Relationship of alcohol production to lipid composition of yeast in a continuous flow bioreactor

1990 ◽  
Vol 68 (3) ◽  
pp. 661-668 ◽  
Author(s):  
G. H. Gil ◽  
W. J. Jones ◽  
T. G. Tornabene
Keyword(s):  
Fatty Acids ◽  
Lipid Composition ◽  
Continuous Flow ◽  
Unsaturated Fatty Acids ◽  
Ethanol Concentration ◽  
Immobilized Cells ◽  
Yeast Cells ◽  
Immobilized Cell ◽  
Alcohol Production ◽  
Respiratory Deficient

Saccharomyces cerevisiae was cultivated in a controlled aerated, dual-stage (column), continuous flow bioreactor in a hybrid free-cell and immobilized-cell state. The yeast cells maintained an ethanol concentration of 58–64 and 91–98 g/L in stages I and II, respectively. The lipid composition of the cells cultivated under these conditions was correlated to the effects of aeration by interrupting the aeration on days 113 and 266 of continuous operation. Under conditions of aeration or nonaeration, an alternating increase and decrease in the contents of squalene, sterols, and fatty acids of the respiratory-competent and -deficient unattached free cells was observed. The cellular free lipid compositions of the immobilized cells in the aerated and nonaerated conditions were similar and characteristic of respiratory-deficient cells with the exception of the immobilized cells exposed to a higher ethanol concentration (stage II). These cells contained a broader range of sterol components and increased levels of unsaturated fatty acids than immobilized cells at a lower ethanol concentration (stage I). The neutral lipid to phospholipid ratio decreased for respiratory-deficient cells with phosphatidylethanolamine and phosphatidylinositol being the principal phospholipids. The data demonstrated the essentiality of the hybrid bioreactor design for continuous long term performance and the importance of maintaining specific yeast lipid constituents for continuous high alcohol productivity.Key words: yeast immobilization, lipids, fatty acids, sterols, phospholipids, continuous flow, aeration, ethanol.

Design of a continuous flow immobilized-cell reactor for biosynthetical production of L-aspartic acid

1985 ◽  
Vol 50 (10) ◽  
pp. 2122-2133 ◽  
Author(s):  
Jindřich Zahradník ◽  
Marie Fialová ◽  
Jan Škoda ◽  
Helena Škodová
Keyword(s):  
Aspartic Acid ◽  
Continuous Flow ◽  
Immobilized Cells ◽  
Scale Up ◽  
Fixed Bed ◽  
Packed Bed ◽  
Fixed Bed Reactor ◽  
Experimental Program ◽  
Design Parameters ◽  
Immobilized Cell

An experimental study was carried out aimed at establishing a data base for an optimum design of a continuous flow fixed-bed reactor for biotransformation of ammonium fumarate to L-aspartic acid catalyzed by immobilized cells of the strain Escherichia alcalescens dispar group. The experimental program included studies of the effect of reactor geometry, catalytic particle size, and packed bed arrangement on reactor hydrodynamics and on the rate of substrate conversion. An expression for the effective reaction rate was derived including the effect of mass transfer and conditions of the safe conversion-data scale-up were defined. Suggestions for the design of a pilot plant reactor (100 t/year) were formulated and decisive design parameters of such reactor were estimated for several variants of problem formulation.

Quantitative effects of unsaturated fatty acids in microbial mutants. VI. Selective growth responses of yeast and bacteria to cis-octadecenoate isomers

1976 ◽  
Vol 54 (8) ◽  
pp. 736-745 ◽  
Author(s):  
John B. Ohlrogge ◽  
Eugene D. Barber ◽  
William E. M. Lands ◽  
F. D. Gunstone ◽  
I. A. Ismail
Keyword(s):  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Ethylenic Bond ◽  
Yeast Cells ◽  
Nutritional Requirement ◽  
Bacterial Cells ◽  
Growth Responses ◽  
Cellular Lipids ◽  
Acyl Chains ◽  
Extensive Growth

