next 24 hours. Plasmid were detected in some of the strains capable of lead processing showing that the gene for lead processing was usually present on chromosomal DNA. Plasmid occurrence frequency was more in an area where there was constant inpouring of industrial wastes for the last many (50) year while it was less in other areas where there were separate ponds.
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