scholarly journals Improving the co-production of triacylglycerol and isoprenoids in Chlamydomonas

2020 ◽  
Vol 7 (4) ◽  
pp. 1235-1244
Author(s):  
Supakorn Potijun ◽  
Suparat Jaingam ◽  
Nuttha Sanevas ◽  
Srunya Vajrodaya ◽  
Anchalee Sirikhachornkit

Biodiesel and natural products derived from microalgae require a smaller land area and have higher production rates compared to plants and animals and has recently attracted considerable interest. However, biodiesel production from microalgal triacylglycerol is still far from commercial realization due to its high production cost. One way to overcome this obstacle is to improve the triacylglycerol accumulation and couple its production with other high-value compounds. Of particular interest is the sterol biosynthetic pathway with squalene as an intermediate due to its close relationship with triacylglycerol and carotenoid biosynthetic pathways. Besides, both squalene and carotenoids are isoprenoid lipids that have health benefits. Perturbation of one pathway has been suggested to affect other pathways. Three terbinafine-sensitive mutants of the green microalga Chlamydomonas reinhardtii were isolated using terbinafine, a drug that inhibits squalene epoxidase, leading to squalene accumulation. One of the mutants, tfs2, accumulated twice the amount of wild-type triacylglycerol. As well as squalene accumulation, the presence of terbinafine further increased the triacylglycerol content. The level of prenyl lipid carotenoid and chlorophyll was also more significant than that of the wild type. Growth and photosynthesis were not compromised in this mutant. This is the first study that has demonstrated a mutant screening method to improve the co-production of TAG and isoprenoid lipids in a green microalgae.

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2449
Author(s):  
Lauren Girard ◽  
Kithsiri Herath ◽  
Hernando Escobar ◽  
Renate Reimschuessel ◽  
Olgica Ceric ◽  
...  

The U.S. Food and Drug Administration’s (FDA′s) Center for Veterinary Medicine (CVM) has been investigating reports of pets becoming ill after consuming jerky pet treats since 2007. Renal failure accounted for 30% of reported cases. Jerky pet treats contain glycerin, which can be made from vegetable oil or as a byproduct of biodiesel production. Glycidyl esters (GEs) and 3-monochloropropanediol esters (3-MCPDEs) are food contaminants that can form in glycerin during the refining process. 3-MCPDEs and GEs pose food safety concerns, as they can release free 3-MCPD and glycidol in vivo. Evidence from studies in animals shows that 3-MCPDEs are potential toxins with kidneys as their main target. As renal failure accounted for 30% of reported pet illnesses after the consumption of jerky pet treats containing glycerin, there is a need to develop a screening method to detect 3-MCPDEs and GEs in glycerin. We describe the development of an ultra-high-pressure liquid chromatography/quadrupole time-of-flight (UHPLC/Q-TOF) method for screening glycerin for MCPDEs and GEs. Glycerin was extracted and directly analyzed without a solid-phase extraction procedure. An exact mass database, developed in-house, of MCPDEs and GEs formed with common fatty acids was used in the screening.


2021 ◽  
Vol 3 (1) ◽  
pp. 19-36
Author(s):  
Tamás Mizik ◽  
Gábor Gyarmati

As Earth’s fossil energy resources are limited, there is a growing need for renewable resources such as biodiesel. That is the reason why the social, economic and environmental impacts of biofuels became an important research topic in the last decade. Depleted stocks of crude oil and the significant level of environmental pollution encourage researchers and professionals to seek and find solutions. The study aims to analyze the economic and sustainability issues of biodiesel production by a systematic literature review. During this process, 53 relevant studies were analyzed out of 13,069 identified articles. Every study agrees that there are several concerns about the first-generation technology; however, further generations cannot be price-competitive at this moment due to the immature technology and high production costs. However, there are promising alternatives, such as wastewater-based microalgae with up to 70% oil content, fat, oils and grease (FOG), when production cost is below 799 USD/gallon, and municipal solid waste-volatile fatty acids technology, where the raw material is free. Proper management of the co-products (mainly glycerol) is essential, especially at the currently low petroleum prices (0.29 USD/L), which can only be handled by the biorefineries. Sustainability is sometimes translated as cost efficiency, but the complex interpretation is becoming more common. Common elements of sustainability are environmental and social, as well as economic, issues.


2021 ◽  
pp. 107754632098820
Author(s):  
Bashir B Muhammad ◽  
Muhammad Bashir ◽  
Mukhtar F Hamza ◽  
Mustapha Abdulhadi ◽  
Muhammad A Shehu ◽  
...  

A chatter mark is a result of irregular vibration that affects the milling process, which results in poor surface finish, reduced work quality, machine impairment, and high production cost. This work presents an active feedback controller design using a new response matrix to suppress the free vibration in the milling process. The proposed controller considers feed rate, tooth passing frequency, and time-varying dynamic milling force coefficients. A milling experiment verifies the effect of the proposed method. The method provides a reliable way of tackling chatter vibration in an industrial process. The procedure is technically and economically beneficial.


2019 ◽  
Vol 11 (8) ◽  
pp. 248
Author(s):  
Francirose Shigaki ◽  
Ludhanna Marinho Veras ◽  
Elane Tyara de Jesus Siqueira ◽  
José Roberto Brito Freitas ◽  
Mayanna Karlla Lima Costa ◽  
...  

