Fatty Acid Composition Data Research Articles

Global Estimates of Dietary Intake of Docosahexaenoic Acid and Arachidonic Acid in Developing and Developed Countries

Background/Aim: For international recommendations on docosahexaenoic acid (DHA) and arachidonic acid (ARA) dietary intake to be valid, there needs to be a greater understanding of dietary patterns across both the developed and developing world. The aim of this investigation was to provide a global overview of dietary intake of DHA and ARA. Methods: Food balance sheets from the Food and Agriculture Organisation Statistics Division and fatty acid composition data from Australian food composition tables in Nutrient Tables 2010 were utilised to generate median per capita intake estimates for DHA and ARA in 175 countries worldwide. Results: Estimated dietary intake per capita for DHA and ARA in 47 developed and 128 developing countries demonstrated that 48% of the 175 countries have an ARA intake of <150 mg/day and 64% have a dietary DHA intake of <200 mg/day. There was a direct relationship between dietary ARA and DHA intake and the per capita gross national income of the country. Regional analysis showed the lowest ARA and DHA dietary intake in Sub-Saharan Africa and Central and Southern Asian populations. Conclusions: This study demonstrates there are many populations worldwide that have ARA and DHA intake that do not reflect current international recommendations, and the public health consequences of this global inadequacy need to be urgently considered.

Modeling the impact of residual fat-soluble vitamin (FSV) contents on the oxidative stability of commercially refined vegetable oils

Fat-soluble vitamins (FSVs) may prevent or delay bulk lipid oxidation by exerting antioxidant action. However, literature data obtained from storage tests on commercial edible oils do not necessarily confirm a direct correlation between FSV contents of bulk oils and their measured oxidative stability. This, of course, may be predominantly due to their refining history, which can strip them of much of their FSV contents and/or standardize these values. The main goal of this study was to quantify the magnitude of the role of FSVs in hindering commercial edible lipid oxidation. Fatty acid composition and FSV content data were collected on a large mixed set of commercial vegetable oils devoid of added antioxidant stabilizers (n=123) in order to establish baseline values for these constituents. Next, a random subset of these oils (n=50) was then subjected to the oil stability index test (OSI at 120°C), as well as accelerated storage testing over time (60°C) whilst monitoring a host of classical methodologies used to monitor oxidation progress. A new aggregate parameter (i.e., a sum area under the lipid oxidation curves, or ‘All Area’) was introduced to better capture the total quantity of primary and secondary oxidation products accumulated in the samples tested over the storage period. Multivariate regression modeling was used to correlate the fatty acid composition of the samples with their oxidative stability data both including and excluding FSV contents in order to determine a magnitude for this relationship. As noted herein, the addition of FSV data improved the fitting of the model from R2Adj. 0.877 to 0.925 using OSI data alone and from R2Adj. 0.938 to 0.960 using the ‘All Area’ parameter. Correlations between specific FSVs and fatty acid compositional parameters exhibited a strong relationship with lipid category. Furthermore, principal component analysis of FSV contents revealed clustering of lipids based both on lipid category and refining history.

Development of a reliable GC-MS method for fatty acid profiling using direct transesterification of minimal quantities of microscopic orchid seeds

AbstractOrchid seeds are among the smallest seeds in nature and they are naturally rich in fatty acids. However, the fatty acid composition of orchid seeds has not been investigated because the sample masses utilized for widely used methods for fatty acid profiling would generally require prohibitively large numbers (i.e. 10,000s) of seeds. The present work aimed to develop a method for fatty acid analysis using gas chromatography–mass spectrometry on small quantities (mg) of seeds. The method was developed using the seeds of two species,Dactylorhiza fuchsii, a temperate terrestrial, andGrammatophyllum speciosum, a tropical epiphyte. A range of sample masses was tested to determine the minimum mass required to achieve reliable fatty acid composition data. A direct transesterification method was used, which did not require extraction of fatty acids from seeds prior to analysis, and the effects of seed processing (crushed versus intact seeds) and incubation time in toluene on fatty acid yield were tested. Stable fatty acid profiles were obtained using as little as 10 mg of seeds. Neither crushing the seeds nor extending the toluene incubation step had much effect on the fatty acid yield. The simple direct transesterification method presented will enable the fatty acid composition of orchid seeds, and possibly other small seeds, to be determined reliably for studies into seed development, storage and germination.

