RESUMO
Biogas has become an alternative clean source of energy. Agricultural residues being renewable and abundant resources could be efficiently used as a feed for methane production. The recalcitrant behaviour of rice straw marks pretreatment an important step to facilitate the transformation into renewable (methane) energy source. Microwave pretreatment has been considered as one of the most effective method, as it can directly (thermal and nonthermal effects) react with the feedstock and destroy its complex matrix. The present study considered the different temperature and exposure time (i.e., 130-230⯰C, 2-5â¯min). Biochemical methane potential was assessed corresponding to the maximum solubilization rate; specific methane yield was obtained as 325.76â¯mL/g/VS. The total net energy gain of 3288.576â¯J/g/VS was obtained. The performance parameters were calculated by using different kinetic models. It followed the trend as modified Gompertzâ¯>â¯transference functionâ¯>â¯logistic function models. Field Emission Scanning Electron Microscopy (FESEM) and Fourier Transform Infrared (FTIR) analysis confirmed the breakdown of lignocellulose structure resulting from the rupture of cuticular surface.
Assuntos
Metano , Oryza , Anaerobiose , Biocombustíveis , Cinética , Micro-OndasRESUMO
The impact of guar gum (GG), crude algae ethanolic extract (CAEE), and turmeric essential oil (TEO) incorporated edible coating formulations on the quality of cut potatoes was investigated at room temperature (27⯱â¯3⯰C, 70-85â¯% RH) storage using a rotatable central composite design. Besides, 30â¯% glycerol, 5â¯% calcium chloride, and 3â¯% ascorbic acid (w/w) were added to the coating solution as additives. The surface color, respiration rate, water vapor transmission rate, visible mold growth, and sensory analysis were assessed after seven days of storage. The inclusion of ascorbic acid and TEO in edible coating demonstrated a more effective delay in browning. The coated potatoes had lower OTR, CTR, and WVTR values for GG concentrations of 0.5 to 1â¯g/100â¯mL than the control. Compared to additives, higher concentrations of GG improved response parameters. The WVTR value of coated potatoes was significantly impacted by the interaction between CAEE and TEO with GG. Incorporating CAEE and TEO into the formulations of guar gum led to a reduction in the permeability of the coating to oxygen and water vapor. The seven days of extended shelf life compared to two days of control were observed with the optimized coating formulation. Furthermore, the application of the coating treatment proved effective in preventing enzymatic browning and creating a barrier against moisture and gases, contributing to prolonged freshness during extended storage periods.
Assuntos
Armazenamento de Alimentos , Galactanos , Mananas , Gomas Vegetais , Solanum tuberosum , Gomas Vegetais/química , Galactanos/química , Mananas/química , Mananas/farmacologia , Solanum tuberosum/química , Armazenamento de Alimentos/métodos , Conservação de Alimentos/métodosRESUMO
Passiflora edulis Var. flavicarpa (passion fruit) generates vast waste (60-70%) in the form of peel and seed after the juice extraction. The study aimed to isolate Scirpusin B (SB) from passion fruit (PF) seed waste collected from Northeast India and to analyse its anti-radical, antibacterial, anti-diabetic, and anti-oral cancer activities. Scirpusin B was isolated following hydro-alcoholic extraction, fractionation, and column chromatography. The isolated fraction was further identified through NMR and mass spectroscopy. SB exhibited significant antiradical activity against six standard antioxidant compounds, indicating its commercial application. SB inhibited α-amylase (IC50 Value: 76.38 ± 0.25 µg/mL) and α-glucosidase digestive enzymes (IC50 Value: 2.32 ± 0.04 µg/mL), signifying its antidiabetic properties. In addition, SB showed profound antibacterial activity against eight gram-positive and gram-negative bacteria reported for the first time. Furthermore, SB inhibited SAS and TTN oral cancer cell proliferation up to 95% and 83%, respectively. SB significantly inhibited colonies of SAS and TTn cells in the clonogenic assay, attributing to its anticancer properties. The PI-FACS assay confirmed the ability of SB (75 µM) to kill SAS and TTn cells by 40.26 and 44.3% in 72 h. The mechanism of SB inhibiting oral cancer cell proliferation was understood through western blot analysis, where SB significantly suppressed different cancer hallmark proteins, such as TNF-α, survivin, COX-2, cyclin D1, and VEGF-A. The present study suggests that SB isolated from PF seed can add noteworthy value to the waste biomass for various industrial and medical applications. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03876-6.
