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| 2. |
- Jakhwal, Parul, et al.
(författare)
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Nutrient removal and biomass production of marine microalgae cultured in recirculating aquaculture systems (RAS) water with low phosphate concentration
- 2024
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Ingår i: Journal of Environmental Management. - : Elsevier. - 0301-4797 .- 1095-8630. ; 358
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Tidskriftsartikel (refereegranskat)abstract
- This study was conducted to investigate the feasibility of microalgal biomass production and nutrient removal from recirculating aquaculture systems (RAS) water (RASW) with low phosphate concentration. For this purpose, Nannochloropsis oculata, Pavlova gyrans, Tetraselmis suecica, Phaeodactylum tricornutum, and their consortium were cultivated in RASW and RASW supplemented with vitamins (+V). Among them, N. oculata showed the maximum biomass production of 0.4 g/L in RASW. Vitamins supplementation significantly increased the growth of T. suecica from 0.16 g/L in RASW to 0.33 g/L in RASW + V. Additionally, T. suecica showed the highest nitrate (NO3–N) removal efficiency of 80.88 ± 2.08 % in RASW and 83.82 ± 2.08 % in RASW + V. Accordingly, T. suecica was selected for scaling up study of microalgal cultivation in RASW and RASW supplemented with nitrate (RASW + N) in 4-L airlift photobioreactors. Nitrate supplementation enhanced the growth of T. suecica up to 2.2-fold (day 15). The fatty acid nutritional indices in T. suecica cultivated in RASW and RASW + N showed optimal polyunsaturated fatty acids (PUFAs)/saturated fatty acid (SFAs), omega-6 fatty acid (n-6)/omega-3 fatty acid (n-3), indices of atherogenicity (IA), and thrombogenicity (IT)). Overall, the findings of this study revealed that despite low phosphate concentration, marine microalgae can grow in RASW and relatively reduce the concentration of nitrate. Furthermore, the microalgal biomass cultivated in RASW consisting of pigments and optimal fatty acid nutritional profile can be used as fish feed, thus contributing to a circular bioeconomy.
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| 3. |
- Mariam, Iqra, et al.
(författare)
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Ameliorating microalgal OMEGA production using omics platforms
- 2024
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Ingår i: Trends in Plant Science. - : Elsevier Ltd. - 1360-1385 .- 1878-4372.
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Forskningsöversikt (refereegranskat)abstract
- Over the past decade, the focus on omega (ω)-3 fatty acids from microalgae has intensified due to their diverse health benefits. Bioprocess optimization has notably increased ω-3 fatty acid yields, yet understanding of the genetic architecture and metabolic pathways of high-yielding strains remains limited. Leveraging genomics, transcriptomics, proteomics, and metabolomics tools can provide vital system-level insights into native ω-3 fatty acid-producing microalgae, further boosting production. In this review, we explore ‘omics’ studies uncovering alternative pathways for ω-3 fatty acid synthesis and genome-wide regulation in response to cultivation parameters. We also emphasize potential targets to fine-tune in order to enhance yield. Despite progress, an integrated omics platform is essential to overcome current bottlenecks in optimizing the process for ω-3 fatty acid production from microalgae, advancing this crucial field.
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| 4. |
- Mariam, Iqra, et al.
(författare)
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Transcriptomics aids in uncovering the metabolic shifts and molecular machinery of Schizochytrium limacinum during biotransformation of hydrophobic substrates to docosahexaenoic acid
- 2024
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Ingår i: Microbial Cell Factories. - : BioMed Central Ltd. - 1475-2859. ; 23:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Biotransformation of waste oil into value-added nutraceuticals provides a sustainable strategy. Thraustochytrids are heterotrophic marine protists and promising producers of omega (ω) fatty acids. Although the metabolic routes for the assimilation of hydrophilic carbon substrates such as glucose are known for these microbes, the mechanisms employed for the conversion of hydrophobic substrates are not well established. Here, thraustochytrid Schizochytrium limacinum SR21 was investigated for its ability to convert oils (commercial oils with varying fatty acid composition and waste cooking oil) into ω-3 fatty acid; docosahexaenoic acid (DHA).Results: Within 72 h SR21 consumed ~ 90% of the oils resulting in enhanced biomass (7.5 g L− 1) which was 2-fold higher as compared to glucose. Statistical analysis highlights C16 fatty acids as important precursors of DHA biosynthesis. Transcriptomic data indicated the upregulation of multiple lipases, predicted to possess signal peptides for secretory, membrane-anchored and cytoplasmic localization. Additionally, transcripts encoding for mitochondrial and peroxisomal β-oxidation along with acyl-carnitine transporters were abundant for oil substrates that allowed complete degradation of fatty acids to acetyl CoA. Further, low levels of oxidative biomarkers (H2O2, malondialdehyde) and antioxidants were determined for hydrophobic substrates, suggesting that SR21 efficiently mitigates the metabolic load and diverts the acetyl CoA towards energy generation and DHA accumulation.Conclusions: The findings of this study contribute to uncovering the route of assimilation of oil substrates by SR21. The thraustochytrid employs an intricate crosstalk among the extracellular and intracellular molecular machinery favoring energy generation. The conversion of hydrophobic substrates to DHA can be further improved using synthetic biology tools, thereby providing a unique platform for the sustainable recycling of waste oil substrates.
