Determining monolignol oxifunctionalization by direct infusion electrospray ionization tandem mass spectrometry.

We have successfully developed a validated high-throughput analysis method for the identification and quantification of native and oxifunctionalized monolignols using direct infusion electrospray ionization tandem mass spectrometry (DI-ESI-MS/MS). Oxifunctionalized monolignols generated through unspecific peroxygenase catalysis present a sustainable alternative to fossil aromatic hydrocarbons. This study emphasizes a sustainable analytical approach for these renewable biocatalytic precursors, addressing challenges such as matrix effects, accuracy, precision, and sensitivity of the method. Our findings demonstrate the potential of overcoming quantification difficulties using DI-ESI-MS. Notably, this analytical methodology represents a novel utilization of DI-ESI-MS/MS in examining monolignols and their functionalization, thereby advancing the exploration of lignin as a valuable and sustainable bioresource.

Explorative characterization and taxonomy-aligned comparison of alterations in lipids and other biomolecules in Antarctic bacteria grown at different temperatures.

Temperature significantly impacts bacterial physiology, metabolism and cell chemistry. In this study, we analysed lipids and the total cellular biochemical profile of 74 fast-growing Antarctic bacteria grown at different temperatures. Fatty acid diversity and temperature-induced alterations aligned with bacterial classification-Gram-groups, phylum, genus and species. Total lipid content, varied from 4% to 19% of cell dry weight, was genus- and species-specific. Most bacteria increased lipid content at lower temperatures. The effect of temperature on the profile was complex and more species-specific, while some common for all bacteria responses were recorded. Gram-negative bacteria adjusted unsaturation and acyl chain length. Gram-positive bacteria adjusted methyl branching (anteiso-/iso-), chain length and unsaturation. Fourier transform infrared spectroscopy analysis revealed Gram-, genus- and species-specific changes in the total cellular biochemical profile triggered by temperature fluctuations. The most significant temperature-related alterations detected on all taxonomy levels were recorded for mixed region 1500-900 cm-1 , specifically the band at 1083 cm-1 related to phosphodiester groups mainly from phospholipids (for Gram-negative bacteria) and teichoic/lipoteichoic acids (for Gram-positive bacteria). Some changes in protein region were detected for a few genera, while the lipid region remained relatively stable despite the temperature fluctuations.

Visible light-exposed lignin facilitates cellulose solubilization by lytic polysaccharide monooxygenases.

Lytic polysaccharide monooxygenases (LPMOs) catalyze oxidative cleavage of crystalline polysaccharides such as cellulose and are crucial for the conversion of plant biomass in Nature and in industrial applications. Sunlight promotes microbial conversion of plant litter; this effect has been attributed to photochemical degradation of lignin, a major redox-active component of secondary plant cell walls that limits enzyme access to the cell wall carbohydrates. Here, we show that exposing lignin to visible light facilitates cellulose solubilization by promoting formation of H2O2 that fuels LPMO catalysis. Light-driven H2O2 formation is accompanied by oxidation of ring-conjugated olefins in the lignin, while LPMO-catalyzed oxidation of phenolic hydroxyls leads to the required priming reduction of the enzyme. The discovery that light-driven abiotic reactions in Nature can fuel H2O2-dependent redox enzymes involved in deconstructing lignocellulose may offer opportunities for bioprocessing and provides an enzymatic explanation for the known effect of visible light on biomass conversion.

Identification and quantification of lipids in wild and farmed Atlantic salmon (Salmo salar), and salmon feed by GC-MS.

The fatty acid profiles of wild and farmed Atlantic salmon (Salmo salar) and salmon feed was elucidated and quantitated. Due to the increasing proportion of vegetable oils in salmon feed, it was of interest to evaluate the effects on the farmed salmon fatty acid profile. There was found to be four times more fat in the muscle in farmed compared to wild salmon, 8.97 ± 0.63% and 2.14 ± 0.32%, respectively. The contents of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids were 15.0%, 55.4%, and 29.6%, respectively, in farmed salmon, while 26.3%, 47.4%, and 26.3% in wild salmon. The lipids were also fractioned into neutral lipids, free fatty acids, and polar lipids by solid-phase extraction. Both wild and farmed salmon contained approximately equal amount of eicosapentaenoic acid and docosahexaenoic acid with 520 and 523 mg/100 g fish muscle, respectively. The salmons of both kinds were evaluated from a health perspective by discussing the contents of n-3 and n-6 fatty acids, saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids together with nutritional quality indices. In conjunction with a lower fat intake by consumption, the wild Atlantic salmon displayed the most nutritionally beneficial profile.