RESUMO
In this study, an eco-friendly supercritical carbon dioxide (SC-CO2) extraction of polyphenolic compounds from Hippophae salicifolia leaf was optimized to achieve the highest extraction yield with maximum total phenolic content (TPC) and minimum IC50. The central composite design was used to establish an experimental design for RSM. The effect of the pressure, temperature, carbon dioxide flow rate, and co-solvent amount was scrutinized using variance analysis (ANOVA). Under optimized condition (25.13 MPa, 47.53 °C, 14.47 g/min, and 2.43%), the experimental data (yield of extraction: 4.38%, TPC: 84.31 mg GAE/g, and IC50: 41.94 µg/mL) showed good agreement with the predicted values (yield of extraction: 4.53%, TPC: 83.37 mg GAE/g, and IC50: 40.2 µg/mL). Nine polyphenolic compounds: gallic acid, caffeic acid, ferulic acid, vanillic acid, p-coumaric acid, quercetin, myricetin, kaempferol, and rutin were analyzed in SC-CO2 extract using HPLC. SC-CO2 extraction was more selective for ferulic acid, myricetin, and quercetin extraction. The study results revealed that SC-CO2 extract had significant antibacterial activity against eight bacterial strains. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-022-03358-1.
RESUMO
The concept of sustainability and the substitution of non-biodegradable packaging using biodegradable packaging has attracted gigantic interest. The objective of the present study was to revalorize the biowaste "de-oiled green algae biomass (DAB)" of Dunaliella tertiolecta using a green approach and the development of biodegradable chitosan (CS)-based edible active biocomposite films and coatings for prolonging the shelf life of fresh produce. Ultrasound-assisted green extraction was conducted using food-grade solvent ethanol for obtaining the bio-actives, namely "crude algae ethanolic extract (CAEE)" from DAB. The edible films (CS/CAEE) and coating solutions were developed by incorporating CAEE with varying concentrations (0 to 28%). The CAEE was subjected to MALDI-TOF-MS, NMR, and other biochemical analyses, and was found to be rich in DPPH antioxidant activity (â¼40%). The CS/CAEE films were fabricated using a solvent casting method and characterized by several biochemical and physicochemical (FESEM, TGA, FTIR, XRD, WVP, UTM, and rheological) characterization techniques. The addition of CAEE into the CS matrix reduced the maximum film transparency (â¼20%), water vapor permeability (â¼60%); improved the crystallinity (â¼24%), tensile strength (â¼25%), and antioxidant activity (â¼27%); and exhibited UV-Vis blocking properties as compared to the control film. Besides, the developed coating solutions and CAEE showed biocompatibility with BHK-21 fibroblast cells and antimicrobial activity against common food pathogens. The developed coating solution was applied on green chilli using a dipping method and stored at ambient temperature (25 ± 2 °C, 50-70 % RH) for 10 days. The shelf life of chillies was extended without altering the quality as compared to uncoated green chillies. Therefore, the formulated coating could be applicable for prolonging the shelf life of fresh produce.