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| 5. |
- Patel, Alok, Dr. 1989-, et al.
(författare)
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A bioprocess engineering approach for the production of hydrocarbons and fatty acids from green microalga under high cobalt concentration as the feedstock of high-grade biofuels
- 2024
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Ingår i: Biotechnology for Biofuels and Bioproducts. - : Springer Nature. - 2731-3654. ; 17
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Tidskriftsartikel (refereegranskat)abstract
- Botryococcus braunii, a colonial green microalga which is well-known for its capacity to synthesize hydrocarbons, has significant promise as a long-term source of feedstock for the generation of biofuels. However, cultivating and scaling up B. braunii using conventional aqua-suspended cultivation systems remains a challenge. In this study, we optimized medium components and light intensity to enhance lipid and hydrocarbon production in a multi-cultivator airlift photobioreactor. BBM 3N medium with 200 μmol/m2/s light intensity and a 16 h light–8 h dark regimen yielded the highest biomass productivity (110.00 ± 2.88 mg/L/day), as well as the highest lipid and hydrocarbon content. Cultivation in a flat-panel bioreactor resulted in significantly higher biomass productivity (129.11 ± 2.74 mg/L/day), lipid productivity (32.21 ± 1.31 mg/L/day), and hydrocarbon productivity (28.98 ± 2.08 mg/L/day) compared to cultivation in Erlenmeyer flasks and open 20-L raceway pond. It also exhibited 20.15 ± 1.03% of protein content including elevated levels of chlorophyll a, chlorophyll b, and carotenoids. This work is noteworthy since it is the first to describe fatty acid and hydrocarbon profiles of B. braunii during cobalt treatment. The study demonstrated that high cobalt concentrations (up to 5 mg/L of cobalt nitrate) during Botryococcus culture affected hydrocarbon synthesis, resulting in high amounts of n-alkadienes and trienes as well as lipids with elevated monounsaturated fatty acids concentration. Furthermore, pyrolysis experiments on microalgal green biomass and de-oiled biomass revealed the lipid and hydrocarbon compounds generated by the thermal degradation of B. braunii that facilitate extra economical value to this system.
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| 6. |
- 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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| 8. |
- Wicker, Rebecca J., et al.
(författare)
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Production of biomethane, biohydrogen, and volatile fatty acids from Nordic phytoplankton biomass grown in blended wastewater
- 2024
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 479
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Tidskriftsartikel (refereegranskat)abstract
- Upgrading carbon-negative microalgal biomass to biofuels and value-added products presents a three-pronged solution for waste treatment, carbon capture, and economically viable bioenergy production. Acidogenesis and methanogenesis are versatile processes at the core of anaerobic digestion systems, facilitating the conversion of diverse biogenic substrates into energy and a wide range of biobased products. The present study was conducted to integrate acidogenesis and methanogenesis for coproduction of biohydrogen, biomethane, and volatile fatty acids from Nordic phytoplankton consortia. For this purpose, microalgal consortia was cultivated in a raceway pond equipped with high surface area structures. Harvested microalgal biomass was subjected to thermoalkaline (2% NaOH solution at 121 °C) and enzymatic (cellulase) pretreatments. The hydrolysates of the pretreated biomass were inoculated with thermally treated sludge for acidogenic fermentation and with mixture of untreated sludge and cow dung (1:1 v/v ratio) for anerobic digestion. The acidogenic process produced a significant amount of biohydrogen (maximum 164.8 mL bioH2/VSload) along with volatile fatty acids (maximum 7.9 g COD/L), while methanogenesis resulted in biomethane production of maximum 210.7 mL bioCH4/VSload, accompanied by an ammonium recovery of 1278 mg NH4+/L. These maximum yields were all achieved by enzymatic pretreatment of the biomass fraction harvested from high surface area brush head structures inserted in the raceway pond. These results have important implications for designing phytoplankton cultivation systems and upstream pathways to optimize energy production from carbon-negative phytoplankton biomass.
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