Translating plasma and whole blood fatty acid compositional data into the sum of eicosapentaenoic and docosahexaenoic acid in erythrocytes

Specific blood levels of eicosapentaenoic plus docosahexaenoic acid (EPA+DHA, wt% of total) in erythrocytes or “the omega-3 index” have been recommended for cardio-protection, but fatty acids are often measured in different blood fractions. The ability to estimate the % of EPA+DHA in erythrocytes from the fatty acid composition of other blood fractions would enable clinical assessments of omega-3 status when erythrocyte fractions are not available and increase the ability to compare blood levels of omega-3 fatty acids across clinical studies. The fatty acid composition of baseline plasma, erythrocytes and whole blood samples from participants (n=1104) in a prospective, multicenter study examining acute coronary syndrome were determined. The ability to predict the % of EPA+DHA in erythrocytes from other blood fractions were examined using bivariate and multiple linear regression modelling. Concordance analysis was also used to compare the actual erythrocytes EPA+DHA values to values estimated from other blood fractions. EPA+DHA in erythrocytes was significantly (p<0.001) correlated EPA+DHA in plasma (r2=0.54) and whole blood (r2=0.79). Using multiple linear regression to predict EPA+DHA in erythrocytes resulted in stronger coefficients of determination in both plasma (R2=0.70) and whole blood (R2=0.84). Concordance analyses indicated agreement between actual and estimated EPA+DHA in erythrocytes, although estimating from plasma fatty acids appears to require translation by categorization rather than by translation as continuous data. This study shows that the fatty acid composition of different blood fractions can be used to estimate erythrocyte EPA+DHA in a population with acute coronary syndrome.

Brachybacterium hainanense sp. nov., isolated from noni (Morinda citrifolia L.) branch.

A Gram-stain-positive bacterial strain, designated as NR2T, isolated from noni (Morinda citrifolia L.) branch was investigated using a polyphasic taxonomic approach. The cells were small coccoid to ovoid, non-spore-forming and motile. Phylogenetic analysis based on 16S rRNA gene sequences showed that the strain was a representative of a member of the genus Brachybacterium, to which the most closely related neighbours were Brachybacterium squillarum M-6-3T (97.90 % similarity), Brachybacterium faecium DSM 4810T (97.50 %), Brachybacterium sacelli LMG 20345T (97.41 %), Brachybacterium phenoliresistens phenol-AT (97.36 %), Brachybacterium nesterenkovii DSM 9573T (97.36 %) and Brachybacterium rhamnosum LMG 19848T (97.32 %). The polar lipid profile of strain NR2T consisted of diphosphatidylglycerol, phosphatidylglycerol, unknown phospholipids and unknown glycolipids. The predominant respiratory quinone was MK-8, with MK-9 and MK-7 as minor components. The major fatty acids were anteiso-C15 : 0 and iso-C15 : 0. Strain NR2T was clearly distinguishable from the type strains of related species on the basis of phylogenetic analysis, DNA-DNA hybridization, fatty acid composition data analysis and a range of physiological and comparison of biochemical characteristics. It is evident from the genotypic and phenotypic data that strain NR2T represents a novel species of the genus Brachybacterium, for which the name Brachybacterium hainanense sp. nov. is proposed. The type strain is NR2T ( = DSM 29535T = CICC 10874T).

Sphingomonas morindae sp. nov., isolated from Noni (Morinda citrifolia L.) branch.

