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1.
J Chromatogr A ; 1716: 464653, 2024 Feb 08.
Article in English | MEDLINE | ID: mdl-38232638

ABSTRACT

The comprehensive study of compound variations in released smoke during the combustion process is a great challenge in many scientific fields related to analytical chemistry like traditional Chinese medicine, environment analysis, food analysis, etc. In this work, we propose a new comprehensive strategy for efficiently and high-thoroughly characterizing compounds in the online released complex smokes: (i) A smoke capture device was designed for efficiently collecting chemical constituents to perform gas chromatography-mass spectrometry (GC-MS) based untargeted analysis. (ii) An advanced data analysis tool, AntDAS-GCMS, was used for automatically extracting compounds in the original acquired GC-MS data files. Additionally, a GC-MS data analysis guided instrumental parameter optimizing strategy was proposed for the optimization of parameters in the smoke capture device. The developed strategy was demonstrated by the study of compound variations in the smoke of traditional Chinese medicine, Artemisia argyi Levl. et Vant. The results indicated that more than 590 components showed significant differences among released smokes of various moxa velvet ratios. Finally, about 88 compounds were identified, of which phenolic compounds were the most abundant, followed by aromatics, alkenes, alcohols and furans. In conclusion, we may provide a novel approach to the studies of compounds in online released smoke.


Subject(s)
Artemisia , Artemisia/chemistry , Medicine, Chinese Traditional , Smoke , Gas Chromatography-Mass Spectrometry/methods
2.
Phys Rev Lett ; 131(18): 186703, 2023 Nov 03.
Article in English | MEDLINE | ID: mdl-37977650

ABSTRACT

The understanding and manipulation of anisotropic Gilbert damping is crucial for both fundamental research and versatile engineering and optimization. Although several works on anisotropic damping have been reported, no direct relationship between the band structure and anisotropic damping was established. Here, we observed an anisotropic damping in Fe/GeTe manipulated by the symmetric band structures of GeTe via angle-resolved photoemission spectroscopy. Moreover, the anisotropic damping can be modified by the symmetry of band structures. Our Letter provides insightful understandings of the anisotropic Gilbert damping in ferromagnets interfaced with Rashba semiconductors and suggests the possibility of manipulating the Gilbert damping by band engineering.

3.
Nat Commun ; 14(1): 4424, 2023 Jul 21.
Article in English | MEDLINE | ID: mdl-37479683

ABSTRACT

Single-particle band theory has been very successful in describing the band structure of topological insulators. However, with decreasing thickness of topological insulator thin films, single-particle band theory is insufficient to explain their band structures and transport properties due to the existence of top and bottom surface-state coupling. Here, we reconstruct this coupling with an equivalently screened Coulomb interaction in Bi2Se3 ultrathin films. The thickness-dependent position of the Dirac point and the magnitude of the mass gap are discussed in terms of the Hartree approximation and the self-consistent gap equation. We find that for thicknesses below 6 quintuple layers, the magnitude of the mass gap is in good agreement with the experimental results. Our work provides a more accurate means of describing and predicting the behaviour of quasi-particles in ultrathin topological insulator films and stacked topological systems.

4.
Food Res Int ; 170: 113015, 2023 08.
Article in English | MEDLINE | ID: mdl-37316023

ABSTRACT

Accurately and high-thoroughly screening illegal additives in health-care foods continues to be a challenging task in routine analysis for the ultrahigh performance liquid chromatography-high resolution mass spectrometry based techniques. In this work, we proposed a new strategy to identify additives in complex food matrices, which consists of both experimental design and advanced chemometric data analysis. At first, reliable features in the analyzed samples were screened based on a simple but efficient sample weighting design, and those related to illegal additives were screened with robust statistical analysis. After the MS1 in-source fragment ion identification, both MS1 and MS/MS spectra were constructed for each underlying compound, based on which illegal additives can be precisely identified. The performance of the developed strategy was demonstrated by using mixture and synthetic sample datasets, indicating an improvement of data analysis efficiency up to 70.3 %. Finally, the developed strategy was applied for the screening of unknown additives in 21 batches of commercially available health-care foods. Results indicated that at least 80 % of false-positive results can be reduced and 4 additives were screened and confirmed.


