Assessment of biomass potentials of microalgal communities in open pond raceways using mass cultivation

Innovative strategies for utilizing microalgae as dual-purpose biofertilizers and phycoremediators in agroecosystems

The increasing need for sustainable agricultural practices due to the overuse of chemical fertilizers has prompted interest in microalgae as biofertilizers. This review investigates the potential of microalgae as biofertilizers and phycoremediators within sustainable agroecosystems, addressing both soil fertility and wastewater management. Microalgae provide a dual benefit by absorbing excess nutrients and contaminants from wastewater, generating nutrient-rich biomass that can replace chemical fertilizers and support plant growth. Implementation strategies include cultivating microalgae in wastewater to offset production costs, using closed photobioreactor systems to enhance growth efficiency, and applying microalgal biomass directly to soil or crops. Additionally, microalgae extracts provide essential bioactive compounds, such as phytohormones and amino acids, that enhance plant growth and resilience. While microalgae offer an eco-friendly solution for nutrient recycling and crop productivity, challenges in scalability, production cost, and regulatory frameworks hinder widespread adoption. This review highlights the potential pathways and technological advancements necessary for integrating microalgae into sustainable agriculture, emphasizing the need for interdisciplinary collaboration and innovative approaches to overcome these barriers. Ultimately, microalgae biofertilizers represent a promising approach to reducing environmental impact and advancing sustainable farming practices.

Advances in Algomics technology: Application in wastewater treatment and biofuel production

Advanced sustainable bioremediation is gaining importance with rising global pollution. This review examines microalgae's potential for sustainable bioremediation and process enhancement using multi-omics approaches. Recently, microalgae-bacterial consortia have emerged for synergistic nutrient removal, allowing complex metabolite exchanges. Advanced bioremediation requires effective consortium design or pure culture based on the treatment stage and specific roles. The strain potential must be screened using modern omics approaches aligning wastewater composition. The review highlights crucial research gaps in microalgal bioremediation. It discusses multi-omics advantages for understanding microalgal fitness concerning wastewater composition and facilitating the design of microalgal consortia based on bioremediation skills. Metagenomics enables strain identification, thereby monitoring microbial dynamics during the treatment process. Transcriptomics and metabolomics encourage the algal cell response toward nutrients and pollutants in wastewater. Multi-omics role is also summarized for product enhancement to make algal treatment sustainable and fit for sustainable development goals and growing circular bioeconomy scenario.

Water monitoring by means of digital microscopy identification and classification of microalgae

Marine and freshwater microalgae belong to taxonomically and morphologically diverse groups of organisms spanning many phyla with thousands of species. These organisms play an important role as indicators of water ecosystem conditions since they react quickly and predictably to a broad range of environmental stressors, thus providing early signals of dangerous changes. Traditionally, microscopic analysis has been used to identify and enumerate different types of organisms present within a given environment at a given point in time. However, this approach is both time-consuming and labor intensive, as it relies on manual processing and classification of planktonic organisms present within collected water samples. Furthermore, it requires highly skilled specialists trained to recognize and distinguish one taxa from another on the basis of often subtle morphological differences. Given these restrictions, a considerable amount of effort has been recently funneled into automating different steps of both the sampling and classification processes, making it possible to generate previously unprecedented volumes of plankton image data and obtain an essential database to analyze the composition of plankton assemblages. In this review we report state-of-the-art methods used for automated plankton classification by means of digital microscopy. The computer-microscope system hardware and the image processing techniques used for recognition and classification of planktonic organisms (segmentation, shape feature extraction, pigment signature determination and neural network grouping) will be described. An introduction and overview of the topic, its current state and indications of future directions the field is expected to take will be provided, organizing the review for both experts and researchers new to the field.