Two yellow bacterial strains, designated NBD5(T) and NBD8, isolated from Noni (Morinda citrifolia L.) branch were investigated using a polyphasic taxonomic approach. Cells were Gram-stain-negative, aerobic, non-spore-forming, non-motile and short rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequences suggested that the strains were members of a novel species of the genus Sphingomonas, the seven closest neighbours being Sphingomonas oligoaromativorans SY-6(T) (96.9% similarity), Sphingomonas polyaromaticivorans B2-7(T) (95.8%), Sphingomonas yantingensis 1007(T) (94.9%), Sphingomonas sanguinis IFO 13937(T) (94.7%), Sphingomonas ginsenosidimutans Gsoil 1429(T) (94.6%), Sphingomonas wittichii RW1(T) (94.6%) and Sphingomonas formosensis CC-Nfb-2(T) (94.5%). Strains NBD5T and NBD8 had sphingoglycolipid, phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and phosphatidylcholine as the major polar lipids, ubiquinone 10 as the predominant respiratory quinone, and sym-homospermidine as the major polyamine. Strains NBD5(T) and NBD8 were clearly distinguished from reference type strains based on phylogenetic analysis, DNA-DNA hybridization, fatty acid composition data analysis, and comparison of a range of physiological and biochemical characteristics. It is evident from the genotypic and phenotypic data that strains NBD5(T) and NBD8 represent a novel species of the genus Sphingomonas, for which the name Sphingomonas morindae sp. nov. is proposed. The type strain is NBD5(T) ( = DSM 29151(T) = KCTC 42183(T) = CICC 10879(T)).

Phaeodactylibacter luteus sp. nov., isolated from the oleaginous microalga Picochlorum sp.

A Gram-staining-negative, orange-pigmented, non-motile, aerobic bacterial strain, designated GYP20T, was isolated from a culture of the alga Picochlorum sp., a promising feedstock for biodiesel production, which was isolated from the India Ocean. Growth was observed at temperatures from 20 to 37 °C, salinities from 0 to 3% and pH from 5 to 9.Mg2+ and Ca2+ ions were required for growth. Phylogenetic analysis based on 16S rRNA gene sequencing revealed that the strain was a member of the genus Phaeodactylibacter, which belongs to the family Saprospiraceae. Strain GYP20T was most closely related to Phaeodactylibacter xiamenensis KD52T (95.5% sequence similarity). The major fatty acids were iso-C15 : 1 G, iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3. The predominant respiratory quinone was menaquinone-7 (MK-7). The polar lipids of strain GYP20T were found to consist of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, four unidentified glycolipids, two unidentified phospholipids and three unidentified aminolipids. According to its morphology, physiology, fatty acid composition and 16S rRNA sequence data, the novel strain most appropriately belongs to the genus Phaeodactylibacter, but can readily be distinguished from Phaeodactylibacter xiamenensis GYP20T. The name Phaeodactylibacter luteus sp. nov. is proposed with the type strain GYP20T ( = MCCC 1F01222T = KCTC 42180T).

Description of Comamonas serinivorans sp. nov., isolated from wheat straw compost.

A Gram-stain-negative bacterium, designated SP-35(T), was isolated from compost and was subjected to a taxonomic study. This isolate was short-rod-shaped and non-spore-forming. Phylogenetic analysis based on 16S rRNA sequence comparison indicated the isolate was related to the genus Comamonas. 16S rRNA gene sequence analysis showed that its closest neighbours were the type strains Comamonas odontotermitis Dant 3-8(T) (96.8 % similarity), Comamonas testosteroni DSM 50244(T) (96.5 %), Comamonas guangdongensis CY01(T) (95.9 %) and Comamonas composti YY287(T) (95.6 %). Using phylogenetic analysis, DNA-DNA hybridization, fatty acid composition data and a range of physiological and biochemical characteristics we could clearly distinguish strain SP-35(T) from type strains of the genus Comamonas. The genomic DNA G+C content of strain SP-35(T) was 63.1 mol%. The predominant cellular fatty acids were C16 : 0, C17 : 0 cyclo, summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c) and summed feature 8 (C18 : 1ω6c and/or C18 : 1ω7c). The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidlyglycerol. Differences in phenotypic and phylogenetic characteristics support the classification of strain SP-35(T) as a representative of a novel species in the genus Comamonas, for which the name Comamonas serinivorans sp. nov. is proposed. The type strain is SP-35(T) ( = DSM 26136(T) = JCM 18194(T)).