Subject(s)
Foods, Specialized , Tandem Mass Spectrometry , Chromatography, High Pressure Liquid , Chromatography, Liquid , Data Analysis
5.
J Agric Food Chem ; 71(23): 8797-8807, 2023 Jun 14.
Article in English | MEDLINE | ID: mdl-37256838

ABSTRACT

Odorant-degrading enzymes in insects play a vital role in maintaining olfactory sensitivity. However, the role and molecular mechanism of glutathione S-transferases (GSTs) in odorant inactivation has been rarely studied. In the present study, 31 GSTs were identified from the antennal transcriptome of Holotrichia parallela. HpGSTd1 possesses the highest transcriptome expression level. Recombinant HpGSTd1 showed degradation activity toward various unsaturated aldehyde volatiles. Furthermore, the metabolite of cinnamaldehyde was identified by high-resolution mass spectrometry (HRMS). The molecular docking analysis and site-directed mutagenesis revealed the key residues of HpGSTd1 in degrading odorants. In addition, the unsaturated aldehyde volatiles elicited the behavioral and electrophysiological responses of H. parallela. Taken together, our findings suggest that HpGSTd1 may play an essential role in inactivating odorants in H. parallela, which provides new insights for identifying molecular targets and exploring effective olfactory regulators for this underground pest.


Subject(s)
Coleoptera , Receptors, Odorant , Animals , Odorants , Glutathione Transferase/genetics , Glutathione Transferase/metabolism , Aldehydes/metabolism , Molecular Docking Simulation , Arthropod Antennae/metabolism , Insect Proteins/metabolism , Coleoptera/metabolism , Receptors, Odorant/genetics , Receptors, Odorant/metabolism
6.
Anal Chim Acta ; 1254: 341127, 2023 May 08.
Article in English | MEDLINE | ID: mdl-37005031

ABSTRACT

Data analysis of ultrahigh performance liquid chromatography-high resolution mass spectrometry (UHPLC-HRMS) is an essential and time-consuming step in plant metabolomics and feature extraction is the fundamental step for current tools. Various methods lead to different feature extraction results in practical applications, which may puzzle users for selecting adequate data analysis tools to deal with collected data. In this work, we provide a comprehensive method evaluation for some advanced UHPLC-HRMS data analysis tools in plant metabolomics, including MS-DIAL, XCMS, MZmine, AntDAS, Progenesis QI, and Compound Discoverer. Both mixtures of standards and various complex plant matrices were specifically designed for evaluating the performances of the involved method in analyzing both targeted and untargeted metabolomics. Results indicated that AntDAS provide the most acceptable feature extraction, compound identification, and quantification results in targeted compound analysis. Concerning the complex plant dataset, both MS-DIAL and AntDAS can provide more reliable results than the others. The method comparison is maybe useful for the selection of suitable data analysis tools for users.


Subject(s)
Metabolomics , Plants , Chromatography, High Pressure Liquid/methods , Chromatography, Liquid , Mass Spectrometry , Metabolomics/methods
7.
Food Chem ; 410: 135453, 2023 Jun 01.
Article in English | MEDLINE | ID: mdl-36682286

ABSTRACT

Volatile compound variations during the roasting procedure play an essential role in the flaxseed-related product. In this work, we proposed a new strategy to high-throughput characterize the dynamic variations of flavors in flaxseed. Volatile compounds released at various roasting times were comprehensively investigated by a newly developed real-time solid-phase microextraction coupled with gas chromatography-mass spectrometry (GC-MS). Raw data files were analyzed by our advanced GC-MS data analysis software AntDAS-GCMS. Chemometric methods such as principal component analysis and partial least squares-discrimination analysis have realized the differences of samples with various roasting times. Finally, a total of 51 compounds from 11 aromas were accurately identified and confirmed with standards, and their variations as a function of roasting time were studied. In conclusion, we provided a new solution for the online monitoring of volatile compounds during the industrial roasting process.


Subject(s)
Flax , Volatile Organic Compounds , Gas Chromatography-Mass Spectrometry/methods , Solid Phase Microextraction/methods , Chemometrics , Odorants/analysis , Volatile Organic Compounds/analysis
8.
Adv Mater ; 35(9): e2208343, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36617232