The full series of positional isomers of cis-octadecenoate were tested for their suitability in meeting the nutritional requirement for unsaturated fatty acids by mutants of Escherichia coli and Saccharomyces cerevisiae that were unable to synthesize unsaturated fatty acids.Quantitative comparisons of the efficiencies of the various isomers showed a range from 0–48 cells per femtomole for the prokaryotic cells and 0–5 for eukaryotic cells. The Δ5 isomer was much more effective than the Δ6 isomer with the bacterial cells whereas the reverse was true with the yeast cells. In general, isomers containing a cis ethylenic bond between carbons 7 and 12 were able to support extensive growth of either type of mutant.Since all of the various isomers were incorporated into cellular lipids by both types of microorganism, the different efficiencies observed in supporting growth were not a simple reflection of the inability of an acid to be esterified. The differences may reflect the suitability of the resultant esterified product to function as a normal membrane lipid.The contents of various fatty acids in the cellular phospholipids when growth ceases may have a linearly cumulative relationship to the degree of expansion of the acyl chains.

Effect of unsaturated fatty acids on the lipid composition of bacteriophage PM2

Nature ◽  
1975 ◽  
Vol 253 (5487) ◽  
pp. 125-126 ◽  
Author(s):  
NORIHIRO TSUKAGOSHI ◽  
MARIANNE H. PETERSEN ◽  
RICHARD M. FRANKLIN
Keyword(s):  
Fatty Acids ◽  
Lipid Composition ◽  
Unsaturated Fatty Acids

scholarly journals The Changes in the Lipid Composition of Mung Bean Seeds as Affected by Processing Methods

2007 ◽  
Vol 3 (5) ◽  
Author(s):  
El-Sayed Ali Abdel-Rahman ◽  
Fawzy A El-Fishawy ◽  
Mohamed A El-Geddawy ◽  
Tomas Kurz ◽  
Mohamed N El-Rify
Keyword(s):  
Fatty Acids ◽  
Lipid Composition ◽  
Mung Bean ◽  
Unsaturated Fatty Acids ◽  
Essential Fatty Acids ◽  
Saturated Fatty Acids ◽  
Gas Liquid Chromatography ◽  
Lipid Fractions ◽  
Total Fatty Acids ◽  
Tlc Analysis

This study was conducted to assess in detail the possible effects of some technological processes such as soaking, germination, cooking, soaking + cooking, and germination + cooking on the lipid composition of mung bean seeds of Giza 1 variety. TLC analysis of mung bean lipids showed that the phospholipids and triglycerides recorded the highest percentage among lipid fractions (32.26 and 30.10%), while the 1,3 diglycerides constituted the least percentage (2.80%) in mung bean seeds. The soaking, germination and cooking processes caused a decrease in the phospholipids, triglycerides and hydrocarbons accompanied with an increase in monoglycerides, 1,2-(2,3)-diglycerides, sterols and free fatty acids. Eleven fractions were separated from phospholipids class of the studied samples; seven of these fractions were identified. The major component of phospholipids was phosphatidyl choline, amounting to 21.30, 17.84, 16.21, 13.87, 13.20 and 11.47% of the total phospholipids in raw, soaked, germinated, raw-cooked, soaked-cooked and germinated-cooked mung bean seeds, respectively. Gas liquid chromatography of the total lipids of mung bean seeds showed that the unsaturated fatty acids represented 69.58, 64.35, 63.3, 63.16, 61.84 and 61.12%, while the levels of saturated fatty acids were low being 30.37, 34.05, 35.66, 34.64, 37.93 and 38.75% of the total fatty acids in raw, soaked, germinated, raw-cooked, soaked-cooked and germinated-cooked, respectively. The total essential fatty acids (linoleic and linolenic) represented the highest proportion of fatty acids (50.10% of the total fatty acids).

scholarly journals Lipid Composition of Sheffersomyces stipitis M12 Strain Grown on Glycerol as a Carbon Source

2020 ◽  
Vol 58 (2) ◽  
pp. 203-213
Author(s):  
Stela Križanović ◽  
Damir Stanzer ◽  
Gordana Čanadi Jurešić ◽  
Elizabeta Kralj ◽  
Karla Hanousek-Čiča ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Lipid Metabolism ◽  
Carbon Source ◽  
Lipid Composition ◽  
Solid Phase ◽  
Neutral Lipids ◽  
Wild Strain ◽  
Yeast Cells ◽  
Sterol Esters ◽  
Ergosterol Synthesis