Chitinimonas prasina sp. nov., isolated from lake water.

A Gram-stain-negative, elongated rod-shaped, motile by gliding, green-pigmented, aerobic bacterial strain, designated LY03(T), was isolated from lake water in Xiamen, Fujian Province, China. Phylogenetic analysis based on 16S rRNA gene sequencing revealed that the isolate was a member of the genus Chitinimonas, which belongs to the family Burkholderiaceae. Strain LY03(T) was most closely related to Chitinimonas taiwanensis LMG 22011(T) (96.02 % 16S rRNA gene sequence similarity), followed by Chitinimonas koreensis KACC 11467(T) (94.85 %), and the three strains formed a distinct lineage from other strains in the phylogenetic analyses. Optimum conditions for growth were 37 °C, pH 7-9 and without NaCl. The major fatty acids were summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), C16 : 0 and C10 : 0 3-OH. The DNA G+C content of strain LY03(T) was 63.6 mol% and the major respiratory quinone was ubiquinone-8 (Q-8). The polar lipids were found to consist of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unknown polar lipids and unidentified phospholipids. Differential phenotypic properties and phylogenetic distinctiveness distinguished strain LY03(T) from all other members of the genus Chitinimonas. On the basis of its morphology, physiology, fatty acid composition and 16S rRNA gene sequence data, strain LY03(T) represents a novel species of the genus Chitinimonas, for which the name Chitinimonas prasina sp. nov. is proposed. The type strain is LY03(T) ( = MCCC 1F01209(T) = KCTC 32574(T)).

Fatty acid composition and desaturase gene expression in flax (Linum usitatissimum L.).

Little is known about the relationship between expression levels of fatty acid desaturase genes during seed development and fatty acid (FA) composition in flax. In the present study, we looked at promoter structural variations of six FA desaturase genes and their relative expression throughout seed development. Computational analysis of the nucleotide sequences of the sad1, sad2, fad2a, fad2b, fad3a and fad3b promoters showed several basic transcriptional elements including CAAT and TATA boxes, and several putative target-binding sites for transcription factors, which have been reported to be involved in the regulation of lipid metabolism. Using semi-quantitative reverse transcriptase PCR, the expression patterns throughout seed development of the six FA desaturase genes were measured in six flax genotypes that differed for FA composition but that carried the same desaturase isoforms. FA composition data were determined by phenotyping the field grown genotypes over four years in two environments. All six genes displayed a bell-shaped pattern of expression peaking at 20 or 24 days after anthesis. Sad2 was the most highly expressed. The expression of all six desaturase genes did not differ significantly between genotypes (P = 0.1400), hence there were no correlations between FA desaturase gene expression and variations in FA composition in relatively low, intermediate and high linolenic acid genotypes expressing identical isoforms for all six desaturases. These results provide further clues towards understanding the genetic factors responsible for FA composition in flax.Electronic supplementary materialThe online version of this article (doi:10.1007/s13353-014-0222-0) contains supplementary material, which is available to authorized users.

Spatial and Temporal Changes in Estuarine Food Web Structure: Differential Contributions of Marsh Grass Detritus

We measured stable isotope signatures and fatty acid profiles in dominant consumers and basal food sources to assess spatial and temporal changes in the trophic structure within an estuarine ecosystem. The consumers analyzed included zooplankton, benthic invertebrates and fishes from the upper, middle and lower reaches of the estuary collected over four seasons. The contributions of different food sources to the consumers were assessed using the isotopic mixing model stable isotope analysis in R (SIAR). Our stable isotope and fatty acid data indicated that the food webs differed significantly among reaches and seasons within the estuary. Benthic invertebrates exhibited lower carbon isotopic (δ13C) values in the upper reaches of the estuary during all seasons, with lowest values occurring during autumn. In contrast, nitrogen isotopic (δ15N) values of consumers were higher in the upper reaches of the estuary and were highest during summer and spring. SIAR models and fatty acid compositional data both indicated greater utilization of marsh grass by consumers inhabiting the lower reaches of the estuary, particularly during autumn and winter. Our data indicated that differential inputs of detritus contributed to spatial changes in the benthic estuarine food web structure and that the trends changed throughout the year.

