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The bioavailability of long-chain omega-3 polyunsaturated fatty acids (n3 PUFA) can be affected by the form in which they are bound. An alternative source of n3 PUFA is Calanus finmarchicus oil (CO), which, unlike fish oil (FO) and krill oil (KO), contains fatty acids primarily bound as wax esters. Recent studies have shown that n3 PUFA from CO are bioavailable to humans, but CO has not been compared to other marine oils such as FO or KO. Therefore, the aim of this study was to investigate the influence of 12 weeks supplementation with CO, FO and KO on the long-term n3 PUFA status in healthy volunteers. The Omega-3 Index (O3I), defined as red blood cell EPA + DHA content as a percentage of total identified fatty acids, was used as a measure to assess n3 PUFA status. Sixty-two participants (mean ± standard deviation [SD] age: 29.7 ± 8.43 years) completed the randomized parallel group study (CO group: n = 21, 4 capsules/day, EPA + DHA dose: 242 mg/day; FO group: n = 22, 1 capsule/day, EPA + DHA dose: 248 mg/day; KO group: n = 19, 2 capsules/day, EPA + DHA dose: 286 mg/day). At baseline, the three groups showed comparable (mean ± SD) O3I values (CO: 5.13 ± 1.12%, FO: 4.90 ± 0.57%, KO: 4.87 ± 0.77%). The post-interventional (mean ± SD) O3I increase was comparable between the three groups (CO: 1.09 ± 0.55%; FO: 1.0 ± 0.53%; KO: 1.15 ± 0.65%, all p < 0.001). The study confirms that CO can increase the n3 PUFA status comparable to FO and KO and is therefore an alternative marine source of bioavailable n3 PUFA, especially with regard to sustainability.

Predation is an interaction during which an organism kills and feeds on another organism. Past and current interest in studying predation in terrestrial habitats has yielded a number of methods to assess invertebrate predation events in terrestrial ecosystems. We provide a decision tree to select appropriate methods for individual studies. For each method, we then present a short introduction, key examples for applications, advantages and disadvantages, and an outlook to future refinements. Video and, to a lesser extent, live observations are recommended in studies that address behavioral aspects of predator-prey interactions or focus on per capita predation rates. Cage studies are only appropriate for small predator species, but often suffer from a bias via cage effects. The use of prey baits or analyses of prey remains are cheaper than other methods and have the potential to provide per capita predation estimates. These advantages often come at the cost of low taxonomic specificity. Molecular methods provide reliable estimates at a fine level of taxonomic resolution and are free of observer bias for predator species of any size. However, the current PCR-based methods lack the ability to estimate predation rates for individual predators and are more expensive than other methods. Molecular and stable isotope analyses are best suited to address systems that include a range of predator and prey species. Our review of methods strongly suggests that while in many cases individual methods are sufficient to study specific questions, combinations of methods hold a high potential to provide more holistic insights into predation events. This review presents an overview of methods to researchers that are new to the field or to particular aspects of predation ecology and provides recommendations toward the subset of suitable methods to identify the prey of invertebrate predators in terrestrial field research.

Consumers’ interest in the way meat is produced is increasing in Europe. The resulting free range and organic meat products retail at a higher price, but are difficult to differentiate from their counterparts. To ascertain authenticity and prevent fraud, relevant markers need to be identified and new analytical methodology developed. The objective of this pilot study was to characterize pork belly meats of different animal welfare classes by their fatty acid (Fatty Acid Methyl Ester—FAME), non-volatile compound (electrospray ionization-tandem mass spectrometry—ESI-MS/MS), and volatile compound (proton-transfer-reaction mass spectrometry—PTR-MS) fingerprints. Well-defined pork belly meat samples (13 conventional, 15 free range, and 13 organic) originating from the Netherlands were subjected to analysis. Fingerprints appeared to be specific for the three categories, and resulted in 100%, 95.3%, and 95.3% correct identity predictions of training set samples for FAME, ESI-MS/MS, and PTR-MS respectively and slightly lower scores for the validation set. Organic meat was also well discriminated from the other two categories with 100% success rates for the training set for all three analytical approaches. Ten out of 25 FAs showed significant differences in abundance between organic meat and the other categories, free range meat differed significantly for 6 out of the 25 FAs. Overall, FAME fingerprinting presented highest discrimination power. View Full-Text

