Microalgae Cultivation Research Articles

Towards maximizing biomass and lipid productivity: high-throughput screening assay for prospecting heterotrophic growth for new microalgal isolates

BackgroundMicroalgae have emerged as sustainable alternatives to fossil fuels and high-value petrochemicals. Despite the commercial potential of microalgae, their low biomass productivity is a significant limiting factor for large-scale production. In the photoautotrophic cultivation of microalgae, achievable cell density levels depend on the light transmittance of the production system, which can significantly decrease the photosynthetic rate and biomass production. In contrast, the mixotrophic cultivation of microalgae using heterotrophic carbon sources enables high-density cultivation, which significantly enhances biomass productivity. The identification of optimal production conditions is crucial for improving biomass productivity; however, it is typically time- and resource-consuming. To overcome this problem, high-throughput screening (HTS) system presents a practical approach to maximize biomass and lipid production and enhance the industrial applicability of microalgae.ResultsIn this study, we proposed a two-step HTS assay that allows effective screening of heterotrophic conditions compatible with new microalgal isolates. To confirm the effectiveness of the HTS assay, three microalgal isolates with distinctive morphological and genetic traits were selected. Suitable cultivation conditions, including various heterotrophic carbon sources, substrate concentrations, and temperatures, were investigated using a two-step HTS assay. The optimized conditions were validated at the flask scale, which confirmed a significant enhancement in the biomass and lipid productivity of each isolate. Moreover, the two-step HTS assay notably enhanced economic and temporal efficiency compared to conventional flask-based optimization.ConclusionsThese results suggest that our two-step HTS assay is an efficient strategy for investigating and optimizing microalgal culture conditions to maximize biomass and lipid productivity. This approach has the potential to enhance the industrial applicability of microalgae and facilitate the seamless transition from laboratory to field applications.

Carbonic anhydrase activity and metabolite variation of different microalgae species at alkaline pHs

A significant increase in atmospheric greenhouse gases over the last century has led to the development of several methods and technologies to remove carbon dioxide (CO2). Microorganisms produce carbonate minerals through the natural mineralization of CO2; however, the feasibility of this process remains in research. This work aimed to study the cultivation of different microalgae under alkaline pH to maintain their potential for carbon mitigation. According to the results, the highest carbonic anhydrase activity has been reached (4.64 mg/g) for Chlamydomonas reinhardtii at a pH of 10. C. reinhardtii, at a pH of 9.5, yielded the highest chlorophyll content (23.58 mg/g), while Spirulina at a pH of 8.5 produced the highest biomass (882.9 mg/L). Also, a positive correlation existed between pH and lipid content for C. reinhardtii. Spirulina, however, exhibits the opposite effect. According to a principal component analysis, there is an opposite relationship between pH and carbonic anhydrase (CA) activity for C. reinhardtii and filamentous-type cyanobacteria from Salda Lake. The following order of the suitability of the microalgae species for high carbon capture is determined by the Analytic hierarchy process method: Spirulina>C. reinhardtii > Chlorella vulgaris > Coccus-type cyanobacteria > Filamentous-type cyanobacteria from Salda Lake. Additionally, this study provided important results regarding the cyanobacteria species isolated from an alkaline lake, Lake Salda. This would contribute to future studies of carbon capture and carbon mitigation mechanisms.

Graph-learning-based machine learning improves prediction and cultivation of commercial-grade marine microalgae Porphyridium

A graph learning [Binarized Attributed Network Embedding (BANE)] model enhances the single-target and multi-target prediction performances of random forest and eXtreme Gradient Boosting (XGBoost) by learning complex interrelationships between cultivation parameters of Porphyridium. The BANE-XGBoost has the best prediction performance (train R2 > 0.96 and test R2 > 0.87). Based on Shapley Additive Explanation (SHAP) model, illumination intensity, culture time, and KH2PO4 are the most critical factors for Porphyridium growth. The combined facilitating roles of cultivation parameters are found using the SHAP value-based heat map and group. To reach high biomass and daily production rate concurrently, one-way and two-way partial dependent plots models find the optimal conditions. The top 2 critical parameters (illumination intensity and KH2PO4) were selected to verify using the graphical user interface website based on the optimized model and lab experiments, respectively. This study shows thegraph-learning-based model can improve prediction performance and optimize intricate low-carbon microalgal cultivation.

