C4-monomethylsterol β-glucoside and its synthase in Aurantiochytrium limacinum mh0186

Glycobiology ◽  
2021 ◽  
Author(s):  
Ikumi Endo ◽  
Takashi Watanabe ◽  
Tomofumi Miyamoto ◽  
Hatsumi Monjusho-Goda ◽  
Junichiro Ohara ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Draft Genome ◽  
Complete Loss ◽  
Gas Chromatography Mass Spectrometry ◽  
Gene Products ◽  
Two Dimensional ◽  
Genome Database ◽  
Marine Protists

Abstract Thraustochytrids, unicellular marine protists, synthesize polyunsaturated fatty acids (PUFAs) and PUFA-containing phospholipids; however, little is known about their glycolipids and their associated metabolism. Here, we report two glycolipids (GL-A, B) and their synthases in Aurantiochytrium limacinum mh0186. Two glycolipids were purified from A. limacinum mh0186, and they were determined by gas chromatography, mass spectrometry and two-dimensional nuclear magnetic resonance to be 3-O-β-D-glucopyranosyl-stigmasta-5,7,22-triene (GL-A) and 3-O-β-D-glucopyranosyl-4α-methyl-stigmasta-7,22-diene (GL-B), both of which are sterol β-glucosides (β-SGs); the structure of GL-B has not been reported thus far. Seven candidate genes responsible for the synthesis of these β-SGs were extracted from the draft genome database of A. limacinum using the yeast sterol β-glucosyltransferase (SGT; EC 2.4.1.173) sequence as a query. Expression analysis using Saccharomyces cerevisiae revealed that two gene products (AlSGT-1 and 2) catalyze the transfer of glucose from UDP-glucose to sterols, generating sterylglucosides (SGs). Compared to AlSGT-1, AlSGT-2 exhibited wide specificity for sterols and used C4-monomethylsterol to synthesize GL-B. The disruption of alsgt-2 but not alsgt-1 in strain mh0186 resulted in a decrease in total SG and almost complete loss of GL-B, indicating that AlSGT-2 is responsible for the synthesis of β-SGs in A. limacinum mh0186, especially GL-B, which possesses a unique sterol structure.

scholarly journals PUFA synthase-independent DHA synthesis pathway in Parietichytrium sp. and its modification to produce EPA and n-3DPA

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Yohei Ishibashi ◽  
Hatsumi Goda ◽  
Rie Hamaguchi ◽  
Keishi Sakaguchi ◽  
Takayoshi Sekiguchi ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Draft Genome ◽  
Fatty Acid Elongase ◽  
Genome Database ◽  
Fed Batch Culture ◽  
Marine Protists ◽  
Near Future ◽  
Reverse Genetic Approach

AbstractThe demand for n-3 long-chain polyunsaturated fatty acids (n-3LC-PUFAs), such as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), will exceed their supply in the near future, and a sustainable source of n-3LC-PUFAs is needed. Thraustochytrids are marine protists characterized by anaerobic biosynthesis of DHA via polyunsaturated fatty acid synthase (PUFA-S). Analysis of a homemade draft genome database suggested that Parietichytrium sp. lacks PUFA-S but possesses all fatty acid elongase (ELO) and desaturase (DES) genes required for DHA synthesis. The reverse genetic approach and a tracing experiment using stable isotope-labeled fatty acids revealed that the ELO/DES pathway is the only DHA synthesis pathway in Parietichytrium sp. Disruption of the C20 fatty acid ELO (C20ELO) and ∆4 fatty acid DES (∆4DES) genes with expression of ω3 fatty acid DES in this thraustochytrid allowed the production of EPA and n-3docosapentaenoic acid (n-3DPA), respectively, at the highest level among known microbial sources using fed-batch culture.

scholarly journals Comprehensive Two-Dimensional Gas Chromatography–Mass Spectrometry Analysis of Exhaled Breath Compounds after Whole Grain Diets

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2667
Author(s):  
Kaisa Raninen ◽  
Ringa Nenonen ◽  
Elina Järvelä-Reijonen ◽  
Kaisa Poutanen ◽  
Hannu Mykkänen ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Metabolic Effects ◽  
Mass Spectrometry Analysis ◽  
Gas Chromatography Mass Spectrometry ◽  
Wheat Bread ◽  
Exhaled Breath ◽  
Two Dimensional ◽  
Whole Grain ◽  
Chromatography Mass Spectrometry

Exhaled breath is a potential noninvasive matrix to give new information about metabolic effects of diets. In this pilot study, non-targeted analysis of exhaled breath volatile organic compounds (VOCs) was made by comprehensive two-dimensional gas chromatography–mass spectrometry (GCxGC-MS) to explore compounds relating to whole grain (WG) diets. Nine healthy subjects participated in the dietary intervention with parallel crossover design, consisting of two high-fiber diets containing whole grain rye bread (WGR) or whole grain wheat bread (WGW) and 1-week control diets with refined wheat bread (WW) before both diet periods. Large interindividual differences were detected in the VOC composition. About 260 VOCs were detected from exhaled breath samples, in which 40 of the compounds were present in more than half of the samples. Various derivatives of benzoic acid and phenolic compounds, as well as some furanones existed in exhaled breath samples only after the WG diets, making them interesting compounds to study further.

scholarly journals Influences of Smoking in Traditional and Industrial Conditions on Flavour Profile of Harbin Red Sausages by Comprehensive Two-Dimensional Gas Chromatography Mass Spectrometry

Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1180
Author(s):  
Xiaoyu Yin ◽  
Qian Chen ◽  
Qian Liu ◽  
Yan Wang ◽  
Baohua Kong
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Volatile Compounds ◽  
Solid Phase ◽  
Meat Products ◽  
Principal Component ◽  
Quality Characteristics ◽  
Gas Chromatography Mass Spectrometry ◽  
Two Dimensional ◽  
Chromatography Mass Spectrometry

Smoking is mainly used to impart desirable flavour, colour and texture to the products. Various food smoking methods can be divided into traditional and industrial methods. The influences of three different smoking methods, including traditional smouldering smoke (TSS), industrial smouldering smoke (ISS) and industrial liquid smoke (ILS), on quality characteristics, sensory attributes and flavour profiles of Harbin red sausages were studied. The smoking methods had significant effects on the moisture content (55.74–61.72 g/100 g), L*-value (53.85–57.61), a*-value (11.97–13.15), b*-value (12.19–12.92), hardness (24.25–29.17 N) and chewiness (13.42–17.32). A total of 86 volatile compounds were identified by headspace solid phase microextraction combined with comprehensive two-dimensional gas chromatography mass spectrometry (GC × GC-qMS). Among them, phenolic compounds were the most abundant compounds in the all sausages. Compared with sausages smoked with smouldering smoke, the ILS sausages showed the highest content of volatile compounds, especially phenols, alcohols, aldehydes and ketones. Principal component analysis showed that the sausages smoked with different methods had a good separation based on the quality characteristics and GC × GC-qMS data. These results will facilitate optimising the smoking methods in the industrial production of smoked meat products.

Sign in / Sign up

Export Citation Format

Share Document