ABSTRACT

Dual topological insulators, simultaneously protected by time-reversal symmetry and crystalline symmetry, open great opportunities to explore different symmetry-protected metallic surface states. However, the conventional dual topological states located on different facets hinder integration into planar opto-electronic/spintronic devices. Here, dual topological superlattices (TSLs) Bi2 Se3 -(Bi2 /Bi2 Se3 )N with limited stacking layer number N are constructed. Angle-resolved photoelectron emission spectra of the TSLs identify the coexistence and adjustment of dual topological surface states on Bi2 Se3 facet. The existence and tunability of spin-polarized dual-topological bands with N on Bi2 Se3 facet result in an unconventionally weak antilocalization effect (WAL) with variable WAL coefficient α (maximum close to 3/2) from quantum transport experiments. Most importantly, it is identified that the spin-polarized surface electrons from dual topological bands exhibit circularly and linearly polarized photogalvanic effect (CPGE and LPGE). It is anticipated that the stacked dual-topology and stacking layer number controlled bands evolution provide a platform for realizing intrinsic CPGE and LPGE. The results show that the surface electronic structure of the dual TSLs is highly tunable and well-regulated for quantum transport and photoexcitation, which shed light on engineering for opto-electronic/spintronic applications.

9.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 39(11): 1211-1215, 2022 Nov 10.
Article in Chinese | MEDLINE | ID: mdl-36317205

ABSTRACT

OBJECTIVE: To investigate the clinical significance of miRNA-146, OX-LDL and ROS in patients with primary ovarian insufficiency (POI). METHODS: 100 patients with POI were prospectively collected and 100 women with normal ovarian function were randomly selected as control group. Serum miRNA-146 expression level was detected by qRT-PCR and serum OX-LDL and ROS expression levels were detected by ELISA. Ovarian granulosa cells of mouse were transfected with miRNA-146 mimics or inhibitors, and then treated with OX-LDL. Cell viability, colony forming ability, apoptosis rate and toll like receptor 4 (TLR4)/nuclear factor-κB (NF-κB) of pathway proteins were evaluated respectively. RESULTS: Compared with control group, the expression level of miRNA-146 in POI group was significantly lower, the expression level of OX-LDL and ROS were significantly higher, and the ovarian volume and peak systolic blood flow velocity of ovarian artery were significantly decreased in POI group. Upregulation of miRNA-146 expression had a protective effect on OX-LDL injured ovarian granulosa cells, as evidenced by increased ovarian granulosa cell viability and colony number, reduced apoptosis, and downregulation of TLR4/NF-κB expression. CONCLUSION: miRNA-146 can target downstream TLR4/NF-κB signaling pathway affects oxidative stress and inflammatory response of POI induced by OX-LDL and ROS, and is expected to become a biomarker for early prediction of POI and a new target for treatment.


Subject(s)
MicroRNAs , Primary Ovarian Insufficiency , Humans , Female , Mice , Animals , Toll-Like Receptor 4/metabolism , NF-kappa B/genetics , NF-kappa B/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , Reactive Oxygen Species/pharmacology , Primary Ovarian Insufficiency/genetics , Apoptosis/genetics
10.
J Chromatogr A ; 1664: 462801, 2022 Feb 08.
Article in English | MEDLINE | ID: mdl-35007865

ABSTRACT

The pseudotargeted metabolomics based on gas chromatography-mass spectrometry (GC-MS) has the advantage of filtering out artifacts originating from sample treatment and accurately quantifying underlying compounds in the analyzed samples. However, this technique faces the problem of selecting high-quality selective ions for performing selected ion monitoring (SIM) on instruments. In this work, we proposed AntDAS-SIMOpt, an automatic untargeted strategy for SIM ion optimization that was accomplished on the basis of an experimental design combined with advanced chemometric algorithms. First, a group of diluted quality control samples was used to screen underlying compounds in samples automatically. Ions in each of the resolved mass spectrum were then evaluated by using the developed algorithms to identify the SIM ion. A Matlab graphical user interface (GUI) was designed to facilitate routine analysis, which can be obtained from http://www.pmdb.org.cn/antdassimopt. The performance of the developed strategy was comprehensively investigated by using standard and complex plant datasets. Results indicated that AntDAS-SIMOpt may be useful for GC-MS-based metabolomics.


Subject(s)
Chemometrics , Metabolomics , Gas Chromatography-Mass Spectrometry , Ions , Mass Spectrometry
11.
Pest Manag Sci ; 78(2): 550-560, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34585511

ABSTRACT

BACKGROUND: Many herbivore-induced volatiles have been proven to act as signaling compounds to regulate nearby plant defense responses. However, the precise roles of key volatiles produced by maize roots after Holotrichia parallela larva feeding remain largely unknown. RESULTS: We investigated changes in phytohormones and volatiles in maize roots after H. parallela larval infestation. Marked increases in the phytohormone jasmonic acid (JA) and the volatiles jasmone and tetradecane were induced by herbivores, whereas the salicylic acid content decreased. In addition, pre-exposure to tetradecane markedly increased the levels of the stress hormone JA, its precursors and derivatives, and related gene expression. In addition, pre-exposure altered the production of defensive benzoxazinoid secondary metabolites, resulting in increased plant resistance to H. parallela larvae. Plants pre-exposed to jasmone did not differ from control plants. In addition, bioassays showed that H. parallela larval growth was suppressed by feeding maize roots after pre-exposure to tetradecane. CONCLUSION: These results demonstrate that tetradecane may function as a potent defense induction signal that prepares neighboring plants for incoming attacks. © 2021 Society of Chemical Industry.