Conversion of Scenedesmus rubescens Lipid into Biodiesel by Biochar of Different Origin

One of the most recent applications studied in recent years is the use of biochar as a catalyst for the conversion of oils into biodiesel. The scope of this work was to evaluate the efficiency of biochars as heterogeneous catalysts for the conversion of Scenedesmus rubescens lipids into biodiesel. Biochar from different materials were employed, namely, malt spent rootlets (MSR), coffee spent grounds (CSG), and olive kernels (OK). Materials were charred at two temperatures (400 and 850 °C) in order to examine the effect of pyrolysis temperature. Homogeneous catalysts such as sulfuric acid and sodium hydroxide were also employed for comparison purposes. In order to explain the different performance of biochar as catalyst, we conducted detailed characterization of these materials. The results of this study showed that homogeneous catalysts (H2SO4 and NaOH) had similar results to the CSG biochar at 400 °C, which was the most productive tested biochar. The pyrolysis temperatures affected the FAMEs recovery of OK and CSG biochar.

Microalgal Biodiesel Production: Realizing the Sustainability Index

Search for new and renewable sources of energy has made research reach the tiny little tots, microalgae for the production of biodiesel. But despite years of research on the topic, a definitive statement, declaring microalgae as an economically, environmentally, and socially sustainable resource is yet to be seen or heard of. With technological and scientific glitches being blamed for this delay in the progress of the production system, an assessment of the sustainability indices achieved so far by the microalgal biodiesel is important to be done so as to direct future research efforts in a more coordinated manner to achieve the sustainability mark. This article provides a review of the current economic, environmental, and social status of microalgal biodiesel and the strategies adopted to achieve them, with suggestions to address the challenges faced by the microalgal biodiesel production system.

Selection of Indigenous Algal Species for Potential Biodiesel Production

Currently, India utilizes an enormous amount of fossil fuels and a major quantity of fossil fuels are imported from other countries. It’s a giant load on the Indian Economy. The burning of fossil fuels causes global warming. Carbon neutral, renewable fuels are essential for environmental protection and it’s economically sustainable for India. Biofuels attention day by day due to a rise in energy demands and environmental concerns. Biodiesel produced from algal oil a possible renewable and carbon-neutral substitute to fossil fuels. The feasibility of the algal-based biodiesel industry depends on the selection of adequate species regarding commercial oil yields and oil quality. Present research work to bioprospecting and screening of 19 algal and blue-green algal species, the oil percentage and the fatty acid profiles, used for analyzing the biodiesel fuel properties. Oil from Tolypothrix phyllophila algal strain and compared it with another eighteen algal and blue-green algal strains from different literature. Tolypothrix phyllophila algal strain contains approximately 12.6% lipid on a dry weight basis. We also compared the FAME profile of 19 algal and blue-green algal strains and calculated and compared the fuel properties such as cetane number, Iodine Value, etc. of the biodiesel derived from these algal and blue-green algal oils based on chain length and saturation. We also investigated the 19 algal and blue-green algal fatty acid profiles and its suitability for biodiesel production and strains selection through PROMETHEE (Preference Ranking Organization Method for Enrichment Evaluations) and GAIA (geometrical analysis for interactive aid) analysis.

Strain-Specific Biostimulant Effects of Chlorella and Chlamydomonas Green Microalgae on Medicago truncatula

Microalgae have been identified to produce a plethora of bioactive compounds exerting growth stimulating effects on plants. The objective of this study was to investigate the plant-growth-promoting effects of three selected strains of eukaryotic green microalgae. The biostimulatory effects of two Chlorella species (MACC-360 and MACC-38) and a Chlamydomonas reinhardtii strain (cc124) were investigated in a Medicago truncatula model plant grown under controlled greenhouse conditions. The physiological responses of the M. truncatula A17 ecotype to algal biomass addition were characterized thoroughly. The plants were cultivated in pots containing a mixture of vermiculite and soil (1:3) layered with clay at the bottom. The application of live algae cells using the soil drench method significantly increased the plants’ shoot length, leaf size, fresh weight, number of flowers and pigment content. For most of the parameters analyzed, the effects of treatment proved to be specific for the applied algae strains. Overall, Chlorella application led to more robust plants with increased fresh biomass, bigger leaves and more flowers/pods compared to the control and Chlamydomonas-treated samples receiving identical total nutrients.