Precision Cultivation of Phaeodactylum tricornutum and Free Lipid Acid Analysis

2011 ◽  
Vol 354-355 ◽  
pp. 226-230
Author(s):  
Feng He ◽  
Peng Cheng Fu ◽  
Chun Ming Xu
Keyword(s):  
Fatty Acid ◽  
Phaeodactylum Tricornutum ◽  
Cell Concentration ◽  
Fatty Acid Content ◽  
Carbon Sources ◽  
Total Lipid Content ◽  
Biomass Accumulation ◽  
Dry Weight ◽  
Optimal Growth ◽  
Growth Conditions

Abstract：A field test was conducted on a photobioreactors for cultivaion of P. tricornutum for optimization cultivation conditions.Here,we use a flat-cuvette pohotobioreactor to control the irradiance, pH, gas composition combined with on-line monitoring by fluorometer and densitometer.By chosing the culture medium in containing glucose，sodium acetate and glycerol, to check for the biomass, cell concentration, biochemical substances and fatty acid content nearly three months . The results show that: Phaeodactylum tricornutum is not only photoautotroph but also mixotroph, which with selectivity for substance concentration and organic carbon sources, the optimum concentration of glucose is 20mmol/L, the optimal growth condition in 500mL flask contains that the temperature is 25±1°C, the light intensity is 50µmol/m2.s, the pH is 8.5. Whatever the carbon sources are able to promote the biomass accumulation. When the cell concentration achieve to 2.5×106 cells/mL in the end of the culture, analyzed total lipid content so as to determine the biomass accumulation and biomass variation in different growth conditions. By ultrasonic extracting and freeze drying, the total of lipid reaches 20%(dry weight); the main content of fatty acid is C16:0,C18:0,which is the better material for biodisel production.

The Spawning of Echinus Esculentus and Some Changes in Gonad Composition

1931 ◽  
Vol 8 (2) ◽  
pp. 133-150
Author(s):  
F. C. STOTT
Keyword(s):  
Fatty Acid ◽  
Acid Content ◽  
Fatty Acid Content ◽  
Dry Weight ◽  
Sea Temperature ◽  
Male And Female ◽  
Simultaneous Decrease ◽  
Post Spawning ◽  
Food Reserves ◽  
Inshore Migration

1. The spring inshore migration of Echinus at Port Erin in 1930 started in early February and reached its maximum in the middle of March. Mature gonads were found at the end of February and throughout March and early April. At the end of June all gonads examined were spent. The sea temperature throughout this period was observed. It is probable that May was the chief month in which natural spawning took place. 2. A cycle of changes in the composition of the gonad are recorded from November 1929 to July 1930. The chief of these are: (a) In the males an increase in percentage dry weight as the gonads mature ; the opposite taking place in the females. (b) A large and simultaneous decrease in percentage glycogen in both male and female gonads prior to spawning followed by a great post-spawning increase. The fatty acid content does not alter with the maturation of the gonad, but an indication is given that an increase in the percentage of carbohydrates other than glycogen occurs. Hence it is suggested that glycogen is transformed in the maturing gonad into carbohydrate food reserves for the ripe eggs and sperm.

The effect of dietary herring meal on the omega-3 fatty acid content of plasma and egg yolk lipids of laying hens

1995 ◽  
Vol 75 (2) ◽  
pp. 247-253 ◽  
Author(s):  
D. M. Nash ◽  
R. M. G. Hamilton ◽  
H. W. Hulan
Keyword(s):  
Fatty Acid ◽  
Acid Content ◽  
Plasma Lipids ◽  
Laying Hens ◽  
Control Diet ◽  
Fatty Acid Content ◽  
Total Lipid Content ◽  
Egg Yolk ◽  
Omega 3 ◽  
Omega 6

