Microbes That Clean Safely

In my previous article, I discussed the proven relationship between microorganisms and air pollution, making you realize that it is surprising how microorganisms adapt to survive and take advantage of chemicals in their environment; it is astonishing that although they are surrounded by very toxic and genotoxic chemical compounds, these microorganisms manage to change their life processes making these deadly and toxic chemicals part of their diet and metabolism. 

Due to these properties, humans have developed a series of strategies to take advantage of these qualities of microorganisms. Microbes with the ability to clean our environment have been found in nature, from toluene and simple molecules in a laboratory to giant colonies cleaning up oil spills at sea; however, everything indicates that the future of this technology is in the hands of genetic engineering to achieve safe, cheaper and most effective cleaning methods.

Image 1: Oil spills in the environment generate remedial microbial cultures.Bioremediation is a name assigned to the processes in which biological organisms are used to eliminate an environmental pollutant (remediation); I have revealed before the sources of pollutants, however, the most researched polluting sources in this topic include concrete, oil, volatiles, and plastic. In addition to emerging pollutants, has also been observed the ability of some microorganisms to purify the pollutants contained in the air; the biological organisms used for this purposes of environmental remediation are microscopic organisms such as fungi, algae, and bacteria. 

Bioremediation has been applied to all contaminated environments including water, air, and land; these include research on industrial emissions, soil vent gases, solids, soils, sediments, sludge, liquids, groundwater, industrial effluents, and industrial processing raw materials. Microbes have shown good efficacy in remediating the polluted environment, their safety use is also supported by scientific studies. 

In this process of restoring the environment, it is necessary to achieve the degradation, eradication, immobilization, or detoxification of the various chemical wastes and hazardous physical materials found in the environment which we have already discussed. In Image 1, we see a disastrous spill of oil in the ocean that contains colonies of purifying microorganisms, to eliminate the pollution and avoid its prevalence for a longer time, since it damages all life in the place.

Image 2: Bacteria structure exposed by an electron microscope (S. Aureus).

This whole topic of bioremediation revolves around degrading and converting pollutants into less toxic forms efficiently, quickly, safely, and economically, at the same time, technological advances seek to investigate new methods that recycle waste in a way that can be used and reused in other processes. Since microorganisms are found everywhere in the world, even in extreme environments such as Antarctica, volcanoes, and the seabed; microbes have also been found in oil wells, plastic dumps, associated with plants to favor air purification, in concrete tanks, sea surfaces, and many more. 

As the field of bioremediation has been developed, it has mixed with other areas, at present, the genetic modification of these cleaning microorganisms and even the creation of new types is of great interest. This works to improve its cleaning properties, such as increasing the number of different compounds that it metabolizes, also increasing the cleaning efficiency and residues safety, among other things. 

Some microorganisms with the capacity to purify polluting substances are mentioned, for example, it has been noted that some specific species of microorganisms such as bacteria, fungi, and algae can clean environments contaminated with heavy metals. 

For example, Desulfovibrio Desulfuricans (a species of bacteria) has been found in water and soil, it has the ability to remove Chromium, Copper, and Nickel with removal efficiencies of 99.8%, 98.2%, and 90.1%. Chlorella Vulgaris is a microalga that is frequently consumed around the world, it is produced as a dietary supplement (more than 3000 tons per year), surprisingly it is extremely effective for the elimination of Cadmium, Copper, and Lead with efficiencies of 95.5%, 97.7 %, and 99.4%. At the same time, mixed colonies between bacteria that are found in contaminated environments also show high efficacy. 

The topic of spread bacteria or microbes in the environment sounds a bit crazy due to the mentality that they cause diseases, well, it is true that not all bacteria that are found in nature and clean pollutants are suitable for use in bioremediation, therefore, the microorganisms used for these purposes are often genetically neutralized, so they are not toxic to the environment where they are added. 

To achieve the optimal processes in bioremediation microorganisms, some factors intervene according to the type of microorganism and its relationship with the place, temperature and solubility, pH, types of acids, chemical transport, metals presence, and bioavailability plays important roles in the adsorption and diffusion of the pollutant in the microbe´s structure; therefore, they are decisive in cleaning contaminated environments by bioremediation processes. In Image 2 we see how the introduction of microbes into polluted media can achieve a clean environment, with the use of oxygen and other nutrients it can convert Petroleum into Carbon Dioxide; while it is another air pollutant, it is less harmful than an oil spill.

Image 2: Injected microbes take pollutants as nutrients, recovering the environment.

Mainly what is sought is that the metabolism of the microorganism allows the complete destruction of pollutants; therefore, there are many methods to promote microbial growth for the purpose of bioremediation. The existing microorganism can be naturally stimulated with nutrients to promote its growth, the influence of air is great; for example, the activity of some microbes against oil increases through microbial respiration, so the result in the degradation of the contaminant from the adsorbed oil becomes greater. 

There are processes in which colonies of these microorganisms, living or dead, are placed to remove heavy metals or other pollutants from the environment, it could be compared to a "sponge effect". Some advantages of bioremediation are that it is a natural process and compatible with the environment, it takes little time, it is effective, it requires less effort than conventional methods, it is a profitable process since it is inexpensive and accessible. Microalgae are promising as they are frequently associated with mosses, rivers, oceans, and other natural sources and have exceptional characteristics for cleaning air pollution; as well as some emerging pollutants such as those derived from oil. 

However, these processes are something that must be optimized with genetic engineering to obtain the best possible results both in terms of safety for the environment and effectiveness in removing the entire spectrum of polluting compounds. Bioremediation is a promising and environmentally friendly option to help clean up contaminants found in the environment; This is an optimal option to restore the environment, but to be fully effective, industrial methods that emit pollutants must be modified by others that do not emit dangerous pollutants, or that their waste is biocompatible with nature, only then the impact of the pollution will be reduced definitively for the health of the global environment.

References

• Tarekegn, Molaligne & Zewdu, Fikirte & Ishetu, Alemitu. (2020). Microbes used as a tool for bioremediation of heavy metal from the environment. Cogent Food & Agriculture. 6. 10.1080/23311932.2020.1783174.

• Sharma, Indu. (2020). Bioremediation Techniques for Polluted Environment: Concept, Advantages, Limitations, and Prospects. 10.5772/intechopen.90453. 

• Abatenh, Endeshaw & Gizaw, Birhanu & Tsegaye, Zerihun & Wassie, Misganaw. (2017). Open Journal of Environmental Biology The Role of Microorganisms in Bioremediation-A Review. Open Journal of Environmental Biology. 1. 038 - 040. 10.17352/ojeb.000007.