Abstract Description

Pollution of soil with heavy metals has become a world-wide environmental problem that has attracted considerable attention largely in the security of agricultural products. South Africa is one of the top mining countries with abundance of mineral resources such as coal, copper, gold and platinum. However, mining of these minerals has led to the increase in the concentrations of toxic heavy metals in all spheres of life. South Africa is one of the world’s largest producers of manganese (Mn) ore accounting for approximately 36% of global production. However, an increase in environmental pollution during transportation and storage of manganese ore has been reported, specifically in the ports of the Eastern Cape which affects mainly soils and plants. In recent years, plants have shown to develop good relationships with microbial members of their ecosystem in order to defend themselves and successfully survive environmental stresses. Bacteria are one of the most important microorganisms shown to develop beneficial associations with plants. No studies have been done in South Africa to test endophytic bacteria as potential for assisting plants with growth under Mn-hyperaccumulated soils. The aim of this study was to test 10 endophytic bacteria isolated from weeds associated with common beans to determine their ability to grow under Mn-accumulated environment. Firstly, the bacteria were streaked out on LB agar media containing MnSO4 and MnCl₂. The bacteria that grow were tested on common beans in plates containing MnSO4 and MnCl₂. All the beans that grew were further tested in the greenhouse, followed by experiments under field conditions. These findings will improve the potential of common beans to grow on Mn infected soils.