Applications of stable isotope metabolic flux analysis in tumor metabolic reprogramming / 中华核医学与分子影像杂志

Metabolic reprogramming is a hallmark of tumors. Tumors own unique metabolic patterns in different stages of their occurrence and development. The stable isotope metabolic flux analysis technology uses stable isotope to trace the metabolites in tumors and crystallize tumor metabolism network. Stable isotope metabolic flux analysis is a useful tool for studying tumor metabolism, which can determine the nutritional sources, find the metabolic liabilities, confirm the metabolic pattern of tumors, and discover new mechanisms of tumor metabolic reprogramming, thus providing theoretical bases for imaging, diagnosis, treatment and evaluation of tumor. This article reviews the applications of stable isotope flux analysis in tumor metabolic reprogramming.

The relationship between methane production metabolic flux and microorganisms in a microbial electrolytic cell coupled anaerobic digestion / 生物工程学报

In this study, voltage was used as a disturbance factor to investigate the relationship between microbial community and methane (CH4) production flux in a microbial electrolytic cell coupled anaerobic digestion (MEC-AD). Metabolic flux analysis (MFA) was used to explore the relationship between the CH4 metabolic flux produced and the microbes. The results showed that both methane production flux and hydrogen production flux changed significantly upon voltage disturbance, while the voltage disturbance had little effect on acetic acid production flux. The maximum CH4 production flux under 0.6 V disturbance was 0.522±0.051, which increased by 77% and 32%, respectively, compared with that of the control group under 1.0 V (0.295±0.013) and under 1.4 V (0.395±0.029). In addition, an average of 15.7%±2.9% of H2 (flux) was used to reduce CO2 to produce CH4 and acetic acid, and an average of 27.7%±6.9% of acetic acid (flux) was converted to CH4. Moreover, the abundance of Lachnospiraceae significantly affected the flux of acetic acid. The flux of CH4 production is positively correlated with the abundances of Petrimonas, Syntrophomonas, Blvii28, and Acinetobacter, and negatively correlated with the abundances of Tuzzerella and Sphaerochaeta. The species that affected the flux of H2 and CH4 were similar, mostly belonging to Bacteroides, Clostridium, Pseudomonas and Firmicutes. Furthermore, the interspecies interaction is also an important factor affecting the MEC-AD methanogenesis flux.

Research progress of metabolic flux analysis technology in glucose metabolism pathway research / 药学学报

With the wide application of stable isotope tracer metabolomics technology, its comprehensive analysis and in-depth mining of data are particularly important, and metabolic flux analysis is one of the main technical means, especially in the study of glucose metabolism. Metabolic flux analysis technology combines isotope tracing with mathematical models to deduce and calculate the metabolic flux between metabolites. The metabolic flux provides more information for research and reflects a dynamic metabolic process more clearly and specifically. This paper reviews the basic process, precautions, and application examples of metabolic flux analysis in glucose metabolism research, and provides a reference for the application of metabolic flux analysis based on stable isotope tracer metabolomics in glucose metabolism research.

Thirty years development of ¹³C metabolic flux analysis: a review / 生物工程学报

¹³C metabolic flux analysis (¹³C-MFA) enables the precise quantification of intracellular metabolic reaction rates by analyzing the distribution of mass isotopomers of proteinogenic amino acids or intracellular metabolites through ¹³C labeling experiments. ¹³C-MFA has received much attention as it can help systematically understand cellular metabolic characteristics, guide metabolic engineering design and gain mechanistic insights into pathophysiology. This article reviews the advances of ¹³C-MFA in the past 30 years and discusses its potential and future perspective, with a focus on its application in industrial biotechnology and biomedicine.

Applications progress of stable isotopic tracer technique in metabolic regulation of endogenous substances / 中草药

With the rapid development of high-sensitivity detection methods, stable isotope tracing technique has received increasing attention. Stable isotope tracing technique can accurately track the activity of labeled compounds in the body through the tracer atoms and determine their specific metabolic pathways based on the distribution of isotopic peaks of the intermediate metabolites. By calculating the flux, the metabolic pathways are analyzed to provide a basis for the study of disease mechanism and drug metabolism. In recent years, the technique has a wide application in the field of biomedicine. This paper summarizes the applications of stable isotopic tracer technique in the metabolic regulation of endogenous substances such as carbohydrate metabolism, lipid metabolism, amino acid metabolism, hormone metabolism, nucleic acid metabolism, and so on.