Isolation is the main bottleneck in the analysis of fatty acids in biological samples and foods. In the last few decades some methods described direct derivatization procedures bypassing these steps. They involve the utilization of methanolic HCL or BF3 as catalysts, but several evidences from previous works suggest these reagents are unstable, lead to the formation of artifacts and alter the distribution of specific compounds as hydroxy fatty acids or CLA. However, the main issue is that they are excellent esterification reagents but poor in transterification, being not suitable for the analysis of all lipid classes and leading to erroneous composition quantitations. The present research work is a comprehensive comparison of six general methylation protocols using base, acid or base/acid catalysts plus a proposed method in the analysis of total fatty acids in lipid standards mixtures, foodstuff and biological samples. The addition of aprotic solvents to the reaction mixture to avoid alterations was also tested. Results confirmed that procedures solely involving acid catalyst resulted in incomplete derivatizations and alteration of the fatty acid profile, partially corrected by addition of the aprotic solvent. The proposed method combining sodium methoxyde and sulfuric acid showed absence of alteration of the FAME profile and the best values for response factors (short chain fatty acids to PUFA), accuracy in the determination of total cholesterol and derivatization performance, thus showing a high reliability in the determination of the total fatty acid composition in biological samples and foods.

Phototransduction, the mechanism underlying the electrical response to light in photoreceptor cells, has been thoroughly investigated in Drosophila melanogaster, an essential model in signal transduction research. These cells present a highly specialized photosensitive membrane consisting of thousands of microvilli forming a prominent structure termed a rhabdomere. These microvilli encompass the phototransduction proteins, most of which are transmembrane and exclusively rhabdomeric. Rhabdomere membrane lipids play a crucial role in the activation of the transient receptor potential ionic channels (TRP and TRPL) responsible for initiating the photoresponse. Despite its importance, rhabdomere lipid composition has not been established. We developed a novel preparation enriched in rhabdomere membranes to perform a thorough characterization of the lipidomics of Drosophila rhabdomeres. Isolated eyes (500) were homogenized and subjected to a differential centrifugation protocol that generates a fraction enriched in rhabdomere membrane. Lipids extracted from this preparation were identified and quantified by gas chromatography coupled to mass spectrometry. We found an abundance of low sterol esters (C16:0, C18:0), highly abundant and diverse triglycerides, free fatty acids, a moderate variety of mono and diacyglycerols (C:16:0, 18:0, C18:1) and abundant phospholipids (principally C18:2). This preparation opens a new avenue for investigating essential aspects of phototransduction.

Background: The beneficial effects of omega-3 polyunsaturated fatty acids (n-3 PUFAs), especially in dyslipidemic subjects with a high risk of cardiovascular disease, are widely described in the literature. A lot of effects of n-3 PUFAs and their oxidized metabolites are triggered by regulating the expression of genes. Currently, it is uncertain if the administration of n-3 PUFAs results in different expression changes of genes related to antioxidative mechanisms in normo- and dyslipidemic subjects, which may partly explain their cardioprotective effects. The aim of this study was to investigate the effects of n-3 PUFA supplementation on expression changes of genes involved in oxidative processes. Methods: Ten normo- and ten dyslipidemic men were supplemented for twelve weeks with fish oil capsules, providing 1.14 g docosahexaenoic acid and 1.56 g eicosapentaenoic acid. Gene expression levels were determined by whole genome microarray analysis and quantitative real-time polymerase chain reaction (qRT-PCR). Results: Using microarrays, we discovered an increased expression of antioxidative enzymes and a decreased expression of pro-oxidative and tissue enzymes, such as cytochrome P450 enzymes and matrix metalloproteinases, in both normo- and dyslipidemic men. An up-regulation of catalase and heme oxigenase 2 in both normo- and dyslipidemic subjects and an up-regulation of cytochrome P450 enzyme 1A2 only in dyslipidemic subjects could be observed by qRT-PCR analysis. Conclusions: Supplementation of normo- and dyslipidemic subjects with n-3 PUFAs changed the expression of genes related to oxidative processes, which may suggest antioxidative and potential cardioprotective effects of n-3 PUFAs. Further studies combining genetic and metabolic endpoints are needed to verify the regulative effects of n-3 PUFAs in antioxidative gene expression to better understand their beneficial effects in health and disease prevention.