Research background. In this study the content and composition of lipids in ergosterol-reduced Sheffersomyces stipitis M12 strain grown on glycerol as a carbon source is determined. Blocking the ergosterol synthesis route in yeast cells is a recently proposed method for increasing S-adenosyl-L-methionine (SAM) production. Experimental approach. The batch cultivation of M12 yeast was carried out under aerobic conditions in a laboratory bioreactor with glycerol as carbon source, and with pulsed addition of methionine. Glycerol and SAM content were monitored by high-performance liquid chromatography, while fatty acid composition of different lipid classes, separated by solid phase extraction, was determined by gas chromatography. Results and conclusion. Despite the reduced amount of ergosterol in yeast cells, thanks to the reorganized lipid metabolism, M12 strain achieved high biomass yield and SAM production. Neutral lipids prevailed (making more than 75 % of total lipids), but their content and composition differed significantly in the two tested types of yeast. Unsaturated and C18 fatty acids prevailed in both the M12 strain and wild type. In all fractions except free fatty acids, the index of unsaturation in M12 strain was lower than in the wild strain. Our tested strain adjusts itself by changing the content of lipids (mainly phospholipids, sterols and sterol esters), and with desaturation adjustments, to maintain proper functioning and fulfil increased energy needs.Novelty and scientific contribution. Reorganization of S. stipitis lipid composition caused by blocking the metabolic pathway of ergosterol synthesis was presented. A simple scheme of actual lipid metabolism during active SAM production in S. stipitis, grown on glycerol was constructed and shown. This fundamental knowledge of lipid metabolic pathways will be a helpful tool in improving S. stipitis as an expression host and a model organism, opening new perspectives for its applied research.

scholarly journals The role of diatom resting spores for pelagic-benthic coupling in the Southern Ocean

2017 ◽  
Author(s):  
Mathieu Rembauville ◽  
Stéphane Blain ◽  
Clara Manno ◽  
Geraint Tarling ◽  
Anu Thompson ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Southern Ocean ◽  
Lipid Composition ◽  
Unsaturated Fatty Acids ◽  
Strong Association ◽  
Ocean Island ◽  
South Georgia ◽  
Resting Spore ◽  
Phytoplankton Communities ◽  
Benthic Coupling

Abstract. Natural iron fertilization downstream of Southern Ocean island plateaus support large phytoplankton blooms and promote carbon export from the mixed layer. In addition to sequestering atmospheric CO2, the biological carbon pump also supplies organic matter (OM) to deep-ocean ecosystems. Although the total flux of OM arriving at the seafloor sets the energy input to the system, the chemical nature of OM is also of significance. However, a quantitative framework linking ecological flux vectors to OM composition is currently lacking. In the present study we report the lipid composition of export fluxes collected by five-moored sediment traps deployed in contrasting productivity regimes of Southern Ocean island systems (Kerguelen, Crozet and South Georgia) and compile them with quantitative data on diatom and fecal pellet fluxes. At the three naturally iron fertilized sites, the relative contribution of labile lipids (mono- and polyunsaturated fatty acids, unsaturated fatty alcohols) is 2–4 times higher than at low productivity sites. There is a strong attenuation of labile components as a function of depth, irrespective of productivity. The three island systems also display regional characteristics in lipid export. The diversity of sterols is greater in the relatively warm waters of the Polar Frontal Zone when compared to the Antarctic zone, reflecting the transition from mixed phytoplankton communities to principally diatom-derived OM. An enrichment of zooplankton dietary sterols, such as C27Δ5, at South Georgia is consistent with high zooplankton and krill biomass in the region and the importance of fecal pellets to POC flux. There is a strong association of diatom resting spore fluxes that dominate productive flux regimes with energy rich unsaturated fatty acids. At the Kerguelen Plateau we provide a statistical framework to link seasonal variation in ecological flux vectors and lipid composition over a complete annual cycle. Our analyses demonstrate that ecological processes in the upper ocean, e.g. resting spore formation and grazing, not only impact the magnitude and stoichiometry of the Southern Ocean biological pump, but also regulate the composition of exported OM and the nature of pelagic-benthic coupling.

