Enhanced growth and lipid production in psychrotolerant Acutodesmus by controlling temperature-dependent nitrogen concentration

2019 ◽  
Vol 127 ◽  
pp. 105267 ◽  
Author(s):  
Nakyeong Lee ◽  
Hyung-Seok Oh ◽  
Hee-Mock Oh ◽  
Hee-Sik Kim ◽  
Chi-Yong Ahn
Keyword(s):  
Nitrogen Concentration ◽  
Lipid Production ◽  
Temperature Dependent

scholarly journals A Mathematical Model of Neutral Lipid Content in terms of Initial Nitrogen Concentration and Validation in Coelastrum sp. HA-1 and Application in Chlorella sorokiniana

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Zhenhua Yang ◽  
Yue Zhao ◽  
Zhiyong Liu ◽  
Chenfeng Liu ◽  
Zhipeng Hu ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Lipid Content ◽  
Lipid Accumulation ◽  
Nitrogen Concentration ◽  
Lipid Production ◽  
Lipid Synthesis ◽  
Quantitative Relationship ◽  
Chlorella Sorokiniana ◽  
High Lipid ◽  
Nitrogen Concentrations

Microalgae are considered to be a potential major biomass feedstock for biofuel due to their high lipid content. However, no correlation equations as a function of initial nitrogen concentration for lipid accumulation have been developed for simplicity to predict lipid production and optimize the lipid production process. In this study, a lipid accumulation model was developed with simple parameters based on the assumption protein synthesis shift to lipid synthesis by a linear function of nitrogen quota. The model predictions fitted well for the growth, lipid content, and nitrogen consumption of Coelastrum sp. HA-1 under various initial nitrogen concentrations. Then the model was applied successfully in Chlorella sorokiniana to predict the lipid content with different light intensities. The quantitative relationship between initial nitrogen concentrations and the final lipid content with sensitivity analysis of the model were also discussed. Based on the model results, the conversion efficiency from protein synthesis to lipid synthesis is higher and higher in microalgae metabolism process as nitrogen decreases; however, the carbohydrate composition content remains basically unchanged neither in HA-1 nor in C. sorokiniana.

scholarly journals Repeated Batch Fermentation Biotechnology for the Biosynthesis of Lipid and Gamma-Linolenic Acid byCunninghamella bainieri2A1

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Marjan Ganjali Dashti ◽  
Peyman Abdeshahian ◽  
Wan Mohtar Wan Yusoff ◽  
Mohd Sahaid Kalil ◽  
Aidil Abdul Hamid
Keyword(s):  
Linolenic Acid ◽  
Glucose Concentration ◽  
Batch Fermentation ◽  
Nitrogen Concentration ◽  
Lipid Production ◽  
Ammonium Tartrate ◽  
Gamma Linolenic Acid ◽  
Harvesting Time ◽  
Repeated Batch Fermentation ◽  
Repeated Batch

The biosynthesis of biomedical products including lipid and gamma-linolenic acid (GLA) byCunninghamella bainieri2A1 was studied in repeated batch fermentation. Three key process variables, namely, glucose concentration, ammonium tartrate concentration, and harvesting time, were optimized using response surface methodology. Repeated batch fermentation was carried out by the cultivation ofCunninghamella bainieri2A1 in nitrogen-limited medium with various nitrogen concentration (1–4 g/L) and glucose concentration (20–40 g/L) at three time intervals (12 h, 24 h, and 48 h). Experimental results showed that the highest lipid concentration of 6.2 g/L and the highest GLA concentration of 0.4 g/L were obtained in optimum conditions, where 20.2 g/L glucose, 2.12 g/L ammonium tartrate, and 48 h harvesting time were utilized. Statistical results showed that the interaction between glucose and ammonium tartrate concentration had highly significant effects on lipid and GLA biosynthesis (P<0.01). Moreover, harvesting time had a significant interaction effect with glucose and ammonium tartrate concentration on lipid production (P<0.05).

Mixotrophic Cultivation of an Algae-Bacteria Consortium in Aluminium Smelter Wastewaters (Quebec, Canada): High Nitrogen Concentration Increases Overall Lipid Production

2017 ◽  
Vol 13 (5) ◽  
pp. 260-269 ◽  
Author(s):  
Nathalie Bourdeau ◽  
Frédérique Bélanger-Lépine ◽  
Kokou Adjallé ◽  
Nathalie Dubois-Caléro ◽  
Rachel Dosnon-Olette ◽  
...  
Keyword(s):  
Nitrogen Concentration ◽  
Lipid Production ◽  
Mixotrophic Cultivation ◽  
High Nitrogen ◽  
Aluminium Smelter ◽  
High Nitrogen Concentration

Electrical Measurement of the Vanadium Acceptor Level in 4H- and 6H-SiC

2006 ◽  
Vol 911 ◽  
Author(s):  
William C Mitchel ◽  
William D. Mitchell ◽  
H. E. Smith ◽  
M. E. Zvanut ◽  
Wonwoo Lee
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Nitrogen Concentration ◽  
Local Strain ◽  
Electrical Measurement ◽  
Acceptor Level ◽  
Temperature Dependent ◽  
Paramagnetic Resonance ◽  
Ionization Energies ◽  
Electron Paramagnetic ◽  
Secondary Ion

AbstractTemperature dependent Hall effect, Fourier transform infrared absorption, and electron paramagnetic resonance (EPR) studies have been performed on both 6H and 4H vanadium doped semi-insulating SiC samples grown by the physical vapor transport technique. Nitrogen and boron concentrations have been measured in some samples by secondary ion mass spectrometry (SIMS). Unlike undoped s.i. SiC, where several different thermal ionization energies have been observed, the ionization energies for all of the vanadium doped s.i. samples studied here were found to cluster around only two values for the two polytypes, EC – 0.85 eV and EC – 1.54 eV for 6H and EC – 1.11 eV and EC – 1.57 eV for 4H. SIMS measurements indicate that the nitrogen concentration exceeds the boron concentration in samples with the shallower of two values while the opposite is true for the deeper level samples. EPR detected both V3+ and V4+ in shallower level samples while only V4+ was detected in the deeper level samples. These results indicate that the vanadium acceptor level, V3+/4+, is located at EC – 0.85 eV in 6H-SiC and EC – 1.11 eV in 4H-SiC. However, some EPR results do show a small, unexpected asymmetry in the angular dependence of the V4+ signal, most noticeably in the 4H samples. This suggests that at least some of the vanadium related levels might be complexed with another defect or be under higher local strain than expected.

scholarly journals Variation of salinity and nitrogen concentration affects the pentacyclic triterpenoid inventory of the haloalkaliphilic aerobic methanotrophic bacterium Methylotuvimicrobium alcaliphilum

Extremophiles ◽  
2021 ◽  
Author(s):  
Alexmar Cordova-Gonzalez ◽  
Daniel Birgel ◽  
Andreas Kappler ◽  
Jörn Peckmann
Keyword(s):  
Nitrogen Concentration ◽  
Lipid Production ◽  
Environmental Parameters ◽  
Full Potential ◽  
Pentacyclic Triterpenoids ◽  
Cell Functions ◽  
Pentacyclic Triterpenoid ◽  
Nitrate Concentrations ◽  
Aerobic Methanotrophs ◽  
Bacterial Lipid

AbstractThe occurrence and activity of aerobic methanotrophs are influenced by environmental conditions, including pH, temperature, salinity, methane and oxygen concentrations, and nutrient availability. Aerobic methanotrophs synthesize a variety of lipids important for cell functions. However, culture-based experiments studying the influence of environmental parameters on lipid production by aerobic methanotrophs are scarce. Such information is crucial to interpret lipid patterns of methanotrophic bacteria in the environment. In this study, the alkaliphilic strain Methylotuvimicrobium alcaliphilum was cultivated under different salinities and different nitrate concentrations to assess the effect of changing conditions on the inventory of pentacyclic triterpenoids. The results indicate that hopanoid abundance is enhanced at lower salinity and higher nitrate concentration. The production of most pentacyclic triterpenoids was favored at low salinity, especially for aminotriol. Interestingly, 3-methyl-aminotetrol and tetrahymanol were favored at higher salinity. Bacteriohopanepolyols (BHPs), particularly aminotriol and 3-methyl-aminotriol, increased considerably at higher nitrate concentrations. Four novel N-containing BHPs—aminodiol, 3-methyl-aminodiol, and isomers of aminotriol and 3-methyl-aminotriol—were identified. This study highlights the significance of environmental factors for bacterial lipid production and documents the need for cultivation studies under variable conditions to utilize the full potential of the biomarker concept.

