Microbial Load as Ecotoxicological Assessment of Heavy Metals Presence in Soil Samples from the Kazakhstan Part of the Caspian Sea

Soil as a natural resource and a powerful regulator of matter flow, plays crucial role in providing habitat for proper structuring and functioning soil microbial communities. Under the influence of unregulated industrial activities with social-economic co-development, soil and water involved a whole range of changes leading to soil erosion-degradation and pollution of aquatic ecosystems. One of the most promising techniques for determining the total effect of exposure to heavy metals on environmental media is bio-indication (bio-testing), which is based on rapid, robust and cost-effective methods. Acquaintance, with the microbial background of soil is essential to assess the degree of soil pollution with heavy metals. In this study, an eco-toxicological assessment using microbial community characteristics on heavy metals in soil samples from the urban ecosystems of the Kazakhstan part of the Caspian Sea (Atyrau and Mangystau regions) has been discussed. According to the results of the soil toxicity, it has been established that the soil of these residential areas are exposed to increased levels of heavy metals, such as Cr, Co, Ni, Pb, etc. Comparative analysis of bio-indicative systems and chemical techniques for assessing the quality of soils indicated a remarkable similarity of the results and the priority (high speed, cheapness) of the microbiological load assessment of the soil quality.