RESUMO
The effect of extrusion cooking on the quality of rice extrudate with infused microencapsulated anthocyanin was investigated. The moisture sorption isotherm of the extrudate was also studied. The rotatable central composite design was used to optimize the extrusion process and the optimized conditions were: screw speed, 121 rpm; barrel temperature, 91.89 °C; and moisture content, 22.03%. The extrudate showed anthocyanin content of 0.218 mg/L; true density, 1.48 g/cc; water activity 0.51, water solubility index, 7.49%; and specific mechanical energy, 31.39 kJ/kg. The antioxidant activity and solubility of the extrudate were higher as compared with native extrudate. The moisture sorption isotherm of the extrudate was found to follow type III isotherm behavior according to the Brunauer-Emmett-Teller classification. The sorption isotherm was analyzed using several models and the Caurie and Peleg models were best fitted with the extrudate isotherm data. The present work manifested a way to develop antioxidant rich extrudate.
RESUMO
The physico-chemical, polyphenols, antioxidant and antibacterial properties of berries and mixture of male and female leaves of Hippophae salicifolia were investigated. The mineral, vitamin C, sugar, total protein, and total tannin contents of the berries and the leaves were evaluated. Further, the extracts of berries and mixture of leaves samples obtained by successive solvent extraction were investigated for their polyphenols, antioxidant and antibacterial properties. Total phenolic content was highest in leaves-methanol extract (157.97 ± 2.09 mg GAE/g) followed by berries-aqueous extract (48.45 ± 1.94 mg GAE/g), while total flavonoid was predominant in leaves-acetone extract (75.64 ± 3.21 mg QE/g) and berries-methanol extract (28.93 ± 2.08 mg QE/g). Gallic acid, caffeic acid, and rutin were the major polyphenols confirmed by HPLC analysis. Berries-aqueous and leaves-methanol extracts showed excellent global antioxidant score. Best antibacterial activity was observed by methanol extracts against eight different strains. Overall, the leaves and berries of Hippophae salicifolia collected from Northeast India exhibited good antioxidant and antibacterial activity and can be utilized by food and pharmaceutical sectors. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10068-021-00988-8.
RESUMO
Marine green algae biomass residue (ABR), a waste by-product of Dunaliella tertiolecta, left behind after the extraction of oil from the algal biomass, was utilized for the fabrication of cellulose nanocrystals (CNCs). The fabricated sulphuric acid hydrolysed CNCs had needle-like morphology, with dominant cellulose type I polymorph and a high crystallinity index of 89 %. ICP-MS elemental analysis confirmed the presence of a variety of minerals in the ABR. Washed ABR (WABR)/PLA and CNC/PLA bio-composite films were developed via solvent casting technique with varying bio-filler loadings for comparing their effectiveness on the crystallization behaviour of PLA. FESEM, FTIR, XRD and TGA were used to characterize the bio-fillers. The nucleating and crystallization behaviour of the bio-composite films were confirmed using DSC, SAXS and POM analysis which indicated better effectiveness of CNCs with a significant reduction in cold crystallization temperature, and noteworthy increment in crystallinity and spherulite growth rate.
Assuntos
Celulose/isolamento & purificação , Clorófitas/química , Nanopartículas , Poliésteres/química , Biomassa , Celulose/química , Celulose/farmacologia , Precipitação Química/efeitos dos fármacos , Clorófitas/metabolismo , Cristalização , Nanopartículas/química , Nanopartículas/metabolismo , Espalhamento a Baixo Ângulo , Difração de Raios XRESUMO
Exploration of biodegradable materials for conventional application has taken a rising interest across the world. The presented work primarily focused on exploring the effectiveness of isolated CNCs from marine de-oiled green algae biomass residue (Dunaliella tertiolecta) in synthesized poly(É-caprolactone) (PCL). The washed algae biomass residue (WABR) and algae derived CNCs were explored as two different bio-fillers incorporated into PCL for comparison and development of biodegradable and flexible bio-composites with varying bio-filler loading. FTIR, XRD, TGA, UTM, DSC, POM, and SAXS characterized the developed PCL/WABR and PCL/CNC bio-composites. Improved thermal stability was observed in PCL/CNC bio-composites by ~10 °C rise. Besides, increased modulus of 18.38 MPa and tensile strength was obtained in PCL/CNC/1 bio-composites. However, the isothermal kinetics study (at 45 °C) revealed the reduction in the degree of crystallinity of bio-composites, and the axialite formation was visualized via POM. Moreover, CNCs was found as an excellent nucleating agent and effective bio-filler as compared to WABR.