Effects of unsaturated fatty acid deprivation on neutral lipid synthesis in Saccharomyces cerevisiae

1982 ◽  
Vol 152 (2) ◽  
pp. 747-756
Author(s):  
T M Buttke ◽  
A L Pyle
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Oleic Acid ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Cell Growth ◽  
Unsaturated Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Lipid Synthesis ◽  
Yeast Cells

The effects of unsaturated fatty acid deprivation on lipid synthesis in Saccharomyces cerevisiae strain GL7 were determined by following the incorporation of [14C]acetate. Compared to yeast cells grown with oleic acid, unsaturated fatty acid-deprived cells contained 200 times as much 14C label in squalene, with correspondingly less label in 2,3-oxidosqualene and 2,3;22,23-dioxidosqualene. Cells deprived of either methionine or cholesterol did not accumulate squalene, demonstrating that the effect of unsaturated fatty acid starvation on squalene oxidation was not due to an inhibition of cell growth. Cells deprived of olefinic supplements displayed additional changes in lipid metabolism: (i) an increase in 14C-labeled diacylglycerides, (ii) a decrease in 14C-labeled triacylglycerides, and (iii) increased levels of 14C-labeled decanoic and dodecanoic fatty acids. The changes in squalene oxidation and acylglyceride metabolism in unsaturated fatty acid-deprived cells were readily reversed by adding oleic acid. Pulse-chase studies demonstrated that the [14C]squalene and 14C-labeled diacylglycerides which accumulated during starvation were further metabolized when cells were resupplemented with oleic acid. These results demonstrate that unsaturated fatty acids are essential for normal lipid metabolism in yeasts.

scholarly journals Fluidization of Membrane Lipids Enhances the Tolerance of Saccharomyces cerevisiae to Freezing and Salt Stress

2006 ◽  
Vol 73 (1) ◽  
pp. 110-116 ◽  
Author(s):  
Sonia Rodríguez-Vargas ◽  
Alicia Sánchez-García ◽  
Jose Manuel Martínez-Rivas ◽  
Jose Antonio Prieto ◽  
Francisca Randez-Gil
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Membrane Lipids ◽  
Fatty Acid Content ◽  
Unsaturation Index ◽  
Monounsaturated Fatty Acids ◽  
Yeast Cells ◽  
Proper Function ◽  
Wild Type

ABSTRACT Unsaturated fatty acids play an essential role in the biophysical characteristics of cell membranes and determine the proper function of membrane-attached proteins. Thus, the ability of cells to alter the degree of unsaturation in their membranes is an important factor in cellular acclimatization to environmental conditions. Many eukaryotic organisms can synthesize dienoic fatty acids, but Saccharomyces cerevisiae can introduce only a single double bond at the Δ9 position. We expressed two sunflower (Helianthus annuus) oleate Δ12 desaturases encoded by FAD2-1 and FAD2-3 in yeast cells of the wild-type W303-1A strain (trp1) and analyzed their effects on growth and stress tolerance. Production of the heterologous desaturases increased the content of dienoic fatty acids, especially 18:2Δ9,12, the unsaturation index, and the fluidity of the yeast membrane. The total fatty acid content remained constant, and the level of monounsaturated fatty acids decreased. Growth at 15°C was reduced in the FAD2 strains, probably due to tryptophan auxotrophy, since the trp1 (TRP1) transformants that produced the sunflower desaturases grew as well as the control strain did. Our results suggest that changes in the fluidity of the lipid bilayer affect tryptophan uptake and/or the correct targeting of tryptophan transporters. The expression of the sunflower desaturases, in either Trp+ or Trp− strains, increased NaCl tolerance. Production of dienoic fatty acids increased the tolerance to freezing of wild-type cells preincubated at 30°C or 15°C. Thus, membrane fluidity is an essential determinant of stress resistance in S. cerevisiae, and engineering of membrane lipids has the potential to be a useful tool of increasing the tolerance to freezing in industrial strains.

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