Forty Erwinia amylovora strains originating from different host plants and locations in Serbia and one strain from Montenegro were characterized by conventional, automated and molecular techniques. All strains were Gram-negative, nonfluorescent, facultative anaerobes, oxidase negative, levan positive, produced necrotic lesions followed by bacterial exudate on artificially inoculated immature pear fruits and caused HR on tobacco. Based on carbon source utilization, all strains tested with the Biolog system were identified as E. amylovora. Based on fatty acid profiles all tested strains clustered into three groups in which strains from north Serbia differed from strains isolated in central and south parts of the country. Restriction analysis of genomic DNA using XbaI and PFGE resulted in six different patterns differentiating the strains into six groups. Most of the investigated strains clustered in one group having the pattern type similar to Pt2 group described earlier as dominant in East Europe and the Mediterranean region. Two strains showed PFGE pattern similar to the previously described Pt3 pattern and one strain had pattern similar to Pt6. Based on size and number of the bands, new restriction patterns, assigned as Pt7, Pt8 and Pt9 were observed. PFGE results showed that E. amylovora population in Serbia is not homogenous and was possibly introduced from different directions. This is the first characterization of E. amylovora collection of strains from Serbia using fatty acid analysis and PFGE.

Forty Erwinia amylovora strains originating from different host plants and locations in Serbia and one strain from Montenegro were characterized by conventional, automated and molecular techniques. All strains were Gram-negative, nonfluorescent, facultative anaerobes, oxidase negative, levan positive, produced necrotic lesions followed by bacterial exudate on artificially inoculated immature pear fruits and caused HR on tobacco. Based on carbon source utilization, all strains tested with the Biolog system were identified as E. amylovora. Based on fatty acid profiles all tested strains clustered into three groups in which strains from north Serbia differed from strains isolated in central and south parts of the country. Restriction analysis of genomic DNA using XbaI and PFGE resulted in six different patterns differentiating the strains into six groups. Most of the investigated strains clustered in one group having the pattern type similar to Pt2 group described earlier as dominant in East Europe and the Mediterranean region. Two strains showed PFGE pattern similar to the previously described Pt3 pattern and one strain had pattern similar to Pt6. Based on size and number of the bands, new restriction patterns, assigned as Pt7, Pt8 and Pt9 were observed. PFGE results showed that the E. amylovora population in Serbia is not homogenous and was possibly introduced from different directions. This is the first characterization of E. amylovora collection of strains from Serbia using fatty acid analysis and PFGE.

Forty Erwinia amylovora strains originating from different host plants and locations in Serbia and one strain from Montenegro were characterized by conventional, automated and molecular techniques. All strains were Gram-negative, nonfluorescent, facultative anaerobes, oxidase negative, levan positive, produced necrotic lesions followed by bacterial exudate on artificially inoculated immature pear fruits and caused HR on tobacco. Based on carbon source utilization, all strains tested with the Biolog system were identified as E. amylovora. Based on fatty acid profiles all tested strains clustered into three groups in which strains from north Serbia differed from strains isolated in central and south parts of the country. Restriction analysis of genomic DNA using XbaI and PFGE resulted in six different patterns differentiating the strains into six groups. Most of the investigated strains clustered in one group having the pattern type similar to Pt2 group described earlier as dominant in East Europe and the Mediterranean region. Two strains showed PFGE pattern similar to the previously described Pt3 pattern and one strain had pattern similar to Pt6. Based on size and number of the bands, new restriction patterns, assigned as Pt7, Pt8 and Pt9 were observed. PFGE results showed that E. amylovora population in Serbia is not homogenous and was possibly introduced from different directions. This is the first characterization of E. amylovora collection of strains from Serbia using fatty acid analysis and PFGE.

Forty Erwinia amylovora strains originating from different host plants and locations in Serbia and one strain from Montenegro were characterized by conventional, automated and molecular techniques. All strains were Gram-negative, nonfluorescent, facultative anaerobes, oxidase negative, levan positive, produced necrotic lesions followed by bacterial exudate on artificially inoculated immature pear fruits and caused HR on tobacco. Based on carbon source utilization, all strains tested with the Biolog system were identified as E. amylovora. Based on fatty acid profiles all tested strains clustered into three groups in which strains from north Serbia differed from strains isolated in central and south parts of the country. Restriction analysis of genomic DNA using XbaI and PFGE resulted in six different patterns differentiating the strains into six groups. Most of the investigated strains clustered in one group having the pattern type similar to Pt2 group described earlier as dominant in East Europe and the Mediterranean region. Two strains showed PFGE pattern similar to the previously described Pt3 pattern and one strain had pattern similar to Pt6. Based on size and number of the bands, new restriction patterns, assigned as Pt7, Pt8 and Pt9 were observed. PFGE results showed that the E. amylovora population in Serbia is not homogenous and was possibly introduced from different directions. This is the first characterization of E. amylovora collection of strains from Serbia using fatty acid analysis and PFGE.