Traditional food in Serbia: Sources, recipes and fatty acids profiles

Traditional foods play a major role in traditions of different cultures and regions for thousands of years while preparation methods of traditional foods are part of the folklore of a country or a region. This paper presents recipes and fatty acid profiles of selected commonly consumed traditional foods in Serbia. The obtained fatty acid composition data are used for making conclusions about meals which are commonly consumed in Serbia. Traditional Serbian dairy products, cheese and kajmak, contained 70% SFAs (mostly palmitic acid). Commonly used meal in Serbian cuisine, prebranac, also contained palmitic acid and oleic acid (38.67% and 35.58% respectively), while linoleic acid was presented with 17.34%, similarly to vanilice. Ajvar, frequently used as a salad, is rich in linoleic acid (49.12%) but less rich in palmitic acid. Trans fatty acids were found in very small amounts in all foods.

Altererythrobacter xiamenensis sp. nov., an algicidal bacterium isolated from red tide seawater

A Gram-stain-negative, yellow-pigmented, aerobic bacterial strain, designated LY02(T), was isolated from red tide seawater in Xiamen, Fujian Province, China. Growth was observed at temperatures from 4 to 44 °C, at salinities from 0 to 9% and at pH from 6 to 10. Phylogenetic analysis based on 16S rRNA gene sequencing revealed that the isolate was a member of the genus Altererythrobacter, which belongs to the family Erythrobacteraceae. Strain LY02(T) was related most closely to Altererythrobacter marensis MSW-14(T) (97.2% 16S rRNA gene sequence similarity), followed by Altererythrobacter ishigakiensis JPCCMB0017(T) (97.1%), Altererythrobacter epoxidivorans JCS350(T) (97.1%) and Altererythrobacter luteolus SW-109(T) (97.0%). The dominant fatty acids were C(18 : 1)ω7c, C(17 : 1)ω6c and summed feature 3 (comprising C(16 : 1)ω7c and/or C(16 : 1)ω6c). DNA-DNA hybridization showed that strain LY02(T) possessed low DNA-DNA relatedness to A. marensis MSW-14(T), A. ishigakiensis JPCCMB0017(T), A. epoxidivorans JCS350(T) and A. luteolus SW-109(T) (mean ± SD of 33.2 ± 1.3, 32.1 ± 1.0, 26.7 ± 0.7 and 25.2 ± 1.1 %, respectively). The G+C content of the chromosomal DNA was 61.2 mol%. The predominant respiratory quinone was ubiquinone-10 (Q-10). According to its morphology, physiology, fatty acid composition and 16S rRNA gene sequence data, the novel strain most appropriately belongs to the genus Altererythrobacter, but can readily be distinguished from recognized species. The name Altererythrobacter xiamenensis sp. nov. is proposed (type strain LY02(T) = CGMCC 1.12494(T) = KCTC 32398(T) = NBRC 109638(T)).

Genetic variation of six desaturase genes in flax and their impact on fatty acid composition.