Subject(s)
Coleoptera , Herbivory , Alkanes , Animals , Cyclopentanes/pharmacology , Larva , Oxylipins , Plant Roots , Zea mays/genetics
12.
Zhen Ci Yan Jiu ; 46(5): 411-5, 2021 May 25.
Article in Chinese | MEDLINE | ID: mdl-34085465

ABSTRACT

OBJECTIVE: To observe the effect of application at Back-Shu with Front-Mu acupoints on serum uric acid (SUA) and kidney uric acid transport related proteins in hyperuricemia rats, so as to explore the mechanism of Shu-Mu acupoint application on treatment of hyperuricemia. METHODS: SD rats were randomly divided into blank control, model, vaseline application and medication application groups, with 8 rats in each group. The hyperuricemia rat model was established by gavage of potassium oxonate. Rats in the vaseline application group received application of vaseline at bilateral "Ganshu"(BL18) and "Qimen"(LI14), "Pishu"(BL20) and "Zhangmen"(LR13), "Shenshu" (BL23) and "Jingmen"(GB25). Rats in the medication application group received application of traditional Chinese medicine at the same acupoints. The contents of SUA and creatinine (SCr) were detected by automatic biochemical analyzer. H.E. staining was used to observe the pathological changes of kidney. And the protein expression levels of organic anion transporter 1(OAT1) and adenosine triphosphate binding cassette transporter G2(ABCG2) were detected by immunohistochemistry. RESULTS: Rats in the model group showed symptoms such as polydipsia, polyuria, loose stools, fatigue, weakness, etc. The renal tubules atrophied, and urate crystals can be seen in the lumen. Compared with the control group. the SUA content in the model group increased (P<0.01)and the expressions of OAT1 and ABCG2 protein in kidney decreased (P<0.01). After intervention and in comparison with the model group showed that, the diet, excretion function, and mental state of the rats in the medication application group returned to normal, and the pathological changes of the kidney tissue were alleviated, the SUA content was down-regulated(P<0.01)and the expression levels of OAT1 and ABCG2 in the kidney up-regulated (P<0.01). There was no statistically significant difference in the SCr content among the 4 groups (P>0.05). CONCLUSION: Medication application at Shu-Mu points can effectively reduce the SUA level of hyperuricemia rats, which may be related to its effects in up-regulating the protein expressions of OAT1 and ABCG2 in the kidney and reducing the damage to the kidneys.


Subject(s)
Hyperuricemia , Acupuncture Points , Animals , Hyperuricemia/drug therapy , Hyperuricemia/genetics , Kidney , Rats , Rats, Sprague-Dawley , Uric Acid
13.
J Phys Condens Matter ; 33(17)2021 Apr 21.
Article in English | MEDLINE | ID: mdl-33530080

ABSTRACT

The determination of intrinsic Gilbert damping is one of the central interests in the field of spintronics. However, some external factors in magnetic films tend to play a remarkable role in the magnetization dynamics. Here, we present a comprehensive study of the magnetic relaxation in ferromagnetic films with various in-plane magnetic anisotropy via ferromagnetic resonance technique. We find that the magnetic drag effect can result in the resonant linewidth broadening and the nonlinear dependence of linewidth on frequency stemming from field-magnetization misalignment. As a result, this could lead to the imprecise extraction of the key dynamic parameter-Gilbert damping and cause the confusing behaviors of ultra-low and anisotropic damping in thin films and multi-layers with high magnetic anisotropy. Our results provide a crucial way for the accurately quantitative estimation of the Gilbert damping in spintronics measurements.