Forty Erwinia amylovora strains originating from different host plants and locations in Serbia and one strain from Montenegro were characterized by conventional, automated and molecular techniques. All strains were Gram-negative, nonfluorescent, facultative anaerobes, oxidase negative, levan positive, produced necrotic lesions followed by bacterial exudate on artificially inoculated immature pear fruits and caused HR on tobacco. Based on carbon source utilization, all strains tested with the Biolog system were identified as E. amylovora. Based on fatty acid profiles all tested strains clustered into three groups in which strains from north Serbia differed from strains isolated in central and south parts of the country. Restriction analysis of genomic DNA using XbaI and PFGE resulted in six different patterns differentiating the strains into six groups. Most of the investigated strains clustered in one group having the pattern type similar to Pt2 group described earlier as dominant in East Europe and the Mediterranean region. Two strains showed PFGE pattern similar to the previously described Pt3 pattern and one strain had pattern similar to Pt6. Based on size and number of the bands, new restriction patterns, assigned as Pt7, Pt8 and Pt9 were observed. PFGE results showed that the E. amylovora population in Serbia is not homogenous and was possibly introduced from different directions. This is the first characterization of E. amylovora collection of strains from Serbia using fatty acid analysis and PFGE.

Forty Erwinia amylovora strains originating from different host plants and locations in Serbia and one strain from Montenegro were characterized by conventional, automated and molecular techniques. All strains were Gram-negative, nonfluorescent, facultative anaerobes, oxidase negative, levan positive, produced necrotic lesions followed by bacterial exudate on artificially inoculated immature pear fruits and caused HR on tobacco. Based on carbon source utilization, all strains tested with the Biolog system were identified as E. amylovora. Based on fatty acid profiles all tested strains clustered into three groups in which strains from north Serbia differed from strains isolated in central and south parts of the country. Restriction analysis of genomic DNA using XbaI and PFGE resulted in six different patterns differentiating the strains into six groups. Most of the investigated strains clustered in one group having the pattern type similar to Pt2 group described earlier as dominant in East Europe and the Mediterranean region. Two strains showed PFGE pattern similar to the previously described Pt3 pattern and one strain had pattern similar to Pt6. Based on size and number of the bands, new restriction patterns, assigned as Pt7, Pt8 and Pt9 were observed. PFGE results showed that E. amylovora population in Serbia is not homogenous and was possibly introduced from different directions. This is the first characterization of E. amylovora collection of strains from Serbia using fatty acid analysis and PFGE.

Fourier-transform infrared (FT-IR) spectroscopy is known as a high-resolution method for the rapid identification of pure cultures of microorganisms. Here, we evaluated FT-IR as a method for the quantification of bacterial populations in binary mixed cultures consisting of Pseudomonas putida and Rhodococcus ruber. A calibration procedure based on Principal Component Regression was developed for estimating the ratio of the bacterial species. Data for method calibration were gained from pure cultures and artificially assembled communities of known ratios of the two member populations. Moreover, to account for physiological variability, FT-IR measurements were performed with organisms sampled at different growth phases. Measurements and data analyses were subsequently applied to growing mixed cultures revealing that growth of R. ruber was almost completely suppressed in co-culture with P. putida. Population ratios obtained by fatty acid analysis as an independent reference method were in high agreement with the FT-IR derived ratios.

