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1.
Water Sci Technol ; 89(10): 2732-2745, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38822611

RESUMO

In this work, microalgae cultivation trials were carried out in a membrane bioreactor to investigate fouling when the cultures of Chlorellavulgaris were grown under mixotrophic, heterotrophic, and phototrophic cultivation regimes. The Chlorella cultures were cultivated in wastewater as a source of nutrients that contained a high concentration of ammonium. In mixotrophic cultivation trials, the results showed that the elevated contents of carbohydrates in the soluble microbial product and proteins in extracellular polymeric substances probably initiated membrane fouling. In this case, the highest protein content was also found in extracellular polymeric substances due to the high nitrogen removal rate. Consequently, transmembrane pressure significantly increased compared to the phototrophic and heterotrophic regimes. The data indicated that cake resistance was the main cause of fouling in all cultivations. Higher protein content in the cake layer made the membrane surface more hydrophobic, while carbohydrates had the opposite effect. Compared to a mixotrophic culture, a phototrophic culture had a larger cell size and higher hydrophobicity, leading to less membrane fouling. Based on our previous data, the highest ammonia removal rate was reached in the mixotrophic cultures; nevertheless, membrane fouling appeared to be the fundamental problem.


Assuntos
Compostos de Amônio , Reatores Biológicos , Membranas Artificiais , Microalgas , Águas Residuárias , Microalgas/metabolismo , Microalgas/crescimento & desenvolvimento , Águas Residuárias/química , Compostos de Amônio/metabolismo , Processos Heterotróficos , Eliminação de Resíduos Líquidos/métodos , Incrustação Biológica , Chlorella/crescimento & desenvolvimento , Chlorella/metabolismo , Processos Fototróficos
2.
Sci Total Environ ; 937: 173481, 2024 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-38795983

RESUMO

Various bisphenols (BPs) have been frequently detected in the aquatic environment and coexist in the form of mixtures with potential huge risks. As we all know, food chain is a media by which BPs mixtures and their mixtures probably enter the organisms at different trophic levels due to their environmental persistence. As a result, the concentrations of BPs and their mixtures may continuously magnify to varying degrees, which can produce higher risks to different levels of organisms, and even human health. However, the related researches about mixtures are few due to the complexity of mixtures. So, the ternary BP mixtures were designed by the uniform design ray method using bisphenol A (BPA), bisphenol S (BPS) and bisphenol F (BPF) to investigate their food chain effects including bioconcentration and biomagnification. Here, Chlorella pyrenoidosa (C. pyrenoidosa) and Daphnia magna (D. magna) were selected to construct a food chain. The toxic effects of single BPs and their mixtures were also systematically investigated by the time-dependent microplate toxicity analysis (t-MTA) method. Toxicity interaction within the ternary mixture was analyzed by the concentration addition model (CA) and the deviation from the CA model (dCA). The results show that the C. pyrenoidosa and D. magna had obvious bioconcentration and biomagnification effects on BPs and their mixture. The mixture had the potential to enrich at higher nutrient levels. And BPF had the largest bioconcentration effect (BCF1 = 481.86, BCF2 = 772.02) and biomagnification effect (BMF = 1.6). Three BPs were toxic to C. pyrenoidosa by destroying algal cells and decreasing protein and chlorophyll contents, and their toxicity order was BPF > BPA > BPS. Moreover, their ternary mixture exhibits synergism with time/concentration-dependency. The obtained results are of significant reference value for objectively and accurately assessing the ecological and environmental risks of bisphenol pollutants.


Assuntos
Compostos Benzidrílicos , Daphnia , Cadeia Alimentar , Fenóis , Sulfonas , Poluentes Químicos da Água , Fenóis/toxicidade , Compostos Benzidrílicos/toxicidade , Poluentes Químicos da Água/análise , Animais , Sulfonas/toxicidade , Chlorella/metabolismo , Testes de Toxicidade
3.
Mar Pollut Bull ; 203: 116421, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38713927

RESUMO

Intensive aquaculture production generates large amounts of sludge. This waste could be considered as a potential source of nutrients that can be recovered and utilized. Little attention has been paid to nutrient recovery from fish sludge. In this study, bioconversion of sludge was evaluated in lab scale under anaerobic (AN), facultative anaerobic (FA) and aerobic (AE) conditions. After 40 days of fermentation, AN recovered the highest values of dissolved total nitrogen (82.7 mg L-1), while AE showed the highest dissolved total phosphorus (11.8 mg L-1) and the highest reduction of total suspended solids (36.0 %). Microbial analysis showed that AN exhibited a distinct bacterial community than that of FA and AE. Furthermore, C. sorokiniana grown in AN effluents collected after 12 days of fermentation achieved the highest biomass production (1.96 g L-1). These results suggest that AN has the best potential to recover nutrients from sludge for production of C. sorokiniana.


