The potential of cyanobacteria to perform a variety of distinct roles vital for the biosphere, including nutrient cycling and environmental detoxification, drives interest in studying their biodiversity. Increasing soil erosion and the overuse of chemical fertilizers are global problems in developed countries. The option might be to switch to organic farming, which entails largely the use of biofertilisers. Cyanobacteria are prokaryotic, photosynthetic organisms with considerable potential, within agrobiotechnology, to produce biofertilisers. They contribute significantly to plant drought resistance and nitrogen enrichment in the soil. This study sought, isolated, and investigated nitrogen-fixing cyanobacterial strains in rice fields, and evaluated the effect of Mo and Fe on photosynthetic and nitrogenase activities under nitrogen starvation. Cyanobacterial isolates, isolated from rice paddies in Kazakhstan, were identified as Trichormus variabilis K-31 (MZ079356), Cylindrospermum badium J-8 (MZ079357), Nostoc sp. J-14 (MZ079360), Oscillatoria brevis SH-12 (MZ090011), and Tolypothrix tenuis J-1 (MZ079361). The study of the influence of various concentrations of Mo and Fe on photosynthetic and nitrogenase activities under conditions of nitrogen starvation revealed the optimal concentrations of metals that have a stimulating effect on the studied parameters.

Microalgae and cyanobacteria, as versatile photoautotrophic microorganisms, hold significant promise for mitigating soil and water pollution—particularly the removal of pesticides. This review examines their multifaceted roles in pesticide biodegradation, emphasizing how their metabolic capabilities simultaneously reduce environmental toxicity, enrich soil properties, and support beneficial microbiota. Cultivation in wastewater treatment systems further highlights their potential for cost-effective bioremediation, as these microbes degrade pesticides, recycle nutrients, break down organic pollutants, and generate biomass with value-added applications. Despite these advantages, implementing large-scale processes remains challenging. Key hurdles include optimizing growth parameters, preventing contamination, improving harvest efficiency, and designing robust bioreactors. Addressing these complexities demands interdisciplinary collaboration in strain selection, metabolic engineering, and process intensification. By capitalizing on microalgae and cyanobacteria’s adaptability and metabolic flexibility, we can develop more sustainable management strategies that reduce reliance on chemical inputs, foster soil health, and contribute to long-term ecological restoration. Ultimately, these microorganisms have the potential to reshape environmental stewardship by combining economic viability with broad-scale ecological benefits.

Cyanobacterial pigments have attracted considerable attention in industry due to their bioactive potential and natural origin. In the present study, the growth dynamics and pigment composition, in terms of chlorophyll a, total carotenoids and phycobiliprotein content, of four cyanobacterial strains isolated from thermal springs, namely Oscillatoria subbrevis CZS 2201, Phormidium ambiguum CZS 2205, Nostoc calcicola TSZ 2203, and Synechococcus sp. CZS 2204, were investigated. The analysis revealed that the maximum quantity of chlorophyll a and total carotenoids was observed in Oscillatoria subbrevis CZS 2201 (26.49 and 3.44 µg mL⁻¹), followed by Phormidium ambiguum CZS 2205 (18.64 and 2.32 µg mL⁻¹), whereas a minimum amount was detected in Synechococcus sp. CZS 2204 (12.13 and 1.24 µg mL⁻¹), respectively. In addition, Oscillatoria subbrevis CZS 2201 showed higher quantity of phycobiliproteins, especially C-phycocyanin (45.81 mg g⁻¹), C-phycoerythrin (64.17 mg g⁻¹) and C-allophycocyanin (27.45 mg g⁻¹). Moreover, carotenoid derivatives of Oscillatoria subbrevis CZS 2201 were also identified, among which β-carotene was the dominant form (1.94 µg mL⁻¹), while the accumulation of zeaxanthin and myxoxanthophyll was relatively high (0.53 and 0.41 µg mL⁻¹, respectively) compared with echinenone and cryptoxanthin (0.34 and 0.23 µg mL⁻¹, respectively). The study revealed that Oscillatoria subbrevis CZS 2201 was a potent producer of secondary carotenoids, including myxoxanthophyll.

Sources of renewable energy as a promising alternative to traditional sources operating on oil, natural gas and coal, are currently of great interest. Among the various types of biofuels, biohydrogen is the most clean and valuable fuel, and may be the most promising candidate for the role of environmentally friendly and renewable energy carrier of the future. Photosynthetic microorganisms have attracted special interest as potential cell factories for production of biohydrogen. In combination with photosynthesis, these organisms can use inexpensive inorganic substrates and solar energy to simultaneously biosynthesize and release hydrogen. Most studies focus on using different metabolic strategies to increase the hydrogen yield in different strains of cyanobacteria, including construction of genetic mutants of cyanobacteria with high capacity for biohydrogen production, followed by a well-chosen metabolic approach to increase its yield, and development of the innovative methods for their cultivation. Our laboratory is currently working on the isolation of heterocystic nitrogen-fixing cyanobacteria cultures from natural sources, as well as on the study of their morphological and cultural properties for use in biotechnology. The fundamental achievements made in these areas are summarized in this review.

Photosynthetic prokaryotes known as cyanobacteria produce an extensive range of primary and secondary metabolites that serve multiple biotechnological and biomedical purposes. The non-model filamentous Phormidium species capture researchers’ attention through their biotechnological potentials from diverse metabolites and their ability to thrive in tough environments while producing bioactive compounds. In this study, a thermotolerant strain of Phormidium ambiguum was isolated from the Chundzha thermal springs in southeastern Kazakhstan and characterized morphologically, physiologically, and biochemically. This cyanobacterium demonstrated fast growth in its culture media along with significant accumulation of proteins (44.8% DM), carbohydrates (45% DM), and photosynthetic pigments like chlorophyll a and valuable carotenoids, including b-carotene, myxoxantophyll and zeaxanthin. The LC-ESI-MS/MS analysis of cyanobacterial non-polar extract identified 150 potential metabolites which include fatty acid derivatives, terpenoids and carotenoid-related compounds known for their antioxidant and antimicrobial properties, as well as immune system stimulation. Biological assays confirmed a weak antioxidant capacity in the DPPH test, while in immunological assays, the extract of P. ambiguum stimulated T lymphocyte proliferation and activation, as well as NK cell proliferation in vitro. It also exhibited moderate antibacterial activity towards tested Gram-negative and Gram-positive bacterial strains. While additional studies are required to address environmental robustness, biosynthetic regulation, and practical scalability, the present findings indicate that P. ambiguum represents a valuable non-model cyanobacterium for exploratory bioprospecting. Its metabolite profile and observed bioactivities support further investigation of this thermotolerant strain as a potential source of immunomodulatory, antioxidant, and antimicrobial compounds under controlled conditions.