| 1. |
- Arora, Neha, et al.
(författare)
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NMR-Based Metabolomic Approach To Elucidate the Differential Cellular Responses during Mitigation of Arsenic(III, V) in a Green Microalga
- 2018
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Ingår i: ACS Omega. - : American Chemical Society (ACS). - 2470-1343. ; 3:9, s. 11847-11856
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Tidskriftsartikel (refereegranskat)abstract
- Nuclear magnetic resonance (NMR)-based metabolomic approach is a high-throughput fingerprinting technique that allows a rapid snapshot of metabolites without any prior knowledge of the organism. To demonstrate the applicability of NMR-based metabolomics in the field of microalgal-based bioremediation, novel freshwater microalga Scenedesmus sp. IITRIND2 that showed hypertolerance to As(III, V) was chosen for evaluating the metabolic perturbations during arsenic stress in both its oxidation states As(III) and As(V). Using NMR spectroscopy, we were able to identify and quantify an array of ∼45 metabolites, including amino acids, sugars, organic acids, phosphagens, osmolytes, nucleotides, etc. The NMR metabolomic experiments were complemented with various biophysical techniques to establish that the microalga tolerated the arsenic stress using a complex interplay of metabolites. The two different arsenic states distinctly influenced the microalgal cellular mechanisms due to their altered physicochemical properties. Eighteen differentially identified metabolites related to bioremediation of arsenic were then correlated to the major metabolic pathways to delineate the variable stress responses of microalga in the presence of As(III, V).
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| 2. |
- Patel, Alok, Dr. 1989-, et al.
(författare)
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A novel rapid ultrasonication-microwave treatment for total lipid extraction from wet oleaginous yeast biomass for sustainable biodiesel production
- 2019
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Ingår i: Ultrasonics sonochemistry. - : Elsevier. - 1350-4177 .- 1873-2828. ; 51, s. 504-516
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Tidskriftsartikel (refereegranskat)abstract
- Oleaginous yeasts have emerged as a sustainable source of renewable oils for liquid biofuels. However, biodiesel production from them has few constraints with respect to their cell disruption and lipid extraction techniques. The lipid extraction from oleaginous yeasts commonly includes dewatering and drying of cell biomass, which requires energy and time. The aim of this work was to establish a process for the lipid extraction techniques from wet biomass applying acid catalyzed hot water, microwave, rapid ultrasonication-microwave treatment together with conventional Bligh and Dyer method. In the wake of testing all procedures, it was revealed that rapid ultrasonication-microwave treatment has great potential to give high lipid content (70.86 % w/w) on the cell dry weight basis. The lipid profile after treatment showed the presence of appropriate quantities of saturated (10.39 ± 0.15%), monounsaturated (76.55 ± 0.19%) and polyunsaturated fatty acids (11.49 ± 0.23%) which further improves biodiesel quality compared to the rest of methods. To the best of our knowledge, this is the first report of using rapid ultrasonication-microwave treatment for the lipid extraction from wet oleaginous yeast biomass in the literature.
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| 3. |
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| 4. |
- Patel, Alok, Dr. 1989-, et al.
(författare)
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Biodegradation of phenol via meta cleavage pathway triggers de novo TAG biosynthesis pathway in oleaginous yeast.
- 2017
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Ingår i: Journal of Hazardous Materials. - : Elsevier BV. - 0304-3894 .- 1873-3336. ; 340, s. 47-56
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Tidskriftsartikel (refereegranskat)abstract
- Phenol is reported to be one of the most toxic environmental pollutants present in the discharge of various industrial effluents causing a serious threat to the existing biome. Biodegradation of phenol by oleaginous yeast Rhodosporidium kratochvilovae HIMPA1 was found to degrade 1000mg/l phenol. The pathways for phenol degradation by both ortho and meta-cleavage were proposed by the identification of metabolites and enzymatic assays of ring cleavage enzymes in the cell extracts. Results suggest that this oleaginous yeast degrade phenol via meta-cleavage pathway and accumulates a high quantity of lipid content (64.92%; wt/wt) as compared to control glucose synthetic medium (GSM). Meta-cleavage pathway of phenol degradation leads to formation of pyruvate and acetaldehyde. Both these end products feed as precursors for de novo triacylglycerols (TAG) biosynthesis pathway which causes accumulation of TAG in the lipid droplets (LD) of 6.12±0.78μm grown on phenol while 2.38±0.52μm observed on GSM. This was confirmed by fluorescence microscopic images of BODIPY505-515nm stained live yeast cells. GC-MS analysis of extracted total lipid showed enhanced amount of monounsaturated fatty acid (MUFA) which was as 51.87%, 58.33% and 62.98% in presence of 0.5, 0.75 and 1g/l of phenol.
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| 5. |
- Patel, Alok, Dr. 1989-, et al.