14.
Zhen Ci Yan Jiu ; 46(1): 73-5, 2021 Jan 25.
Article in Chinese | MEDLINE | ID: mdl-33559430

ABSTRACT

For a long time, there have been many opinions about the location of Xuanzhong(GB39) point in the academic field. The author analyzed the location of GB39 in the main acupuncture literature in ancient times, textbooks of universities and colleges of traditional Chinese medicine after the founding of the People's Republic of China, national standards and more influential acupuncture works. From ancient times to the evolution of the location of the point, it is believed that the point should be located 3 cun above the lateral malleolus, between the tibial anterior ridge and the anterior edge of the fibula.


Subject(s)
Acupuncture Therapy , Acupuncture , Acupuncture Points , China , Humans , Medicine, Chinese Traditional
15.
Shanghai Kou Qiang Yi Xue ; 30(6): 573-578, 2021 Dec.
Article in Chinese | MEDLINE | ID: mdl-35587009

ABSTRACT

PURPOSE: To investigate the effect of Met kinase inhibitor BMS-777607 on proliferation and apoptosis of tongue squamous cell carcinoma cell line CAL27. METHODS: The effect of BMS-777607 on proliferation of CAL27 was detected by MTT method, clone formation assay and EdU cell imaging. Morphological changes of apoptosis of CAL27 cells induced by BMS-777607 were observed by Heochst33342 staining. JC-1 staining was used to detect the changes of mitochondrial membrane potential of CAL27 cells treated with BMS-777607. Western blot was used to detect the effect of BMS-777607 on the expression of proliferation protein Akt, p-Akt and apoptosis-related proteins Bcl-2, Cleaved caspase-3, Bax and Parp in CAL27 cells. The data were analyzed using SPSS 22.0 software package. RESULTS: BMS-777607 inhibited proliferation and promoted apoptosis of CAL27 cells in a concentration-dependent manner(P<0.05). It also inhibited the expression of Bcl-2 and p-Akt and promoted the expression of Bax, Cleaved caspase-3 and Parp protein (P<0.05). CONCLUSIONS: BMS-777607 can inhibit proliferation and promote apoptosis of CAL27 cells.


Subject(s)
Carcinoma, Squamous Cell , Tongue Neoplasms , Aminopyridines , Apoptosis , Apoptosis Regulatory Proteins , Carcinoma, Squamous Cell/metabolism , Caspase 3/pharmacology , Caspase 3/therapeutic use , Cell Line, Tumor , Cell Proliferation , Humans , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , Poly(ADP-ribose) Polymerase Inhibitors/therapeutic use , Proto-Oncogene Proteins c-akt , Proto-Oncogene Proteins c-bcl-2/pharmacology , Proto-Oncogene Proteins c-bcl-2/therapeutic use , Pyridones , Tongue , Tongue Neoplasms/drug therapy , bcl-2-Associated X Protein/pharmacology
16.
Nano Lett ; 21(1): 77-83, 2021 Jan 13.
Article in English | MEDLINE | ID: mdl-33263408

ABSTRACT

Ferroelectric Rashba semiconductors (FERSCs) have recently attracted intensive attention due to their giant bulk Rashba parameter, αR, which results in a locking between the spin degrees of freedom and the switchable electric polarization. However, the integration of FERSCs into microelectronic devices has provoked questions concerning whether the Rashba effect can persist when the material thickness is reduced to several nanometers. Here we find that αR can keep a large value of 2.12 eV Å in the 5.0 nm thick GeTe film. The behavior of αR with thickness can be expressed by the scaling law and provides a 3D thickness limit of the bulk Rashba effect, dc = 2.1 ± 0.5 nm. Finally, we find that the thickness can modify the Berry curvature as well, which influences the polarization and consequently alters the αR. Our results give insight into understanding the factors influencing αR in FERSCs and pave a novel route for designing Rashba-type quantum materials.

17.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 38(5): 495-501, 2020 Oct 01.
Article in Chinese | MEDLINE | ID: mdl-33085231

ABSTRACT

OBJECTIVE: This study aims to study the effect of the enhancer of zeste homolog 2 (EZH2) inhibitor GSK126 on the proliferation and apoptosis of human tongue squamous cell carcinoma cells in vitro and explore its related mechanisms in order to obtain insights into the clinical treatment of tongue squamous cell carcinoma. METHODS: Different concentrations of GSK126 were applied to CAL-27 cells of tongue squamous cell carcinoma, and the effects of drugs on cell proliferation were detected through methyl thiazolyl tetrazolium (MTT) assay, colony formation assay, and 5-ethynyl-2'-deoxyuridine (EdU) fluorescence staining. Hoechst33342 fluorescence staining and the JC-1 method were used in observing apoptosis. The expression levels of extracellular regulated protein kinases (ERK), phospho-extracellular regulated protein kinases (p-ERK), Bax, Bcl-2, and Cleaved caspase-9 in Cal-27 cells were detected through Western blot. RESULTS: GSK126 inhibited CAL-27 cell proliferation and promoted apoptosis. GSK126 down-regulated the expression of p-ERK and Bcl-2 and increased the expression of Bax and Cleaved caspase-9 (P<0.05). CONCLUSIONS: GSK126 can inhibit the proliferation of CAL-27 cells in tongue squamous cell carcinoma and promote its apoptosis, and the related mechanism may be associated with the inhibition of the MEK/ERK signaling pathway and activation of the Bax/Bcl-2 pathway.