Optimization of the marine microalgae Nannochloropsis oculata harvesting by flocculation: Effects on biomass quality and residual medium reuse for a new cycle

ABSTRACT Flocculation using natural plant-based biopolymers from Moringa oleifera seeds and Acacia mearnsii flocculant as Tanfloc® (TSG) has emerged as an efficient strategy for microalgae biomass harvesting. This study optimized the recovery process of Nannochloropsis oculata by varying flocculant concentration, sedimentation time, and culture pH. Results revealed that 1.2 mg.L−1 of TSG at pH 8.9 achieved optimal conditions, although TSG proved effective across different pH ranges. Alkaline flocculation (ALK) also enhanced microalgae harvesting, yielding a high harvesting efficiency (>96%) within 30 minutes of sedimentation. Both methods achieved a concentration factor exceeding 20. However, the use of ALK resulted in reduced lipid and carbohydrate content compared to the control condition. Carotenoid levels showed no significant difference. TSG influenced lipid extraction but not fatty acid quality or carbohydrate extraction. Importantly, the residual medium from TSG flocculation could sustain subsequent cultivation cycles without nutrient supplementation, presenting a cost-effective solution for microalgae cultivation and harvesting.

Distinct exposure impact of non-degradable and biodegradable microplastics on freshwater microalgae (Chlorella pyrenoidosa): Implications for polylactic acid as a sustainable plastic alternative

Microplastics (MPs) are increasingly recognized as significant sources of harm to biota in various environments. However, the detrimental impacts of aged MPs with different structures and degradability remain poorly understood. In this study, aged MPs from polylactic acid (PLA), polyethylene (PE), and polystyrene (PS), representing biodegradable, aliphatic, and aromatic plastics, respectively, were prepared to examine their effects on microalgae (Chlorella pyrenoidosa). Structural and property analyses indicated the presence of aging and oxygen-containing functional groups on the surfaces of the MPs, which correlated with an increase in negative electrical charge (i.e., aged PLA > aged PE ≈ aged PS). Aged PLA MPs affected microalgae biomass, promoted protein synthesis, and elevated mild oxidative stress. In contrast, aged PE and PS MPs not only affected biomass, protein, and carbohydrate synthesis but also inhibited photosynthetic pigment production and activity, resulting in intracellular oxidative stress. Excitation-emission-matrix spectra analysis showed that PLA induced microalgae to secrete large amounts of humic acid-like extracellular polymers, whereas aged PE and aged PS groups contained only small amounts of them and proteins. This study addresses critical knowledge gaps in the toxicology of various aged MPs on microalgae and provides valuable insights into the potential of PLA as a sustainable alternative to conventional plastics in microalgae culture industry.

Sweet sorghum as alternative carbon sources for Chlorella sp. valued-added compounds production: A mechanistic insight using transcriptomics

Substituting agricultural by-products for glucose as a carbon source is an effective strategy for reducing the cultivation cost of Chlorella sp. However, the response mechanism of Chlorella sp. to variations in carbon sources remains unclear, and the potential of microalgal biomass for food development warrants further exploration. This study used hydrolysate of sweet sorghum stem juice (HSJ) for the mixotrophic cultivation of Chlorella sp. And transcriptomic analysis was performed to investigate the physiological and metabolic mechanisms as well as the biosynthesis of value-added compounds (e.g., pigments and proteins) of Chlorella sp. in response to changes in carbon sources. The HSJ + NM group (HSJ supplemented with nitrogen and minerals) significantly increased total chlorophyll, carotenoids, lutein, and protein levels by 18.02 %, 13.34 %, 35.95 %, and 20.36 %, respectively, compared to the control (adjusted BG-11 medium supplemented with 10 g/L glucose). Notably, transcript levels of genes for multiple key enzymes involved in glycolysis/gluconeogenesis, TCA cycle, oxidative phosphorylation pathway, and photosynthesis pathways were significantly up-regulated. The activity of these pathways promoted the pigments and proteins synthesis in Chlorella sp. Encouragingly, the cost of cultivating Chlorella sp. with HSJ + NM (0.495 USD/kg) was 43.35 % of glucose (1.142 USD/kg). Further, by fermenting Chlorella sp. cultures with Saccharomyces cerevisiae and further homogenizing and blending the fermentation broth, we developed a nutritious and palatable Chlorella sp. fermented beverage, addressing the common issue of algal odor in such products. This study provides theoretical and practical foundations for the mixotrophic cultivation of microalgae and the application of microalgal biomass in food innovation.