Assuntos
Celulose/química , Microalgas/química , Nanocompostos/química , Nanopartículas/química , Poliésteres/química , Resistência à TraçãoRESUMO
Application of ultrasound technology in modulating the hydration process during paddy germination was analyzed in this study. The effect of hydropriming (24 h) and sono-hydro priming (ultrasound priming, 12 h) on the hydration behaviour of paddies was determined at different temperatures (25-40 °C). Ultrasound pulse was applied for 10 min after every one hour for sono-hydro priming. Germination potential and microstructure analysis of treated paddies were also performed. Downward concave curve observed in hydration process of paddies indicates initial high-water absorptionthrough diffusion process. Sono-hydro priming process showed higher hydration rate compared to hydropriming. The changes in moisture content during hydration processes fitted to theoretical (Fick's model) and empirical model (Peleg model) exhibited high regression coefficient (R2 > 0.95) indicating suitability for predicting hydration behaviour in both paddies for germination. The Peleg model adequately predicted saturation moisture content and sono-hydro priming efficiently increased the water absorption rate. Effective moisture diffusivity determined from Fick's diffusion model increased for sono-hydro priming. Activation energy estimated from effective moisture diffusivity required in sono-hydro priming (Ea = 20.32 and 19.19 KJ/mol respectively) for pigmented rice and non-pigmented rice was lower than hydropriming (Ea = 27.11 and 32.15 KJ/mol respectively). Both hydration processes were endothermic and non-spontaneous inferred from thermodynamic properties. Sono-hydro priming exhibited < 95% germination potential with shorter soaking time (12 h) owing to the high mass transfer rate. SEM micrograph revealed water absorption through various micro-cavities during sono-hydro priming. Thus, sono-hydro priming potentially reduced the soaking process (approximately 50%) with higher germination rate in paddies beneficial for commercial malting of grains.
Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Germinação , Modelos Teóricos , Oryza/crescimento & desenvolvimento , Sonicação/métodos , Cinética , Água/químicaRESUMO
The study reports shelf-life enhancement of candied mango by infusion of gingerols. Gingerols infused product (GIP), with 3.67 mg gingerols/100 g and non-infused products (control) were packed in multilayer metalized (MET), and ethylene vinyl alcohol (EVOH) based pouches and stored at 25, 35 and 45 °C for 120 days. Degradation kinetics of browning and related parameters showed following order: kß-carotene > ksensory (color) > knon-enzymatic browning > kvitamin C > kantioxidant capacity > k sensory (overall) > ktotal phenolics > kgingerols, resulting in multiple cutoff criteria and predicted shelf-lives (SLpredicted). The application of chemometrics simplified the kinetic interpretations and hence the predictions. Gingerols infusion retarded the deterioration of all quality parameters and substantially enhanced SLpredicted of GIP over control, irrespective of storage conditions. Finally, chemometric based SLpredicted of 144 days closely predicted the actual shelf-life of 142 days for control samples stored in EVOH pouches at 25 °C, in contrast to kinetics based SLpredicted of 185 days.
