Oil extraction from microalga Nannochloropsis sp. with isopropyl alcohol

An efficient process for fractioning microalgae oil and non-lipid biomass was developed. Isopropyl alcohol (IPA) was used to extract oil from Nannochloropsis sp. at 80 °C, leaving the majority of non-lipid biomass in the solid fraction. The effectiveness of extraction with or without a dewatering pretreatment (DW) was compared. Effects of dewatering time and solvent ratio, IPA concentration, IPA refluxing time, and sonication pretreatment on the oil and biomass yields were studied. The dewatering conditions with a high water-to-alcohol ratio (W/A = 2:1) and mild mixing (1 min gentle shaking) had 14 % less oil loss in the DW fraction than that with a low water-to-alcohol ratio (W/A = 1:1) and vigorous mixing (30 min and 300 rpm mixing). Sonication resulted in 14?26 % more oil loss in the DW fraction when compared to intact cell treatment. Without dewatering, 85 % of the total oil from intact cells was extracted by a single extraction using 70 % (wt) IPA aqueous solution. The 88 and 95 % IPA treatments extracted similar percentages of oil to that of the 70 % IPA, but used two- and fivefold more solvent. The amount of oil extracted from broken cells increased with increasing IPA concentrations. An effective extraction can be completed in 30 min. On a 100-g (wet matter) scale, the 70 % IPA achieved 92 % oil yield and 93 % non-lipid biomass yield.Fil: Yao, Linxing. IOWA STATE UNIVERSITY (ISU);Fil: Gerde, Jose Arnaldo. IOWA STATE UNIVERSITY (ISU); . Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Rosario; ArgentinaFil: Wang, Tong. IOWA STATE UNIVERSITY (ISU)

Metabolic compounds within the porcine uterine environment are unique to the type of conceptus present during the early stages of blastocyst elongation

The objective of this study was to identify metabolites within the porcine uterine milieu during the early stages of blastocyst elongation. At Days 9, 10, or 11 of gestation, reproductive tracts of White cross‐bred gilts (n = 38) were collected immediately following harvest and flushed with Roswell Park Memorial Institute‐1640 medium. Conceptus morphologies were assessed from each pregnancy and corresponding uterine flushings were assigned to one of five treatment groups based on these morphologies: (a) uniform spherical (n = 8); (b) heterogeneous spherical and ovoid (n = 8); (c) uniform ovoid (n = 8); (d) heterogeneous ovoid and tubular (n = 8); and (e) uniform tubular (n = 6). Uterine flushings from these pregnancies were submitted for nontargeted profiling by gas chromatography–mass spectrometry (GC–MS) and ultra performance liquid chromatography (UPLC)–MS techniques. Unsupervised multivariate principal component analysis (PCA) was performed using pcaMethods and univariate analysis of variance was performed in R with false discovery rate (FDR) adjustment. PCA analysis of the GC–MS and UPLC–MS data identified 153 and 104 metabolites, respectively. After FDR adjustment of the GC–MS and UPLC–MS data, 38 and 59 metabolites, respectively, differed (p \u3c .05) in uterine flushings from pregnancies across the five conceptus stages. Some metabolites were greater (p \u3c .05) in abundance for uterine flushings containing earlier stage conceptuses (i.e., spherical), such as uric acid, tryptophan, and tyrosine. In contrast, some metabolites were greater (

Microalgae Lipid Characterization

To meet the growing interest of utilizing microalgae biomass in the production of biofuels and nutraceutical and pharmaceutical lipids, we need suitable analytical methods and a comprehensive database for their lipid components. The objective of the present work was to demonstrate methodology and provide data on fatty acid composition, lipid class content and composition, characteristics of the unsaponifiables, and type of chlorophylls of five microalgae. Microalgae lipids were fractionated into TAG, FFA, and polar lipids using TLC, and the composition of fatty acids in total lipids and in each lipid class, hydrocarbons, and sterols were determined by GC-MS. Glyco- and phospholipids were profiled by LC/ESI-MS. Chlorophylls and their related metabolites were qualified by LC/APCI-MS. The melting and crystallization profiles of microalgae total lipids and their esters were analyzed by DSC to evaluate their potential biofuel applications. Significant differences and complexities of lipid composition among the algae tested were observed. The compositional information is valuable for strain selection, downstream biomass fractionation, and utilization

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe