472 research outputs found
Light enhanced the accumulation of total fatty acids (TFA) and docosahexaenoic acid (DHA) in a newly isolated heterotrophic microalga Crypthecodinium sp SUN
No full textIn the present study, light illumination was found to be efficient in elevating the total fatty acid content in a newly isolated heterotrophic microalga, Crypthecodinium sp. SUN. Under light illumination, the highest total fatty acid and DHA contents were achieved at 96 h as 24.9% of dry weight and 82.8 mg g (1) dry weight, respectively, which were equivalent to 1.46-fold and 1.68-fold of those under the dark conditions. The elevation of total fatty acid content was mainly contributed by an increase of neutral lipids at the expense of starches. Moreover, light was found to alter the cell metabolism and led to a higher specific growth rate, higher glucose consumption rate and lower non-motile cell percentage. This is the first report that light can promote the total fatty acids accumulation in Crypthecodinium without growth inhibition. (C) 2016 Elsevier Ltd. All rights reserved.National Research Foundation (NRF); Prime Minister's Office, Singapore under its Campus for Research Excellence and Technological Enterprise (CREATE) Programme [R-182-000-205-592]; 985 Project of Peking University; National Natural Science Foundation of China [31471717]SCI(E)ARTICLE227-23422
Simultaneous production of triacylglycerol and high-value carotenoids by the astaxanthin-producing oleaginous green microalga Chlorella zofingiensis
No full textThe production of lipids and astaxanthin, a high-value carotenoid, by Chlorella zofingiensis was investigated under different culture conditions. Comparative analysis revealed a good correlation between triacylglycerol (TAG) and astaxanthin accumulation in C. zofingiensis. Stress conditions promoted cell size and weight and induced the accumulation of neutral lipids, especially TAG and astaxanthin, with a concomitant decrease in membrane lipids. The highest contents of TAG and astaxanthin achieved were 387 and 4.89 mg g(-1) dry weight, respectively. A semi-continuous culture strategy was developed to optimize the TAG and astaxanthin productivities, which reached 297 and 3.3 mg L-1 day(-1), respectively. Additionally, astaxanthin accumulation was enhanced by inhibiting de novo fatty acid biosynthesis. In summary, our study represents a pioneering work of utilizing Chlorella for the integrated production of lipids and high-value products and C. zofingiensis has great potential to be a promising production strain and serve as an emerging oleaginous model alga. (C) 2016 Elsevier Ltd. All rights reserved.National Natural Science Foundation of China [31571807]; start-up grant from National Youth Thousand Talents Program; 985 Project of Peking UniversitySCI(E)[email protected]
Effects of pulsed electric field treatment on enhancing lipid recovery from the microalga, Scenedesmus
No full textabstract: Chloroform and methanol are superior solvents for lipid extraction from photosynthetic microorganisms, because they can overcome the resistance offered by the cell walls and membranes, but they are too toxic and expensive to use for large-scale fuel production. Biomass from the photosynthetic microalga Scenedesmus, subjected to a commercially available pre-treatment technology called Focused-Pulsed® (FP), yielded 3.1-fold more crude lipid and fatty acid methyl ester (FAME) after extraction with a range of solvents. FP treatment increased the FAME-to-crude-lipid ratio for all solvents, which means that the extraction of non-lipid materials was minimized, while the FAME profile itself was unchanged compared to the control. FP treatment also made it possible to use only a small proportion of chloroform and methanol, along with isopropanol, to obtain equivalent yields of lipid and FAME as with 100% chloroform plus methanol.NOTICE: this is the author's version of a work that was accepted for publication in BIORESOURCE TECHNOLOGY. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in BIORESOURCE TECHNOLOGY, 173, 457-461. DOI: 10.1016/j.biortech.2014.09.12
A Combined Activated Sludge Anaerobic Digestion Model (CASADM) to understand the role of anaerobic sludge recycling in wastewater treatment plant performance