Effect of Different Carbon Sources on Succinic Acid Production of Actinobacillus succinogenes and Metabolic Flux Analysis / 微生物学通报

In anaerobic bottles fermentation,glucose,fructose,xylose,lactose,maltose,sucrose and sugar alcohols could be used to produce succinic acid with Actinobacillus succinogenes. When sorbitol was utilized as the carbon source in the batch fermentation,more succinate and ethanol were produced compared with those using glucose,while producing less acetate and formate. The metabolic flux analysis results showed that the flux partitioning at PEP node was stable when glucose was replaced by sorbitol,but the flux partitioning at PYR and AcCoA nodes changed a lot because more reducing power(NADH) was generated to meet the more requirement the synthesis of succinate and ethanol.

Analysis of Mass Isotopomer Distributions of Proteingenic Amino Acids Used GC-MS during ~(13)CMFA / 中国生物工程杂志

13C metabolic flux analysis(13CMFA)have been the research hotspots of metabolic engineering internationally due to its accuracy and applicability.It is vital that the measurement of 13C labelling pattern of proteinogenic amino acids for 13C metabolic flux analysis.To acquire 13C-labelling proteinogenic amino acids,Pseudomonas denitrifican which products Vitamin B12 was firstly fed with mimimal culture medium contained 20% U-13C and 80% natural glucose,after the culture reached a steady state,then about 20 mg biomass was hydrolyzed by 1 ml of 6 mol/L hydrochloric acid for 24h at 110℃.Then amino acids was separated,concentrated,evaporated in a vacuum,and derivatized with MBDSTFA,TBDMS-derivatized amino acids can be observed by GC-MS last we get 13C labelling pattern of fifteen aminio acids through mass spectrum.The experimental methods and sample preparation offers referential value for the development of 13C metabolic flux analysis in our courtry.

Screening and Metabolic Flux Analysis of Glutathione-high-yielding Strain from Saccharomyces cerevisiae / 中国生物工程杂志

The zinc chloride and cystine resistant strain of S.cerevisiae YZM-14(ZnCl2r,Cysr) was screened with the mutant processing of the protoplast of S.cerevisiae by combinative mutagens of ultraviolet and nitrite.The glutathione(GSH) production(84.72 mg/L),dry cell weight(7.63 g/L) and the intracellular GSH content(11.10 mg/g) of YZM-14 were 2.79,1.63 and 1.71 times compared with that of the initial strain.The biosynthetic process of GSH was divided into three phases according to the time course of the specific cell growth rate and GSH yielding coefficient.In the second phase,the metabolic flux of the pentose phosphate pathway and the GSH precursors biosynthetic pathway of the mutant strain increased by 8.1 mmol/(g?h),compared with that of the initial strain.Furthermore,the metabolic flux of the organic acids secretion of the mutant strain decreased.Through these mechanisms,the utilization efficiency of the carbon sources was enhanced and high production of GSH was obtained.

Metabolic Flux Analysis of L-Arginine Fermentation in Corynebacterium glutamicum / 微生物学通报

In this paper, metabolic networks of the Corynebacterium glutamicum GWY020 and the two de-rivatives carrying additional mutations HUI821and GUI089 were established and modified. The concentra-tions of extra-cellular metabolites were determined under sub-steady-state (50 h~52 h) of the batch culture. The metabolic flux distribution maps of the three strains were obtained, compared and analyzed. These re-sults indicate that the introduction of analog supersensitive marker or analog resistant marker skew the metabolic flux towards the formation of L-Arginine. This study revealed the usefulness of the metabolic flux analysis as a tool for verification of existing production strains. The analysis may play an important role in helping us to rationally re-design metabolism for further improvement of fermentation process.

ANALYSIS OF L-VALINE BIOSYNTHESIS MECHANISM BY METABOLIC FLUX BALANCE MODEL / 微生物学通报

Using metabolic flux balance model , the metabolic flux balance of L- v aline synthesis was established in this paper by material balances and linear p rogramming method. The analysis results indicate that 62.8% metabolic flux ent er ed EMP pathway and 38.2% metabolic flux entered the HMP pathway. And only 9.2 % c arbon entered the TCA cycle. But comparing to the optimal flux distributions of 92.31, the production of L-valine should be improved from the genetic manipula ti on and fermentation control through reducing byproduct of amino acid and decreas ing the metabolic flux.