Flax (Linum usitatissimum L.) is one of the richest plant sources of omega-3 fatty acids praised for their health benefits. In this study, the extent of the genetic variability of genes encoding stearoyl-ACP desaturase (SAD), and fatty acid desaturase 2 (FAD2) and 3 (FAD3) was determined by sequencing the six paralogous genes from 120 flax accessions representing a broad range of germplasm including some EMS mutant lines. A total of 6 alleles for sad1 and sad2, 21 for fad2a, 5 for fad2b, 15 for fad3a and 18 for fad3b were identified. Deduced amino acid sequences of the alleles predicted 4, 2, 3, 4, 6 and 7 isoforms, respectively. Allele frequencies varied greatly across genes. Fad3a, with 110 SNPs and 19 indels, and fad3b, with 50 SNPs and 5 indels, showed the highest levels of genetic variations. While most of the SNPs and all the indels were silent mutations, both genes carried nonsense SNP mutations resulting in premature stop codons, a feature not observed in sad and fad2 genes. Some alleles and isoforms discovered in induced mutant lines were absent in the natural germplasm. Correlation of these genotypic data with fatty acid composition data of 120 flax accessions phenotyped in six field experiments revealed statistically significant effects of some of the SAD and FAD isoforms on fatty acid composition, oil content and iodine value. The novel allelic variants and isoforms identified for the six desaturases will be a resource for the development of oilseed flax with unique and useful fatty acid profiles.Electronic supplementary materialThe online version of this article (doi:10.1007/s00122-013-2161-2) contains supplementary material, which is available to authorized users.

Tenacibaculum xiamenense sp. nov., an algicidal bacterium isolated from coastal seawater

A Gram-stain-negative, elongated rod-shaped, yellow-pigmented, aerobic bacterial strain, designated WJ-1(T), was isolated from coastal seawater in Xiamen, Fujian province, China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain WJ-1(T) fell within the genus Tenacibaculum and was most closely associated with Tenacibaculum aestuarii SMK-4(T) (96.7% 16S rRNA gene sequence similarity); lower similarities were shown to other members of the genus Tenacibaculum (<96.2%). The strain formed a distinct lineage with Tenacibaculum litopenaei B-I(T) (96.0%), Tenacibaculum geojense YCS-6(T) (94.5%) and Tenacibaculum jejuense CNURIC 013(T) (95.4%). Growth was observed at temperatures from 16 to 38 °C, at salinities from 2 to 4% and at pH 6-9. The major fatty acids were summed feature 3 (C(16:1)ω6c and/or C(16 1)ω7c), iso-C(17:0) 3-OH, iso-C(15:0) and iso-C(15:0) 3-OH. The DNA G+C content of strain WJ-1(T) was 33.2 mol% and the major respiratory quinone was menaquinone-6 (MK-6). Differential phenotypic properties and phylogenetic distinctiveness in this study distinguished strain WJ-1(T) from all other members of the genus Tenacibaculum. According to the morphology, physiology, fatty acid composition and 16S rRNA gene sequence data, strain WJ-1(T) represents a novel species of the genus Tenacibaculum, for which the name Tenacibaculum xiamenense sp. nov. is proposed. The type strain is WJ-1(T) ( =CGMCC 1.12378(T) =LMG 27422(T)).

Mangrovimonas yunxiaonensis gen. nov., sp. nov., isolated from mangrove sediment

A Gram-negative, short-rod-shaped, orange-pigmented bacterium, strain LYYY01(T), was isolated from a mangrove sediment sample collected from Yunxiao mangrove National Nature Reserve, Fujian Province, China. 16S rRNA gene sequence comparisons showed that strain LYYY01(T) is a member of the family Flavobacteriaceae, forming a distinct lineage with species of the genera Meridianimaribacter, Sediminibacter, Gelidibacter and Subsaximicrobium. The 16S rRNA gene sequence similarity between strain LYYY01(T) and the type strains of related species ranged from 93.9 to 90.9%. Growth was observed at temperatures from 10 to 38 °C, at salinities from 1 to 7% and at pH from 6 to 10. The DNA G+C content of the strain was 38.6 mol% and the major respiratory quinone was menaquinone-6 (MK-6). The major fatty acids were iso-C15:1 (27.6%), iso-C15:0 (24.0%), iso-C17:0 3-OH (12.0%) and iso-C16:0 3-OH (6.2%). According to its morphology, physiology, fatty acid composition and 16S rRNA gene sequence data, strain LYYY01(T) is considered to represent a novel species of a new genus in the family Flavobacteriaceae, for which the name Mangrovimonas yunxiaonensis gen. nov., sp. nov. is proposed. The type strain of Mangrovimonas yunxiaonensis is LYYY01(T) (=CGMCC 1.12280(T)=LMG 27142(T)).

