The Role of Microorganisms in Bioremediation

The physicochemical properties of the environment, the availability of pollutants to microorganisms, and the chemical makeup and concentration of pollutants all of these affect the effectiveness of  bioremediation .

The presence of a microbial population that can break down the pollutants, the accessibility of the contaminants to the microbial population, and environmental conditions such as soil type, temperature, pH, oxygen or other electron acceptors, and nutrients are the some of the factors that affect the  bioremediation processes.

Biological factors

Biologic variables can influence the breakdown of organic molecules by causing microbes to compete for scarce carbon sources, interact antagonistically, or be preyed upon by bacteriophages and protozoa. The expression of specific enzymes by the microbial cells can increase or decrease the rate of contaminant degradation.

Environmental factors

Potential interactions during the Bioremediation procedure are determined by the physicochemical features of the targeted pollutants and the metabolic traits of the microorganisms.

pH, temperature, moisture, soil structure, solubility in water, nutrients, site characteristics, redox potential, oxygen content, and the physical-chemical bioavailability of pollutants (contaminant concentration, type, solubility, chemical structure, and toxicity) all have an impact on the growth and activity of microorganisms. 

Availability of nutrients

The addition of nutrients modifies the vital nutritional balance for microbial growth and reproduction. By adjusting the bacterial C: N: P ratio, nutrient balancing—particularly the provision of vital nutrients like N and P—can increase the biodegradation efficiency. Microorganisms require a variety of nutrients, including carbon, nitrogen, and phosphorus, in order to live and carry out their microbiological functions. 

Temperature

Temperature is the most crucial physical factor in regulating the content of hydrocarbons and the survival of microbes. In cold environments such as the Arctic, oil degradation via natural processes is very slow and puts the microbes under more pressure to clean up the spilled petroleum. Most oleophilic microorganisms become metabolically inactive due to the sub-zero water temperature in this area, which shuts off the transport channels inside the microbial cells or may even freeze the entire cytoplasm.Biological enzymes are participated in the degradation pathway have an optimum temperature and will not have the same metabolic turnover for every temperature. 

Concentration of oxygen

 Biological degradation occurs under both aerobic and anaerobic conditions. In most situations, oxygen can improve the metabolism of hydrocarbons.

Moisture content

Microorganisms require adequate water to accomplish their growth

pH

pH has its own impact on microbial metabolic activity and also increase and decrease removal process. The measurement of pH in soil could indicate the potential for microbial growth 

Site characterization and selection

Sufficient remedial investigation work must be performed prior to proposing a bioremediation remedy to adequately characterize the magnitude and extent of contamination.

Metal ions

Metals are important in small amount for bacteria and fungus, but in high quantity inhibit the metabolic activity of the cells. Metal compounds have direct and indirect impact on rate of degradation.

Toxic compounds

When in high concentrations of toxic nature of some contaminants, can create toxic effects to microorganisms and slow down decontamination. The degree and mechanisms of toxicity vary with specific toxicants, their concentration, and the exposed microorganisms.