The effect of dietary HM on plasma and egg yolk lipids of commercial White Leghorn hens was studied over 350 d. A total of 192 birds were given corn-wheat-soybean meal diets that contained either 0, 4, 8, or 12% HM. Analysis of plasma lipids at four periods in the laying cycle (169, 211, 253 and 287 d) and at five times during the test day (0800, 1000, 1200, 1400 and 1600 h) were performed. Egg lipids were analyzed at each of the four periods.Plasma total lipids were inversely related (P < 0.01) to dietary HM levels while omega-3 and omega-6 fatty acid levels were positively and inversely related (P < 0.001), respectively. HM levels did not influence the total lipid content of the egg yolk lipids but omega-3 and omega-6 fatty acid content were positively and inversely related, respectively. The levels of eicosapentaenoic (20:5n3, EPA) and docosahexaenoic (22:6n3, DHA) acid were 11 and 3 times higher, respectively (7.8 and 100.5 mg yolk−1) in the yolks from hens given the 12% HM diet compared to the control diet. Key words: Herring meal, laying hens, omega-3 fatty acids, eicosapentaenoic acid, docosahexaenoic acid

scholarly journals Psychromonas boydii sp. nov., a gas-vacuolate, psychrophilic bacterium isolated from an Arctic sea-ice core

2010 ◽  
Vol 60 (1) ◽  
pp. 84-92 ◽  
Author(s):  
Ann J. Auman ◽  
Jennifer L. Breezee ◽  
John J. Gosink ◽  
Peter Schumann ◽  
Carmen R. Barnes ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Sea Ice ◽  
Fatty Acid Content ◽  
Ice Core ◽  
Carbon Sources ◽  
Distinct Species ◽  
Arctic Sea Ice ◽  
Rrna Gene ◽  
Psychrophilic Bacterium ◽  
Phenotypic Analysis

A gas-vacuolate bacterium, strain 174T, was isolated from a sea-ice core collected from Point Barrow, Alaska, USA. Comparative analysis of 16S rRNA gene sequences showed that this bacterium was most closely related to Psychromonas ingrahamii 37T, with a similarity of >99 %. However, strain 174T could be clearly distinguished from closely related species by DNA–DNA hybridization; relatedness values determined by two different methods between strain 174T and P. ingrahamii 37T were 58.4 and 55.7 % and those between strain 174T and Psychromonas antarctica DSM 10704T were 46.1 and 33.1 %, which are well below the 70 % level used to define a distinct species. Phenotypic analysis, including cell size (strain 174T is the largest member of the genus Psychromonas, with rod-shaped cells, 8–18 μm long), further differentiated strain 174T from other members of the genus Psychromonas. Strain 174T could be distinguished from its closest relative, P. ingrahamii, by its utilization of d-mannose and d-xylose as sole carbon sources, its ability to ferment myo-inositol and its inability to use fumarate and glycerol as sole carbon sources. In addition, strain 174T contained gas vacuoles of two distinct morphologies and grew at temperatures ranging from below 0 to 10 °C and its optimal NaCl concentration for growth was 3.5 %. The DNA G+C content was 40 mol%. Whole-cell fatty acid analysis showed that 16 : 1ω7c and 16 : 0 comprised 44.9 and 26.4 % of the total fatty acid content, respectively. The name Psychromonas boydii sp. nov. is proposed for this novel species, with strain 174T (=DSM 17665T =CCM 7498T) as the type strain.

scholarly journals Transcriptome, Biochemical and Growth Responses of the Marine Phytoplankter Phaeodactylum Tricornutum Bohlin (Bacillariophyta) to Copepod Grazer Presence

2018 ◽  
Vol 46 (3) ◽  
pp. 1091-1111 ◽  
Author(s):  
Si Li ◽  
Stefanie M.H. Ismar
Keyword(s):  
Fatty Acid ◽  
Phaeodactylum Tricornutum ◽  
Fatty Acid Biosynthesis ◽  
Fatty Acid Content ◽  
Model Organism ◽  
Cellular Responses ◽  
Pathogen Resistance ◽  
Nutritional Composition ◽  
Growth Responses ◽  
Transcriptomic Response

