L.N. Gumilyov Eurasian National University, a dissertation defense for the degree of Doctor of Philosophy (PhD) by Evneeva Dinara on the topic «Ecological characteristics of the hydrobiocenosis of Lake Taldykol and microbiological approaches to its restoration» to the educational program «8D05208 – Ecology and nature management».
The dissertation was carried out at the «Management and Engineering in environmental protection education department» of L.N. Gumilyov Eurasian National University.
The language of defense is russian
Official reviewers:
Shorabayev Yerik Zharylkasynovich - Candidate of Biological Sciences (PhD), Director of LLP «Industrial Microbiology» (Almaty, Republic of Kazakhstan).
Shamshedenova Samal Salamatovna - Doctor of Philosophy (PhD), Acting Associate Professor, Department of Ecology, Kh. Dosmukhamedov Atyrau University (Atyrau, Republic of Kazakhstan).
Temporary members of the Dissertation Council:
Kanaev Ashimkhan Toktasynovich – Doctor of Biological Sciences, Professor of the Department of Biodiversity and Bioresources of the Faculty of Biology and Biotechnology of the Al-Farabi Kazakh National University (Almaty, Republic of Kazakhstan).
Zayadan Bolatkhan Kazykhanuly - Doctor of Biological Sciences, Professor of the Department of Biotechnology, Al-Farabi Kazakh National University (Almaty, Republic of Kazakhstan).
Popkova Anna Vladimirovna - Candidate of Biological Sciences, Associate Professor, Patris Lumumba Peoples' Friendship University of Russia (Moscow, Russia).
Scientific advisors:
Abzhalelov Akhan Begmanovich – doctor of Biological Sciences, Professor of the department «Management and Engineering in the Sphere of Environmental Protection» Eurasian National University named after L.N. Gumilyov (Astana, Republic of Kazakhstan).
Kuzmetov Abdulakhmet - doctor of biological sciences, professor, Professor of the Department of Medical Biology. General Genetics at Alfraganus University (Tashkent, Uzbekistan).
The defense will take place on March 13, 2026, at 11:00 AM in the Dissertation Council for the training direction «8D052 – Environment» in the specialty «8D05208 – Ecology and nature management» of L.N. Gumilyov Eurasian National University. The defense meeting is planned to be held online.
Link: https://twi.kz/GGC3j
Address: Astana, Kazhymukhan st., 13, Educational building No. 3, room. No. 333.
Abstract (English): General Description of the Study. The work is devoted to a comprehensive ecological and microbiological investigation of the Taldykol lake system located within the urbanized territory of Astana city. The relevance of the study is determined by global processes of aquatic ecosystem degradation, increasing anthropogenic pressure, and climate variability. The Taldykol lake system serves as an example where unique natural features coexist with the consequences of long-term anthropogenic impact. The ecological problems of Lake Taldykol include long-term wastewater inflow, high biogenic load, siltation, and recurrent water “blooms.” At the same time, Taldykol remains a natural dynamic water body where many species and communities act as indicators of environmental factors. The lake is in a state of increasing degradation; however, it also retains the potential for restoration of natural biocenoses and self-purification processes. Under conditions of intensified urbanization and climate variability, the study of Taldykol lake biocenoses acquires particular significance. This research makes it possible to determine which groups of organisms are involved in natural water purification processes; how the structure of biocenoses reflects the degree of anthropogenic load; and which mechanisms and biological indicators can serve as a basis for ecosystem assessment and restoration. Microorganisms play a special role in the stable functioning of aquatic ecosystems, as they are key participants in biogeochemical cycles and self-purification processes of water bodies. They ensure mineralization of organic compounds, transformation of nitrogen, phosphorus, and sulfur compounds, participate in biodegradation of organic pollutants and detoxification of toxic substances. Due to their high adaptability and metabolic activity, microorganisms are among the first to respond to environmental changes, allowing them to be considered sensitive indicators of ecosystem state. Aim and Objectives of the Study. The aim of the work is to provide qualitative and quantitative characterization of the hydrobiocenosis structure of Lake Taldykol, as well as to create a microbial consortium based on active strains involved in self-purification processes of the water body. The main objectives of the study are: to investigate the hydrochemical composition of Lake Taldykol and identify trends in water quality changes; to study the structure and seasonal variability of phytoplankton, zooplankton, and zoobenthos as indicators of the ecological condition of the water body; to conduct a microbiological study of bacterioplankton, isolate and identify active microbial strains; to determine the biochemical activity of the isolated microorganisms and their role in self-purification processes; to assess current ecological problems of the lake and propose measures for hydrobiocenosis restoration using autochthonous microbial consortia. Scientific Novelty. For the first time, it has been shown that