Assuntos
Catecóis/farmacologia , Álcoois Graxos/farmacologia , Mangifera/efeitos dos fármacos , Antioxidantes/metabolismo , Ácido Ascórbico/metabolismo , Doces , Cor , Armazenamento de Alimentos , Mangifera/metabolismo , Fenóis/metabolismo , beta Caroteno/metabolismoRESUMO
Transformation of renewable biomass into value-added chemicals and biofuels has evolved to be a vital field of research in recent years. Accurate estimation of reducing sugars post pretreatment of lignocellulosic biomass has been very inconsistent. For a few decades, 3,5-dinitrosalicylic acid (DNS) assay has been widely employed for the estimation of reducing sugars derived from pretreatment of lignocellulosic biomass. This assay tests for the presence of free carbonyl group (C=O), the so-called reducing sugars. This involves the oxidation of the aldehyde functional group present to the corresponding acid while DNS is simultaneously reduced to 3-amino-5-nitrosalicylic acid under alkaline conditions. However, the presence of other active carbonyl groups can potentially also react with DNS leading to incorrect yields of reducing sugars. Therefore, a detailed study has been carried out to evaluate the influence of active carbonyl compounds like furfural and 5-hydroxymethylfurfural (5-HMF) in the overall estimation of reducing sugars (glucose, xylose and arabinose) by DNS assay. In addition to this, reducing sugars estimation in the presence of furans were also investigated, it reveals that reducing sugars estimation was found to be 68% higher than actual sugars. Therefore, current findings strongly indicate that the employment of DNS assay for quantifying the reducing sugars in the presence of furans is not appropriate.
Assuntos
Furaldeído/análogos & derivados , Furaldeído/metabolismo , Substâncias Redutoras/química , Substâncias Redutoras/metabolismo , Salicilatos/química , Salicilatos/metabolismo , Açúcares/análise , Aldeídos/análise , Artefatos , Calibragem , Cromatografia Líquida de Alta Pressão , Colorimetria , Furaldeído/análise , Furaldeído/química , Lignina/química , Espectrofotometria , Açúcares/químicaRESUMO
The influence of three different fungal strains-namely, Pleurotus ostreatus (PO), Phanerochaete chrysosposrium (PC), and Ganoderma lucidum (GL)-on pretreatment of rice straw, followed by biochemical methane potential assay was evaluated on the basis of structural (Field Emission Scanning Electron Microscopy, X-ray diffraction etc.) and quantitative (soluble chemical oxygen demand, volatile fatty acids, etc.) analysis. Maximum lignocellulosic degradation was obtained with PC pretreated rice straw (36% more than an untreated sample), followed by PO. Enhancement in the methane yield after 5â¯weeks of inoculation time was obtained after pretreatment, which was 269.99, 295.91, and 339.31â¯mL/g VSadded, for PO, GL, and PC, respectively, 1.64-2.22-fold higher than the untreated one. Kinetic modelling of cumulative methane yield showed that modified gompertz model showed the best fit among all analysed models. This study demonstrated the usefulness of fungal species in enhancing the methane yield.
Assuntos
Metano , Oryza , Anaerobiose , Biocombustíveis , Hidrólise , CinéticaRESUMO
BACKGROUND: Extracellular polymeric substances (EPS) from Cr(VI) resistant acid-tolerant biofilm forming bacterium (CrRAtBb) Lysinibacillus sphaericus RTA-01 was used for synthesis of magnetic iron oxide nanoparticles (MIONPs) in removal of Cr(VI). METHODS: MIONPs synthesized in EPS matrix were characterized by UV-Vis, DLS, ATR-FTIR, XRD, FESEM, HRTEM and VSM. Primarily, the synthesis of MIONPs was established by the formation of black-colored precipitate through surface plasmon resonance (SPR) peak in between 330 and 450 nm. RESULTS: The size of the spherical MIONPs with diameter range 13.75-106 nm was confirmed by DLS, XRD and FESEM analysis. HRTEM study confirmed the size of the MIONPs in the range of 10-65 nm. Moreover, the EDX and SAED confirmed the purity and polycrystalline nature of MIONPs. The ATR-FTIR peaks below 1000 cm-1 designated the synthesis of MIONPs. Also, the magnetic property of MIONPs was confirmed for separation from the aqueous solution. MIONPs were further checked for the adsorption of Cr(VI) with initial concentration range of 50-200 mg L-1. An adsorption isotherm and thermodynamic study were also carried out and the experimental data was best fitted in Langmuir isotherm model with maximum adsorption percent of 1052.63 mg g-1 of Cr(VI). Post interaction with Cr(VI), the surface characteristic of MIONPs in EPS matrix was evaluated by zeta potential, EDX, ATR-FTIR and XRD. CONCLUSION: This study ascertained the adsorption of Cr(VI) over EPS stabilized MIONPs whereas the zeta potential and XRD analysis confirmed the presence of reduced Cr(IV) on the adsorbent surface.