Physiological Effects and Mechanisms of Chlorella vulgaris as a Biostimulant on the Growth and Drought Tolerance of Arabidopsis thaliana

Microalgae have demonstrated biostimulant potential owing to their ability to produce various plant growth-promoting substances, such as amino acids, phytohormones, polysaccharides, and vitamins. Most previous studies have primarily focused on the effects of microalgal biostimulants on plant growth. While biomass extracts are commonly used as biostimulants, research on the use of culture supernatant, a byproduct of microalgal culture, is scarce. In this study, we aimed to evaluate the potential of Chlorella vulgaris culture as a biostimulant and assess its effects on the growth and drought tolerance of Arabidopsis thaliana, addressing the gap in current knowledge. Our results demonstrated that the Chlorella cell-free supernatant (CFS) significantly enhanced root growth and shoot development in both seedlings and mature Arabidopsis plants, suggesting the presence of specific growth-promoting compounds in CFS. Notably, CFS appeared to improve drought tolerance in Arabidopsis plants by increasing glucosinolate biosynthesis, inducing stomatal closure, and reducing water loss. Gene expression analysis revealed considerable changes in the expression of drought-responsive genes, such as IAA5, which is involved in auxin signaling, as well as glucosinolate biosynthetic genes, including WRKY63, MYB28, and MYB29. Overall, C. vulgaris culture-derived CFS could serve as a biostimulant alternative to chemical products, enhancing plant growth and drought tolerance.

Cultivation of Microalgae Mixed Culture from Mahoni Small Lake UI Campus Depok using Zeolite Substrate with Varying Pb Concentration

Research on the cultivation of mixed cultures of Situ (small lake) Mahoni UI Campus Depok has been done. This research was a preliminary study to measure and compare the growth of Situ Mahoni mixed cultures microalgae grown in Bold's Basal Medium (BBM) with addition of zeolite and without addition of zeolite, and varying concentrations of heavy metal Pb. The concentrations of heavy metal Pb used were 0 ppm, 20 ppm, 40 ppm, 60 ppm, 80 ppm, and 100 ppm for two treatments. The results of this research were that the growth of mixed cultures with the addition of zeolite had the highest abundance of 8.800 cells/mL on day 5 (T5) at a Pb concentration of 40 ppm. Meanwhile, the growth of mixed culture without the addition of zeolite had the highest abundance of 21.700 cells/mL on day 10 (T10) at a Pb concentration of 60 ppm. The growth of microalgae mixed cultures in the medium without addition of zeolite was higher than using zeolite. The activation of zeolite pores causes the microalgae growth is relatively lower. This work aimed to study the growth of a mixed cultures microalgae in varying concentrations of Pb with and without the addition of zeolite

Comparison of Biohydrogen Production by Tetraselmis subcordiformis During Cultivation Using Soil-Less Agricultural Wastewater and Effluent from Microbial Fuel Cells

The development and implementation of innovative production technologies have a direct influence on the creation of new sources of pollution and types of waste. An example of this is the wastewater from soil-less agriculture and the effluent from microbial fuel cells. An important topic is the development and application of methods for their neutralisation that take into account the assumptions of global environmental policy. The aim of the present study was to determine the possibilities of utilising this type of pollution in the process of autotrophic cultivation of the biohydrogen-producing microalgae Tetraselmis subcordiformis. The highest biomass concentration of 3030 ± 183 mgVS/L and 67.9 ± 3.5 mg chl-a/L was observed when the culture medium was wastewater from soil-less agriculture. The growth rate in the logarithmic growth phase was 270 ± 16 mgVS/L-day and 5.95 ± 0.24 mg chl-a/L-day. In the same scenario, the highest total H2 production of 161 ± 8 mL was also achieved, with an observed H2 production rate of 4.67 ± 0.23 mL/h. Significantly lower effects in terms of biomass production of T. subcordiformis and H2 yield were observed when fermented dairy wastewater from the anode chamber of the microbial fuel cell was added to the culture medium.

