From the Depths of İğneada: A Green Revolution Below Our Feet

Nestled in the Demirköy district of Tekirdağ, the İğneada floodplain forests are a breathtaking blend of blue and green. Picture a lake stretching endlessly, surrounded by a sea of trees—ash, alder, oak, and more—casting their shadows on water lilies swaying gently on the surface. It's nature's symphony at its finest.

Head back to Earth. Think of towering chimneys spewing smoke, cities where you need a mask to breathe, a global pandemic, senseless wars, energy security crises, global warming, frequent natural disasters, slaughtered animals, and deforested lands. It's a bleak picture, isn't it?

Despite the promises made in the Paris Agreement, many governments have lagged in their commitments to reduce emissions. Developing countries, including Turkey, are struggling to make significant progress in cutting carbon dioxide emissions, let alone achieving a green transformation. To keep global temperature rise under 1.5°C, we must control greenhouse gas emissions [1]. A key solution in realizing this goal is the gradual abandonment of fossil fuels and the use of renewable resources in almost every field of industry, especially in energy production. We all know what renewable energy is. However, exactly how the green transformation, which will be led by renewable resources and energy, will be carried out is unknown. Everyone knows about solar and wind energy, but what if the answer isn't just in the sky, but also beneath our feet, literally on the ground?

Let's go back to İğneada. This marvel is bursting with biodiversity. It is, after all, a habitat for perhaps hundreds of species of trees and animals. But what about microorganisms? Considering that only 1 gram of soil can harbor up to 1 billion microorganisms and the unique climate of İğneada floodplain forests, it is no surprise that it is also very rich in this regard [2]. Likewise, the field research we conducted before my thesis was proof of this [3]. Another characteristic of the İğneada floodplain forests is that they are the closest ecosystem to rainforests and mangrove forests, which are impossible to have due to Turkey's latitude. This is due to, among many other factors, the high accumulation of organic matter in the soil and the fact that the forest surface is in a sediment-like wet form due to regular rainfall, which deprives the soil just below the soil of oxygen. This environment creates oxygen-poor conditions just below the surface, ideal for certain microorganisms. If you are wondering why I am telling you all this, I would like to invite you to my master's thesis.

Rather than torturing you with the 13-word title of my thesis, here's the gist: I aimed to discover microorganisms in the İğneada floodplain forests that can break down lignin without oxygen. What's lignin, you ask? Do you remember that I mentioned the high amount of organic matter accumulation in İğneada? Well, lignin is one of the most abundant molecules among those substances. It's a major component of plant cells, adding hardness and resistance. This makes it tough for other organisms to break down plant structures, both physically and chemically. That’s why lignin is one of the biggest obstacles to the digestion or chemical breakdown of plant structures by other living things [4]. Also, in the utilization of biomass led by plant wastes or the approximately 50 billion tons of lignin waste generated annually in various industries. The list could go on and on, but the most important of these is that it is the biggest obstacle to the revitalization of waste biomass in the form of biogas and its use as renewable energy.

Our hypothesis that the microorganisms we assumed to live just below the soil in the İğneada floodplain forests could be a cure for this problem led me to the scene in October 2021. We collected samples and they were transported to Boğaziçi University laboratories for experimentation. As I mentioned before, the aim was to measure by physicochemical analysis whether the microorganisms in the samples could digest lignin through enzymes in an oxygenfree environment. I won't bore you with the long and tedious laboratory process, but I am thrilled to share that our hypothesis was successful: microorganisms that digest lignin without oxygen do indeed exist in the İğneada floodplain forests! And of course, we published our exciting findings with the scientific community through two published manuscripts in a prestigious journal [5, 6].

Now, the next step is to characterize these microorganisms, analyze their genomes, find the responsible gene and enzyme, and finally purify the enzyme for use. Considering that the work so far has been going on for more than 3 years, we hope to see you in approximately 10 years. When that day comes, we hope that İğneada's unique ecosystem will be a medicine not only for itself but also for the whole world.

References
1. https://unfccc.int/process-and-meetings/the-paris-agreement/the-paris-agreement
2. Trevors, J. (2009). One gram of soil: a microbial biochemical gene library. Antonie Van Leeuwenhoek, 97(2), 99-106. doi: 10.1007/s10482-009-9397-5
3. Özbayram, E., Miraloğlu, I., & İnce, B. (2021). Assessment of microbial community diversity in lakes of İğneada floodplain forest by metabarcoding approach. Aquatic Research, 4(4), 304-312. doi: 10.3153/ar21025
4. Yoo, C., Meng, X., Pu, Y., & Ragauskas, A. (2020). The critical role of lignin in lignocellulosic biomass conversion and recent pretreatment strategies: A comprehensive review. Bioresource Technology, 301, 122784. doi: 10.1016/j.biortech.2020.122784
5. Ozsefil, I. C., Miraloglu, I. H., Ozbayram, E. G., Uzun, O., Ince, B., & Ince, O. (2023). Is a floodplain forest a valuable source for lignin-degrading anaerobic microbial communities: A metagenomic approach. Chemosphere, 339, 139675.
6. Ozsefil, I. C., Miraloglu, I. H., Ozbayram, E. G., Ince, B., & Ince, O. (2024). Bioaugmentation of anaerobic digesters with the enriched lignin-degrading microbial consortia through a metagenomic approach. Chemosphere, 355, 141831.