Assuntos
Chlorella , Microalgas , Nitrogênio , Nutrientes , Fósforo , Esgotos , Chlorella/crescimento & desenvolvimento , Animais , Peixes , Aquicultura , Eliminação de Resíduos Líquidos/métodos , Biomassa , Anaerobiose , Fermentação
4.
J Hazard Mater ; 473: 134679, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38795485

RESUMO

The phycosphere is an essential ecological niche for the proliferation of antibiotic resistance genes (ARGs). However, how ARGs' potential hosts change and the driving mechanism of metabolites under antibiotic stress in the phycosphere have seldom been researched. We investigated the response of Chlorella pyrenoidosa and the structure and abundance of free-living (FL) and particle-attached (PA) bacteria, ARGs, and metabolites under sulfadiazine by using real-time quantitative PCR, 16 S rRNA high-throughput. The linkage of key bacterial communities, ARGs, and metabolites through correlations was established. Through analysis of physiological indicators, Chlorella pyrenoidosa displayed a pattern of "low-dose promotion and high-dose inhibition" under antibiotic stress. ARGs were enriched in the PA treatment groups by 117 %. At the phylum level, Proteobacteria, Bacteroidetes, and Actinobacteria as potential hosts for ARGs. At the genus level, potential hosts included Sphingopyxis, SM1A02, Aquimonas, Vitellibacter, and Proteiniphilum. Middle and high antibiotic concentrations induced the secretion of metabolites closely related to potential hosts by algae, such as phytosphingosine, Lysophosphatidylcholine, and α-Linolenic acid. Therefore, changes in bacterial communities indirectly influenced the distribution of ARGs through alterations in metabolic products. These findings offer essential details about the mechanisms behind the spread and proliferation of ARGs in the phycosphere.


Assuntos
Antibacterianos , Bactérias , Chlorella , Genes Bacterianos , Sulfadiazina , Chlorella/genética , Chlorella/metabolismo , Chlorella/efeitos dos fármacos , Antibacterianos/farmacologia , Sulfadiazina/farmacologia , Bactérias/genética , Bactérias/metabolismo , Bactérias/efeitos dos fármacos , Microalgas/genética , Microalgas/efeitos dos fármacos , Microalgas/metabolismo , RNA Ribossômico 16S/genética , Farmacorresistência Bacteriana/genética , Resistência Microbiana a Medicamentos/genética , Microbiota/efeitos dos fármacos
5.
Environ Sci Technol ; 58(23): 10262-10274, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38809112

RESUMO

Zinc oxide nanoparticles (ZnO NPs) expedite the conversion of organic phosphorus (OP) into PO4-P (Pi), facilitating phosphorus (P) absorption by algae. Our study explored the mechanisms of converting OP (2-aminoethylphosphonic acid (AEP) and ß-glycerol phosphate (ß-GP)) into Pi in Chlorella pyrenoidosa under P deficiency with sunscreen and ZnO NPs. Cell density followed the order of K2HPO4 > ß-GP+ZnO > ß-GP > AEP+ZnO > AEP > P-free. ZnO NPs promoted the conversion of ß-GP, containing C-O-P bonds (0.028-0.041 mg/L), into Pi more efficiently than AEP, which possesses C-P bonds (0.022-0.037 mg/L). Transcriptomics revealed Pi transport/metabolism (phoB (3.99-12.01 fold), phoR (2.20-5.50 fold), ppa (4.49-10.40 fold), and ppk (2.50-5.40 fold)) and phospholipid metabolism (SQD1 (1.85-2.79 fold), SQD2 (2.60-6.53 fold), MGD (2.13-3.21 fold), and DGD (4.08-7.56 fold)) were up-regulated compared to K2HPO4. 31P nuclear magnetic resonance spectroscopy identified intracellular P as polyphosphate, orthophosphate, and pyrophosphate. Synchrotron radiation-based X-ray near-edge structure spectroscopy indicated that K2HPO4 and Zn3(PO4)2 in ß-GP+ZnO were increased by 8.09% and 7.28% compared to AEP+ZnO, suggesting superior P storage in ß-GP+ZnO. Overall, ZnO NPs improved photoinduced electron-hole pair separation and charge separation efficiency and amplified the ·OH and ·O2- levels, promoting OP photoconversion into Pi and algae growth.


