| 1. |
- 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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| 2. |
- Patel, Alok, Dr. 1989-, et al.
(författare)
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Extraction of lipids from algae using supercritical carbon dioxide
- 2020
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Ingår i: Green Sustainable Process for Chemical and Environmental Engineering and Science. - : Elsevier. ; , s. 17-39
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- Microalgal oils are considered an important source of industrially valuable oleochemicals with significant applications ranging from the energy to pharmaceutical sectors. Industrial production of microalgal oil is emerging rapidly; however, the high cost associated with downstream processes may constrain this process. Oils are accumulated intracellularly in oleaginous microalgae in the form of lipid droplets, which in turn require cell wall disruption followed by extraction in order to recover them. Disruption of the microalgal cell is very challenging owing to its distinctive features like high water content, hard cell wall, presence of algaenan, and sporopollenin like biopolymers that in turn create hurdles in efficient extraction of lipids. Various conventional pretreatment methods have been explored to rupture the cellular integrity of microalgal cells to enhance lipid extraction, and each method has certain advantages and disadvantages. Supercritical fluid extraction is the oldest technique for the extraction of valuable compounds from microalgae and is considered an alternative to conventional solvent extraction methods. It has several advantageous features such as being free from organic solvents (and their disposal), environment-friendly, and operating at a mild range of temperature (40–80°C). CO2 is considered to be an ideal supercritical fluid due to its non-toxic, non-flammable, and lipophilic nature. In this chapter, use of supercritical carbon dioxide extraction of lipids from microalgae is discussed and compared with other available lipid extraction methods.
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| 3. |
- Sartaj, Km, et al.
(författare)
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Detailed investigation on FAME capped metal nanocomposite synthesis as potential antifungal agent
- 2024
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Ingår i: Journal of Drug Delivery Science and Technology. - : Elsevier. - 1773-2247. ; 98
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Tidskriftsartikel (refereegranskat)abstract
- Oleaginous yeast lipid derived fatty acid methyl esters (FAMEs) are renowned for their exceptional potential towards bioenergy production specially in biodiesel domain. FAME application in other realms of biotechnology including nanotechnology (offer large possibilities for industry and contemporary science) has hitherto remained unexplored. Present study has investigated the novel use of FAME as biogenic capping agents to synthesize amphotericin B loaded CuO-CT (CT: chitosan) nanocomposites. The utilization of FAME-modified formulation (CuO-CTY@.L.F-AmpB) is evident in providing steric stability, as indicated by various physiochemical characterization techniques, accompanied by a low polydispersity index 0.24 ± 0.06 and a partial negative surface charge. Additional insights from HRTEM reveal a nanocarrier with a rod-shaped morphology, featuring 40–50 nm length and a 5–6 nm diameter. Amphotericin B release from CuO-CT@Y.L.F-AmpB followed a sustained pattern for up to 100 h, suggested FAME coating facilitated the drug release for a longer time duration. FAME stabilization has improved antibiofilm activity against Candida albicans (BEC50: 15 μg/mL) evinced by multitude assays that were found concordant with each other. A comprehensive FAME profiling conducted through GC-MS unveiled the predominance of oleic (84.02 ± 0.30 %) and palmitic acid methyl esters (9.40 ± 0.15 %) in the sample. This observation identifies them as concealed factors contributing to the stability of the nanocomposite. Conclusively, present study stipulated FAME as an efficient capping agent where it impart stability as well as efficacy to the nanocarrier. Moreover, current research work opens an innovative path for biorefinery approach integrating simultaneous production of lipid and multiphase nano-material synthesis, vital for a sustainable and circular bio-economy.
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| 4. |
- Sartaj, Km, et al.
(författare)
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Detailed mechanistic investigation of stress-induced lipogenesis in oleaginous yeast for value-added metabolites
- 2023
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 471
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, a marine red yeast Rhodotorula glutinis ISO A1 cultivated under combinations of artificial seawater (ASW) and sewage wastewater (SWW) has been subjected to detailed mechanistic investigations via physiological and biochemical analysis to dissect the pathway of halotolerance behavior and carbon flux channelization towards enhanced lipid synthesis. Amid all tested groups (25–100% ASW), cells grown in 25% ASW yielded ∼ 1.4-fold higher lipid yield than glucose synthetic medium (GSM) and revealed metabolic rewiring of cells to channelize carbon pools for producing neutral lipids of vehicular quality. Detailed carbohydrate profiling showed enhanced glycerol, trehalose, mannose, and xylitol/arabitol under saline stress, suggesting the interplay of these metabolites to impart tolerance against osmotic imbalance. Further, the strengthened enzymatic activity (glutathione reductase, superoxide dismutase, ascorbate peroxidase) and non-enzymatic metabolites (betaine, proline) highlighted the active yeast defence network to counter altered redox state arise due to high salinity. The stress-induced responses also constituted substantial variations in membrane fluidity and production of biodiesel-quality lipids. Further findings like low thermal degradation temperature (at ∼ 265°C) and high chitin (can be converted into chitosan) entity in yeast de-oiled biomass primarily derived from yeast cells grown under contaminated environment; sea and sewage wastewater, signified its potential utilization for chitosan recovery, a commercially important product. Conclusively, this study elucidated a competent model of yeast-based biorefinery approach integrating seawater-wastewater utilization and simultaneous production of biodiesel and value-added products vital for a sustainable and circular bioeconomy.