Environmental impact assessment in microalgal lipid production: carbon footprint and net emissions

This study focuses on analyzing the role of microalgae in mitigating climate change through CO2 capture and lipid production, which can be used in the development of energy products and commercially relevant products. The objective was to evaluate the net CO2 emissions in three lipid production scenarios from microalgae, in addition to analyzing the impact of various biomass pretreatment technologies before lipid extraction. For this purpose, only the emissions directly generated by energy consumption in the process and the amount of CO2 that can be captured by microalgae cultivation were considered. In all three scenarios, CO2 capture during biomass cultivation and emissions associated with maintaining the process in operation were evaluated. The results show that the emissions generated by energy consumption were 3.56 kg-CO2/kg-oil, 2.19 kg-CO2/kg-oil, and 2.36 kg-CO2/kg-oil in scenarios 1, 2, and 3, respectively, while the CO2 emissions captured in microalgae cultivation were three to four times higher, ultimately resulting in negative emissions in all scenarios. The efficiency of CO2 capture per kilogram of oil produced varies between scenarios, suggesting that the choice of technology and process conditions significantly influence the overall environmental impact. This analysis identifies areas of opportunity to improve microalgal biomass utilization processes, highlighting the stages of the process with the greatest impact on the carbon footprint and enabling the comparison of different technologies on the same basis.

Studying the Antioxidant and Antimicrobial Activity of Lipsticks Made with Phycoerythrin Under the Influence of Different Magnetic Fields

Background: Several studies have shown the benefits of magnetic treatment on the productivity of secondary metabolites, growth, and the state of microalgae cultures Objective: This study examined the antioxidant and antimicrobial activity of lipsticks made with phycoerythrin (PE) extracted from the cyanobacterium Nostoc sp. under the influence of different magnetic fields (30 mT and 60 mT). Material and Methods: After cyanobacterial culture under magnetic fields of 30 mT and 60 mT, the PE was extracted and lipsticks were formulated. The primary evaluation methods used in this study are melting point, breaking point, linoleic acid peroxidation assay, force of application, stability, surface abnormalities, skin irritation, thixotropy character, dispersibility test, perfume stability, colorimetric assay, antioxidant, and microbial analysis Results: The 30 mT treatment showed the highest concentration, purity, dry weight, antioxidant activity, and percentage of PE extraction compared to control cultures. No significant differences were found in the melting point, stability, thixotropy character, dispersibility, or perfume stability tests. The breaking point and force of application decreased significantly during 30 days. Peroxidation assay tests revealed lipstick increased oxidation and antioxidant activity after 30 days of 30 and 60 mT treatments compared to non-PE cultures. The study found that the amount of ΔE increased significantly in cultures without PE over time, while this increase was lower in magnetic field-treated cultures. However, no signs of crystal formation, surface wrinkles, liquid secretion, itching, or skin irritation were observed in 30 days of 30 and 60 mT magnetic treatments compared to control cultures with PE. Microbial analyzes over 30 days showed a significantly lower number of bacteria under magnetic fields than control cultures. In addition, the results of counting Escherichia coli and coliform bacteria were negative for thirty days. The antioxidant activity of PE was significantly higher in magnetic field-treated cultures. The number of Staphylococcus aureus decreased significantly in all cultures under magnetic field influence. Conclusions: The overall results of this study showed that magnetic fields had a significant effect in many evaluation tests on the culture of cyanobacteria Nostoc sp. As a result, lipsticks made with extracted PE have more antioxidant and antimicrobial activity

Exploring the Impact of Environmental Conditions and Bioreactors on Microalgae Growth and Applications

Microalgae and their bioproducts have diverse applications, including wastewater remediation, CO2 fixation, and the synthesis of nutraceuticals, pharmaceuticals, and biofuels. However, the production of these organisms heavily relies upon environmental conditions, which can significantly impact growth. Furthermore, microalgae cultivation itself can be a source of economic and environmental concerns. Thus, microalgae growth systems have become a critical consideration for both research and industry, to bolster microalgae cultivation and address its accompanying issues. Both open and closed systems, such as raceway ponds and photobioreactors, respectively, are commonly used during the growth process but have their own advantages and drawbacks. However, for microalgae growth, photobioreactors may address most concerns as the system’s design lowers the risk of contamination and provides the ability to control the delivery of desired growth factors. To determine the appropriate system for targeted microalgae cultivation, it is crucial to determine factors such as the scale of cultivation and growth and productivity targets. Additionally, efficient usage of these growth systems and carefully selected incubation factors can aid in addressing some of the economic and environmental issues associated with microalgae production. This review will summarize the current applications of bioreactors in both research and industrial capacities and summarize growth and incubation factors for microalgae.