RESUMO
Presence of pungent gingerols in ginger oleoresin makes it an ideal natural flavoring candidate for the food industry. The study reports its incorporation for synergistic enhancement of flavor and nutraceutical portfolio of candied mango. The process is systematically optimized at bench-scale for gingerols infusion and subsequent candying treatment in a range of hypo and hypertonic osmotic solutions for critical transport properties. After that, optimization of the drying process and the scale-up study was conducted with a 200 folds increase in the batch size. Collated effects of multistep optimization resulted in 85.6, 76.8, 60.2% retention in ß-carotene, total phenolics, Vitamin C, respectively, along with minor color difference and significant improvement in sensory scores over fresh mango. Mass transfer and quality parameters were comparable in both scales, implying excellent repeatability and scalability of the process. Compared with a similar commercial product, substantial improvement in quality characteristics along with 376.7% reduction in overall processing time was achieved.
Assuntos
Doces , Catecóis/química , Álcoois Graxos/química , Aromatizantes/química , Indústria de Processamento de Alimentos/métodos , Mangifera/química , Ácido Ascórbico/análise , Ácido Ascórbico/química , Cor , Dessecação/métodos , Suplementos Nutricionais/análise , Qualidade dos Alimentos , Frutas/química , Zingiber officinale/química , Humanos , Fenóis/análise , Fenóis/química , Paladar , beta Caroteno/análise , beta Caroteno/químicaRESUMO
The kinetics of epoxidation of cottonseed oil by peroxyacetic acid generated in situ from hydrogen peroxide and glacial acetic acid in the presence of liquid inorganic acid catalysts were studied. It was possible to obtain up to 78% relative conversion to oxirane with very less oxirane cleavage by in situ technique. The rate constants for sulphuric acid catalysed epoxidation of cottonseed oil were in the range 0.39-5.4 x 10(-6)L mol(-1)s(-1) and the activation energy was found to be 11.7 kcal mol(-1). Some thermodynamic parameters such as enthalpy, entropy, and free energy of activation were determined to be of 11.0 kcal mol(-1), -51.4 cal mol(-1)K(-1) and 28.1 kcal mol(-1), respectively. The order of effectiveness of catalysts was found to be sulphuric acid>phosphoric acid>nitric acid>hydrochloric acid. Acetic acid was found to be superior to formic acid for the in situ cottonseed oil epoxidation.
Assuntos
Ácidos não Carboxílicos/farmacologia , Óleo de Sementes de Algodão/química , Compostos de Epóxi/química , Peróxido de Hidrogênio/farmacologia , Ácido Acético/química , Catálise/efeitos dos fármacos , Óxido de Etileno/química , Etilenos/química , Formiatos/química , Glicóis/química , Cinética , Oxigênio , Ácidos Sulfúricos , Temperatura , Termodinâmica , Fatores de TempoRESUMO
The use of ionic liquids (ILs) in the biorefinery process has been increasing for the past few decades. In biorefinery, the separation process with respect to sugars needs to be evaluated for an efficient process design. Therefore, the present work aims to investigate the separation of sugars and ILs by means of a precipitation process using an antisolvent method. For this purpose, both theoretical and experimental studies were conducted. Initially, the conductor-like screening model for real solvents model was employed to screen the suitable antisolvents for the separation of sugars from the ILs. From the screening study, dichloromethane (DCM) and 1,2-dichloroethane were found to be the better antisolvents for the separation process. With the selected antisolvents, precipitation experiments were conducted for the mixtures involving four different sugars and three ILs at different experimental conditions. The process variables such as different antisolvents, sugars, ILs, antisolvent-IL molar ratios, and temperatures were examined in terms of their effect on sugar removal and IL recovery. DCM was found to be the most suitable antisolvent in this study with 90-99% of sugar removal and 80-98% of IL recovery. Further, molecular dynamics simulations were adopted to understand the structural properties of carbohydrates with ILs and antisolvents via interaction energies, hydrogen bonding, and coordination numbers. It was observed that the interaction energy between the sugars and IL plays a critical role in the removal of sugar. Higher the interaction energy between the sugars and IL, lower is the sugar removal.