No full textabstract: The Combined Activated Sludge-Anaerobic Digestion Model (CASADM) quantifies the effects of recycling anaerobic-digester (AD) sludge on the performance of a hybrid activated sludge (AS)-AD system. The model includes nitrification, denitrification, hydrolysis, fermentation, methanogenesis, and production/utilization of soluble microbial products and extracellular polymeric substances (EPS). A CASADM example shows that, while effluent COD and N are not changed much by hybrid operation, the hybrid system gives increased methane production in the AD and decreased sludge wasting, both caused mainly by a negative actual solids retention time in the hybrid AD. Increased retention of biomass and EPS allows for more hydrolysis and conversion to methane in the hybrid AD. However, fermenters and methanogens survive in the AS, allowing significant methane production in the settler and thickener of both systems, and AD sludge recycle makes methane formation greater in the hybrid system.“NOTICE: this is the author’s version of a work that was accepted for publication in Bioresource Technology. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Bioresource Technology, 136, 196-204. doi:10.1016/j.biortech.2013.02.090
Mixing effect on thermophilic anaerobic digestion of source-sorted organic fraction of municipal solid waste
No full textThis paper examines the effect of mixing on the performance of thermophilic anaerobic digestion of source-sorted organic fraction of municipal solid waste during the start-up phase and in the absence of an acclimated seed. For this purpose, two digesters were used under similar starting conditions and operated for 235days with different mixing schemes. While both digesters exhibited a successful startup with comparable specific methane yield of 0.327 and 0.314l CH 4-gVS, continuous slow stirring improved stability by reducing average VFA accumulation from 2890 to 825mg HAc-l, propionate content from 2073 to 488mg-l, and VFA-to-alkalinity ratio from 0.32 to 0.07. As a result, the startup with slow mixing was faster and smoother accomplishing a higher loading capacity of 2.5gVS-l-d in comparison to 1.9gVS-l-d for non-mixing. Mixing equally improved microbial abundance from 6.6 to 10gVSS-l and enhanced solids and soluble COD removal. © 2012 Elsevier Ltd.Angelidaki I, 2006, WATER RES, V40, P2621, DOI 10.1016-j.watres.2006.05.015; ANGELIDAKI I, 1993, BIOTECHNOL BIOENG, V42, P159, DOI 10.1002-bit.260420203; APHA AWWA WEF, 1998, STAND METH EX WAT WA; Banks CJ, 2008, WATER SCI TECHNOL, V58, P1475, DOI 10.2166-wst.2008.513; Bouskova A, 2005, WATER RES, V39, P1481, DOI 10.1016-j.watres.2004.12.042; Bridgeman J, 2012, ADV ENG SOFTW, V44, P54, DOI 10.1016-j.advengsoft.2011.05.037; Chelliapan S, 2011, DESALINATION, V271, P257, DOI 10.1016-j.desal.2010.12.045; Chen AC, 2003, BIOTECHNOL LETT, V25, P719, DOI 10.1023-A:1023458631699; Conklin AS, 2008, WATER RES, V42, P4895, DOI 10.1016-j.watres.2008.09.024; Elnekave M, 2006, FRESEN ENVIRON BULL, V15, P1098; Ferrer I, 2010, BIORESOURCE TECHNOL, V101, P2972, DOI 10.1016-j.biortech.2009.12.006; Gerardi M.H, 2003, MICROBIOLOGY ANAEROB; Gomez X, 2006, RENEW ENERG, V31, P2017, DOI 10.1016-j.renene.2005.09.029; Halalsheh M, 2011, BIORESOURCE TECHNOL, V102, P748, DOI 10.1016-j.biortech.2010.08.075; Hawkes FR, 2007, INT J HYDROGEN ENERG, V32, P172, DOI 10.1016-j.ijhydene.2006.08.014; Ike M, 2010, BIORESOURCE TECHNOL, V101, P3952, DOI 10.1016-j.biortech.2010.01.028; Kaparaju P, 2008, BIORESOURCE TECHNOL, V99, P4919, DOI 10.1016-j.biortech.2007.09.015; Karim K, 2005, WATER RES, V39, P3597, DOI 10.1016-j.watres.2005.06.019; Kim M, 2002, WATER RES, V36, P4369, DOI 10.1016-S0043-1354(02)00147-1; Kim SH, 2006, PROCESS BIOCHEM, V41, P199, DOI 10.1016-j.procbio.2005.06.013; Neumann L, 2011, BIORESOURCE TECHNOL, V102, P2931, DOI 10.1016-j.biortech.2010.11.068; Pandey PK, 2011, BIOMASS BIOENERG, V35, P2705, DOI 10.1016-j.biombioe.2011.03.017; Pavan P, 2000, WATER SCI TECHNOL, V41, P75; Penteado TZ, 2011, WATER SCI TECHNOL, V63, P995, DOI 10.2166-wst.2011.281; RIPLEY LE, 1986, J WATER POLLUT CON F, V58, P406; Sanchez E, 2005, BIORESOURCE TECHNOL, V96, P335, DOI 10.1016-j.biortech.2004.04.003; Steinberg LM, 2011, BIORESOURCE TECHNOL, V102, P8790, DOI 10.1016-j.biortech.2011.07.017; Stroot PG, 2001, WATER RES, V35, P1804, DOI 10.1016-S0043-1354(00)00439-5; Sung SW, 2003, CHEMOSPHERE, V53, P43, DOI 10.1016-S0045-6535(03)00434-X; Suwannoppadol S, 2011, BIORESOURCE TECHNOL, V102, P7762, DOI 10.1016-j.biortech.2011.06.008; Ward AJ, 2008, BIORESOURCE TECHNOL, V99, P7928, DOI 10.1016-j.biortech.2008.02.044; Wu SY, 2008, INT J HYDROGEN ENERG, V33, P1542, DOI 10.1016-j.ijhydene.2007.10.020; Zabranska J, 2002, WATER SCI TECHNOL, V46, P447; Zhang M.-L., 2009, WATER RES, V4, P1923; Zhang ZP, 2006, PROCESS BIOCHEM, V41, P2118, DOI 10.1016-j.procbio.2006.05.02112121