Subject(s)
Apoptosis , Carcinoma, Squamous Cell , Tongue Neoplasms , Carcinoma, Squamous Cell/drug therapy , Cell Line, Tumor , Cell Proliferation , Enhancer of Zeste Homolog 2 Protein , Humans , Indoles , Pyridones , Tongue Neoplasms/drug therapy
18.
Bioresour Technol ; 247: 395-401, 2018 Jan.
Article in English | MEDLINE | ID: mdl-28961445

ABSTRACT

Oleaginous yeast Cryptococcus curvatus MUCL 29819, an acid-tolerant lipid producer, was tested to spill lipids extracellularly using different concentrations of acetic acid as carbon source. Extracellular lipids were released when the yeast was cultured with acetic acid exceeding 20g/L. The highest production of lipid (5.01g/L) was obtained when the yeast was cultured with 40g/L acetic acid. When the yeast was cultivated with moderate concentration (20g/L) of acetic acid, lipid production was further increased by 49.6% through preculture with 40g/L acetic acid as stimulant. When applying high concentration (40g/L) of acetic acid as carbon source in sequencing batch cultivation, extracellular lipids accounted up to 50.5% in the last cycle and the extracellular lipids reached 5.43g/L through the whole process. This study provides an effective strategy to enhance extracellular lipid production and facilitate the recovery of microbial lipids.


Subject(s)
Acetic Acid , Lipids , Batch Cell Culture Techniques , Biomass , Carbon , Cryptococcus
19.
Bioresour Technol ; 241: 645-651, 2017 Oct.
Article in English | MEDLINE | ID: mdl-28609752

ABSTRACT

The oleaginous yeast Cryptococcus curvatus ATCC 20509 can use 5-40g/L of acetic, propionic, or butyric acid as sole carbon source to produce lipids. High concentrations (30g/L) of mixed volatile fatty acids (VFAs) were used to cultivate C. curvatus to explore the effects of different ratios of mixed VFAs on lipid production and composition. When mixed VFAs (VFA ratio was 15:5:10) were used as carbon sources, the highest cell mass and lipid concentration were 8.68g/L and 4.93g/L, respectively, which were significantly higher than those when 30g/L of acetic acid was used as sole carbon source. The highest content and yield of odd-numbered fatty acids were 45.1% (VFA ratio was 0:15:15) and 1.62g/L (VFA ratio was 5:15:10), respectively. These results indicate that adjusting the composition ratios of mixed VFAs effectively improves microbial lipid synthesis and the yield of odd-numbered fatty acids.


Subject(s)
Cryptococcus , Fatty Acids, Volatile , Fatty Acids , Lipids , Yeasts
20.
Bioresour Technol ; 239: 394-401, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28535491

ABSTRACT

The lower utilization ratios of high-content VFAs resulted in less lipid yield by the oleaginous yeast Cryptococcus curvatus ATCC 20509. In this work, increasing the inoculation concentration to OD600=5.1 improved the acetic acid utilization ratio (99.8%) and lipids production (4.63g/L) in mediums with 30g/L of acetic acid. For the higher acetic acid concentration (40g/L), increasing the nitrogen to carbon ratio (0.033) and raising the initial pH (pH=8) was superior over improvement in the inoculate, with the lipid production increased from 1.08g/L to 6.49g/L. Subsequently, mixed VFAs at concentrations of 30g/L and 40g/L were used as the carbon source to simulate waste-derived VFAs. High lipid production (4.82 and 7.45g/L, respectively) was correspondingly achieved with similar high lipid yield (0.187g/g). This study provides an effective strategy to enhance the bioconversion of high-content VFAs into microbial lipids.


Subject(s)
Cryptococcus , Fatty Acids, Volatile , Lipids , Carbon , Fatty Acids , Nitrogen
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