Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Bioresour Technol ; 343: 126110, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34648966

RESUMO

Electro-Fenton process (EFP) was studied as a potential cell disruption technique for recovery of lipids from wet biomass of the microalga Chlorella homosphaera. A novel approach of electrochemical dissolution of a sacrificial steel anode was used to provide Fe2+ required to initiate EFP and microalgae cell disruption. Response surface methodology (RSM) was employed to optimize the process parameters and maximize the lipid yield of EFP. The RSM model (R2 = 90.66%, Adj.R2 = 87.71%) showed that a maximum lipid yield of 18.29% could be obtained at 40 min reaction time and 4.38 g/L biomass concentration. Experimental validation resulted in a lipid yield of 19.99 ± 1.33%, which was significantly higher than wet lipid extraction without cell disruption. However, the lipid yield of EFP should be further improved to achieve comparable results to mechanical cell disruption methods. Nonetheless, biodiesel synthesized from lipids obtained via EFP conformed to the ASTM D6751-12 standard.


Assuntos
Chlorella , Microalgas , Biocombustíveis , Biomassa , Eletrodos , Lipídeos , Aço
2.
Bioresour Technol ; 342: 126018, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34571169

RESUMO

The freshwater microalgae Haematococcus pluvialis and Chlorella zofingiensis are attractive biorefinery feedstocks in view of their ability to simultaneously synthesize astaxanthin and other valuable metabolites. Nonetheless, there are concerns regarding the sustainability of such biorefineries due to the high freshwater footprint of microalgae cultivation. The integration of wastewater as an alternative growth media is a promising approach to reduce freshwater demand. Wastewater-based cultivation enables the recovery of essential nutrients required for microalgae growth and consequently results in phycoremediation of wastewater, thus promoting the concept of a circular economy and further enhancing the sustainability of the process. In this review, recent developments in wastewater-integrated cultivation of H. pluvialis and C. zofingiensis for astaxanthin production are discussed. Furthermore, prospective strategies for overcoming the inherent challenges of wastewater-based cultivation are reviewed. Moreover, the biorefinery potential of wastewater-grown H. pluvialis and C. zofingiensis is delineated and future perspectives of wastewater-based biorefineries are outlined.

3.
Bioresour Technol ; 340: 125670, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34364083

RESUMO

The present research describes yeast assisted algal flocculation followed by evaluation of algae-yeast flocs for nutritional profile as potent food product. Co-flocculation of Chlorella pyrenoidosa using Saccharomyces cerevisiae showed 58.33 ± 2.37% flocculation efficiency. Nutrient composition of algae-yeast flocs (CP-Y) depicted higher protein content (35.52%) as compared to algae (23.72%) and yeast biomass (33.89). Amino acid profiles of CP-Y biomass depicted increase in essential amino acid content with higher ratio of essential to non-essential amino acid (0.68) as compared to Y (0.57) and CP (0.57) biomass. Lipid and carbohydrate content of CP-Y flocs was estimated as 26.95 ± 0.57% and 21.12 ± 0.83%, respectively. Fatty Acid Methyl Esters (FAME) analysis showed presence of omega rich polyunsaturated fatty acids (PUFAs) like α-linolenic acid (ω-3), Linoleic acid (ω-6), Palmitoleic acid (ω-7) etc in CP-Y biomass. The study provides novel insights on nutrition enriched biomass obtained after algal-yeast flocculation, which can be a better alternative to existing flocculation methods for food applications.


Assuntos
Chlorella , Microalgas , Biomassa , Suplementos Nutricionais , Floculação , Saccharomyces cerevisiae
4.
Water Sci Technol ; 80(10): 1910-1918, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32144223

RESUMO

Most currently employed textile effluent decolourization methods use physical and chemical processes where dyes do not get degraded instead concentrated or transferred into a solid phase. Therefore, further treatment processes are required to destroy dyes from the environment. In contrast, biological decolourization may result in degradation of the dye structure due to microbial activities and hence biological processes can be considered environmentally friendly. In the present study, bacterial strains with dye decolourization potential were isolated from the natural environment and their ability to decolourize four different reactive textile dyes was studied individually and in a bacterial consortium. The developed bacterial consortium composed with Proteus mirabilis, Morganella morganii and Enterobacter cloacae indicated more than 90% color removals for all four dyes and optimum decolourization of the dye mixture was observed at 40 °C and pH 7. The developed bacterial consortium decolourized 60% of dyes in textile industry effluent at 35 °C and pH 7 showing their ability to endure in highly complex and toxic environments and application in textile industry wastewaters.