Assuntos
Chlorella , Nanopartículas , Fósforo , Protetores Solares , Óxido de Zinco , Óxido de Zinco/química , Óxido de Zinco/farmacologia , Chlorella/metabolismo , Nanopartículas/química
6.
Environ Res ; 254: 119168, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38762007

RESUMO

The multiple microalgal collaborative treatment of domestic wastewater has been extensively investigated, but its whole life cycle tracking and consequent potential have not been fully explored. Herein, a dual microalgal system was employed for domestic wastewater treatment, tracking the variation in microalgal growth and pollutants removal from shake flask scale to 18 L photobioreactors scales. The results showed that Chlorella sp. HL and Scenedesmus sp. LX1 combination had superior growth and water purification performance, and the interspecies soluble algal products promoted their growth. Through microalgae mixing ratio and inoculum size optimized, the highest biomass yield (0.42 ± 0.03 g/L) and over 91 % N, P removal rates were achieved in 18 L photobioreactor. Harvested microalgae treated in different forms all promoted wheat growth and suppressed yellow leaf rate. This study provided data support for the whole process tracking of dual microalgal system in treating domestic wastewater and improving wheat growth.


Assuntos
Chlorella , Microalgas , Triticum , Eliminação de Resíduos Líquidos , Águas Residuárias , Triticum/crescimento & desenvolvimento , Microalgas/crescimento & desenvolvimento , Eliminação de Resíduos Líquidos/métodos , Chlorella/crescimento & desenvolvimento , Scenedesmus/crescimento & desenvolvimento , Biomassa , Fotobiorreatores , Purificação da Água/métodos , Poluentes Químicos da Água/análise
7.
Bioresour Technol ; 403: 130868, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38782193

RESUMO

Prior research has emphasized the potential of microalgae in biodiesel production, driven by their ability to replace fossil fuels. However, the significant costs associated with microalgae cultivation present a major obstacle to scaling up production. This study aims to develop an eco-friendly microalgae cultivation system by integrating carbon dioxide from flue gas emissions with an affordable photobioreactor, providing a sustainable biomass production. The research evaluates the growth performance of Chlorella sorokiniana and Chlorella vulgaris across this integrated system for biomass and lipid production. Results indicate substantial biomass yields of 1.97 and 1.84 g/L, with lipid contents of 35 % and 41 % for C. sorokiniana and C. vulgaris, respectively. The macrobubble photobioreactor demonstrates high potential for microalgae biomass and lipid production, yielding quality fatty acid methyl esters such as palmitic, linoleic and stearic. This study presents an environmentally friendly system for efficient microalgae cultivation, generating lipid-rich biomass suitable for biodiesel production.


Assuntos
Biocombustíveis , Biomassa , Chlorella vulgaris , Chlorella , Lipídeos , Chlorella vulgaris/crescimento & desenvolvimento , Chlorella vulgaris/metabolismo , Chlorella/crescimento & desenvolvimento , Chlorella/metabolismo , Lipídeos/biossíntese , Fotobiorreatores , Ácidos Graxos/metabolismo , Microalgas/crescimento & desenvolvimento , Microalgas/metabolismo
8.
Aquat Toxicol ; 271: 106937, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38728928

RESUMO

In aquaculture around the world, sulfamonomethoxine (SMM), a long-acting antibiotic that harms microalgae, is widely employed in combination with trimethoprim (TMP), a synergist. However, their combined toxicity to microalgae under long-term exposures at environmentally relevant concentrations remains poorly understood. Therefore, we studied the effects of SMM single-exposures and co-exposures (SMM:TMP=5:1) at concentrations of 5 µg/L and 500 µg/L on Chlorella pyrenoidosa within one aquacultural drainage cycle (15 days). Photosynthetic activity and N assimilating enzyme activities were employed to evaluate microalgal nutrient assimilation. Oxidative stress and flow cytometry analysis for microalgal proliferation and death jointly revealed mechanisms of inhibition and subsequent self-adaptation. Results showed that exposures at 5 µg/L significantly inhibited microalgal nutrient assimilation and induced oxidative stress on day 7, with a recovery to levels comparable to the control by day 15. This self-adaptation and over 95 % removal of antibiotics jointly contributed to promoting microalgal growth and proliferation while reducing membrane-damaged cells. Under 500 µg/L SMM single-exposure, microalgae self-adapted to interferences on nutrient assimilation, maintaining unaffected growth and proliferation. However, over 60 % of SMM remained, leading to sustained oxidative stress and apoptosis. Remarkably, under 500 µg/L SMM-TMP co-exposure, the synergistic toxicity of SMM and TMP significantly impaired microalgal nutrient assimilation, reducing the degradation efficiency of SMM to about 20 %. Consequently, microalgal growth and proliferation were markedly inhibited, with rates of 9.15 % and 17.7 %, respectively, and a 1.36-fold increase in the proportion of cells with damaged membranes was observed. Sustained and severe oxidative stress was identified as the primary cause of these adverse effects. These findings shed light on the potential impacts of antibiotic mixtures at environmental concentrations on microalgae, facilitating responsible evaluation of the ecological risks of antibiotics in aquaculture ponds.


