Extraction and methylation parameters of phospholipid fatty acid analysis and their effect on total yield and community structure

Mapping Intimacies ◽

10.5194/egusphere-egu21-9462 ◽

2021 ◽

Author(s):

Guido Wiesenberg ◽

Cyrill Zosso

Keyword(s):

Fatty Acids ◽

Community Composition ◽

Cell Walls ◽

Phospholipid Fatty Acid ◽

Total Yield ◽

Fatty Acid Analysis ◽

Phospholipid Fatty Acids ◽

Acid Catalyzed ◽

Relative Abundances ◽

Microbial Groups

<p>Phospholipid fatty acids are membrane compounds of microbial cell walls and the structure of individual compounds is indicative for specific microbial groups. The extraction and analysis of phospholipid fatty acids in soils improved our understanding of factors driving microbial abundance and community composition. Despite the wide application of this method, important pitfalls persist which impede comparability of PLFA results between studies.</p><p>Here, we show that there was an effect of freeze-drying on the community composition. However, compared to the effect of using of old extraction solution (4 weeks) and two different methylation procedures, this effect seems negligible. Using old extraction solution, the overall yield of PLFA was 12% lower and and we observed significant differences in the relative abundances of functional microbial groups. But most importantly, base catalyzed methylation yielded 35% less PLFA compared to acid catalyzed methylation and the relative abundances of all microbial groups were completely different. Our results show that it is crucial to keep the analytical parameters constant to capture subtle treatment effects and that especially the use of different methylation methods prevents comparability between studies.</p>

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Effect of dietary linseed and fish oil on the composition of phospholipid fatty acids, eating quality and cooked flavour volatiles of beef Longissimus lumborum muscle

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200594897 ◽

1997 ◽

Vol 1997 ◽

pp. 48-48

Author(s):

M. Enser ◽

E Kurt ◽

G.R. Nute ◽

J.D. Wood ◽

D.S. Mottram ◽

...

Keyword(s):

Fatty Acids ◽

Fish Oil ◽

Phospholipid Fatty Acid ◽

Phospholipid Fatty Acids ◽

Oxidation Products ◽

Eating Quality ◽

Phospholipid Fatty Acid Composition ◽

Dietary Recommendations ◽

Dietary Polyunsaturated Fatty Acids ◽

Longissimus Lumborum

The reaction of thermal oxidation products of phospholipid fatty acids with other meat components is an important source of cooked meat flavour and odour (Mottram and Edwards, 1983) and preferences for meat from forage or concentrate finished beef have been attributed to differences in the feed fatty acids (Melton, 1990). Therefore modifying lipids to meet human dietary recommendations to raise the P:S and n-3:n-6 ratios of dietary polyunsaturated fatty acids (PUFA) is likely to affect meat quality. We have investigated the effect on eating quality, flavour volatiles and phospholipid fatty acid composition of feeding steers linseed, which is high in α-linolenic acid (18:3 n-3), and fish oil containing EPA (20:5 n-3) and DHA (22:6 n-3).

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Changes in Microbial Community Composition and Geochemistry during Uranium and Technetium Bioimmobilization

Applied and Environmental Microbiology ◽

10.1128/aem.00309-07 ◽

2007 ◽

Vol 73 (18) ◽

pp. 5885-5896 ◽

Cited By ~ 30

Author(s):

Mandy M. Michalsen ◽

Aaron D. Peacock ◽

Anne M. Spain ◽

Amanda N. Smithgal ◽

David C. White ◽

...