Background/Aims: As a model organism for a pleiomorphic marine planktonic primary producer, Phaeodactylum tricornutum has been studied on a molecular level under diverse cultural conditions. But little is known about its morphological, nutritional or transcriptomic responses under grazing stress. Methods: To assess microalgal molecular and cellular responses to grazer presence, we conducted transcriptome profiling in combination with growth rate, biovolume, fatty acid content, carbon and nitrogen content measurements in the model diatom Phaeodactylum tricornutum. RNA-sequencing was used to evaluate the transcriptomic response to grazing stress for P. tricornutum strain CCAP 1055/1. Results: Among the differentially expressed genes, we found down-regulation of genes involved in pathogen resistance, and in fatty acid biosynthesis pathways, while mitosis-involved genes were up-regulated. Experimentally testing morphological and biochemical responses in five strains of the species, we detected strain-specific significant effects of simulated grazing pressure in altered growth rates, biovolume and nutritional composition. Conclusion: Our research reveals the associated molecular and cellular responses to grazing effects in P. tricornutum and extends the understanding of co-evolutionary roles in regulating grazing defence between P. tricornutum and its grazer.

Effects of desiccation on temperate recalcitrant seeds: differential scanning calorimetry, gas chromatography, electron microscopy, and moisture studies on Quercusnigra and Quercusalba

1996 ◽  
Vol 26 (10) ◽  
pp. 1813-1821 ◽  
Author(s):  
K.F. Connor ◽  
F.T. Bonner ◽  
J.A. Vozzo
Keyword(s):  
Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Cell Wall ◽  
Fatty Acid ◽  
Moisture Content ◽  
Fatty Acid Content ◽  
Heat Content ◽  
Dry Weight ◽  
Scanning Calorimetry ◽  
Seed Moisture

Investigations into the nature of desiccation-sensitive, or recalcitant, seed behavior have as yet failed to identify exact causes of this phenomenon. Experiments with Quercusnigra L. and Quercusalba L. were conducted to examine physiological and biochemical changes brought about by seed desiccation and to determine if there were predictable changes in seed moisture content, in enthalpy (heat content) of seed moisture, in the lipid fraction, or in seed ultrastructure as viability declined. Quercusnigra intact acorn moisture contents at 50% and 5% viability were 15% and less than 14%, respectively; those of intact Q. alba at 50% and 0% viability were much higher, 32% and 22%, respectively. Generally, it was found that as the seeds of both species dried, the moisture content of the axes remained high (26–27%), even after 9 days of drying. In Q. nigra acorns, there was little difference in average percent moisture lost per day among axes, proximal cotyledon tissue, and distal cotyledon tissue. Quercusalba acorns, however, lost moisture more rapidly from the axes than from the cotyledons. This was probably caused by the longitudinal splitting of the pericarp during the drying process. Lipids composed 28.4% of the dry weight of Q. nigra and 5.7% of Q. alba dry weight. Neither individual fatty acids nor total fatty acid content exhibited definite patterns of change over the course of the experiment. The most prevalent saturated fatty acid in both species was palmitic acid, and the most common unsaturated fatty acid was generally oleic acid. Electron microscopy studies of Q. nigra showed cell wall trauma after 3 days of drying (moisture content 23%); by day 7, when moisture content had dropped to 15.6%, there was a definite dissolution of cytoplasmic density and a reduction of spherosome concentration. Quercusalba exhibited similar responses to drying, but cell wall integrity was maintained. Differential scanning calorimetry studies revealed strong relationships between onset and enthalpy values of all acorn tissues and percent germination, as did regressions involving moisture content and seed germination.

scholarly journals Isolation and Molecular Identification of Phenol Degrading Bacterium from Industrial Wastes, Collected from Jeddah Saudi Arabia

