RESUMO
The intricate composition of microalgal pigments plays a crucial role in various biological processes, from photosynthesis to biomarker identification. Traditional pigment analysis methods involve complex extraction techniques, posing challenges in maintaining analyte integrity. In this study, we employ Electron Transfer Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry (ET-MALDI-MS) to compare the pigmentary profiles of Chlorella vulgaris intact cells, chloroplasts, and solvent extracts. We aim to obtain comprehensive extracts rich in polar and non-polar compounds using ultrasound-assisted and supercritical fluid extraction methods. Additionally, intact chloroplasts are isolated using a lysis buffer and sucrose density gradient centrifugation. Our ET-MALDI-MS analysis reveals distinct compositional differences, highlighting the impact of extraction protocols on microalgal pigment identification. We observe prominent signals corresponding to radical cations of key pigments, including chlorophylls and carotenoids, which are crucial for C. vulgaris identification. Furthermore, ET-MALDI-MS facilitates the identification of specific lipids within chloroplast membranes and other organelles. This study underscores the rapid and precise nature of ET-MALDI-MS in microalgal biomarker analysis, providing valuable insights into phytoplankton dynamics, trophic levels, and environmental processes. C. vulgaris emerges as a promising model for studying pigment composition and membrane lipid diversity, enhancing our understanding of microalgal ecosystems.
Assuntos
Chlorella vulgaris , Cloroplastos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Chlorella vulgaris/química , Chlorella vulgaris/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Cloroplastos/química , Cloroplastos/metabolismo , Carotenoides/análise , Carotenoides/química , Clorofila/análise , Clorofila/química , Pigmentos Biológicos/análise , Pigmentos Biológicos/químicaRESUMO
The food and beverage industries in Mexico generate substantial effluents, including nejayote, cheese-whey, and tequila vinasses, which pose significant environmental challenges due to their extreme physicochemical characteristics and excessive organic load. This study aimed to assess the potential of Chlorella vulgaris in bioremediating these complex wastewaters while also producing added-value compounds. A UV mutagenesis treatment (40 min) enhanced C. vulgaris adaptability to grow in the effluent conditions. Robust growth was observed in all three effluents, with nejayote identified as the optimal medium. Physicochemical measurements conducted pre- and post-cultivation revealed notable reductions of pollutants in nejayote, including complete removal of nitrogen and phosphates, and an 85 % reduction in COD. Tequila vinasses exhibited promise with a 66 % reduction in nitrogen and a 70 % reduction in COD, while cheese-whey showed a 17 % reduction in phosphates. Regarding valuable compounds, nejayote yielded the highest pigment (1.62 mg·g-1) and phenolic compound (3.67 mg·g-1) content, while tequila vinasses had the highest protein content (16.83 %). The main highlight of this study is that C. vulgaris successfully grew in 100 % of the three effluents (without additional water or nutrients), demonstrating its potential for sustainable bioremediation and added-value compound production. When grown in 100 % of the effluents, they become a sustainable option since they don't require an input of fresh water and therefore do not contribute to water scarcity. These findings offer a practical solution for addressing environmental challenges in the food and beverage industries within a circular economy framework.
Assuntos
Biodegradação Ambiental , Chlorella vulgaris , Eliminação de Resíduos Líquidos , Águas Residuárias , Chlorella vulgaris/metabolismo , Águas Residuárias/química , México , Eliminação de Resíduos Líquidos/métodos , Bebidas , Indústria Alimentícia , Poluentes Químicos da Água/análise , Resíduos Industriais/análiseRESUMO
This research appraised the simultaneous biofixation, that is not quite common in scientific literature, of carbon dioxide (CO2) and nitric oxides (NOx) by microalgae species Chlorella vulgaris, Haematococcus pluvialis, and Scenedesmus subspicatus. The experimental design was established by five treatments with gas concentrations between control-0.04% of CO2, 5 to 15% of CO2, and 30 to 100 ppm of NOx. Parameters such as pH, growth, productivity, lipids, protein, carbon/ nitrogen ratio, and astaxanthin were evaluated. For all species, the maximal growth and productivity were achieved with 5% of CO2 and 30 ppm of NOx. Regarding protein content, for all the three species, better results were obtained at higher concentrations of CO2 and NOx. These results prove the microalgae capacity for CO2 and NOx biofixation and reuse of biomass as a source of high value-added products, such as lipids, proteins, and astaxanthin. These findings support the indication of these species for flue gas treatment process and use in biorefineries systems.