Microalgae cultivation: from waste as nutrients source to CO2 mitigation – a review containing CFD modeling

Microalgae cultivation: from waste as nutrients source to CO2 mitigation – a review containing CFD modeling

Enhanced Production of Microalgal Metabolites Through Aeration Coupled with Stirring

Adequate mixing is a key factor for microalgal cultivation to achieve high biomass production, so it is essential to clarify the comparative effects of different mixing methods on microalgal productivity, which has rarely been studied previously. This work therefore aimed to investigate the effects of different mixing methods (stirring, aeration, and aeration coupled with stirring) on the growth and metabolite composition of Chlorella sorokiniana SDEC-18, a strain with potential for large-scale application. The results showed that mixing was beneficial for carbohydrate accumulation, while dual mixing (aeration coupled with stirring) promoted growth and achieved the highest dry mass and metabolite productivities (including carbohydrates, proteins, and lipids) through enhancement of light energy capture in the entire system. The stirring speed in the dual mixing approach of aeration coupled with stirring was also considered: the optimal condition was found to be 800 rpm. The maximum biomass was 3.56 g L−1, and the carbohydrate productivity was as high as 119.45 mg L−1 d−1, which was the highest metabolite productivity (higher than proteins or lipids), obtained from aeration coupled with stirring at 800 rpm. Our study suggests that aeration coupled with stirring provides a feasible strategy for microalgal production, due to the optimal availability of CO2 and light achieved through effective mixing.

Machine learning-based prediction models unleash the enhanced production of fucoxanthin in Isochrysis galbana.

The marine microalga Isochrysis galbana is prolific producer of fucoxanthin, which is a xanthophyll carotenoid with substantial global market value boasting extensive applications in the food, nutraceutical, pharmaceutical, and cosmetic industries. This study presented a novel integrated experimental approach coupled with machine learning (ML) models to predict the fucoxanthin content in I. galbana by altering the type and concentration of phytohormone supplementation, thus overcoming the multiple methodological limitations of conventional fucoxanthin quantification. A novel integrated experimental approach was developed, analyzing the effect of varying phytohormone types and concentrations on fucoxanthin production in I. galbana. Morphological analysis was conducted to assess changes in microalgal structure, while growth rate and fucoxanthin yield correlations were explored using statistical analysis and machine learning models. Several ML models were employed to predict fucoxanthin content, with and without hormone descriptors as variables. The findings revealed that the Random Forest (RF) model was highly significant with a high of 0.809 and of 0.776 when hormone descriptors were excluded, and the inclusion of hormone descriptors further improved prediction accuracy to of 0.839, making it a useful tool for predicting the fucoxanthin yield. The model that fitted the experimental data indicated methyl jasmonate (0.2 mg/L) as an effective phytohormone. The combined experimental and ML approach demonstrated rapid, reliable, and cost-efficient prediction of fucoxanthin yield. This study highlights the potential of machine learning models, particularly Random Forest, to optimize parameters influencing microalgal growth and fucoxanthin production. This approach offers a more efficient alternative to conventional methods, providing valuable insights into improving fucoxanthin production in microalgal cultivation. The findings suggest that leveraging diverse ML models can enhance the predictability and efficiency of fucoxanthin production, making it a promising tool for industrial applications.

Suitable site analysis for microalgae biofuel production as a source of renewable energy

The global demand for renewable energy sources has been increasing. Microalgae is considered one of the best energy sources among renewable options, as it efficiently produces biofuel on a large scale. Pakistan has advantageous conditions for cultivating microalgae as a biofuel source, including abundant sunlight, favorable climate conditions, ample land and water resources. This research aims to identify suitable sites in Karachi for microalgae cultivation using geographic information systems. The potential sites were classified into four categories: highly suitable, moderately suitable, less suitable, and unfavorable. The study shows that Karachi provides an environment conducive to large-scale microalgae cultivation, which could help to alleviate energy shortages. Moreover, identifying viable cultivation locations can attract domestic and international interest, leading to future developments in the field.

