Lead resistance in micro-organisms

Abstract

Lead (Pb) is an element present in the environment that negatively affects all living organisms. To diminish its high toxicity, micro-organisms have developed several mechanisms that allow them to survive exposure to Pb(II). The main mechanisms of lead resistance involve adsorption by extracellular polysaccharides, cell exclusion, sequestration as insoluble phosphates, and ion efflux to the cell exterior. This review describes the various lead resistance mechanisms, and the regulation of their expression by lead binding regulatory proteins. Special attention is given to the Pbr system from Cupriavidus metallidurans CH34, which involves a unique mechanism combining efflux and lead precipitation.

Effectiveness of Indigenous Lead (Pb) Reducing Bacteria Consortia of Waste Water Treatment in Agar Flour Industry

“…Degradation of wastes by bacterial consortia is highly significant [17]. Based on stastistical data analysis, value of Pb reduction by bacteria decrease significantly and also it fullfill quality standard of Governor of East Java Regulation No.…”

“…Indigenous bacteria of both species from Pb contaminated habitat was adapted and it can still grow on their environment. Reducing Pb levels by bacteria consortia produced significantly higher and more efficient results [17].…”

“…Gram positive bacteria have the ability to bind heavy metal compared to Gram negative bacteria, because its cells wall structure, it contains peptidoglycan, teichoic, teichuronic acid that responsible for Pb binding. Phosphate and carboxyl group in the cells wall also plays an important role to bind Pb [17,18,19] [22].…”

Removing Lead from Iranian Industrial Wastewater

“…Volumes of 20 ml of this medium was poured into 8 cm plates. Then 10µL of bacterial suspensions (1.5 × 10 8 CFU ml -1 ) were inoculated on each plate and incubated at 37 °C for 48 h. Bacterial isolates were able to grow in a high concentration of Pb (NO 3 ) 2 and were selected (one isolate from each group) [16,17].…”

Removal of anthropogenic lead pollutions by a potent Bacillus species AS2 isolated from geogenic contaminated site

“…It causes serious health hazards, that is, permanent brain damage, learning disabilities, hearing loss, anaemia, insomnia, headache, dizziness, irritability, weakness of muscles, renal damages and heart disease (Naseem and Tahir 2001). Industrial activities, such as production of batteries, pigments and metal smelting, as well as manufacturing of products, such as Pb arsenate insecticides or Pb water pipes, are the main anthropogenic sources of Pb (Jarosławiecka and Piotrowska-Seget 2014;Ismail et al 2013). Accordingly, large volumes of Pb-containing wastes from these industries are introduced into environments.…”