Assuntos
Microalgas , Estresse Oxidativo , Sulfamonometoxina , Trimetoprima , Poluentes Químicos da Água , Trimetoprima/toxicidade , Poluentes Químicos da Água/toxicidade , Microalgas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Sulfamonometoxina/toxicidade , Chlorella/efeitos dos fármacos , Chlorella/metabolismo , Chlorella/crescimento & desenvolvimento , Nutrientes/metabolismo , Fotossíntese/efeitos dos fármacos , Antibacterianos/toxicidade
9.
Chemosphere ; 358: 142270, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38719126

RESUMO

To reduce the high cost of organic carbon sources in waste resource utilization in the cultivation of microalgae, volatile fatty acids (VFAs) derived from activated sludge were used as the sole carbon source to culture Chlorella sorokiniana under the heterotrophic cultivation. The addition of VFAs in the heterotrophic condition enhanced the total nitrogen (TN) and phosphorus (TP) removal of C. sorokiniana, which proved the advantageous microalgae in using VFAs in the heterotrophic culture after screening in the previous study. To discover the possible mechanism of nitrogen and phosphorus adsorption in heterotrophic conditions by microalgae, the effect of different ratios of VFAs (acetic acid (AA): propionic acid (PA): butyric acid (BA)) on the nutrient removal and growth properties of C. sorokiniana was studied. In the 8:1:1 group, the highest efficiency (77.19%) of VFAs assimilation, the highest biomass (0.80 g L-1) and lipid content (31.35%) were achieved, with the highest TN and TP removal efficiencies of 97.44 % and 91.02 %, respectively. Moreover, an aerobic denitrifying bacterium, Pseudomonas, was determined to be the dominant genus under this heterotrophic condition. This suggested that besides nitrate uptake and utilization by C. sorokiniana under the heterotrophy, the conduct of the denitrification process was also the main reason for obtaining high nitrogen removal efficiency.


Assuntos
Chlorella , Ácidos Graxos Voláteis , Processos Heterotróficos , Microalgas , Nitrogênio , Fósforo , Eliminação de Resíduos Líquidos , Águas Residuárias , Chlorella/metabolismo , Chlorella/crescimento & desenvolvimento , Ácidos Graxos Voláteis/metabolismo , Nitrogênio/metabolismo , Microalgas/metabolismo , Águas Residuárias/química , Fósforo/metabolismo , Eliminação de Resíduos Líquidos/métodos , Esgotos/microbiologia , Biomassa , Desnitrificação , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental
10.
Environ Sci Pollut Res Int ; 31(26): 38274-38287, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38802614

RESUMO

With the wide application of nanomaterials, the concentration of nanomaterials in natural water continues to increase, which poses a severe threat to the water environment. However, the influence of organic matter and nanomaterials rich in natural water on the toxic effect of algae growth is still unclear. In this study, the effects of humic acid (HA) and nano-cerium oxide (nCeO2) on the physiology and transcriptome of Chlorella sp. were analyzed, and the mechanism of the toxic effect of HA on Chlorella sp. under nCeO2 stress was revealed. Under 20-200 mg/L nCeO2 stress, the growth of Chlorella cells was inhibited and the highest inhibition rate reached 52% within 200 mg/L nCeO2. The Fv/Fm and ETRmax values of Chlorella sp. decreased from 0.490 and 24.45 (20 mg/L nCeO2) to 0.488 and 23.4 (100 mg/L nCeO2), respectively. Under the stimulation of nCeO2, the level of reactive oxygen species in algal cells was increased, accompanied by lipid peroxidation and membrane damage. However, the addition of HA at concentrations of 5-10 mg/L effectively alleviated the toxic effect of nCeO2 on Chlorella sp. Transcriptome analysis showed that 10 mg/L HA could alleviate the cellular stress at 100 mg/L nCeO2 on Chlorella sp. by regulating genes related to photosynthesis and metabolism pathways. Moreover, the downregulation of genes (e.g., Lhca1, Lhcb1, AOC3, and AOC2) indicated that HA reduced the level of oxidative stress in Chlorella sp. These findings offer novel insights of evaluating the ecotoxicity nCeO2 and HA in natural water environment and their impact on Chlorella sp.