Variations in fatty acid and amino acid profiles of doi and rasomalai made from buffalo milk.

OBJECTIVE: This study investigated and compared the chemical composition, cholesterol content, fatty acid (FA), and amino acid (AA) profiles of doi and rasomalai made from buffalo milk. MATERIALS AND METHODS: Bangladesh Agricultural University Dairy Farm, Mymensingh-2202, Bangladesh was the source of raw buffalo milk. Then, doi and rasomalai were produced and analyzed. Prior to the production of doi and rasomalai, the gross composition and AAs of milk were evaluated. Milk and dairy products were evaluated for gross composition using an automated milk analyzer and the Association of Agricultural Chemists techniques, respectively. At the Bangladesh Council for Scientific and Industrial Research, Dhaka, Bangladesh, the cholesterol, FA, and AA levels of doi and rasomalai were determined. Additionally, atherogenic and thrombogenic indices were determined using established equations. RESULTS: The results indicated that the majority of the proximate components were significantly greater (p < 0.05) in rasomalai than in doi. Rasomalai had 3.64 mg more cholesterol (p > 0.05) than doi. The FA profile was identical across doi and rasomalai with the exception of oleic acid (C18:1cis-9), which was 1.50% greater (p < 0.05) in rasomalai. The atherogenicity index was found to be statistically higher in doi than in rasomalai (p > 0.05). Similarly, the thrombogenic index was found to be significantly higher (p > 0.05) in doi (1.98) when compared to the rasomalai (1.92). The concentrations of all AAs were found to be quantitatively higher in doi than in rasomalai (p > 0.05). CONCLUSION: The conclusion is that buffalo milk rasomalai appears to have a higher nutritional density than buffalo milk doi.

Evaluation and optimisation of direct transesterification methods for the assessment of lipid accumulation in oleaginous filamentous fungi.

BACKGROUND: Oleaginous filamentous fungi can accumulate large amount of cellular lipids and potentially serve as a major source of oleochemicals for food, feed, chemical, pharmaceutical, and transport industries. Transesterification of microbial oils is an essential step in microbial lipid production at both laboratory and industrial scale. Direct transesterification can considerably reduce costs, increase sample throughput and improve lipid yields (in particular fatty acid methyl esters, FAMEs). There is a need for the assessment of the direct transesterification methods on a biomass of filamentous fungi due to their unique properties, specifically resilient cell wall and wide range of lipid content and composition. In this study we have evaluated and optimised three common direct transesterification methods and assessed their suitability for processing of fungal biomass. RESULTS: The methods, based on hydrochloric acid (Lewis method), sulphuric acid (Wahlen method), and acetyl chloride (Lepage method), were evaluated on six different strains of Mucoromycota fungi by using different internal standards for gas chromatography measurements. Moreover, Fourier transform infrared (FTIR) spectroscopy was used for the detection of residual lipids in the biomass after the transesterification reaction/extraction, while transesterification efficiency was evaluated by nuclear magnetic resonance spectroscopy. The results show that the majority of lipids, in particular triglycerides, were extracted for all methods, though several methods had substandard transesterification yields. Lewis method, optimised with respect to solvent to co-solvent ratio and reaction time, as well as Lepage method, offer precise estimate of FAME-based lipids in fungal biomass. CONCLUSIONS: The results show that Lepage and Lewis methods are suitable for lipid analysis of oleaginous filamentous fungi. The significant difference in lipid yields results, obtained by optimised and standard Lewis methods, indicates that some of the previously reported lipid yields for oleaginous filamentous fungi must be corrected upwards. The study demonstrates value of biomass monitoring by FTIR, importance of optimal solvent to co-solvent ratio, as well as careful selection and implementation of internal standards for gas chromatography.