Keyword(s):

Microbial Community ◽

Community Composition ◽

Denaturing Gradient Gel Electrophoresis ◽

Phospholipid Fatty Acid ◽

Microbial Community Composition ◽

Fatty Acid Analysis ◽

16S Rrna Genes ◽

Rrna Genes ◽

Significant Difference ◽

And Control

ABSTRACT In a previous column study, we investigated the long-term impact of ethanol additions on U and Tc mobility in groundwater (M. M. Michalsen et al., Environ. Sci. Technol. 40:7048-7053, 2006). Ethanol additions stimulated iron- and sulfate-reducing conditions and significantly enhanced U and Tc removal from groundwater compared to an identical column that received no ethanol additions (control). Here we present the results of a combined signature lipid and nucleic acid-based microbial community characterization in sediments collected from along the ethanol-stimulated and control column flow paths. Phospholipid fatty acid analysis showed both an increase in microbial biomass (∼2 orders of magnitude) and decreased ratios of cyclopropane to monoenoic precursor fatty acids in the stimulated column compared to the control, which is consistent with electron donor limitation in the control. Spatial shifts in microbial community composition were identified by PCR-denaturing gradient gel electrophoresis analysis as well as by quantitative PCR, which showed that Geobacteraceae increased significantly near the stimulated-column outlet, where soluble electron acceptors were largely depleted. Clone libraries of 16S rRNA genes from selected flow path locations in the stimulated column showed that Proteobacteria were dominant near the inlet (46 to 52%), while members of candidate division OP11 were dominant near the outlet (67%). Redundancy analysis revealed a highly significant difference (P = 0.0003) between microbial community compositions within stimulated and control sediments, with geochemical variables explaining 68% of the variance in community composition on the first two canonical axes.

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Microbial Biomass and Community Composition Analysis Using Phospholipid Fatty Acids

Springer Protocols Handbooks - Hydrocarbon and Lipid Microbiology Protocols ◽

10.1007/8623_2016_213 ◽

2016 ◽

pp. 65-76 ◽

Cited By ~ 3

Author(s):

Aaron D. Peacock ◽

David C. White

Keyword(s):

Fatty Acids ◽

Microbial Biomass ◽

Community Composition ◽

Phospholipid Fatty Acids ◽

Composition Analysis

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Phospholipid fatty acids of brain and liver are modified by α-tocopherol and dietary fat in growing chicks

British Journal Of Nutrition ◽

10.1079/bjn19960013 ◽

1996 ◽

Vol 76 (1) ◽

pp. 109-122 ◽

Cited By ~ 26

Author(s):

H. Fuhrmann ◽

H. P. Sallmann

Keyword(s):

Fatty Acids ◽

Linoleic Acid ◽

Vitamin E ◽

Dietary Fat ◽

Phospholipid Fatty Acid ◽

Tocopherol Content ◽

Phospholipid Fatty Acids ◽

Dietary Fatty Acids ◽

Phospholipid Fatty Acid Composition ◽

Liver Membranes

Dietary fatty acids modify phospholipid fatty acids in brain and liver of growing chickens post-hatching.The effect of vitamin E deficiency on this process is unknown and may be relevant to the pathogenesis of chick nutritional encephalomalacia (NE). Therefore laying hens received a diet low in vitamin E (10 mg α-tocopherol/kg feed). Resulting chicks were assigned to nine dietary groups each fed with either oleic (18:ln-9, 58 g/kg), linoleic (18:2n-6, 57 g/kg) or linolenic (18:3n-3, 56 g/kg) acid together with 5, 25 or 125 mg α-tocopherol/kg feed. NE affecting the cerebellum only occurred in the group given linoleic acid and 5 mg α-tocopherol/kg.In l-d-old chicks and after 1 and 2 weeks the phospholipid fatty acid composition of liver, cerebrum and cerebellum (additionally after 3 weeks) was determined. The feed fatty acids were incorporated into the liver very efficiently during the first week of life. Unsaturation of liver membranes decreased in the orderdietary linolenic >linoleic >oleic acid. In liver, also, the effect of α-tocopherol supplementation on phospholipid fatty acids was most pronounced. Theunsaturation index increased during deficiency, whereas n-9 fatty acids decreased. In the chicken brain the alterations were delayed and less distinct. The cerebellum phospholipids were rich in n-9 fatty acids and as a whole more saturated in comparison with the cerebrum. Cerebellar unsaturation increased when linolenic or linoleic acid was given. However, NE-producing dietary conditions were not accompanied by specific alterations in cerebellar phospholipid fatty acids due to the α-tocopherol content of the diet. Rather the alterations of membrane fatty acids in the liver seem to play a role in the pathogenesis of NE.