Assuntos
Cério , Chlorella , Substâncias Húmicas , Chlorella/efeitos dos fármacos , Cério/toxicidade , Nanopartículas/toxicidade , Espécies Reativas de Oxigênio/metabolismo
11.
Sci Total Environ ; 939: 173643, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-38821282

RESUMO

Mariculture effluent polishing with microalgal biofilm could realize effective nutrients removal and resolve the microalgae-water separation issue via biofilm scraping or in-situ aquatic animal grazing. Ubiquitous existence of antibiotics in mariculture effluents may affect the remediation performances and arouse ecological risks. The influence of combined antibiotics exposure at environment-relevant concentrations towards attached microalgae suitable for mariculture effluent polishing is currently lack of research. Results from suspended cultures could offer limited guidance since biofilms are richer in extracellular polymeric substances that may protect the cells from antibiotics and alter their transformation pathways. This study, therefore, explored the effects of combined antibiotics exposure at environmental concentrations towards seawater Chlorella sp. biofilm in terms of microalgal growth characteristics, nutrients removal, anti-oxidative responses, and antibiotics removal and transformations. Sulfamethoxazole (SMX), tetracycline (TL), and clarithromycin (CLA) in single, binary, and triple combinations were investigated. SMX + TL displayed toxicity synergism while TL + CLA revealed toxicity antagonism. Phosphorus removal was comparable under all conditions, while nitrogen removal was significantly higher under SMX and TL + CLA exposure. Anti-oxidative responses suggested microalgal acclimation towards SMX, while toxicity antagonism between TL and CLA generated least cellular oxidative damage. Parent antibiotics removal was in the order of TL (74.5-85.2 %) > CLA (60.8-69.5 %) > SMX (13.5-44.1 %), with higher removal efficiencies observed under combined than single antibiotic exposure. Considering the impact of residual parent antibiotics, CLA involved cultures were identified of high ecological risks, while medium risks were indicated in other cultures. Transformation products (TPs) of SMX and CLA displayed negligible aquatic toxicity, the parent antibiotics themselves deserve advanced removal. Four out of eight TPs of TL could generate chronic toxicity, and the elimination of these TPs should be prioritized for TL involved cultures. This study expands the knowledge of combined antibiotics exposure upon microalgal biofilm based mariculture effluent polishing.


Assuntos
Antibacterianos , Biofilmes , Chlorella , Água do Mar , Poluentes Químicos da Água , Chlorella/fisiologia , Chlorella/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Antibacterianos/toxicidade , Poluentes Químicos da Água/toxicidade , Água do Mar/química , Medição de Risco , Eliminação de Resíduos Líquidos/métodos , Aquicultura , Microalgas/efeitos dos fármacos , Microalgas/fisiologia
12.
Int J Mol Sci ; 25(10)2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38791551

RESUMO

Rotavirus is the main cause of acute diarrhea in children up to five years of age. In this regard, probiotics are commonly used to treat or prevent gastroenteritis including viral infections. The anti-rotavirus effect of Bifidobacterium longum and Chlorella sorokiniana, by reducing viral infectivity and improving IFN-type I response, has been previously reported. The present study aimed to study the effect of B. longum and/or C. sorokiniana on modulating the antiviral cellular immune response mediated by IFN-γ, IL-10, SOCS3, STAT1, and STAT2 genes in rotavirus-infected cells. To determine the mRNA relative expression of these genes, HT-29 cells were treated with B. longum and C. sorokiniana alone or in combination, followed by rotavirus infection. In addition, infected cells were treated with B. longum and/or C. sorokiniana. Cellular RNA was purified, used for cDNA synthesis, and amplified by qPCR. Our results demonstrated that the combination of B. longum and C. sorokiniana stimulates the antiviral cellular immune response by upregulating IFN-γ and may block pro-inflammatory cytokines by upregulating IL-10 and SOCS3. The results of our study indicated that B. longum, C. sorokiniana, or their combination improve antiviral cellular immune response and might modulate pro-inflammatory responses.