Unlocking sustainable solutions: Harnessing residual biomass from Colombia's non-centrifugal sugar chain for green market deployment
No full textGreen markets offer an alternative to bolster the economic and social dimensions of rural areas by valorizing surplus agroindustrial waste. This study aims to assess the environmental impacts of Panela, an agroindustrial crop with high relevance for the economies of Latin American and Asian countries. The Life Cycle Assessment (LCA) methodology revealed that producing 1 t of Non-centrifugal sugar results in a global warming potential of 0.262 t of CO2-eq. Additionally, the acidification potential, freshwater eutrophication, particulate matter, and photochemical oxidant formation were found to be 0.135 kg SO2-eq., 0.0081 kg P-eq. 0.020 kg PM2.5-eq., and 0.043 kg NOx-eq., respectively. A nutrient balance and bagasse combustion analysis were conducted, indicating that environmental impacts were reduced by 45 %. As a result of these impact abatements, the surplus residual biomass could potentially cover 1 % of the national urea demand in a decentralized scheme, thereby reducing dependency on imports from other countries. © 2024 The Author
White and red LEDs as two-phase batch for cyanobacterial pigments production
No full textCarotenoids and phycobiliproteins have a high economic value, due to their wide range of biological and industrial applications. The implementation of strategies to increase their production, such as the application of two-phase light cultivation systems, can stimulate pigments production, increasing economic turnover. In this sense, Cyanobium sp. was grown in seven different two-phase white/red cultivation arrangements, varying the time of each light from 0 to 21 days. Biomass, photosynthetic activity, pigments profile and antioxidant capacity were measured along time. Red light increased photosynthetic activity and pigments content (ca. 1.8-fold), and the use of a two-phase cultivation system generally raised bioactivity and production of phytochemicals. Among the studied, the optimal cultivation condition was found with 10 days of white followed by 4 days of red light. The optimized growth led to a productivity of 137.4 ± 0.8 mg L−1 d−1 of biomass, 17.0 ± 0.2 mg L−1 d−1 of total phycobiliproteins and 4.5 ± 0.2 mg L−1 d−1 of carotenoids. © 2020 Elsevier LtdA PhD fellowship [SFRH/BD/136767/2018] for author F.P. was granted by Fundação para a Ciência e Tecnologia (FCT, Portugal) under the auspices of Programa Operacional Capital Humano (POCH), supported by the European Social Fund and Portuguese funds (MECTES). This work was financially co-supported by the strategical funding from FCT UIDB/04423/2020 and UIDP/04423/2020 and the Atlantic Interreg Projects Enhance MicroAlgae - High added-value industrial opportunities for microalgae in the Atlantic Area [EAPA_338/2016] and BLUEHUMAN – BLUE biotechnology as a road for innovation on HUMAN’s health aiming smart growth in Atlantic Area [EAPA_151/ 2016]. The authors acknowledge the support and the use of resources of EMBRC-ERIC, specifically of the Portuguese infrastructure node of the European Marine Biological Resource Centre (EMBRC-PT) CIIMAR – PINFRA/22121/2016 – ALG-01-0145-FEDER-022121, financed by the European Regional Development Fund (ERDF) through COMPETE2020 - Operational Programme for Competitiveness and Internationalisation (POCI) and national funds through FCT/MCTES
Mitigation of greenhouse gas emissions from agricultural fields through bioresource management