long-term and multifactor anthropogenic transformation of Lake Taldykol has led to the formation of a hydrobiocenosis specific in structure and functioning, characterized by simplified hydrobiont community structure. It was established that under these conditions microbial communities represent a functionally significant component of the hydrobiocenosis, participating in regulation of biogenic processes and maintenance of the ecological state of the water body. Unlike previous studies, a comprehensive assessment of hydrobiological structure, species composition of microorganisms, and their functional activity under conditions of an anthropogenically transformed shallow lake was conducted for the first time. For the first time for Lake Taldykol, the taxonomic composition of culturable bacteria isolated from water was determined using genetic identification (16S rRNA gene sequencing). The isolated strains were found to possess a broad spectrum of enzymatic activity (proteolytic, amylolytic, lipolytic, cellulolytic), indicating the high potential of the autochthonous microbiota for biodegradation of organic pollutants. Theoretical and Scientific Significance. The theoretical significance lies in expanding understanding of patterns of formation and transformation of biocenoses in shallow endorheic lakes of arid zones under urbanization and anthropogenic pressure. The obtained results supplement scientific knowledge on the structure and functions of microbial communities as regulators of biogeochemical cycles in freshwater ecosystems. Scientific significance is associated with identification of structural and functional features of phytoplankton, zooplankton, benthic, and microbial communities within the Taldykol lake system. The study complements existing theoretical knowledge on microbial complexes regulating transformation of organic and mineral matter involved in self-purification and biotic stabilization of freshwater ecosystems. Based on the obtained data, the state of aquatic ecosystems was assessed using a complex of biotic and abiotic indicators, including saprobity indices, diversity indices, community structure, and microbiota activity. This allows biocenoses to be considered indicators of ecological processes and to be used for diagnosing directions of successional changes. Practical Significance. The practical significance of the work lies in the possibility of applying the results in developing environmental monitoring and water resource management programs for Astana city and Akmola region. The developed recommendations may be used for restoration and bioremediation of Taldykol lakes and similar urbanized water bodies of Kazakhstan. The isolated bacterial cultures represent a basis for creating biopreparations capable of reducing biogenic load and improving water quality. The research materials may be useful for scientists and specialists working in ecology and environmental protection, healthcare, zoology, and agriculture, as well as for профиль students. The results may also be used in establishing a specially protected natural area within the water area of the Taldykol lake system. Main Provisions Submitted for Defense. The hydrochemical state of Big and Small Taldykol Lakes is characterized by stable exceedance of regulatory limits for organic substances, biogenic elements, and salts, determining their classification as eutrophic and indicating unfavorable ecological status. Seasonal dynamics of phytoplankton, zooplankton, and zoobenthos reflect the response of hydrobiocenosis to changes in water quality and allow these communities to be used as ecological indicators. Microbiological analysis revealed 76 natural isolates dominated by representatives of the genera Aeromonas, Bacillus, Pseudomonas, and Serratia, indicating high organic load and active destructive potential of the microbial community. The isolated microbial strains exhibit pronounced enzymatic activity and participate in transformation of organic and biogenic substances, indicating their role in self-purification processes. The formed local microbial consortium demonstrated the ability for biological degradation of compounds and can be applied for bioremediation of polluted waters. The consortium created from autochthonous bacteria showed stability and high activity in laboratory tests, allowing it to be considered a natural biotechnological tool for restoration of aquatic ecosystems in urbanized areas. Approbation of the Work. Certain results were presented at the international scientific-practical conference “State and Prospects of Development of Fundamental and Applied Microbiology” (Tashkent, September 24–25, 2025) and the international scientific-practical conference “Aspects and Innovations of Environmental Biotechnology and Bioenergy” (Almaty: Al-Farabi Kazakh National University, 2021). Publications. The dissertation results are reflected in 9 publications: 2 articles in an international peer-reviewed journal indexed in Scopus; 3 articles in national journals included in Lists No. 2 and 3 of the Committee for Quality Assurance in Science and Higher Education of the Ministry of Science and Higher Education of the Republic of Kazakhstan; 4 conference proceedings and 1 utility model patent.
Conclusion of the Research Ethics Committee
Defense of the dissertation: https://www.youtube.com/watch?v=do7QdauNF6w