Part of the energy consumed in the world comes from limited sources, which eventually are expected to be depleted. The search for alternative sources to meet energy needs is crucial. Biodiesel derived from vegetable oils and animal fats stands out as a biodegradable and renewable alternative source of energy. Sunflower is among the top four oil crops produced worldwide, and Brazil has a high production potential for this crop. This study aimed to identify the sunflower genotypes with the highest potential for biodiesel production in the Pre-amazon region of Brazil, where the advance of agricultural frontier represents an important role on biodiesel production. This study was conducted over 2 years of observations. The following genotypes were used: M734 (T), Helio358, EMBRAPA 122, and BRS G 35. The following parameters were assessed: initial flowering date (IFD), physiological maturity date (PMD), plant height (PH), grain yield (YIELD), thousand achene weight (TAW), and oil content (%OC). The climatic conditions of each experimental period were distinctive and directly affected the results obtained. The genotype Embrapa 122 showed the best performance regarding yield and was recommended for the pre-Amazon region of Brazil as the best adapted genotype to the local environmental conditions.


2021 ◽  
Vol 47 (2) ◽  
pp. 66-70
Author(s):  
Atınç Pırtı

Post-processing kinematics (PPK) is positioning process in which signals received from a mobile receiving device store location data can be adjusted using corrections from a reference station after data has been collected. The processed kinematic screening method provides the surveyor with a technique for high production survey measurements and can be used in areas with minimal satellite barriers. PPK uses significantly reduced observation times compared to static or fast static observations. This method requires least squares adjustment or another multiple basic statistical analysis that can produce a weighted average of observations. The results obtained using PPK are between 1 cm and 3 cm for horizontal coordinates and from 1 cm to 10 cm for vertical coordinates.


2021 ◽  
Vol 58 (4) ◽  
pp. 246-258
Author(s):  
Jayata Mawani ◽  
Jagruti Jadhav ◽  
Amit Pratap

Abstract Mannosylerythritol lipids are glycolipid biosurfactants with promising industrial applications. However, their commercial production is hindered due to its high production cost. The current study investigates the use of sweetwater, a by-product of the fat-splitting industry in combination with soybean oil for the production of mannosylerythritol lipids using Pseudozyma antarctica (MTCC 2706). The optimum sweetwater and soybean oil concentration of 22% and 7% (w/v) yielded 7.52 g L–1and 21.5 g L–1 mannosylerythritol lipids at shake flask and fermenter level respectively. The structure and functional groups of mannosylerythritol lipids were confirmed by fourier transform infrared (FTIR) spectroscopy, liquid chromatography-mass spectrometry (LC/MS) and 1H- and 13C-nuclear magnetic resonance (NMR) analysis. Surfactant properties, such as surface tension, critical micelle concentration, foaming and emulsification of mannosylerythritol lipids were also explored.


2011 ◽  
Vol 63 (2) ◽  
pp. 151-157 ◽  
Author(s):  
Virginia A. Herrera-Valencia ◽  
Patricia Y. Contreras-Pool ◽  
Silvia J. López-Adrián ◽  
Santy Peraza-Echeverría ◽  
Luis F. Barahona-Pérez

Microbiology ◽  
2006 ◽  
Vol 152 (7) ◽  
pp. 2003-2012 ◽  
Author(s):  
Verena Seidl ◽  
Irina S. Druzhinina ◽  
Christian P. Kubicek

To identify carbon sources that trigger β-N-acetylglucosaminidase (NAGase) formation in Hypocrea atroviridis (anamorph Trichoderma atroviride), a screening system was designed that consists of a combination of Biolog Phenotype MicroArray plates, which contain 95 different carbon sources, and specific enzyme activity measurements using a chromogenic substrate. The results revealed growth-dependent kinetics of NAGase formation and it was shown that NAGase activities were enhanced on carbon sources sharing certain structural properties, especially on α-glucans (e.g. glycogen, dextrin and maltotriose) and oligosaccharides containing galactose. Enzyme activities were assessed in the wild-type and a H. atroviridis Δnag1 strain to investigate the influence of the two NAGases, Nag1 and Nag2, on total NAGase activity. Reduction of NAGase levels in the Δnag1 strain in comparison to the wild-type was strongly carbon-source and growth-phase dependent, indicating the distinct physiological roles of the two proteins. The transcript abundance of nag1 and nag2 was increased on carbon sources with elevated NAGase activity, indicating transcriptional regulation of these genes. The screening method for the identification of carbon sources that induce enzymes or a gene of interest, as presented in this paper, can be adapted for other purposes if appropriate enzyme or reporter assays are available.


2019 ◽  
Vol 37 (1_suppl) ◽  
pp. 73-82 ◽  
Author(s):  
Marco Limburg ◽  
Jan Stockschläder ◽  
Peter Quicker

The increasing use of carbon fibre reinforced polymers requires suitable disposing and recycling options, the latter being especially attractive due to the high production cost of the material. Reclaiming the fibres from their polymer matrix however is not without challenges. Pyrolysis leads to a decay of the polymer matrix but may also leave solid carbon residues on the fibre. These residues prevent fibre sizing and thereby reuse in new materials. In state of the art, these residues are removed via thermal treatment in oxygen containing atmospheres. This however may damage the fibre’s tensile strength. Within the scope of this work, carbon dioxide and water vapour were used to remove the carbon residues. This aims to eliminate or at least minimize fibre damage. Improved quality of reclaimed fibres can make fibre reuse more desirable by enabling the production of high-quality recycling products. Still, even under ideal recycling conditions the fibres will shorten with every new life-cycle due to production-based blending. Fibre disposal pathways will therefore always also be necessary. The problems of thermal fibre disintegration are summarized in the second part of this article (Part 2: Energy recovery).


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