Assuntos
Indústria Têxtil , Águas Residuárias , Biodegradação Ambiental , Corantes , Resíduos Industriais , Têxteis
5.
Food Chem ; 277: 128-134, 2019 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-30502128

RESUMO

Astaxanthin and ß-carotene are important carotenoids used in numerous pharmaceutical and nutraceutical applications, owing to their vigorous antioxidant properties. The microalgal strains Haematococcus pluvialis and Dunaliella salina accumulate the highest quantities of astaxanthin and ß-carotene (up to 7% and 13% dry weight respectively) and are therefore considered as sustainable feedstock for the commercial production of carotenoids. Thus, from an economical perspective, it becomes desirable to optimize recovery of carotenoids from microalgal cells. To this end, here, we have summarized the conventional and modern extraction techniques generally used for the recovery of astaxanthin from Haematococcus pluvialis and ß-carotene from Dunaliella salina. Furthermore, we have also discussed the optimum process conditions employed for numerous extraction protocols including solvent extraction, ultrasonic-assisted extraction (UAE), microwave-assisted extraction (MAE) and supercritical fluid extraction (SFE). Overall, our study highlights the sustainability of integrated co-production of biofuels and carotenoids in a biorefinery framework.


Assuntos
Fracionamento Químico/métodos , Clorofíceas/química , beta Caroteno/isolamento & purificação , Xantofilas/química , Xantofilas/isolamento & purificação , beta Caroteno/química
6.
Curr Genomics ; 19(1): 50-59, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29491732

RESUMO

Cystathionine ß-synthase (CBS) domains have been identified in a wide range of proteins of unrelated functions such as, metabolic enzymes, kinases and channels, and usually occur as tandem re-peats, often in combination with other domains. In plants, CBS Domain-Containing Proteins (CDCPs) form a multi-gene family and only a few are so far been reported to have a role in development via regu-lation of thioredoxin system as well as in abiotic and biotic stress response. However, the function of majority of CDCPs still remains to be elucidated in plants. Here, we report the cloning, characterization and functional validation of a CBS domain containing protein, OsCBSCBSPB4 from rice, which pos-sesses two CBS domains and one PB1 domain. We show that OsCBSCBSPB4 encodes a nucleo-cytoplasmic protein whose expression is induced in response to various abiotic stress conditions in salt-sensitive IR64 and salt-tolerant Pokkali rice cultivars. Further, heterologous expression of OsCBSCB-SPB4 in E. coli and tobacco confers marked tolerance against various abiotic stresses. Transgenic tobac-co seedlings over-expressing OsCBSCBSPB4 were found to exhibit better growth in terms of delayed leaf senescence, profuse root growth and increased biomass in contrast to the wild-type seedlings when subjected to salinity, dehydration, oxidative and extreme temperature treatments. Yeast-two hybrid stud-ies revealed that OsCBSCBSPB4 interacts with various proteins. Of these, some are known to be in-volved in abiotic stress tolerance. Our results suggest that OsCBSCBSPB4 is involved in abiotic stress response and is a potential candidate for raising multiple abiotic stress tolerant plants.

7.
Physiol Plant ; 152(1): 1-16, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24410953

RESUMO

ETHYLMALONIC ENCEPHALOPATHY PROTEIN 1 (ETHE1) encodes sulfur dioxygenase (SDO) activity regulating sulfide levels in living organisms. It is an essential gene and mutations in ETHE1 leads to ethylmalonic encephalopathy (EE) in humans and embryo lethality in Arabidopsis. At present, very little is known regarding the role of ETHE1 beyond the context of EE and almost nothing is known about factors affecting its regulation in plant systems. In this study, we have identified, cloned and characterized OsETHE1, a gene encoding ETHE1-like protein from Oryza sativa. ETHE1 proteins in general are most similar to glyoxalase II (GLYII) and hence OsETHE1 has been earlier annotated as OsGLYII1, a putative GLYII gene. Here we show that OsETHE1 lacks GLYII activity and is instead an ETHE1 homolog being localized in mitochondria like its human and Arabidopsis counterparts. We have isolated and analyzed 1618 bp OsETHE1 promoter (pOsETHE1) to examine the factors affecting OsETHE1 expression. For this, transcriptional promoter pOsETHE1: 5-bromo-5-chloro-3-indolyl-ß-D-glucuronide (GUS) fusion construct was made and stably transformed into rice. GUS expression pattern of transgenic pOsETHE1:GUS plants reveal a high root-specific expression of OsETHE1. The pOsETHE1 activity was stimulated by Ca(II) and required light for induction. Moreover, pOsETHE1 activity was induced under various abiotic stresses such as heat, salinity and oxidative stress, suggesting a potential role of OsETHE1 in stress response.


Assuntos
Cálcio/metabolismo , Dioxigenases/genética , Regulação da Expressão Gênica de Plantas , Oryza/fisiologia , Estresse Fisiológico , Sequência de Aminoácidos , Dioxigenases/metabolismo , Genes Reporter , Luz , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Dados de Sequência Molecular , Mutação , Cebolas/citologia , Cebolas/genética , Cebolas/fisiologia , Especificidade de Órgãos , Oryza/efeitos dos fármacos , Oryza/genética , Oryza/efeitos da radiação , Filogenia , Epiderme Vegetal/efeitos dos fármacos , Epiderme Vegetal/genética , Epiderme Vegetal/fisiologia , Epiderme Vegetal/efeitos da radiação , Reguladores de Crescimento de Plantas/farmacologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/genética , Raízes de Plantas/fisiologia , Raízes de Plantas/efeitos da radiação , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , Proteínas Recombinantes de Fusão , Alinhamento de Sequência
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...