Corrigendum to "Fatty Acid Profiles of Stipe and Blade from the Norwegian Brown Macroalgae Laminaria Hyperborea with Special Reference to Acyl Glycerides, Polar Lipids, and Free Fatty Acids".

[This corrects the article DOI: 10.1155/2017/1029702.].

The influence of phosphorus source and the nature of nitrogen substrate on the biomass production and lipid accumulation in oleaginous Mucoromycota fungi.

Oleaginous filamentous fungi grown under the nitrogen limitation, accumulate high amounts of lipids in the form of triacylglycerides (TAGs) with fatty acid profiles similar to plant and fish oils. In this study, we investigate the effect of six phosphorus source concentrations combined with two types of nitrogen substrate (yeast extract and ammonium sulphate), on the biomass formation, lipid production, and fatty acid profile for nine oleaginous Mucoromycota fungi. The analysis of fatty acid profiles was performed by gas chromatography with flame ionization detector (GC-FID) and the lipid yield was estimated gravimetrically. Yeast extract could be used as both nitrogen and phosphorus source, without additional inorganic phosphorus supplementation. The use of inorganic nitrogen source (ammonium sulphate) requires strain-specific optimization of phosphorus source amount to obtain optimal lipid production regarding quantity and fatty acid profiles. Lipid production was decreased in ammonium sulphate-based media when phosphorus source was limited in all strains except for Rhizopus stolonifer. High phosphorus source concentration inhibited the growth of Mortierella fungi. The biomass (22 g/L) and lipid (14 g/L) yield of Umbelopsis vinacea was the highest among all the tested strains. KEY POINTS: • The strain specific P requirements of Mucoromycota depend on the nature of N source. • Yeast extract leads to consistent biomass and lipid yield and fatty acids profiles. • Umbelopsis vinacea showed the highest biomass (22 g/L) and lipid (14 g/L) yield. • High P source amounts inhibit the growth of Mortierella fungi.

Identification and Quantification of Fatty Acids in T. viridissima, C. biguttulus, and C. brunneus by GC-MS.

Fatty acid (FA) profiles of the species Tettigonia viridissima, Chorthippus biguttulus, and Chorthippus brunneus were determined and quantitated. Extracted lipids were derivatized into FA methyl esters (FAMEs) prior to analysis by GC-MS. A total of 37 different FAs were identified in T. viridissima, yielding a total FA content of 10.4 g/100 g of dry matter. The contents of saturated FAs, monounsaturated FAs, and polyunsaturated FAs were 31.1, 35.9, and 33.0%, respectively. Lipids from T. viridissima were also fractioned into neutral lipids, free fatty acids, and polar lipids by offline solid phase extraction. For C. brunneus and C. biguttulus, 33 FAs were identified, yielding a total FA content of 6.14 g/100 g of dry matter. SFAs, MUFAs, and PUFAs, respectively, constituted 32.7, 25.1, and 42.1% of the total FA content. The contents of MUFAs, PUFAs, n-3 FAs, and n-6 FAs of each species, and the n-6/n-3 ratio, were subsequently discussed.

High-throughput screening of Mucoromycota fungi for production of low- and high-value lipids.