Historically considered to be simple membrane components serving as structural elements and energy storing entities, fatty acids are now increasingly recognized as potent signaling molecules involved in many metabolic processes. Quantitative determination of fatty acids and exploration of fatty acid profiles have become common place in lipid analysis. We present here a reliable and sensitive method for comprehensive analysis of free fatty acids and fatty acid composition of complex lipids in biological material. The separation and quantitation of fatty acids are achieved by capillary gas chromatography. The analytical method uses pentafluorobenzyl bromide derivatization and negative chemical ionization gas chromatography-mass spectrometry. The chromatographic procedure provides base line separation between saturated and unsaturated fatty acids of different chain lengths as well as between most positional isomers. Fatty acids are extracted in the presence of isotope-labeled internal standards for high quantitation accuracy. Mass spectrometer conditions are optimized for broad detection capacity and sensitivity capable of measuring trace amounts of fatty acids in complex biological samples. .

Automated method of fatty acid analysis was used to identify and study heterogeneity of 41 Erwinia amylovora strains, originating from 8 plant species grown in 13 locations in Serbia and one in Montenegro. All strains contained 14:0 3OH fatty acid, characteristic for the 'amylovora' group. According to fatty acid composition 39 strains were identified as E. amylovora as the first choice from the database. Due to their specific fatty acid composition, two strains were identified as E. amylovora, but as a second choice. Fatty acid analysis also showed that E. amylovora population from Serbia could be differentiated in three groups, designated in this study as α, β and γ. All strains originating from central or south Serbia, as well as four strains from north Serbia clustered into group α. Group β and γ contained only strains isolated in northern Serbia (Vojvodina). The results show that E. amylovora population in this area is heterogeneous and indicate pathogen introduction from different directions. Fatty acid analysis enabled identification at species level, as well as new insights of heterogeneity of E. amylovora population., Automatizovana metoda analize masnih kiselina primenjena je za identifikaciju i proučavanje heterogenosti Erwinia amylovora. Kao materijal za analizu prikupljen je 41 soj E. amylovora izolovan iz 8 različitih vrsta domaćina gajenih u 13 lokaliteta u Srbiji i jednom lokalitetu u Crnoj Gori. Rezultati ukazuju da svi proučavani sojevi poseduju 14:0 3OH masnu kiselinu, koja je karakteristična za 'amylovora' grupu. Na osnovu sastava masnih kiselina 39 sojeva je identifikovano kao E. amylovora, kao prvi izbor iz baze podataka. Dva soja su identifikovana kao E. amylovora, ali tek kao drugi izbor iz baze podataka, što je najverovatnije posledica specifičnosti u sastavu njihovih masnih kiselina. Rezultati analize masnih kiselina takođe pokazuju da populacija E. amylovora poreklom iz Srbije nije homogena i da među sojevima postoje tri grupe ili profila, koji su u ovom radu obeleženi sa α, β i γ. Svi sojevi koji su izolovani na prostoru centralne ili južne Srbije pripadaju grupi α, kao i četiri soja izolovana na području Vojvodine. Grupama β i γ pripadaju samo sojevi izolovani na području Vojvodine. Dobijeni rezultati predstavljaju dokaz heterogenosti populacije E. amylovora na ovim prostorima i ukazuju na mogućnost prodora patogena u naše područje iz različitih pravaca. Analiza masnih kiselina omogućila je ne samo identifikaciju do nivoa vrste, već i nova saznanja o heterogenosti populacije E. amylovora na ovim prostorima.

Historically considered to be simple membrane components serving as structural elements and energy storing entities, fatty acids are now increasingly recognized as potent signaling molecules involved in many metabolic processes. Quantitative determination of fatty acids and exploration of fatty acid profiles have become common place in lipid analysis. We present here a reliable and sensitive method for comprehensive analysis of free fatty acids and fatty acid composition of complex lipids in biological material. The separation and quantitation of fatty acids are achieved by capillary gas chromatography. The analytical method uses pentafluorobenzyl bromide derivatization and negative chemical ionization gas chromatography-mass spectrometry. The chromatographic procedure provides base line separation between saturated and unsaturated fatty acids of different chain lengths as well as between most positional isomers. Fatty acids are extracted in the presence of isotope-labeled internal standards for high quantitation accuracy. Mass spectrometer conditions are optimized for broad detection capacity and sensitivity capable of measuring trace amounts of fatty acids in complex biological samples. .