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| 5. |
- Sartaj, Km, et al.
(författare)
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Photo-induced biomitigation of sewage wastewater by new isolate of Rhodotorula glutinis ISO A1–lipid augmentation and profiling
- 2022
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Ingår i: Renewable energy. - : Elsevier. - 0960-1481 .- 1879-0682. ; 195, s. 742-754
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Tidskriftsartikel (refereegranskat)abstract
- Development of efficient wastewater treatment technologies along with circular economic approaches are the most imperative biotechnological attention presently. Thus, to add more value in this process, current study accessed a novel oleaginous yeast strain, R. glutinis ISO A1 for its biodegrading potential in sewage wastewater encompassing toxic formulations. To achieve improved performance light irradiance of various intensities (50 lux–150 lux) was applied during the cultivation period as an abiotic stress factor. All irradiances significantly stimulated nutrient removal efficiency of R. glutinis and improved growth rate but intracellular accumulation of carotenoids was found slightly inhibited. Boosted lipogenesis (lipid content ⁓40.66%) along with phenomenal reduction in COD (88.33 ± 1.88%), nitrate (73.2 ± 3.95%) and phosphate (85.1 ± 2.97%) was monitored with an optimum exposure condition at 100 lux. Cultures illuminated with light (50 lux–150 lux) also showed excellent tolerance for multiple heavy metals (Zn, Cd, Cr) and exhibited their complete removal. Further, analysis of fatty acid methyl esters (FAME) presented an increase in saturated fatty acids that reveal modulations in R. glutinis's membrane fluidity against stress generated due to the light exposure. Besides, estimated biodiesel properties of obtained FAME complying European and American fuel standards. These findings shed new light on the factors affecting wastewater bioremediation and successfully established a photo-induced biological treatment system in an oleaginous yeast for the very first time with an addition to successive lipid enhancement.
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| 6. |
- Sartaj, Km, et al.
(författare)
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Transforming recalcitrant wastes into biodiesel by oleaginous yeast: An insight into the metabolic pathways and multi-omics landscape
- 2023
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 474
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Forskningsöversikt (refereegranskat)abstract
- The escalating challenge of waste disposal and the potential threat to global energy supply have sparked renewed interest in repurposing waste materials for the production of sustainable and renewable fuels. In line with this objective, there has been a growing focus on biodiesel production from oleaginous yeast through the valorization of waste. While numerous reports have been published on this subject, only a limited number of studies provide a comprehensive overview of recent advancements. To address this gap and the economic viability challenges associated with yeast-derived biodiesel production, the present review aims to highlight the opportunities offered by various recalcitrant wastes as a renewable feedstock for oleaginous yeast cultivation. The review also delves into extensive knowledge about the metabolic pathways that facilitate the conversion of different recalcitrant wastes into single-cell oil (SCO), which has not been extensively covered in a single platform before. Moreover, the most promising species of oleaginous yeast are described, taking into consideration economic aspects and the sustainability of the overall process. Furthermore, the review emphasizes the application of omics techniques to advance waste bioconversion into lipids for the purpose of commercialization. In summary, this study contributes to expanding our current understanding of the topic and facilitates the future upscaling and commercialization of biodiesel derived from oleaginous yeasts.
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| 7. |
- Sartaj, Km, et al.
(författare)
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Unravelling Metagenomics Approach for Microbial Biofuel Production
- 2022
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Ingår i: Genes. - : MDPI. - 2073-4425. ; 13:11
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Forskningsöversikt (refereegranskat)abstract
- Renewable biofuels, such as biodiesel, bioethanol, and biobutanol, serve as long-term solutions to fossil fuel depletion. A sustainable approach feedstock for their production is plant biomass, which is degraded to sugars with the aid of microbes-derived enzymes, followed by microbial conversion of those sugars to biofuels. Considering their global demand, additional efforts have been made for their large-scale production, which is ultimately leading breakthrough research in biomass energy. Metagenomics is a powerful tool allowing for functional gene analysis and new enzyme discovery. Thus, the present article summarizes the revolutionary advances of metagenomics in the biofuel industry and enlightens the importance of unexplored habitats for novel gene or enzyme mining. Moreover, it also accentuates metagenomics potentials to explore uncultivable microbiomes as well as enzymes associated with them.
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