2021 ◽  
Vol 14 (4) ◽  
pp. 1992-2001
Author(s):  
Bothaina A. Alaidaroos
Keyword(s):  
Phenol Degradation ◽  
Carbon Sources ◽  
Dry Weight ◽  
Degradation Process ◽  
Industrial Area ◽  
Growth Conditions ◽  
Industrial Wastes ◽  
Aquatic Life ◽  
Environment And Health ◽  
Degrading Bacterium

In the past two decades, phenolic compounds have had different applications, however their use in densification has increased considerably due to Covid 19. Discharge of these dangerous materials is highly toxic and causes risk and severe problems to the environment and health of human and animals, in addition to it being harmful to the aquatic life. Phenol degradation is very important due to high toxicity and stability. The aim of this study is to isolate phenol-degrading aerobic bacteria from hydrocarbon contaminated soil or wastewater, collected from the industrial area of Jeddah. Minimal medium containing phenol as carbon source was used to isolate different bacteria. About 30 actinomycete isolates were obtained, purified and preserved on Starch nitrate. Out of 30 isolates, eight isolates (27%) grow well in medium containing 0.1% phenol. After growing in broth medium, isolate BA4 and isolate BA8 were very active in phenol degradation. Growth and phenol degradation was measured in liquid medium for the two isolates. Morphological and physiological characters of these isolates were detected using different methods. Using molecular methods, they were belonging to a genus of actinomycetes. They were identified as Streptomyces flavabus BA4 and Streptomyces sp. BA8.The effects of some growth factors on growth and phenol degradation were determined. Growth was measured by dry weight (mg/l) while phenol degradation was detected by assaying the residual phenol concentration. The presence of electron donors such as glucose, starch, glycine, peptone, and Na acetate affect both growth and phenol degradation. It was clear that addition of 1 g/l peptone enhanced both growth and phenol degradation. The isolate use phenol and its derivatives m-cresol and o-cresol as carbon sources and addition of vitamin B complex increased the bacterial growth. In conclusion, phenol degradation was detected by actinobacteria and was affected by some physical and biochemical factors. It was noticed that optimization of growth conditions enhanced both growth and phenol degradation by the two selected Streptomyces isolate. Degradation process by isolate BA4 could be a promising solution for removal of phenol from wastewater.

scholarly journals Insertion of Transposon Tn5tac1 in the Sinorhizobium meliloti Malate Dehydrogenase (mdh) Gene Results in Conditional Polar Effects on Downstream TCA Cycle Genes

2004 ◽  
Vol 17 (12) ◽  
pp. 1318-1327 ◽  
Author(s):  
Sergiy l. Dymov ◽  
David J. J. Meek ◽  
Blaire Steven ◽  
Brian T. Driscoll
Keyword(s):  
Malate Dehydrogenase ◽  
Sinorhizobium Meliloti ◽  
Tricarboxylic Acid Cycle ◽  
Root Nodules ◽  
Carbon Sources ◽  
Dry Weight ◽  
Tca Cycle ◽  
Growth Conditions ◽  
Oxoglutarate Dehydrogenase ◽  
Succinyl Coa Synthetase