scholarly journals KERAGAMAN DAN KARAKTERISASI MIKROALGA DARI SUMBER AIR PANAS CIWALINI YANG BERPOTENSI SEBAGAI SUMBER BIODISEL

BIOSCIENTIAE ◽  
2018 ◽  
Vol 7 (2) ◽  
Author(s):  
Gunawan Gunawan
Keyword(s):  
Growth Rate ◽  
Light Intensity ◽  
Lipid Content ◽  
Diversity Index ◽  
Nitrogen Concentration ◽  
Lipid Production ◽  
Nile Red ◽  
Continuous Light ◽  
Maximum Growth ◽  
Culture Technique

The objectives of the research were to obtain specific microalgae that are able to produce high lipid, and to determine suitable culture technique for optimum growth and maximum lipid production. Microalgae were identified, isolated, selected and then grown on IMK medium at 27-29oC under continuous light irradiation for 24 hours.   The microalgae were then selected for lipid content using Nile Red. The selected microalgae were then grown under the same medium and condition as before followed by selection based on their growth rate. To find an appropriate medium for specific microalgae, the selected microalgae were then grown on various media such as BG11, Zarrouk, MBM, PHM and BBM media.  When a medium was selected, it was then used as the medium for the nitrogen source and light intensity experiments. Those selected microalgae from each location were cultured on the selected medium at different nitrogen concentration (0,5, 1 and 2 M) and different light intensities (35, 70 and 140 µmol photon/m2/sec).  The result showed that Ciwalini has diversity index (H) 2,21. Identification indicated that ciwalini species was Chlorophyta. In this research maximum growth rate was at 2 M  nitrogen consentratiom with 140 µmol photon/m2/sec light intensity. Lipid content ranged from 11,7% - 28%. The highest lipid content was occurred on media 0,5 M nitrogen consentration and 140 µmol photon/m2/sec light intensity. Lipid Productivity ranged from 0,070,18 g/l/day.

scholarly journals Two-Stage Fermentation of Lipomyces starkeyi for Production of Microbial Lipids and Biodiesel

2021 ◽  
Vol 9 (8) ◽  
pp. 1724
Author(s):  
Le Zhang ◽  
Ee Yang Lim ◽  
Kai-Chee Loh ◽  
Yanjun Dai ◽  
Yen Wah Tong
Keyword(s):  
Nitrogen Concentration ◽  
Lipid Production ◽  
Operating Cost ◽  
Total Carbon ◽  
Yeast Cells ◽  
Microbial Lipids ◽  
Lipomyces Starkeyi ◽  
Two Stage ◽  
One Stage ◽  
Significant Difference

The high operating cost is currently a limitation to industrialize microbial lipids production by the yeast Lipomyces starkeyi. To explore economic fermentation technology, the two-stage fermentation of Lipomyces starkeyi using yeast extract peptone dextrose (YPD) medium, orange peel (OP) hydrolysate medium, and their mixed medium were investigated for seven days by monitoring OD600 values, pH values, cell growth status, C/N ratios, total carbon concentration, total nitrogen concentration, residual sugar concentration, lipid content, lipid titer, and fatty acids profiles of lipids. The results showed that two-stage fermentation with YPD and 50% YPD + 50% OP medium contributed to lipid accumulation, leading to larger internal lipid droplets in the yeast cells. However, the cells in pure OP hydrolysate grew abnormally, showing skinny and angular shapes. Compared to the one-stage fermentation, the two-stage fermentation enhanced lipid contents by 18.5%, 27.1%, and 21.4% in the flasks with YPD medium, OP medium, and 50%YPD + 50%OP medium, and enhanced the lipid titer by 77.8%, 13.6%, and 63.0%, respectively. The microbial lipids obtained from both one-stage and two-stage fermentation showed no significant difference in fatty acid compositions, which were mainly dominated by palmitic acid (33.36–38.43%) and oleic acid (46.6–48.12%). Hence, a mixture of commercial medium and lignocellulosic biomass hydrolysate could be a promising option to balance the operating cost and lipid production.

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