BACKGROUND: Mucoromycota fungi are important producers of low- and high-value lipids. Mortierella alpina is used for arachidonic acid production at industrial scale. In addition, oleaginous Mucoromycota fungi are promising candidates for biodiesel production. A critical step in the development of such biotechnological applications is the selection of suitable strains for lipid production. The aim of the present study was to use the Duetz-microtiter plate system combined with Fourier transform infrared (FTIR) spectroscopy for high-throughput screening of the potential of 100 Mucoromycota strains to produce low- and high-value lipids. RESULTS: With this reproducible, high-throughput method, we found several promising strains for high-value omega-6 polyunsaturated fatty acid (PUFA) and biodiesel production purposes. Gamma-linolenic acid content was the highest in Mucor fragilis UBOCC-A-109196 (24.5% of total fatty acids), and Cunninghamella echinulata VKM F-470 (24.0%). For the first time, we observed concomitant gamma-linolenic acid and alpha-linolenic acid (up to 13.0%) production in psychrophilic Mucor flavus strains. Arachidonic acid was present the highest amount in M. alpina ATCC 32222 (41.1% of total fatty acids). Low cultivation temperature (15 °C) activated the temperature sensitive ∆17 desaturase enzyme in Mortierella spp., resulting in eicosapentaenoic acid production with up to 11.0% of total fatty acids in M. humilis VKM F-1494. Cunninghamella blakesleeana CCM-705, Umbelopsis vinacea CCM F-539 and UBOCC-A-101347 showed very good growth (23-26 g/L) and lipid production (7.0-8.3 g/L) with high palmitic and oleic acid, and low PUFA content, which makes them attractive candidates for biodiesel production. Absidia glauca CCM 451 had the highest total lipid content (47.2% of biomass) of all tested strains. We also demonstrated the potential of FTIR spectroscopy for high-throughput screening of total lipid content of oleaginous fungi. CONCLUSIONS: The use of Duetz-microtiter plate system combined with FTIR spectroscopy and multivariate analysis, is a feasible approach for high-throughput screening of lipid production in Mucoromycota fungi. Several promising strains have been identified by this method for the production of high-value PUFA and biodiesel.

Characterization of Pseudo-Lignin from Steam Exploded Birch.

There is a growing interest in a more wholesome utilization of biomass as the need for greener chemistry and non-mineral oil-based products increases. Lignin is the largest renewable resource for aromatic chemicals, which is found in all types of lignocellulosic biomass. Steam-explosion of lignocellulosic biomass is a useful pretreatment technique to make the polymeric material more available for processing. However, this heat-based pretreatment is known to result in the formation of pseudo-lignin, a lignin-like polymer made from carbohydrate degradation products. In this work, we have analyzed steam-exploded birch with a varying severity factor (3.1-5.0) by pyrolysis-gas chromatography-mass spectrometry, 2D-NMR, and Fourier transform infrared spectroscopy. The main results reveal a consumption of acetic acid at higher temperatures, with the increase of furan components in the pyrolyzate. The IR and NMR spectral data support these results, and there is a reason to believe that the conditions for humin formation are accomplished under steam explosion. Pseudo-lignin seems to be a humin-like compound.

Fatty Acid Profiles of Stipe and Blade from the Norwegian Brown Macroalgae Laminaria hyperborea with Special Reference to Acyl Glycerides, Polar Lipids, and Free Fatty Acids.

A thorough analysis of the fatty acid profiles of stipe and blade from the kelp species Laminaria hyperborea is presented. Lipid extracts were fractionated into neutral lipids, free fatty acids, and polar lipids, prior to derivatization and GC-MS analysis. A total of 42 fatty acids were identified and quantified, including the n-3 fatty acids α-linolenic acid, stearidonic acid, and eicosapentaenoic acid. The fatty acid amounts are higher in blade than in stipe (7.42 mg/g dry weight and 2.57 mg/g dry weight, resp.). The highest amounts of n-3 fatty acids are found within the neutral lipid fractions with 590.6 ug/g dry weight and 100.9 ug/g dry weight for blade and stipe, respectively. The amounts of polyunsaturated fatty acids are 3.4 times higher in blade than stipe. The blade had the highest PUFA/SFA ratio compared to stipe (1.02 versus 0.76) and the lowest n-6/n-3 ratio (0.8 versus 3.5). This study highlights the compositional differences between the lipid fractions of stipe and blade from L. hyperborea. The amount of polyunsaturated fatty acids compared to saturated- and monounsaturated fatty acids is known to influence human health. In the pharmaceutical, food, and feed industries, this can be of importance for production of different health products.

Synthesis, in vitro and in vivo biological evaluation of new oxysterols as modulators of the liver X receptors.

Liver X Receptor (LXR) modulators have shown potential as drugs since they target genes affecting metabolism and fatty acid synthesis. LXR antagonists are of particular interest since they are able to reduce the synthesis of complex fatty acids and glucose uptake. Based on molecular modeling, five new cholesterol mimics were synthesized, where four contained a hydroxyl group in the 22-S-position. The new compounds were screened in vitro against several genes affecting lipid metabolism. The compound that performed best in vitro was a dimethylamide derivative of 22(S)-hydroxycholesterol and it was chosen for in vivo testing. However, the blood plasma analysis from the in vivo tests revealed a concentration lower than needed to give any response, indicating either rapid metabolism or low bioavailability.