To isolate Sinorhizobium meliloti mutants deficient in malate dehydrogenase (MDH) activity, random transposon Tn5tac1 insertion mutants were screened for conditional lethal phenotypes on complex medium. Tn5tac1 has an outward-oriented isopropyl-β-D-thiogalactopyranoside (IPTG)- inducible promoter (Ptac). The insertion in strain Rm30049 was mapped to the mdh gene, which was found to lie directly upstream of the genes encoding succinyl-CoA synthetase (sucCD) and 2-oxoglutarate dehydrogenase (sucAB and lpdA). Rm30049 required IPTG for wild-type growth in complex media, and had a complex growth phenotype in minimal media with different carbon sources. The mdh∷ Tn5tac1 insertion eliminated MDH activity under all growth conditions, and activities of succinyl-CoA synthetase, 2-oxoglutarate dehydrogenase, and succinate dehydrogenase were affected by the addition of IPTG. Reverse-transcriptase polymerase chain reaction (RT-PCR) studies confirmed that expression from Ptac was induced by IPTG and leaky in its absence. Alfalfa plants inoculated with Rm30049 were chlorotic and stunted, with small white root nodules, and had shoot dry weight and percent-N content values similar to those of uninoculated plants. Cosmid clone pDS15 restored MDH activity to Rm30049, complemented both the mutant growth and symbiotic phenotypes, and was found to carry six complete (sdhB, mdh, sucCDAB) and two partial (lpdA, sdhA) tricarboxylic acid cycle genes.

scholarly journals Heterologous Production of Dihomo-γ-Linolenic Acid in Saccharomyces cerevisiae

2007 ◽  
Vol 73 (21) ◽  
pp. 6965-6971 ◽  
Author(s):  
Hisashi Yazawa ◽  
Hitoshi Iwahashi ◽  
Yasushi Kamisaka ◽  
Kazuyoshi Kimura ◽  
Tsunehiro Aki ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Linolenic Acid ◽  
Acid Content ◽  
Kluyveromyces Lactis ◽  
Fatty Acid Content ◽  
Fatty Acid Desaturase ◽  
Dry Weight ◽  
Medium Composition

ABSTRACT To make dihomo-γ-linolenic acid (DGLA) (20:3n-6) in Saccharomyces cerevisiae, we introduced Kluyveromyces lactis Δ12 fatty acid desaturase, rat Δ6 fatty acid desaturase, and rat elongase genes. Because Fad2p is able to convert the endogenous oleic acid to linoleic acid, this allowed DGLA biosynthesis without the need to supply exogenous fatty acids on the media. Medium composition, cultivation temperature, and incubation time were examined to improve the yield of DGLA. Fatty acid content was increased by changing the medium from a standard synthetic dropout medium to a nitrogen-limited minimal medium (NSD). Production of DGLA was higher in the cells grown at 15�C than in those grown at 20�C, and no DGLA production was observed in the cells grown at 30�C. In NSD at 15�C, fatty acid content increased up until day 7 and decreased after day 10. When the cells were grown in NSD for 7 days at 15�C, the yield of DGLA reached 2.19 μg/mg of cells (dry weight) and the composition of DGLA to total fatty acids was 2.74%. To our knowledge, this is the first report describing the production of polyunsaturated fatty acids in S. cerevisiae without supplying the exogenous fatty acids.

Screening of fatty acid composition in Nitzschia sp.

2017 ◽  
Vol 42 (3) ◽  
Author(s):  
Zeliha Demirel ◽  
Esra Imamoglu ◽  
Meltem Conk Dalay
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Lipid Content ◽  
Palmitoleic Acid ◽  
Dry Weight ◽  
Monounsaturated Fatty Acids ◽  
Growth Conditions ◽  
Light Intensities ◽  
Main Target ◽  
Total Fatty Acids

AbstractIntroduction:The main target of this study was to compare the effects of nitrogen limitation and light intensities on cell growth, lipid content and fatty acid profile ofMethods:F/2 medium and N-free F/2 medium were both tested at two different light intensities of 11 and 56 μEmResults:The presence of nitrogen led to more cells grown efficiently. Furthermore, the increase in chlorophyll content went parallel to the increase in dry weight. The most abundant saturated and monounsaturated fatty acids were pentadecanoic acid (C15:0) and palmitoleic acid (C16:1) which constituted 17%–42% and 15%–48% of total fatty acids for all growth conditions, respectively. It was recorded that palmitoleic acid was present at higher concentrations than palmitic acid.Discussion and conclusion:The noteworthy finding was that the lipid content increased with increasing the growth rate of

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