Assuntos
Bifidobacterium longum , Chlorella , Interferon gama , Interleucina-10 , Probióticos , Infecções por Rotavirus , Rotavirus , Proteína 3 Supressora da Sinalização de Citocinas , Humanos , Interleucina-10/metabolismo , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo , Proteína 3 Supressora da Sinalização de Citocinas/genética , Interferon gama/metabolismo , Probióticos/farmacologia , Infecções por Rotavirus/imunologia , Infecções por Rotavirus/virologia , Chlorella/virologia , Células HT29 , Fator de Transcrição STAT1/metabolismo
13.
Water Res ; 257: 121722, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38723359

RESUMO

The development of wastewater treatment processes capable of reducing and fixing carbon is currently a hot topic in the wastewater treatment field. Microalgae possess a natural carbon-fixing advantage, and microalgae that can symbiotically coexist with indigenous bacteria in actual wastewater attract more significant attention. Ultraviolet (UV) mutagenesis and dissolved organic carbon (DOC) acclimation were applied to strengthen the carbon-fixing performance of microalgae in this study. The mechanisms associated with microalgal water purification ability, gene regulation at the molecular level and photosynthetic potential under different trophic modes resulting from carbon fixation and transformation were disclosed. The superior performance of Chlorella sp. MHQ2 was eventually screened out among a large number of mutants generated from 3 wild-type Chlorella strains. Results indicated that the dry cell weight of the optimal species Chlorella sp. HQ mutant MHQ2 was 1.91 times that of the wild strain in the pure algal system, more carbon from municipal wastewater (MW) were transferred to the microalgae and re-entered into the biological cycle through resource utilization. In addition, COD, NH3-N and TP removal efficiencies of MW by Chlorella sp. MHQ2 were found to increase to 95.8% (1.1-times), 96.4% (1.4-times), and 92.9% (1.2-times), respectively, under the extra DOC supply and the assistance of indigenous bacteria in the MW. In the transcriptome analysis of the logarithmic phase, the glycolytic pathway was inhibited, and the pentose phosphate pathway was mainly carried out for microalgal life activities, further promoting efficient energy utilization. Upon analysis of carbon capture capacity and photosynthetic potential in trophic mode, the addition of NaHCO3 increased the photosynthetic rate of Chlorella sp. MHQ2 in mixotrophy whereas it was attenuated in autotrophy. This study could provide a new perspective for the study of resource utilization and microalgae carbon- fixing mechanisms in the actual wastewater treatment process.


Assuntos
Carbono , Chlorella , Microalgas , Fotossíntese , Águas Residuárias , Microalgas/genética , Carbono/metabolismo , Chlorella/genética , Mutagênese , Eliminação de Resíduos Líquidos
14.
Sci Total Environ ; 932: 172856, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38697534

RESUMO

Antibiotics are frequently detected in surface water and pose potential threats to organisms in aquatic ecosystem such as microalgae. The occurrence of biphasic dose responses raised the possibility of stimulation of microalgal biomass by antibiotics at environmental-relevant concentration and caused potential ecological risk such as algal bloom. However, the underlying mechanisms of low concentration-induced hormetic effects are not well understood. In this study, we evaluated the hormesis of ofloxacin on Chlorella pyrenoidosa under environmental-relevant concentration and long-term exposure. Results showed the hormetic effects of ofloxacin on cell density and carbon fixation rate (RC). The predicted maximum promotion was 17.45 % by 16.84 µg/L and 20.08 % by 15.78 µg/L at 21 d, respectively. The predicted maximum concentration of non-effect on cell density and RC at 21 d was 3.24 mg/L and 1.44 mg/L, respectively. Ofloxacin induced the mobilization of pigments and antioxidant enzymes to deal with oxidative stress. PCA analysis revealed Chl-a/Chl-b could act as a more sensitive biomarker under acute exposure while chlorophyll fluorescence parameters were in favor of monitoring long-term implication. The hormesis in increased secretion of extracellular organic matters was regarded as a defensive mechanism and accelerated indirect photodegradation of ofloxacin. Bioremoval was dominant and related to biomass accumulation in the total dissipation while abiotic removal appeared slight contributions. This study provided new insights into the understanding of hormesis of microalgae induced by antibiotics.


Assuntos
Antibacterianos , Chlorella , Hormese , Ofloxacino , Poluentes Químicos da Água , Chlorella/efeitos dos fármacos , Ofloxacino/toxicidade , Poluentes Químicos da Água/toxicidade , Antibacterianos/toxicidade , Microalgas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos
15.
J Nanobiotechnology ; 22(1): 227, 2024 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-38711078