Ex vivo Digestion of Milk from Red Chittagong Cattle Focusing Proteolysis and Lipolysis.

Ex vivo digestion of proteins and fat in Red Chittagong Cattle milk from Bangladesh was carried out using human gastrointestinal enzymes. This was done to investigate the protein digestion in this bovine breed's milk with an especial focus on the degradation of the allergenic milk proteins; αs1-casein and ß-lactoglobulin and also to record the generation of peptides. Lipolysis of the milk fat and release of fatty acids were also under consideration. After 40 min of gastric digestion, all the αs-caseins were digested completely while ß-lactoglobulin remained intact. During 120 min of duodenal digestion ß-lactoglobulin was reduced, however, still some intact ß-lactoglobulin was observed. The highest number of peptides was identified from ß-casein and almost all the peptides from κ-casein and ß-lactoglobulin were identified from the gastric and duodenal samples, respectively. No lipolysis was observed in the gastric phase of digestion. After 120 min of duodenal digestion, milk fat showed 48% lipolysis. Medium (C10:0 to C16:0) and long (≥C17:0) chain fatty acids showed 6% to 19% less lipolysis than the short (C6:0 to C8:0) chain fatty acids. Among the unsaturated fatty acids C18:1∑others showed highest lipolysis (81%) which was more than three times of C18:2∑all and all other unsaturated fatty acids showed lipolysis ranging from 32% to 38%. The overall digestion of Bangladeshi Red Cattle milk was more or less similar to the digestion of Nordic bovine milk (Norwegian Red Cattle).

Effect of intramuscular fat, breed, and age at slaughter on fatty acid composition in green hams.

UNLABELLED: The evolution of fatty acid classes (ΣSFA, ΣMUFA, and ΣPUFA) in neutral lipids (NL) and phospholipids (PL) in pigs were studied. The M. biceps femoris in green hams from Norwegian breeds Landrace (LR), Duroc (DU), and Hampshire (HS) slaughtered at 6, 7.5, and 9 mo of age were examined. The parameters were analyzed for age and breed effects with and without adjustment for NL or PL content. The fatty acid class contents of NL were not significantly different between the age groups. However, when NL content was adjusted, deposition of ΣSFA and ΣMUFA in NL significantly increased and deposition of ΣPUFA in NL significantly decreased with age. Duroc had consistently higher fatty acid class contents, but after adjusting for NL content, only the deposition of ΣSFA proved to be genetically different. The nonlinear relationship between NL content and ΣMUFA and ΣPUFA, together with the genetic potential of HS to deposit less ΣSFA than LR, gave significantly different fatty acid class compositions between the breeds. The content and proportion of ΣMUFA in PL increased with age. Specific ratios were also determined. The fat firmness index, C18:0/C18:2n - 6 in NL, increased with age and was lowest in HS due to genetics and highest in DU due to its high NL content. The sensory rancidity index C18:1n - 9/Σn - 6 increased in NL and decreased in PL between 7.5 and 9 mo. The C18:1n - 9/Σn - 6 in NL was highest in DU due to higher NL content. The Σn - 6/Σn - 3 in NL and PL increased between 7.5 and 9 mo. PRACTICAL APPLICATION: Knowledge of age-related changes and breed differences in fat content and composition would be helpful in determining the optimal breed and slaughter time in terms of raw ham quality.

A GC-magnetic sector MS method for identification and quantification of fatty acids in ewe milk by different acquisition modes.

A general method for qualitative and quantitative determination of fatty acids (FAs) using GC-MS was developed and tested on ewe milk. A total number of 38 poly unsaturated FAs, monounsaturated FAs and saturated FAs, from C6:0 to C24:1, were used in a comparative study of scan, reconstructed ion chromatogram and SIM. Fatty acid methyl esters in standard solutions as well as in milk from ewe were analyzed by these techniques, using a sector instrument. Instrument precision, linearity, LOD and LOQ, as well as calibration behavior and response factors were investigated for each approach. The quantitative results obtained by each technique were compared. All techniques had values for LOD and LOQ in the ng/mL region.