Algoriphagus zhangzhouensis sp. nov., isolated from mangrove sediment

A Gram-negative, short-rod-shaped and non-motile bacterium, strain 12C11(T), was isolated from an oil-degrading consortium, enriched from the Fugong mangrove sediment, Fujian Province of China. Optimum growth was observed at 25 °C, at pH 7.5 and with 4 % (w/v) NaCl. Comparative 16S rRNA gene sequence analysis demonstrated that it shared highest similarity with members of the genus Algoriphagus (97.5-93.4 %), exhibiting 97.5 % sequence similarity to Algoriphagus ornithinivorans IMSNU 14014(T), followed by Algoriphagus vanfongensis KMM 6241(T) (97.2 %); it shared <96.0 % sequence similarity with other members of the genus. Levels of nucleotide sequence similarity between gyrB (DNA gyrase subunit B) genes of strain 12C11(T) and A. vanfongensis KMM 6241(T), A. ornithinivorans IMSNU 14014(T), Algoriphagus marincola SW-2(T) and Algoriphagus hitonicola 7-UAH(T) were 78.8, 78.6, 75.6 and 77.4 %, respectively. Phylogenetic trees based on these housekeeping genes showed that strain 12C11(T) and other Algoriphagus strains formed a distinct lineage. The dominant fatty acids were iso-C15 : 0 (32.1 %), C16 : 1ω7c/C16 : 1ω6c (11.6 %), iso-C17 : 1 I/anteiso-C17 : 1 B (10.1 %), iso-C17 : 0 3-OH (9.2 %) and iso-C17 : 1ω9c/C16 : 0 10-methyl (7.1 %), which accounted for 70.0 % of the total fatty acids. DNA-DNA hybridization showed that strain 12C11(T) shared low DNA-DNA relatedness with A. vanfongensis KMM 6241(T) and A. ornithinivorans IMSNU 14014(T) (30.7±0.9 and 30.5±1.8 %, respectively). The G+C content of the chromosomal DNA of strain 12C11(T) was 38.4 mol%. The major respiratory quinones were MK-7 (96.0 %) and MK-6 (4.0 %). According to its morphology, physiology, fatty acid composition and 16S rRNA gene sequence data, the novel strain most appropriately belongs to the genus Algoriphagus, but can readily be distinguished from known Algoriphagus species. The name Algoriphagus zhangzhouensis sp. nov. is proposed (type strain 12C11(T) = CGMCC 1.11027(T) = MCCC 1F01099(T) = DSM 25035(T)).

Distinguishing Coconut Oil from Coconut Paring Oil using Principle Component Analysis of Fatty Acid Data

A study was carried out to distinguish coconut oil from coconut pairing oil by the application of principal component analysis (PCA) to fatty acid compositional and iodine value data. Five samples of ordinary coconut oil extracted from five different batches of copra and five samples of coconut pairing oil obtained from five batches of dried coconut pairings were employed. Fatty acid composition and iodine values of oil samples were determined individually and the data were analyzed statistically. PCA analysis showed that lauric and oleic acid contents and iodine value data are the most influencing parameters to discriminate coconut oil from coconut pairing oil. Hence, the application of PCA to fatty acid compositional and iodine value data was successful in distinguishing coconut oil from coconut pairing oil.

Development of Pattern Recognition Algorithms for Identification of Gut Microorganisms using Fatty Acid Signatures

A pattern recognition algorithm was developed that was capable of accurately identifying the presence of specific microbial species in gut samples from the sample's composite fatty acid signature. We focused on 51 different species found in the human gut and 61 different fatty acids produced by those species. The unique fatty acid signatures of the individual microorganisms were obtained by gas chromatography (provided by MIDI Inc). Several algorithms were developed in Matlab to differentiate individual species using the fatty acid composition data of the simulated mixtures. These algorithms utilized Hamming distance, least‐squares optimization, and combinatorics methods to identify the presence of each species. The algorithms were tested against myriad virtual samples to analyze their ability to detect the presence of selected species. While more complex mixtures of species decreased the probability of detection, we found that utilizing a constrained least‐squares method with Hamming‐based filters provided high probabilities of detection for all tested samples. This algorithm was capable of detecting the presence of a selected species over 90% of the time for instrument tolerances as high as 15%.

