KazNU Scientists Isolate Thermophilic Bacteria from Geothermal Springs to Biodegrade Plastic Waste

Every year, more than 280 million tons of single-use plastic products end up in landfills worldwide, while global plastic production reaches 360 million tons annually. Improper disposal of such volumes damages soils, water resources, and marine flora and fauna, while microplastics enter food chains, posing long-term health risks. In Kazakhstan, over 100,000 tons of PET-based plastic waste are generated annually, of which less than 4% is recycled. Total plastic waste in the country reaches 630,000-884,000 tons per year.

Traditional disposal methods — landfilling and incineration — are environmentally harmful and insufficient. Microbial biodegradation is considered one of the most promising approaches to combating plastic pollution. However, global experience shows that most biodegradation attempts at 20-30°C have proven ineffective. Using thermophilic bacteria that thrive at 50-90°C therefore opens new possibilities: their enzymes (thermozymes) show high stability at elevated temperatures, while reduced substrate viscosity increases diffusion coefficients.

The scientific novelty of the project is expressed in several directions. First and foremost, new bacterial strains with high plastic-degrading activity will be isolated and studied for the first time from geothermal springs in Kazakhstan and Armenia. Based on these strains, a biocompatible consortium of thermophilic bacteria with diverse enzymatic specificity will be formed — in other words, a group of bacteria will be created for the first time that, rather than suppressing one another, work synergistically together. To effectively cultivate this consortium, a new specialized mineral medium will be developed in which plastic serves as the sole carbon source. In addition, the study will for the first time identify specific enzymes associated with plastic biodegradation in Kazakhstani thermophilic bacteria, along with their genetic and proteomic characterization. The final outcome of the project will be a technological scheme and set of regulations for industrial-scale plastic biodegradation proposed for the first time, laying the groundwork for translating the acquired scientific knowledge into practical application. 

Achieving the project's goal will require the sequential completion of several tasks. In the first stage, thermophilic bacteria will be isolated from geothermal springs with water temperatures of 50-90°C located in plastic-contaminated areas, followed by screening of their plastic-degrading capacity. Next, using genomic, metagenomic, and proteomic analysis methods — including the Orbitrap mass spectrometer at the Proteomics Unit (PROBE) of the University of Bergen — the most promising strains producing plastic-degrading enzymes will be identified. In the third stage, a biocompatible consortium will be formed from the strains with the highest activity, and cultivation conditions — temperature, pH, aeration, and medium composition — will be optimized to enhance their combined growth and enzymatic activity. In the final stage, based on all data obtained, a complete technological protocol for plastic biodegradation under laboratory conditions will be developed, including a detailed description of experimental conditions and criteria for evaluating biodegradation efficiency. 

The study comprises five stages: sample collection and pre-treatment (soil, water, thermal spring material); screening for degradation of PET, PE, PS, PVC, and PP, with plastic as the sole carbon source; strain identification through 16S rRNA gene sequencing, BLAST/PFAM bioinformatic analysis, and proteomic studies; consortium development via co-cultivation; and technological trials in the semi-industrial EDF-15.1 bioreactor. Statistical data processing uses JMP 13.0 software with a Box-Behnken design.

The project is carried out in close collaboration with scientists from Norway (University of Bergen, Professor Nils-Kåre Birkeland) and Armenia (Yerevan State University). This partnership continues the international DIKU CPEA-LT-2017/10061 project, under which a metagenomic analysis of a thermal spring in the Almaty region was previously conducted. The Armenian team's expertise in extremophilic ecosystems and the involvement of Norwegian proteomics specialists significantly strengthen the project's scientific level.

The developed biotechnology could be applied at solid waste landfills, for water body remediation, and in industrial chains converting plastic into biodegradable products. The project will result in one Kazakhstani patent and a technological scheme and regulations for industrial-scale plastic biodegradation, enabling enterprises to meet environmental responsibility standards and achieve long-term economic benefits.

Implementation of the project will yield a number of specific, measurable scientific results. In particular, the research findings will be published in at least two articles in international peer-reviewed journals ranked in the first or second quartile by impact factor in the Web of Science database, or with a CiteScore percentile of at least 65 in Scopus, with one of these articles required to fall within a multidisciplinary category. In addition, at least two further articles will be published in domestic or foreign peer-reviewed journals recommended by the Committee for Quality Assurance in Education and Science (KOKSON) of the Republic of Kazakhstan. The project also envisions the development of human capital — at least one Doctor of Philosophy (PhD) will be trained, with the dissertation defense taking place no later than two years after the project's completion. To ensure the practical application of the scientific results, one patent will be obtained from the Kazakhstani patent office. Finally, based on all the experimental data and knowledge accumulated during the research, a complete technological scheme and set of regulations for industrial-scale plastic biodegradation will be developed, ready for practical implementation at enterprises. 

Spanning 36 months (2025-2027), the project will be among the first systematic studies of plastic biodegradation in Kazakhstan, generating new knowledge at the intersection of microbiology, biochemistry, biotechnology, and ecology. The project is carried out by scientists at the Laboratory of Applied Microbiology at Al-Farabi Kazakh National University, with international collaboration with Norway and Armenia elevating its scientific potential to a global level.