A total of twenty aerobic endospore-forming bacilli, isolated from marine invertebrates and sea water of different areas of the Pacific Ocean, were taxonomically characterized. Most of the bacilli (11 strains) of marine origin belonged to the species Bacillus subtilis, according to their phenotypic characteristics, antibiotic susceptibility profiles, and fatty acids patterns. A group of four alkaliphilic strains formed a separate cluster that was tentatively classified as B. horti. One isolate, KMM 1717, associated with a sponge from the Coral Sea was identified as B. pumilus. Two strains, Bacillus KMM 1916 and KMM 1918, showed antibiotic sensitivity profiles similar to B. licheniformis, but they had a distinct fatty acid composition and peculiar phenotypic traits. The taxonomic affiliation of KMM 1810 and KMM 1763 remained unclear since their fatty acid composition and antibiotic sensitivity patterns were not resembled with none of these obtained for Bacillus strains.

A new preparation scheme is proposed to fractionate neutral lipids (acylglycerines, sterol esters, long-chain free fatty acids) from polar phospholipids in biological matrices. This fractionation is mandatory in the microbial community, for the control of bioremediation processes, in the study of phytoplankton growth in lakes and rivers, and in the quality control of processed food. Basically, a two-step pressurized liquid extraction (PLE) scheme is combined with an “in-cell-fractionation” using silica-based sorbents placed at the outlet of the PLE cartridge. The optimized extraction scheme consists of n-hexane/acetone (9:1, v/v) extraction at 50 °C (2 cycles, 10 min each) to obtain neutral lipids followed by chloroform/methanol (1:4, v/v) extraction at 110 °C (2 cycles, 10 min each). Thermally pre-treated silicic acid and cyanoproyl-modified silica turned out to be appropriate sorbents to ensure clear-cut boundaries between neutral lipids and phospholipids. The proposed protocol is superior to commonly used approaches consisting of an exhaustive lipid extraction followed by off-line lipid fractionation using solid-phase extraction (SPE) regarding fractionation efficiency, time and solvent consumption. In this paper, it is also shown that the transmethylation using trimethylchlorosilane/methanol (1:9, v/v) provides a complete reaction to give methyl esters without artefact formation across the array of different lipid classes even with polyunsaturated fatty acid moieties.

Microbial fatty acid analysis represents a simple and rapid method for identification of strains mainly for taxonomic purpose. Fatty acid composition in the whole cells and lipopolysaccharides in Rhizobiaceae were studied to point at biochemical events of the nitrogen-fixing symbiosis too. In this study the fatty acid profiles of six strains Bradyrhizobium japonicum and three strains Sinorhizobium meliloti were analyzed. The strains were isolated from soils of Serbia and obtained from collection of Institute of Soil Science. Methyl esters of total fatty acids were prepared from lyophilised biomass using toluene-methanol-sulphuric acid mixture and analyzed using GC-MS method. In Sinorhizobium meliloti strains the main components are 16:0, 218:1. cy-19:0 and in lesser proportion are cy 17:0. 17:0. 18:0. 16:1, 3-OH 14:0, 15:0 and 14:0 fatty acids. The results obtained are in accordance with previously reported data. The absence of 20:3(0 6,9,12cis and 3-OH 16:0 fatty acids in all chromatograms might be explained by differences in derivation method or growth medium used. The ineffective strain (Nod+Fix-) contains remarkable less cyl7:0 acid. Dominant components in Bradyrhizobium japonicum strains are 118:1 and 16:0 fatty acids. Also cy19:0, 18:0 and 16:1 components were detected and certain shifts in the amount of these minor components observed. However, on the basis of our results there is no correlation between the relative content of particular fatty acid and the fixing effectiveness of tested strain., Analiza masnih kiselina mikroorganizama, jednostavna i brza metoda za identifikaciju sojeva, često se koristi u taksonomiji. Masne kiseline celih ćelija i lipopolisaharida kod Rhizobiaccae su od posebnog značaja za proučavanje simbiotske azot o fiksacije. U ovom radu su analizirani profili masnih kiselina šest sojeva Bradvrhizobium japonicum i tri soja Sinorhizobium meliloti. Sojevi su ili izolovani iz uzoraka zemlje rz Srbije ili potiču iz kolekcije Instituta za zemljište. Metil estri ukupnih masnih kiselina su pripremani digestijom liofilizovane biomase u smesi toluol-metanol-sumporna kiselina i analizirani GC-MS metodom. Kod sojeva Sinorhizobium meliloti glavne komponente su 16:0, Z18; l, cj'19:0 i u manjem procentu cy 17:0, 17:0, 18:0, 16:1, 3-OH 14:0, 15:0 i 14:0 masne kiseline. Dobijeni rezultati su u saglasnosti sa literaturnim podacima, a odsustvo 20:3co 6,9.12r/s i 3-OH 16:0 masnih kiselina u svim hromatogramima se može objasniti razlikama u sastavu podloge korišćene za gajenje i načinu pripreme metil estara. Neefektivni soj (Nod+Fix-) sadrži znatno manje cy 17:0 kiseline. Dominantne komponente kod sojeva Bradyrhizobium japonicum su Z18: l i 16:0 masne kiseline. Pored toga detektovane su i cy 19:0, 18:0 and 16:1 masne kiseline. Uočene razlike u koncentraciji ovih minornih komponenata su verovatno posledica različite brzine rasta, pa na osnovu dobijenih rezultata nema korelacije između sadržaja masnih kiselina i efektivnosti azotofiksacije kod ispitivanih sojeva.