RESUMO

BACKGROUND: Elevated interstitial fluid pressure within tumors, resulting from impaired lymphatic drainage, constitutes a critical barrier to effective drug penetration and therapeutic outcomes. RESULTS: In this study, based on the photosynthetic characteristics of algae, an active drug carrier (CP@ICG) derived from Chlorella pyrenoidosa (CP) was designed and constructed. Leveraging the hypoxia tropism and phototropism exhibited by CP, we achieved targeted transport of the carrier to tumor sites. Additionally, dual near-infrared (NIR) irradiation at the tumor site facilitated photosynthesis in CP, enabling the breakdown of excessive intratumoral interstitial fluid by generating oxygen from water decomposition. This process effectively reduced the interstitial pressure, thereby promoting enhanced perfusion of blood into the tumor, significantly improving deep-seated penetration of chemotherapeutic agents, and alleviating tumor hypoxia. CONCLUSIONS: CP@ICG demonstrated a combined effect of photothermal/photodynamic/starvation therapy, exhibiting excellent in vitro/in vivo anti-tumor efficacy and favorable biocompatibility. This work provides a scientific foundation for the application of microbial-enhanced intratumoral drug delivery and tumor therapy.


Assuntos
Chlorella , Portadores de Fármacos , Fotossíntese , Animais , Camundongos , Linhagem Celular Tumoral , Portadores de Fármacos/química , Humanos , Terapia Combinada , Fotoquimioterapia/métodos , Neoplasias/terapia , Antineoplásicos/farmacologia , Camundongos Endogâmicos BALB C , Sistemas de Liberação de Medicamentos/métodos , Verde de Indocianina/farmacocinética , Verde de Indocianina/química , Feminino
16.
Pak J Biol Sci ; 27(4): 210-218, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38812112

RESUMO

<b>Background and Objective:</b> The remarkable surface-to-volume ratio and efficient particle interaction capabilities of nanoparticles have garnered significant attention among researchers. Microalgal synthesis presents a sustainable and cost-effective approach to nanoparticle production, particularly noteworthy for its high metal uptake and ion reduction capabilities. This study focuses on the eco-friendly and straightforward synthesis of Silver (AgNPs) and Iron (FeNPs) nanoparticles by utilizing Spirulina (<i>Arthrospira platensis</i>) and <i>Chlorella pyrenoidosa</i> extract, devoid of any chemical reducing or capping agents. <b>Materials and Methods:</b> Following the mixing of 1 mM AgNO<sub>3</sub> and 1 mM iron oxide solution with the algal extract, the resulting filtrated solution underwent comprehensive characterization, including UV-visible absorption spectra analysis, observation of particle morphology, Zetasizer measurements and Scanning Electron Microscope-Energy Dispersive X-Ray (SEM-EDX) analysis. <b>Results:</b> The UV-visible spectroscopy revealed a maximum absorbance peak at 430-440 nm, confirming the successful green synthesis of AgNPs and FeNPs, as indicated by the distinct color change from transparent to dark reddish-yellow and brown to reddish-brown, respectively. The SEM-EDX analysis further elucidated the spherical morphology of the nanoparticles, with an average diameter of 93.71 nm for AgNPs and 6198 nm for FeNPs. The Zeta potential measurements indicated average values of -56.68 mV for AgNPs and 29.73 mV for FeNPs, with conductivities of 0.1764 and 0.6786 mS/cm, respectively. <b>Conclusion:</b> The observed bioaccumulation of silver and iron nanoparticles within the algal extract underscores its potential as an environmentally friendly and cost-effective method for nanoparticle synthesis. These findings suggested a promising avenues for the application of silver and iron nanoparticles in the field of nanobiotechnology. Future research endeavors could focus on optimizing preparation conditions and controlling nanoparticle size to further enhance their utility and effectiveness.


Assuntos
Ferro , Nanopartículas Metálicas , Microalgas , Prata , Spirulina , Prata/química , Microalgas/metabolismo , Nanopartículas Metálicas/química , Ferro/química , Spirulina/metabolismo , Spirulina/química , Química Verde/métodos , Chlorella/metabolismo , Nanotecnologia/métodos
17.
Aquat Toxicol ; 271: 106922, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38615581

RESUMO

The photodegradation products (PDPs) of antibiotics in the aquatic environment received increasing concern, but their chronic effects on microalgae remain unclear. This study initially focused on examining the acute effects of erythromycin (ERY), then explored the chronic impacts of ERY PDPs on Chlorella pyrenoidosa. ERY of 4.0 - 32 mg/L ERY notably inhibited the cell growth and chlorophyll synthesis. The determined 96 h median effective concentration of ERY to C. pyrenoidosa was 11.78 mg/L. Higher concentrations of ERY induced more serious oxidative damage, antioxidant enzymes alleviated the oxidative stress. 6 PDPs (PDP749, PDP747, PDP719, PDP715, PDP701 and PDP557) were identified in the photodegradation process of ERY. The predicted combined toxicity of PDPs increased in the first 3 h, then decreased. Chronic exposure showed a gradual decreasing inhibition on microalgae growth and chlorophyll content. The acute effect of ERY PDPs manifested as growth stimulation, but the chronic effect manifested as growth inhibition. The malonaldehyde contents decreased with the degradation time of ERY at 7, 14 and 21 d. However, the malonaldehyde contents of ERY PDPs treatments were elevated compared to those in the control group after 21 d. Risk assessment still need to consider the potential toxicity of degradation products under long-term exposure.