RESUMO
The present study aims at the extraction of a polyaromatic hydrocarbon from fuel oils using a novel low-cost deep eutectic solvent (DES). The DES is prepared by mixing the hydrogen bond acceptor (HBA; methyltriphenylphosphonium bromide, MTPB) and hydrogen bond donor (HBD; ethylene glycol) at a molar ratio of 1:4. The liquid-liquid equilibrium is then measured at ambient condition. The classical molecular dynamic (MD) simulation technique is then employed to investigate and compare the experimental phase behavior of a DES-quinoline-heptane ternary system. For performing the MD simulations, two experimental feed points are considered which gave high selectivity and distribution coefficient values. The interaction energies of different species and the structural properties such as radial distribution functions, average number of hydrogen bonds, and spatial distribution functions (SDFs) are then computed. It is found that the cation within the HBA, namely, MTP, possesses favorable interactions with quinoline when compared to HBD or anion (Br). MTP here acts as a HBA and contributes to the hydrogen bonding with quinoline, which results in higher experimental selectivity values. The calculations of SDFs further reveal the fact that the DES molecules are evenly distributed around the active sites of the quinoline molecule, whereas heptane molecules are found to be distributed around the nonactive sites of the aromatic ring.
RESUMO
This work aimed to gain mechanistic insights into the salt stress mediated enhanced lipid accumulation in microalgae. Two freshwater microalgae were isolated from North Guwahati Assam, and were identified as Chlorella sorokiniana CG12(KR905186) and Desmodesmus GS12(KR905187). The effects of various salts such as NaCl, KCl, MgCl2 and CaCl2 were investigated where CaCl2 exhibited the maximum effect on lipid enhancement up to 40.02% and 44.97% in CG12 and GS12, respectively. Furthermore, the substantial increase was observed in oleic acid content up to 64.18% and 53.46% in CG12 and GS12 in the presence of 25mM and 5mM CaCl2, respectively. Cluster analysis revealed the correlation between lipid profile alterations by varying concentration of salts. Based on the outcomes of the present study, it is hypothesized that Ca2+ plays a decisive role in the cell signaling under salt stress conditions and subsequently enhances the synthesis of lipid molecules.
Assuntos
Lipídeos , Microalgas , Salinidade , Biomassa , ChlorellaRESUMO
Sesbania grandiflora (L.) Pers. is one of the fast growing tree legumes having the efficiency to produce around 50tha-1 above ground dry matters in a year. In this study, biomass of 2years old S. grandiflora was selected for the chemical composition, pretreatments and enzymatic hydrolysis studies. The stem biomass with a wood density of 3.89±0.01gmcm-3 contains about 38% cellulose, 12% hemicellulose and 28% lignin. Enzymatic hydrolysis of pretreated biomass revealed that phosphoric acid (H3PO4) pretreated samples even at lower cellulase loadings [1 Filter Paper Units (FPU)], could efficiently convert about 86% glucose, while, even at higher cellulase loadings (60FPU) alkali pretreated biomass could convert only about 58% glucose. The effectiveness of phosphoric acid pretreatment was also supported by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectroscopy (FTIR) analysis.