Microorganisms resistant to heavy metals and toxic chemicals as indicators of environmental pollution and their use in bioremediation

Microorganisms present in water samples from various industrial effluents were analysed for their resistance to lead, chromium, and cadmium. The ability of these microorganisms to grow on or metabolize toxic hydrocarbons and pesticides was also checked. Microorganisms in samples from the steel and tanning industries were generally resistant to metal ions but were not capable of metabolizing toxic hydrocarbons. Conversely, microorganisms found in samples of pesticide and from the chemical industry were capable of metabolizing hydrocarbons and pesticides but were not much resistant to metal ions. Microorganisms from effluents of the paint industry and urban wastes were resistant to lead. A correlation between the population of microorganisms and the type of pollution was observed. Indigenous microorganism could be regarded as indicators of pollution and be used in various operations to resist, process, metabolize, and detoxify toxic industrial wastes.     

Biocidal activity of Bacillus species for Anopheles larvae

It is generally accepted that Bacillus thuringiensis (B.t.) is specifically toxic to some insects but does not pose any threat to the environment, operators, or consumers. There are several other Bacillus species which can be used as effective bioinsecticides. In this study four different species of Bacillus, i.e., B. coagulans, B. megaterium, B. brevis, and B. sphaericus were isolated from soil samples collected from Kala Shah Kakoo and Kasur areas, in the suburbs of Lahore. Isolated Bacillus species were administered to mosquito larvae to evaluate their biocidal activity. B. coagulans I from Kala Shah Kakoo showed 93% mortality, while B. coagulans III from Kasur showed 70% mortality. Bacterial isolates most toxic to Anopheles larvae showed optimum growth at 37 degrees C and pH 7. These isolates have a great potency to controlling anopheline population.