Ion-neutral reactions in the ion source of a mixture of CO2/CH3OH, CO2/C2H5OH, and CO2/2-C3H7OH by packed capillary supercritical fluid chromatography-mass spectrometry (SFC-MS).

Ion neutral reactions in the gas phase in mixtures of ROH/CO(2), R = CH(3), C(2)H(5), and 2-C(3)H(7) were studied by supercritical fluid chromatography-mass spectrometry (SFC-MS). Three main reaction series were found for this system; ionization followed by alpha-cleavage, formation of clusters, and formation of protonated dialkyl ethers from the corresponding alcohol. The ion chemistries were similar for the three alcohols, but that of 2-propanol was somewhat more complex.

Aldose-ketose interconversion in pyridine in the presence of aluminium oxide.

The reaction rate of the Lobry de Bruyn-Alberda van Ekenstein transformation of aldoses to ketoses in boiling pyridine was strongly increased by the addition of aluminium oxide. In addition to aldose-ketose transformation, 2-epimers of the starting aldoses and 3-epimers of the primarily produced ketoses were formed to some extent, as reported also when these reactions are carried out without aluminium oxide. The relative amounts of the primary ketose and the starting aldose in the reaction mixtures may be explained on the basis of their stability, predicted from reported free energy calculations. Isomerisation of ketoses to aldoses was much slower than the reverse reaction. The relative free energies are also in these cases important, the very stable xylo-2-hexulose gave only 7% and 6% of the aldoses gulose and idose, respectively, after boiling for 7h in pyridine in the presence of aluminium oxide.

Polyphenol composition and antioxidant activity in strawberry purees; impact of achene level and storage.

In this study the impact of achenes on polyphenolic compounds, ascorbic acids, and antioxidant activities in strawberry purees at production and after storage at 6 and 22 degrees C for 8 and 16 weeks was investigated. Strawberry purees were made from flesh, berry, and achene-enriched homogenate and contained 0, 1.2, and 2.9% achenes, respectively. At production, strawberry purees made from flesh contained more anthocyanins, p-coumaroyl glycosides, and ascorbic acids, whereas increasing achene levels caused increasing levels of ellagic acid derivatives, proanthocyanidins, flavonols, total phenolics (TP), and antioxidant activities. In addition, the anthocyanins, TP, and ferric reducing ability power (FRAP) in purees with more achenes were better retained during storage. Ascorbic acids and anthocyanins declined rapidly during storage, whereas other polyphenols and antioxidant activities were more stable; that is, the contributions from anthocyanins and ascorbic acids to TP and antioxidant activities decreased. The findings that achenes contributed significantly to polyphenol content and stability of strawberry purees may be interesting in a nutritional and, thus, commercial, perspective.

Characterization of phenolic compounds in strawberry (Fragaria x ananassa) fruits by different HPLC detectors and contribution of individual compounds to total antioxidant capacity.

Phenolic compounds in strawberry (Fragaria x ananassa) fruits were identified and characterized by using the complementary information from different high-performance liquid chromatography detectors: diode array, mass spectrometer in positive and negative mode, and coulometric array. Electrochemical profiles obtained from the coulometric array detector contributed to the structural elucidation suggested from the UV-vis and mass spectra. About 40 phenolic compounds including glycosides of quercetin, kaempferol, cyanidin, pelargonidin, and ellagic acid, together with flavanols, derivatives of p-coumaric acid, and ellagitannins, were described, providing a more complete identification of phenolic compounds in strawberry fruits. Quercetin-3-malonylhexoside and a deoxyhexoside of ellagic acid were reported for the first time. Antioxidative properties of individual components in strawberries were estimated by their electrochemical responses. Ascorbic acid was the single most important contributor to electrochemical response in strawberries (24%), whereas the ellagitannins and the anthocyanins were the groups of polyphenols with the highest contributions, 19 and 13% at 400 mV, respectively.