Concerns over the reporting of inconsistent data on fatty acid composition for microalgae of the genus Nannochloropsis (Eustigmatophyceae)

Letter to editor The current research focus on the development of nextgeneration alternative sources of biofuel from microalgal oil has led to a considerable increase in the number of studies on various oleaginous species. The studies have been examining species promising for high neutral lipid (mainly triacylglycerol; TAG) and biomass productivity under diverse cultivation conditions, with the aim to develop sustainable, commercially feasible, and economic processes for the production of biofuels (Rodolfi et al. 2009; Tredici 2010). Given the relative robustness and marine origin of microalgae of the genus Nannochloropsis and their high content of neutral lipids (Sukenik 1999; Sukenik et al. 2009; Rodolfi et al. 2009), a large number of projects have been devoted to these microalgae, including studies focusing on evaluating the effects of growth conditions on lipid productivity and fatty acid composition (Boussiba et al. 1987; Chini Zittelli et al. 1999; Chiu et al. 2009; Hodgson et al. 1991; Renaud et al. 1991; Renaud and Parry 1994; Richmond et al. 2003; Sukenik 1999; Sukenik et al. 2009). Nannochloropsis species are also a valuable source of the ω3 long-chain polyunsaturated fatty acid, eicosapentaenoic acid (20:5n-3, EPA) for aquaculture and even for human nutrition. These eustigmatophytes are characterized by a typical fatty acid composition that features four abundant fatty acids (Table 1): palmitic (16:0), palmitoleic (16:1n-7), arachidonic acid (20:4n-6), and eicosapentaenoic acid (20:5n-3) (Sukenik 1999; Volkman et al. 1993). C18 fatty acids are represented mainly by oleic acid (18:1); unsaturated 18:2 and n-3 and n-6 isomers of 18:3 account for only a small portion of the total fatty acids, with the actual amounts depending on the growth conditions. Although the proportions of the major fatty acids vary under different cultivation conditions, their abundances are fairly consistent across the different strains and thus constitute a useful chemotaxonomic feature. Table 1 presents the well-established characteristic features of several well-studied strains of N. salina (strain CS-190) and three strains of Nannochloropsis oculata (CS-170, CS179, and CS-216; data taken from Volkman et al. 1993; Renaud and Parry 1994). We have noticed that a recent publication reports fatty acid composition data for Nannochloropsis cultures (Su et al. 2010) that are inconsistent with the above data in that it describes high relative percentages of 18:2 and 18:3(n-3) (Table 1). It is likely that the high proportions of these fatty acids are due to severe contamination of the cultures with green microalgae, typically rich in C18 PUFA. Moreover, the marked increase in the proportion of oleic acid 18:1(n-9) and disappearance of 16:1(n-7) under nitrogen starvation conditions further indicates the enhanced formation of storage TAG in cells of the contaminating algae but not in N. oculata. Characteristically, TAG of Nannochloropsis species are rich in 16:0 and 16:1(n-7) fatty acids (Sukenik 1999); their combined proportions increase up to 70–80% of total fatty acids under stress conditions, such as nitrogen starvation or high light intensity (Pal, Khozin-Goldberg, Boussiba, unpublished), while 18:1 accounts for about 10% of total fatty acids. Results for biomass and lipid productivity that are obtained in the cultures featuring fatty acid profile I. Khozin-Goldberg (*) : S. Boussiba Microalgal Biotechnology Laboratory, French Associates Institute of Agriculture and Biotechnology, J. Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Midreshet Ben-Gurion 84990, Israel e-mail: khozin@bgu.ac.il