Climate change impacts many aspects of our lives and almost every environment on earth. Industrial activity is widely accepted to be the main driving force behind this. The presence of microbes and their role in the climate is of paramount concern to scientists working in the field of climate science. Knowledge of this 'unseen majority' is vitally important to fully understand their function and how they can be used in technological applications that combat climate change itself.
Micro-organisms and the Environment
Micro-organisms are involved in many environmental processes including the nitrogen and carbon cycle. They are abundant in nearly all environments including the air, soil, the abyssal depths of the ocean, deep underneath the Earth's surface, and in environments that range widely in temperature, pressure, and chemical composition. It is estimated that there is something in the region of ~1030 total bacteria and archaea on Earth.
Microbes play an important role in the production and consumption of powerful greenhouse gases including CO2 and methane, have negative and positive feedback responses to temperature changes, and play a vital function in the regulation of ocean acidity. All of these can suffer perturbations due to anthropogenic climate change. They also have important functions in agriculture and the food web. Loss of habitat and the biodiversity of animal and plant species and communities is relatively well-publicized. However, the role of microbial communities is still poorly understood as they live in diverse communities that interact with the environment and other organisms in a complex way.
Therefore, including microbial activity in climate models is gaining prominence in the field of climate science. Microbial communities support all higher lifeforms and any significant perturbation to them (for example, rising levels of ocean acidity and the sensitivity of marine microbes to these changes) has a knock-on effect on the existence of all life. Undoubtedly, as we come to understand more about how micro-organisms respond to environmental disturbances, data gathered by studies will help us to elucidate the overall impact of climate change itself.
Using Micro-organisms to Limit the Impact of Climate Change
Climate science is not just about studying the impact of climate change itself, though that does contribute a large part of the field, it also is about developing technological solutions that can ease the burden of human activity on fragile ecosystems. Some uses of microbes and biotechnology to solve this issue are listed below.
Using Microbes to Absorb CO2
The best way to combat climate change remains the mitigation and reduction of greenhouse gases. The main greenhouse gas that most people know about is carbon dioxide and for years scientists have been researching ways to mitigate the levels of this gas in the atmosphere. A team at the Weizmann Institute of Science in Rehovot, Israel, has used a combination of lab evolution and genetic engineering to create a strain of E. Coli which uses CO2 as its sole source of carbon. It is hoped that systems can be developed to use this modified form of E. Coli to consume atmospheric CO2 and either store it or produce biofuel and foodstuffs. However, the team is still working on increasing the efficiency of the bacteria in consuming atmospheric CO2.
Reducing Nitrous Oxide Emissions
Another critical greenhouse gas is nitrous oxide. It is the third most important GHC and is also a major ozone-depleting substance. One of the major routes of production of this harmful gas, which is also a major pollutant responsible for numerous deaths worldwide, is car exhausts. Another significant contributor is the agrochemical industry. Recently, several mitigation techniques based upon microbiological methods have been the subject of research. These include the manipulation of microbiomes in diverse environments and integrating microbiome-based knowledge of nitrous oxide sources and sinks. There has also been research into using bacteria-based systems for directly removing nitrous oxide from car exhausts and power stations.
Smart Agriculture Applications
Soil microbes play an important part in regulating greenhouse gas emissions, as well as productivity and sustainability of agricultural systems, and degradation of soil and water. All this has a real impact on climate change. Climate-smart agriculture (CSA) is an integrative approach to agriculture that aims to limit the impact of the agricultural industry upon the long-term viability of the climate. Understanding the specifics of how these soil microbiomes respond to agricultural practices and climatic pressures such as temperature and extreme weather events is an integral part of this discipline. Increased knowledge of microbial ecology and the interactions between plants and microbes in soil is essential for the use of microbial biotechnology for climate change adaptation and mitigation.
Living Concrete
The construction industry has a huge impact on climate change. According to some studies, the contribution of construction projects contributes to 40% of total energy use globally. One innovative use of micro-organisms to combat this issue is the use of 'living concrete' which utilizes photosynthetic cyanobacteria called Synechococcus sp. PCC, held in a biosynthetic gel. Another benefit of this technology is that it can be used to absorb CO2 from the atmosphere.
In Conclusion
Climate change is, without a doubt, the most pressing concern for humanity. It affects the long-term viability of not only our civilization but for all life on Earth. To maintain a healthy global ecosystem, microbes are vitally important. Understanding the complex interactions of microbial biomes with higher organisms (especially plants) and how these communities of microbes can be affected by climate change is therefore critical. Microbial-based applications for climate-mitigation technology are also an increasingly important area of research.
Sources
- Hu, H.W, He, JZ, & Singh, B (2017) Harnessing microbiome-based biotechnologies for sustainable nitrous oxide emissions Microbial Biotechnology 10 (5) (Accessed 15th June 2020) sfamjournals.onlinelibrary.wiley.com/doi/full/10.1111/1751-7915.12758
- Gleizer, S et al. (2019) Conversion of Escherichia coli to Generate All Biomass Carbon from CO2 Cell 179(6) pp. 1255-1263 (Accessed 15th June 2020) https://doi.org/10.1016/j.cell.2019.11.009
- Das, S, Ho, A & Kim, P (2019) Editorial: Role of Microbes in Climate Smart Agriculture Front. Microbiol (Accessed 15th June 2020 https://www.frontiersin.org/articles/10.3389/fmicb.2019.02756/full
- Caviccholi, R, Ripple, W.J & Webster, N.S (2019) Scientists' warning to humanity: microorganisms and climate change Nature Reviews Microbiology 17 pp. 569-586 (Accessed 15th June 2020) https://www.nature.com/articles/s41579-019-0222-5