Assuntos
Chlorella vulgaris , Microalgas , Biomassa , Biotecnologia/métodos , Dióxido de Carbono/metabolismo , Chlorella vulgaris/metabolismo , Lipídeos , Microalgas/metabolismoRESUMO
AIMS: This study assessed, at the physiological and molecular levels, the effect of biogas on indole-3-acetic acid (IAA) biosynthesis by Azospirillum brasilense as well as the impact of this bacterium during CO2 fixation from biogas by Chlorella vulgaris and Scenedesmus obliquus. METHODS AND RESULTS: IpdC gene expression, IAA production and the growth of A. brasilense cultured under air (control) and biogas (treatment) were evaluated. The results demonstrated that A. brasilense had a better growth capacity and IAA production (105.7 ± 10.3 µg ml-1 ) when cultured under biogas composed of 25% CO2 + 75% methane (CH4 ) with respect to the control (72.4 ± 7.9 µg ml-1 ), although the ipdC gene expression level was low under the stressful condition generated by biogas. Moreover, this bacterium was able to induce a higher cell density and CO2 fixation rate from biogas by C. vulgaris (0.27 ± 0.08 g l-1 d-1 ) and S. obliquus (0.22 ± 0.08 g l-1 d-1 ). CONCLUSIONS: This study demonstrated that A. brasilense has the capacity to grow and actively maintain its main microalgal growth-promoting mechanism when cultured under biogas and positively influence CO2 fixation from the biogas of C. vulgaris and S. obliquus. SIGNIFICANCE AND IMPACT OF THE STUDY: These findings broaden research in the field of Azospirillum-microalga interactions and the prevalence of Azospirillum in environmental and ecological topics in addition to supporting the uses of plant growth-promoting bacteria to enhance biotechnological strategies for biogas upgrading.
Assuntos
Azospirillum brasilense , Chlorella vulgaris , Microalgas , Atmosfera , Azospirillum brasilense/genética , Azospirillum brasilense/metabolismo , Biocombustíveis , Dióxido de Carbono/metabolismo , Chlorella vulgaris/metabolismo , Ácidos Indolacéticos/metabolismo , Microalgas/metabolismoRESUMO
4-Nonylphenol (4-NP) is an anthropogenic contaminant found in different environmental matrices that has an effect over the biotic and abiotic factors within the environment. Bioremediation by microorganisms can be used as a potential treatment to remove this pollutant. In this work, a consortium of two microorganisms, Arthrospira maxima and Chlorella vulgaris, was employed to remove 4-NP from water. The parameters analyzed included cell growth, removal of 4-NP, and 4-NP remnant in the biomass. In addition, the metabolites produced in the process by this consortium were identified. It was found that C. vulgaris is more resistant to 4-NP than A. maxima (cell growth inhibition by 4-NP of 99%). The consortium used in this study had an IC50 greater than any strain of microalgae or cyanobacteria reported for 4-NP removal (9.29â¯mg/L) and reduced up to 96% of 4-NP in water in the first 48â¯h of culture. It was also observed that there is a bio-transformation of 4-NP, comparable with the process carried out by another bacterium, in which three similar metabolites were found (4-(1-methyl-octyl)-4-hydroxy-cyclohex-2-enone, 4-nonyl-4-hydroxy-ciclohexa-2,5-dienone and 4-nonyl-4-hydroxy- ciclohex-2-enone) and one that is similar to plant metabolism (4-nonyl-(1-methyl,6,8-metoxy)-hydroxybenzene). These results indicate that microalgae and cyanobacteria consortium can be used to remove 4-NP from water.
Assuntos
Biotransformação , Chlorella vulgaris/metabolismo , Fenóis/metabolismo , Spirulina/metabolismo , Poluentes Químicos da Água/metabolismo , Biomassa , MicroalgasRESUMO
This research evaluated the influence of organic matter (OM) and CO2 addition on the bioremediation potential of two microalgae typically used for wastewater treatment: Chlorella vulgaris (CV) and Scenedesmus almeriensis (SA). The heavy metal (HM) removal efficiencies and biosorption capacities of both microalgae were determined in multimetallic solutions (As, B, Cu, Mn, and Zn) mimicking the highest pollutant conditions found in the Loa river (Northern Chile). The presence of OM decreased the total biosorption capacity, specially in As (from 2.2 to 0.0â¯mg/g for CV and from 2.3 to 1.7â¯mg/g for SA) and Cu (from 3.2 to 2.3â¯mg/g for CV and from 2.1 to 1.6â¯mg/g for SA), but its influence declined over time. CO2 addition decreased the total HM biosorption capacity for both microalgae species and inhibited CV growth. Finally, metal recovery using different eluents (HCl, NaOH, and CaCl2) was evaluated at two different concentrations. HCl 0.1â¯M provided the highest recovery efficiencies, which supported values over 85% of As, 92% of Cu, and ≈100% of Mn and Zn from SA. The presence of OM during the loaded stage resulted in a complete recovery of As, Cu, Mn, and Zn when using HCl 0.1â¯M as eluent.
