## 1 Introduction  
As annual global energy consumption continues to rise, there is increasing interest in renewable energy sources as alternatives to fossil fuels. Non-renewable energy consumption, such as fossil fuels, increased by 84% from 2000 to 2023, while the capacity of renewable energy expanded by 414% [1]. Non-renewable energy encompasses fossil fuels, including coal and oil, as well as nuclear energy. The reliance on non-renewable energy has heightened interest in renewable energy due to its significant contribution to greenhouse gas emissions and global warming [2]. Global warming can also have a negative impact on major crops in many agricultural regions [3, 4]. As a result, interest in biofertilizers usingmicroalgae is also increasing [5; 6]. Despite the rapid growth in renewable energy capacity, climate-related challenges associated with non-renewable energy persist [7]. Addressing these issues requires sustained efforts to enhance the adoption and utilization of renewable energy resources. The first generation of renewable energy sources, such as corn, wheat, and soybeans, faced limitations, including competition with food production and extensive farmland requirements. To address these drawbacks, second-generation renewable energy resources, primarily derived from woody plants, were introduced. However, their reliance on land required for food production posed additional challenges [8; 9]. As a solution, microalgae have been identified as third-generation renewable energy resources due to their ability to overcome the limitations of the previous generations [8; 10]. Microalgae have garnered significant interest due to their ability to accumulate substantial lipid levels and convert them into biodiesel via the transesterification process, highlighting their potential for biofuel production [11; 12; 13]. Microalgae are microorganisms that grow by photosynthesizing in various aquatic environments. They can grow in a variety of culture conditions, including salt water, fresh water, and wastewater, so they offer great production flexibility [14; 15]. Microalgae, which can also be cultivated in wastewater, utilize nutrients such as nitrogen and phosphorus from wastewater for growth, thereby contributing to wastewater purification [16]. Furthermore, microalgae are recognized as a sustainable resource for various biotechnological applications, including the production of high-value compounds such as omega-3 fatty acids and lutein [17]. For instance, microalgae species like _Nannochloropsis_ and _Schizophrenia_ are rich in eicosapentaenoic acid (EPA) and docosahexaenoicenoic acid (DHA) and are widely utilized as raw materials in health supplements and pharmaceuticals [18]. Unlike omega-3 fatty acids derived from fish, microalgae-based omega-3 production offers a sustainable alternative that does not compromise marine ecosystems [19; 20; 21]. Microalgae have the advantages of fast growth rate, efficient carbon dioxide fixation, and the inclusion of various high-value compounds, including pigments that can be utilized as bioactive ingredients in food, pharmaceutical, and cosmetic applications [22; 23]. In addition, microalgae can accumulate lipids, carbohydrates, proteins, various bioactive compounds, and essential inorganic nutrients, enabling their utilization in the production of bio-based products such as biofuels and biofertilizers [24; 25]. Furthermore, as a biofertilizer, microalgae contribute to soil fertility enhancement and reduce dependence on synthetic fertilizers, positioning them as a sustainable alternative to conventional fertilization practices [22]. Despite these advantages, scaling up microalgae cultivation and processing to meet industrial demands poses significant challenges. Large-scale production encounters numerous technical and economic barriers, such as optimizing growth conditions, developing cost-effective harvesting techniques, and streamlining downstream processing.