Microflora of areas with occurrence and processing of sulfide ores and phosphorites in cold and temperate climate zones ( Krasnoyarsk territory )

Institute of Biophysics, SB RAS, Krasnoyarsk

Head of the Institute:

Andrey G.Degermendzhy, Doctor of Physical and Mathematics Sciences
Academgorodok, Krasnoyarsk, 660036, Russia
Tel. (7-3912) 431 179, Fax: (7-3912) 433 400
email: ibp@ibp.krasnoyarsk.su

Principal researchers:

Yu.L.Gurevich, Ph.D.

Project objectives

To develop the knowledge of and to understand the microbial biodiversity of soils and water bodies, effects of microbiological transformation of organic and inorganic matter, including the turnover of biogenic elements, on the mobility of heavy metals, degradation of contaminants and sustenance of soil fertility in mineral resource exploitation, land use, waste dump sites.

To collect data on the activity, diversity of Fe-, S-oxidising bacteria at the sites of occurrence and development of sulphide ores, in areas with temperate and cold climate, as well as the mobility of heavy metals.

To gain a more profound insight into the effect of microflora of soils and water bodies (microorganisms and protozoa) on the mobility of phosphorus, soil fertility and degradation of compounds of technogenic origin (bio- and phytoremediation).

Background and significance of objectives

Methods for isolating microorganisms with certain functional properties employing a continuous cultivation technique have been developed. Selection employing design and technological procedures resulted in pure and mixed cultures to degrade aromatic carbohydrates, surfactants, to study kinetic characteristics of microorganisms and peculiarities of biodegradation of toxic compounds.

A method has been developed for introducing active strains and forming mixed microorganism culture with the structure most efficient in degrading toxic agents. The method has been tested in biological purification of phenol wastewater under industrial conditions.

Data on the functioning of a community of microorganisms and protozoa under technogenic load have been collected. This component is vital for the transformation and mobility of substances in soil and water systems. A specific effect of the forming microorganism film on biodegradation of toxic compounds has been demonstrated experimentally and by a mathematical model. Essential factors of bacterial aggregation and certain specific effects of this phenomenon in degrading a substance and transfer of plasmids have been studied.

The biodiversity of protistoplankton and bacterioplankton of Lake Khanka (Far East) has been investigated. Silicate and other microorganisms featuring an elevated capacity of transferring biogenous elements from poorly solved compounds (phosphorites, potassium aluminium silicates) to mobile states have been isolated. Strains of psychrophylic microorganisms have been isolated in areas with steady low temperature (Krasnoyarsk Kray). Experience has been gained in isolating and studying iron-oxidising bacteria responsible for leaching sulphide minerals.

Methods have been developed for studying matter transformation in microcosms where plant residues decompose in “plants-mushrooms-worms-microorganisms” systems. The system forms a soil-like substrate and simulates matter turnover in the soil system. In the course of a year plants may undergo 3-4 vegetation cycles and, accordingly, reduce time to study phytoremediation processes.

Migration of heavy metals in soils and water system largely depends on microbiological transformation of minerals. A great contribution into the process is made by iron- and sulphur-oxidising bacteria, as well as microorganisms capable of destructuring poorly solved compounds (potassium aluminium silicates, phosphorites). To collect data on this microflora at sites with high technological activity in temperate and cold climate areas, it is necessary to evaluate status of the environment and to better understand trends of its development.

The effect of mobile phosphorus on behaviour of heavy metals is, on the whole, known, but it has never been studied in connection with the activity of iron-oxidising bacteria. Dissolution of phosphorites involves many microorganism species, among them – nonspecific. The isolated silicate microorganisms can play an important role in supplying biogenous elements (primarily – phosphorus and potassium) for biological processes in soils and water bodies.

However, releasing phosphorus from poorly dissolved compounds may be interesting from the viewpoint of its considerable effect on degradation of organic compounds. An increasing supply of plants with phosphorus eliminates the limitation of processes by the vital biogenous element. At the same time roots increase emission of exudates, which are the substrate for microorganisms. As a result, microbiological processes enhance their intensity and elevated mobility of phosphorus and activity of microorganisms establish feedback. Rhizosphere is the first to manifest emission of exudates. All this makes investigation of biodecomposition of poorly dissolved phosphorus compounds important for a better understanding of the effect of contaminants on biodegradation and phytoremediation. Of special interest for cold climate areas is biodegradation of contaminants by psychrophilic microorganisms.

Ripple effects of this research is to evaluate feasibility of using the isolated bacteria with elevated activity in biotechnology, viz. to process mineral raw material and in bioremediation.

Research plan: approaches and methods

To isolate microorganisms belonging to specific physiological groups (iron- sulfur-oxidising, silicate, psychrophilic). To evaluate their specific activity in an increasing mobility of heavy metals and the capacity of taking part in degrading toxic compounds. Mathematical simulation of microbiological processes.

To examine:

Methods. Field and laboratory studies of the microbial diversity of objects by conventional microbiological methods and continuous cultivation. These methods are used to study capacity of isolated microorganisms and communities to degrade contaminants and transform wastes. The continuous cultivation technique is more suitable for evaluating degradation of contaminants in aquatic systems. To study phytoremediation, it is proposed to develop experimental models “soil-plants-microorganisms”. This system is to study the mobility of phosphorus and the effect of microorganisms degrading contaminants.

Expected results

To develop a database on microflora of temperate and cold climate areas of Krasnoyarsk Kray:

List of publications of participants related to the project

Fig. 1. Result of the exchange of the bacterial community structure (1 – 8 months indigenous or initial structure, in succeeding – changed).

Fig. 2. The effect of Fe-, S-oxidizing bacteria on mobility of metals under mine development.