Assuntos
Chlorella , Clorofila , Eritromicina , Microalgas , Fotólise , Poluentes Químicos da Água , Chlorella/efeitos dos fármacos , Chlorella/efeitos da radiação , Eritromicina/toxicidade , Eritromicina/farmacologia , Poluentes Químicos da Água/toxicidade , Microalgas/efeitos dos fármacos , Clorofila/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiação , Antibacterianos/toxicidade , Antibacterianos/farmacologia , Malondialdeído/metabolismo
18.
Arch Microbiol ; 206(5): 218, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38625565

RESUMO

There is a great scientific curiosity to discover all environments sheltering microalgae, especially those with exceptional characteristics from coldest to hottest ones, the purpose remains to explore the potential of the native microalgae flora and the research for new bioactive compounds. This study aimed to isolate a polysaccharide-producing microalga from an extreme ecosystem and to evaluate its capacity to inhibit the α-D-glucosidase enzyme. Chlorella strain is isolated from hypersaline Lake in the Algerian desert. The exopolysaccharide extraction was performed by the concentration of free-cell supernatant in a rotary evaporator. The infrared analysis showed a characteristic footprint of carbohydrates with particular functional groups, such as sulfate. Gas chromatography-mass spectrometry has revealed a hetero-exopolysaccharide composed of galactose 35.75%, glucose 21.13%, xylose 16.81%, fructose 6.96%, arabinose 5.10%, and glucuronic acid 2.68%. The evaluation of the anti-hyperglycemic activity demonstrated a significant α-D-glucosidase inhibition of 80.94 ± 0.01% at 10 mg mL-1 with IC50 equal to 4.31 ± 0.20 mg mL-1. This study opens a vast prospect to use exopolysaccharides as natural nutraceutical or food additive.


Assuntos
Chlorella , Sulfatos , Ecossistema , Arabinose , Glucosidases
19.
PLoS Biol ; 22(4): e3002563, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38573881

RESUMO

Exploring the mechanisms that underpin symbiosis requires an understanding of how these complex interactions are maintained in diverse model systems. The ciliate protist, Paramecium bursaria, offers a valuable insight into how emergent endosymbiotic interactions have evolved.


Assuntos
Chlorella , Cilióforos , Paramecium , Simbiose
20.
J Hazard Mater ; 470: 134241, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38608594

RESUMO

Artemisinin, a novel plant allelochemical, has attracted attention for its potential selective inhibitory effects on algae, yet to be fully explored. This study compares the sensitivity and action targets of Microcystis aeruginosa (M. aeruginosa) and Chlorella pyrenoidosa (C. pyrenoidosa) to artemisinin algaecide (AMA), highlighting their differences. Results indicate that at high concentrations, AMA displaces the natural PQ at the QB binding site within M. aeruginosa photosynthetic system, impairing the D1 protein repair function. Furthermore, AMA disrupts electron transfer from reduced ferredoxin (Fd) to NADP+ by interfering with the iron-sulfur clusters in the ferredoxin-NADP+ reductases (FNR) domain of Fd. Moreover, significant reactive oxygen species (ROS) accumulation triggers oxidative stress and interrupts the tricarboxylic acid cycle, hindering energy acquisition. Notably, AMA suppresses arginine synthesis in M. aeruginosa, leading to reduced microcystins (MCs) release. Conversely, C. pyrenoidosa counters ROS accumulation via photosynthesis protection, antioxidant defenses, and by regulating intracellular osmotic pressure, accelerating damaged protein degradation, and effectively repairing DNA for cellular detoxification. Additionally, AMA stimulates the expression of DNA replication-related genes, facilitating cell proliferation. Our finding offer a unique approach for selectively eradicating cyanobacteria while preserving beneficial algae, and shed new light on employing eco-friendly algicides with high specificity.


Assuntos
Artemisininas , Chlorella , Microcystis , Fotossíntese , Espécies Reativas de Oxigênio , Microcystis/efeitos dos fármacos , Microcystis/metabolismo , Chlorella/efeitos dos fármacos , Chlorella/metabolismo , Artemisininas/farmacologia , Fotossíntese/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Microcistinas/metabolismo
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