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Microbial dormancy improves predictability of soil respiration at the seasonal time scale

10.1101/434654 ◽

2018 ◽

Author(s):

A. Salazar ◽

J.T. Lennon ◽

J.S Dukes

Keyword(s):

Climate Change ◽

Microbial Biomass ◽

Soil Respiration ◽

Phospholipid Fatty Acid ◽

Soil C ◽

Metabolic States ◽

Global Soil ◽

Relative Abundances ◽

Seasonal Time Scale ◽

Microbial Groups

AbstractClimate change is accelerating global soil respiration, which could in turn accelerate climate change. The biological mechanisms through which soil carbon (C) responds to climate are not well understood, limiting our ability to predict future global soil respiration rates. As part of a climate manipulation experiment, we tested whether differences in soil heterotrophic respiration driven by season or climate treatment (RH) are linked to 1) relative abundances of microbes in active and dormant metabolic states, 2) net changes in microbial biomass and/or 3) changes in the relative abundances of microbial groups with different C-use strategies. We used a flow-cytometric single-cell metabolic assay to quantify the abundance of active and dormant microbes, and the phospholipid fatty acid (PLFA) method to determine microbial biomass and ratios of fungi:bacteria and Gram-positive:Gram-negative bacteria. RH did not respond to climate treatments but was greater in the warm and dry summer than in the cool and less-dry fall. These dynamics were better explained when microbial data were taken into account compared to when only physical data (temperature and moisture) were used. Overall, our results suggest that RH responses to temperature are stronger when soil contains more active microbes, and that seasonal patterns of RH can be better explained by shifts in microbial activity than by shifts in the relative abundances of fungi and Gram-positive and Gram-negative bacteria. These findings contribute to our understanding of how and under which conditions microbes influence soil C responses to climate.

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Content and composition of phospholipids, fatty acids and sterols in commercial natural phospholipid excipients

Current Pharmaceutical Analysis ◽

10.2174/1573412916999200605162707 ◽

2020 ◽

Vol 16 ◽

Author(s):

Luxia Zheng ◽

Xiong Shen ◽

Yingchun Wang ◽

Jian Liang ◽

Mingming Xu ◽

...

Keyword(s):

Fatty Acids ◽

Cluster Analysis ◽

Fatty Acid ◽

High Performance ◽

Comprehensive Evaluation ◽

Phospholipid Fatty Acid ◽

Egg Yolk ◽

Systematic Research ◽

Manufacturing Enterprises ◽

The Many

Background: Phospholipids are widely used in food and pharmaceutical industry as functional excipients. In spite of the many analytical methods reported, there are very limited reports concerning systematic research and comparison of phospholipid excipients. Objective: To present a comprehensive evaluation of commercial natural phospholipid excipients (CNPEs). Methods: Seventeen batches of CNPEs from five manufacturing enterprises, isolated either from soybean or egg yolk, were investigated. The content and composition of phospholipids, fatty acids and sterols as a whole were considered as the evaluative index of CNPEs. Eight kinds of phospholipids were determined by supercritical fluid chromatography (SFC), twenty-one kinds of fatty acids were determined by gas chromatography (GC) after boron trifluoride-methanol derivatization, and nine kinds of sterols were determined by high performance liquid chromatography (HPLC) after separation and derivatization of the unsaponifiable matter. Cluster analysis was employed for classification and identification of the CNPEs. Results: The results showed that each kind of CNPEs had its characteristic content and composition of phospholipids, fatty acids and sterols. Seventeen batches of samples were divided into eight groups in cluster analysis. CNPEs of the same type from different source (soybean or egg yolk) or enterprises presented different content and composition of phospholipids, fatty acids and sterols. Conclusion: Each type of CNPEs had its characteristic content and composition of phospholipid, fatty acid and sterol. The compositions of phospholipid, fatty acid and sterol as a whole can be applied as an indicator of the quality and characteristics for CNPEs.

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