Assuntos
Biodegradação Ambiental , Dióxido de Carbono/metabolismo , Chlorella vulgaris/metabolismo , Metais Pesados/metabolismo , Scenedesmus/metabolismo , Poluentes Químicos da Água/metabolismo , Chile , Metais Pesados/análise , Microalgas , Águas Residuárias , Poluentes Químicos da Água/análiseRESUMO
Anthropogenic activities have increased the amount of urban wastewater discharged into natural aquatic reservoirs containing a high amount of nutrients such as phosphorus (Pi and PO 4 - 3 ), nitrogen (NH 3 and NO 3 - ) and organic contaminants. Most of the urban wastewater in Mexico do not receive any treatment to remove nutrients. Several studies have reported that an alternative to reduce those contaminants is using consortiums of microalgae and endogenous bacteria. In this research, a genome-scale biochemical reaction network is reconstructed for the co-culture between the microalga Chlorella vulgaris and the bacterium Pseudomonas aeruginosa. Metabolic Pathway Analysis (MPA), is applied to understand the metabolic capabilities of the co-culture and to elucidate the best conditions in removing nutrients. Theoretical yields for phosphorus removal under photoheterotrophic conditions are calculated, determining their values as 0.042 mmol of PO 4 - 3 per g DW of C. vulgaris, 19.43 mmol of phosphorus (Pi) per g DW of C. vulgaris and 4.90 mmol of phosphorus (Pi) per g DW of P. aeruginosa. Similarly, according to the genome-scale biochemical reaction network the theoretical yields for nitrogen removal are 10.3 mmol of NH 3 per g DW of P. aeruginosa and 7.19 mmol of NO 3 - per g DW of C. vulgaris. Thus, this research proves the metabolic capacity of these microorganisms in removing nutrients and their theoretical yields are calculated.
Assuntos
Chlorella vulgaris/metabolismo , Redes e Vias Metabólicas , Nitrogênio/metabolismo , Fósforo/metabolismo , Pseudomonas aeruginosa/metabolismo , Técnicas de Cocultura , Águas Residuárias/microbiologia , Purificação da ÁguaRESUMO
A Chlorella vulgaris UTEX 26 semicontinuous culture was implemented in 2000â¯L raceways with M medium during spring season at greenhouse conditions. Areal biomass productivities between 20 and 26â¯gâ¯m-2â¯d-1 were reached on the third day. The maximal areal lipid productivity obtained was 6.1â¯gâ¯m-2â¯d-1 and an increment in the saturated fatty acids (SFA) proportion (C14-C18) was favored in comparison with the fatty acids obtained with M medium in photobioreactors of 1â¯L and photoperiod light:darkness 12:12â¯h. After the eighth day of the culture or biomass concentrations above 0.25â¯gâ¯L-1, the microalgal cultures were prone to contamination by ciliates and amoebae, due to the sugars excreted by C. vulgaris UTEX 26. The periodical addition of NH4HCO3 to the microalgal culture maintained the ammonium concentration between 25 and 50â¯mgâ¯L-1, which contributed to diminish the contamination risks by protozoa.
Assuntos
Biomassa , Chlorella vulgaris/metabolismo , Lipídeos/biossíntese , Microalgas , Fotobiorreatores , Lagoas , Estações do AnoRESUMO
This work aimed to produce ethyl esters from Chlorella vulgaris microalgae biomass, using an immobilized enzymatic catalyst associated with pressurized fluid (propane) by direct transesterification. In order to optimize the ethyl conversion, different temperatures (46.7-68.1 °C) and pressures (59.5-200.5 bar) were applied a central composite design rotational (CCDR) obtaining the high conversion (74.39%) at 50 °C and 180 bar. The molar ratio also was investigated showing conversions ~ 90% using a molar ratio of 1:24 (oil:ethanol). From the best transesterification conditions, 50 °C, 180 bar, 20% enzymatic concentration, and 1:24 oil:ethanol molar ratio were obtained with success 98.9% conversion in 7 h of reaction. The enzyme reuse maintained its activity for three successive cycles. Thus, this simple process was effective to convert microalgal biomass into ethyl ester by direct transesterification and demonstrate high yields.
Assuntos
Biomassa , Chlorella vulgaris/metabolismo , Ésteres/metabolismo , Microalgas/metabolismo , Pressão , Propano/metabolismo , Biocatálise , Biocombustíveis , Biotransformação , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Esterificação , Etanol/metabolismoRESUMO
Cultures under nitrogen limitation for Chlorella vulgaris were kept under different light quality (white, blue, yellow and violet) at 70 and 140 µE m-2 s-1; to evaluate the effect on fatty acids profiles and biodiesel quality. The results showed a maximum biomass and cell density at 140 µE m-2 s-1 of: white light (0.69 g L-1 and 6.5 × 106 cells mL-1, respectively) and blue light (0.65 g L-1 and 8.0 × 106 cells mL-1, respectively); compared to violet and yellow light. The chlorophyll concentration (µg mg-1 biomass dry weight) at 70 µE m-2 s-1 were in the order of light: white (25.61) > violet (17.10) > yellow (11.68) > blue (11.40) and, at 140 µE m-2 s-1 were: violet (23.64) > white (10.20) > yellow (9.66) > blue (7.99), suggesting the violet light stimulates the increase of chlorophyll a at higher intensity. The maximum lipid content (% w/w) were present under blue light (43.11), yellow (70.92) and violet (83.87) at 140 µE m-2 s-1. The different wavelengths did not have a negative effect on the quality of the biodiesel, however; violet light presented greater productivity and the indicators such as CFPP were related to the oxidative stability value and low PUFA content, leading biodiesel to good oxidative stability.