No full textEfficient bioresource management can alter soil biochemistry and soil physical properties, leading to reduced greenhouse gas (GHG) emissions from agricultural fields. The objective of this study was to evaluate the role of organic amendments including biodigestate (BD), biochar (BC), and their combinations with inorganic fertilizer (IF) in increasing carbon sequestration potential and mitigation of GHG emissions from potato (Solanum tuberosum) fields. Six soil amendments including BD, BC, IF, and their combinations BDIF and BCIF, and control (C) were replicated four times under a completely randomized block design during the 2021 growing season of potatoes in Prince Edward Island, Canada. An LI-COR gas analyzer was used to monitor emissions of carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) from treatment plots. Analysis of variance (ANOVA) results depicted higher soil moisture-holding capacities in plots at relatively lower elevations and comparatively lesser volumetric moisture content in plots at higher elevations. Soil moisture was also impacted by soil temperature and rainfall events. There was a significant effect of events of data collection, i.e., the length of the growing season (p-value ≤ 0.05) on soil surface temperature, leading to increased GHG emissions during the summer months. ANOVA results also revealed that BD, BC, and BCIF significantly (p-value ≤ 0.05) sequestered more soil organic carbon than other treatments. The six experimental treatments and twelve data collection events had significant effects (p-value ≤ 0.05) on the emission of CO2. However, the BD plots had the least emissions of CO2 followed by BC plots, and the emissions increased with an increase in atmospheric/soil temperature. Results concluded that organic fertilizers and their combinations with inorganic fertilizers help to reduce the emissions from the agricultural soils and enhance environmental sustainability.Atlantic Canada Opportunities AgencyDepartment of Environment, Energy and Climate Action, Government of Prince Edward Islan
Staged cultivation enhances biomass accumulation in the green growth phase of Haematococcus pluvialis
No full textAn innovative staged cultivation (SC) method was proposed to overcome the limiting factors associated with the growth of Haematococcus pluvialis in the green growth phase. This strategy led to a 1.16-fold increase in biomass concentration. Light wavelength, nutrient concentration and extracellular metabolite were identified to be key limiting factors when cells of H. pluvialis were in the low, medium, and high cell density sub-phase, respectively. A mix of red and white light (2:1) was demonstrated for the first time to accelerate cell growth in the low cell density sub-phase. Shortage of nutrients during the medium density sub-phase was overcome with a fed-batch approach maintained at stable pH, while the inhibitory effect of extracellular metabolites during the high density sub-phase was overcome with replacement cultivation. The findings of the present study suggest SC in the green growth phase may be a promising approach to significantly enhance biomass accumulation in culturing microalgae. (C) 2017 Elsevier Ltd. All rights reserved.Public Science and Technology Research Funds Projects of Ocean [201505032]; National Natural Science Foundation of China [31471717]; Special National Key Research and Development Plan [2016YFD0400204]SCI(E)ARTICLE326-33123
Investigation of aqueous phase recycling for improving bio-crude oil yield in hydrothermal liquefaction of algae
No full textIn this study, the aqueous phase obtained from catalytic/non-catalytic hydrothermal liquefaction (HTL) of Chlorella vulgaris was recycled as the reaction medium with an aim to reduce water consumption and increase bio-crude oil yield. Although both Na2CO3 and HCOOH catalysts have been proven to be effective for promoting biomass conversion, the bio-crude oil yield obtained from HTL with Na2CO3 (11.5 wt%) was lower than that obtained from the non-catalytic HTL in pure water at 275 °C for 50 min. While, the HCOOH led to almost the same bio-crude yield from HTL (29.4 wt%). Interestingly, bio-crude oil yield obtained from non-catalytic or catalytic HTL in recycled aqueous phase was much higher than that obtained from HTL in pure water. Recycling aqueous phase obtained from catalytic HTL experiments resulted in a sharp increase in the bio-crude oil yield by 32.6 wt% (Na2CO3-HTL) and 16.1 wt% (HCOOH-HTL), respectively.BioFuelNet CanadaNetwork of Centres of ExcellenceNSER
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