Microbial fatty acid analysis represents a simple and rapid method for identification of strains mainly for taxonomic purpose. Fatty acid composition in the whole cells and lipopolysaccharides in Rhizobiaceae were studied to point at biochemical events of the nitrogen-fixing symbiosis too. In this study the fatty acid profiles of six strains Bradyrhizobium japonicum and three strains Sinorhizobium meliloti were analyzed. The strains were isolated from soils of Serbia and obtained from collection of Institute of Soil Science. Methyl esters of total fatty acids were prepared from lyophilised biomass using toluene-methanol-sulphuric acid mixture and analyzed using GC-MS method. In Sinorhizobium meliloti strains the main components are 16:0, 218:1. cy-19:0 and in lesser proportion are cy 17:0. 17:0. 18:0. 16:1, 3-OH 14:0, 15:0 and 14:0 fatty acids. The results obtained are in accordance with previously reported data. The absence of 20:3(0 6,9,12cis and 3-OH 16:0 fatty acids in all chromatograms might be explained by differences in derivation method or growth medium used. The ineffective strain (Nod+Fix-) contains remarkable less cyl7:0 acid. Dominant components in Bradyrhizobium japonicum strains are 118:1 and 16:0 fatty acids. Also cy19:0, 18:0 and 16:1 components were detected and certain shifts in the amount of these minor components observed. However, on the basis of our results there is no correlation between the relative content of particular fatty acid and the fixing effectiveness of tested strain., Analiza masnih kiselina mikroorganizama, jednostavna i brza metoda za identifikaciju sojeva, često se koristi u taksonomiji. Masne kiseline celih ćelija i lipopolisaharida kod Rhizobiaccae su od posebnog značaja za proučavanje simbiotske azot o fiksacije. U ovom radu su analizirani profili masnih kiselina šest sojeva Bradvrhizobium japonicum i tri soja Sinorhizobium meliloti. Sojevi su ili izolovani iz uzoraka zemlje rz Srbije ili potiču iz kolekcije Instituta za zemljište. Metil estri ukupnih masnih kiselina su pripremani digestijom liofilizovane biomase u smesi toluol-metanol-sumporna kiselina i analizirani GC-MS metodom. Kod sojeva Sinorhizobium meliloti glavne komponente su 16:0, Z18; l, cj'19:0 i u manjem procentu cy 17:0, 17:0, 18:0, 16:1, 3-OH 14:0, 15:0 i 14:0 masne kiseline. Dobijeni rezultati su u saglasnosti sa literaturnim podacima, a odsustvo 20:3co 6,9.12r/s i 3-OH 16:0 masnih kiselina u svim hromatogramima se može objasniti razlikama u sastavu podloge korišćene za gajenje i načinu pripreme metil estara. Neefektivni soj (Nod+Fix-) sadrži znatno manje cy 17:0 kiseline. Dominantne komponente kod sojeva Bradyrhizobium japonicum su Z18: l i 16:0 masne kiseline. Pored toga detektovane su i cy 19:0, 18:0 and 16:1 masne kiseline. Uočene razlike u koncentraciji ovih minornih komponenata su verovatno posledica različite brzine rasta, pa na osnovu dobijenih rezultata nema korelacije između sadržaja masnih kiselina i efektivnosti azotofiksacije kod ispitivanih sojeva.