(författare)
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Biodiesel production from non-edible lignocellulosic biomass of Cassia fistula L. fruit pulp using oleaginous yeast Rhodosporidium kratochvilovae HIMPA1
- 2015
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 197, s. 91-8
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Tidskriftsartikel (refereegranskat)abstract
- This study explored biodiesel production from a low cost, abundant, non-edible lignocellulosic biomass from aqueous extract of Cassia fistula L. (CAE) fruit pulp. The CAE was utilized as substrate for cultivating novel oleaginous yeast Rhodosporidium kratochvilovae HIMPA1. This oleaginous yeast accumulates high amount of triacylglycerides as large intracellular lipid droplets (4.35±0.54μm) using CAE as sole nutritional source. Total lipids (4.86±0.54g/l) with lipid content of 53.18% (w/w) were produced by R. kratochvilovae HIMPA1 on CAE. The FAME profile obtained revealed palmitic acid (C16:0) 43.06%, stearic acid (C18:0) 28.74%, and oleic acid (C18:1) 17.34% as major fatty acids. High saturated fatty acids content (72.58%) can be blended with high PUFA feedstocks to make it an industrially viable renewable energy product.
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| 6. |
- Patel, Alok, Dr. 1989-, et al.
(författare)
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Innovative screening approach for the identification of triacylglycerol accumulating oleaginous strains
- 2019
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Ingår i: Renewable energy. - : Elsevier. - 0960-1481 .- 1879-0682. ; 135, s. 936-944
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Tidskriftsartikel (refereegranskat)abstract
- Currently, triacylglycerides (TAG) accumulation in the form of lipid droplets (LDs) in oleaginous microorganisms is of immense importance due to their ability to get transesterified into value-added products in the form of biodiesel. Hence, in order to search for oleaginous microorganisms having high lipid content among a wide range of samples from different niches, there is a compulsive need to develop simple, reliable and rapid methods for screening of TAG accumulating strains. Conventional methods require multistep processes for the isolation, cultivation, extraction and estimation of lipids to identify oleagenic strains. To overcome these challenges, we are proposing an easy, live cellimaging technique for the estimation of lipids via visualization of TAG accumulation in probable strains at the single cell level that gives real-time monitoring of intracellular lipid accumulation in yeasts. In this screening technique, only 100 μl of specific neutral lipid accumulating medium was used to grow the isolated culture in the microtiter plate. The harvested cells were stained with LipidTOX™ Green and visualized by a LED based digital inverted fluorescence microscope. Among 446 yeast colonies screened, maximum lipid producing yeast strains Rhodosporidium kratochvilovae HIMPA1 and Rhodotorula minuta,having supersized lipid body of 5.05 ± 0.87 μm and 4.46 ± 0.61 μm, respectively, were identified as potential candidates for biodiesel production. To the best of our knowledge, this is the first report of using LipidTOX™ Green for the staining of lipid droplets present in yeast cells as per the literature.
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| 7. |
- Patel, Alok, et al.
(författare)
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Potential of aquatic oomycete as a novel feedstock for microbial oil grown on waste sugarcane bagasse
- 2018
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Ingår i: Environmental Science and Pollution Research. - : Springer. - 0944-1344 .- 1614-7499. ; 25:33, s. 33443-33454
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Tidskriftsartikel (refereegranskat)abstract
- Biodiesel production from vegetable oils is not sustainable and economical due to the food crisis worldwide. The development of a cost-effective non-edible feedstock is essential. In this study, we proposed to use aquatic oomycetes for microbial oils, which are cellulolytic fungus-like filamentous eukaryotic microorganisms, commonly known as water molds. They differ from true fungi as cellulose is present in their cell wall and chitin is absent. They show parasitic as well as saprophytic nature and have great potential to utilize decaying animal and plant debris in freshwater habitats. To study the triacylglycerol (TAG) accumulation in the aquatic oomycetes, the isolated water mold Achlya diffusa was cultivated under semi-solid-state conditions on waste sugarcane bagasse, which was compared with the cultivation in Czapek (DOX) medium. A. diffusa grown on waste sugarcane bagasse showed large lipid droplets in its cellular compartment and synthesized 124.03 ± 1.93 mg/gds cell dry weight with 50.26 ± 1.76% w/w lipid content. The cell dry weight and lipid content of this water mold decreased to 89.54 ± 1.21 mg/gds and 38.82% w/w, respectively, when cultivated on standard medium Czapek-Dox agar (CDA). For the fatty acid profile of A. diffusa grown in sugarcane bagasse and CDA, in situ transesterification (IST) and indirect transesterification (IDT) approaches were evaluated. The lipid profile of this mold revealed the presence of C12:0, C14:0, C16:0, C18:0, C18:1, C18:2, C20:0, and C21:0 fatty acids, which is similar to vegetable oils. The biodiesel properties of the lipids obtained from A. diffusa satisfied the limits as determined by international standards ASTM-D6751 and EN-14214 demonstrating its suitability as a fuel for diesel engines.
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