Fe and Mn Removal from Acid Mine Drainage by Utilizing Chlorella sorokiniana and Monoraphidium neglectum as Biosorbent

The mining industry generates acid mine drainage (AMD) characterized with a low pH value and high dissolved metal concentration that leads to the negative impacts on the environment and human health. The objectives of this research were to investigate the growth response of mixed culture of microalgae Chlorella sorokiniana and Monoraphidium neglectum in a liquid media contaminated with AMD; generate the optimum environmental conditions (pH value and contact time) to determine the efficiency biosorption of iron and manganese contained in the solution of AMD into the consortium of microalgae; and quantify the maximum removal amount of iron and manganese contained in the solution of AMD by utilizing microalgae consortium of Chlorella sorokiniana and Monoraphidium neglectum as biosorbent. AMD used in this research was characterized with a pH value of 1.65 with iron and manganese concentrations of 8.28 mg/L and 4.57 mg/L. The research of biosorption was conducted in 150 rpm with pH level variations of 4, 5, and 6, and contact time variations of 60, 120, and 180 min. The maximum value of iron and manganese removals occurred when pH level reached 5 at 180 min of contact time with removal efficiency of 89.73% for iron and 94.53% for manganese. The results proved that the mixed culture of microalgae namely Chlorella sorokiniana and Monoraphidium neglectum can be utilized to remove iron and manganese contained in acid mine drainage.

Mixotrophic cultivation of microalgae-bacteria consortia enhances dark fermentation effluent treatment

Dark fermentation (DF) is a waste treatment bioprocess which produces biohydrogen and volatile fatty acids (VFAs) such as acetate or butyrate. DF can be coupled with microalgae cultivation, allowing VFA conversion into valuable biomass. Nevertheless, the process is hindered by slow butyrate consumption. In this study, novel artificial microalgae-bacteria consortia were used as a strategy to accelerate butyrate removal. Three microalgal strains with various trophic metabolisms, Chlorella sorokiniana, Euglena gracilis and Ochromonas danica, were cultivated on DF effluent that was either sterile or contained endogenous bacteria. Bacteria did not impact microalgal biomass production of C. sorokiniana or E. gracilis while accelerating butyrate removal rates 2 to 10-fold. O. danica greatly impacted microbial diversity, probably due to its phagotrophic metabolism. These results show that bacteria in organic rich effluents can greatly aid in substrate removal while allowing microalgal growth, inspiring bioprocesses coupling raw fermentation effluents with microalgae biomass production and valorization.

Novel three-stage microalgal cultivation system for lipid production utilizing nutrients derived from refinery waste

The pollution and transformation of refineries are receiving increasing attention. The carbonic anhydrase in Tetradesmus obliquus was found exhibiting a hysteresis phenomenon in response to periodic changes in the composition of external carbon sources, with a surge in inorganic carbon concentration stressing the carbonic anhydrase activity to increase by 6–9 times. On this basis, a novel three-stage culture system of T. obliquus was proposed, which mainly uses refinery waste as the nutrients. By controlling the nutrient content in the environment, especially the composition of carbon sources, microalgae could sequentially complete rapid biomass accumulation, efficient inorganic carbon assimilation, and oil production. Compared to a single-environment culture system, the biomass yield increased by 1.34 times, the oil content increased by more than 6%, and the oil productivity increased by 2.08 times. Above findings may lay a partial theoretical foundation for the future evolution of traditional refineries towards “fossil–algal-biomass” hybrid refineries.

Bioprocess to produce biostimulants/biofertilizers based on microalgae grown using piggery wastewater as nutrient source

In the present work, two downstream processes − high-pressure homogenization at 100 (HPH-100) and 1200 bar (HPH-1200), and enzymatic hydrolysis (EH) − were tested to produce biostimulant extracts from Tetradesmus obliquus grown in piggery wastewater at two concentrations (12.8 and 88.3 g/L). Extracts before and after centrifugation (C) were evaluated in four bioassays using garden cress (germination), mung bean (auxin-like activity), and cucumber (auxin- and cytokinin-like activity) relative to distilled water. The initial microalgal culture, without any treatment, had the best germination results (162 % at 0.2 g/L) and the only one that showed cytokinin-like activity (141 % at 0.5 g/L). In both auxin-like bioassays, the HPH-1200 + C and EH + C originated high values (186 and 155 % for cucumber, 290 and 285 % for mung bean, respectively). For mung bean, the HPH-1200 achieved the highest auxin-like effect (378 %). Finally, the extracted biomass contained essential nutrients for biofertilization, complementing the biostimulant extracts for sustainable agriculture application.