Microbial fatty acid analysis represents a simple and rapid method for identification of strains mainly for taxonomic purpose. Fatty acid composition in the whole cells and lipopolysaccharides in Rhizobiaceae were studied to point at biochemical events of the nitrogen-fixing symbiosis too. In this study the fatty acid profiles of six strains Bradyrhizobium japonicum and three strains Sinorhizobium meliloti were analyzed. The strains were isolated from soils of Serbia and obtained from collection of Institute of Soil Science. Methyl esters of total fatty acids were prepared from lyophilised biomass using toluene-methanol-sulphuric acid mixture and analyzed using GC-MS method. In Sinorhizobium meliloti strains the main components are 16:0, 218:1. cy-19:0 and in lesser proportion are cy 17:0. 17:0. 18:0. 16:1, 3-OH 14:0, 15:0 and 14:0 fatty acids. The results obtained are in accordance with previously reported data. The absence of 20:3(0 6,9,12cis and 3-OH 16:0 fatty acids in all chromatograms might be explained by differences in derivation method or growth medium used. The ineffective strain (Nod+Fix-) contains remarkable less cyl7:0 acid. Dominant components in Bradyrhizobium japonicum strains are 118:1 and 16:0 fatty acids. Also cy19:0, 18:0 and 16:1 components were detected and certain shifts in the amount of these minor components observed. However, on the basis of our results there is no correlation between the relative content of particular fatty acid and the fixing effectiveness of tested strain., Analiza masnih kiselina mikroorganizama, jednostavna i brza metoda za identifikaciju sojeva, često se koristi u taksonomiji. Masne kiseline celih ćelija i lipopolisaharida kod Rhizobiaccae su od posebnog značaja za proučavanje simbiotske azot o fiksacije. U ovom radu su analizirani profili masnih kiselina šest sojeva Bradvrhizobium japonicum i tri soja Sinorhizobium meliloti. Sojevi su ili izolovani iz uzoraka zemlje rz Srbije ili potiču iz kolekcije Instituta za zemljište. Metil estri ukupnih masnih kiselina su pripremani digestijom liofilizovane biomase u smesi toluol-metanol-sumporna kiselina i analizirani GC-MS metodom. Kod sojeva Sinorhizobium meliloti glavne komponente su 16:0, Z18; l, cj'19:0 i u manjem procentu cy 17:0, 17:0, 18:0, 16:1, 3-OH 14:0, 15:0 i 14:0 masne kiseline. Dobijeni rezultati su u saglasnosti sa literaturnim podacima, a odsustvo 20:3co 6,9.12r/s i 3-OH 16:0 masnih kiselina u svim hromatogramima se može objasniti razlikama u sastavu podloge korišćene za gajenje i načinu pripreme metil estara. Neefektivni soj (Nod+Fix-) sadrži znatno manje cy 17:0 kiseline. Dominantne komponente kod sojeva Bradyrhizobium japonicum su Z18: l i 16:0 masne kiseline. Pored toga detektovane su i cy 19:0, 18:0 and 16:1 masne kiseline. Uočene razlike u koncentraciji ovih minornih komponenata su verovatno posledica različite brzine rasta, pa na osnovu dobijenih rezultata nema korelacije između sadržaja masnih kiselina i efektivnosti azotofiksacije kod ispitivanih sojeva.

The role of the cell envelope in the solvent tolerance mechanisms of Pseudomonas putida was investigated. The responses of a solvent-tolerant strain, P. putida Idaho, and a solvent-sensitive strain, P. putida MW1200, were examined in terms of phospholipid content and composition and of phospholipid biosynthetic rate following exposure to a nonmetabolizable solvent, o-xylene. Following o-xylene exposure, P. putida MW1200 exhibited a decrease in total phospholipid content. In contrast, P. putida Idaho demonstrated an increase in phospholipid content 1 to 6 h after exposure. Analysis of phospholipid biosynthesis showed P. putida Idaho to have a higher basal rate of phospholipid synthesis than MW1200. This rate increased significantly following exposure to xylene. Both strains showed little significant turnover of phospholipid in the absence of xylene. In the presence of xylene, both strains showed increased phospholipid turnover. The rate of turnover was significantly greater in P. putida Idaho than in P. putida MW1200. These results suggest that P. putida Idaho has a greater ability than the solvent-sensitive strain MW1200 to repair damaged membranes through efficient turnover and increased phospholipid biosynthesis., Published in the Journal of Bacteriology, v179 n13 p4219-4226, Jul 1997.