scholarly journals Effects of Medium Components on Isocitric Acid Production by Yarrowia lipolytica Yeast

Fermentation ◽  
2020 ◽  
Vol 6 (4) ◽  
pp. 112
Author(s):  
Svetlana V. Kamzolova ◽  
Vladimir A. Samoilenko ◽  
Julia N. Lunina ◽  
Igor G. Morgunov
Keyword(s):  
Isocitrate Lyase ◽  
Nitrogen Deficiency ◽  
Aconitate Hydratase ◽  
Isocitric Acid ◽  
Medium Components ◽  
Regulatory Approach ◽  
Nutrition Medium ◽  
Key Enzyme ◽  
Nitrogen Phosphorus ◽  
Oxalic Acids

The microbiological production of isocitric acid (ICA) is more preferable for its application in medicine and food, because the resulting product contains only the natural isomer—threo-DS. The aim of the present work was to study ICA production by yeast using sunflower oil as carbon source. 30 taxonomically different yeast strains were assessed for their capability for ICA production, and Y. lipolytica VKM Y-2373 was selected as a promising producer. It was found that ICA production required: the limitation of Y. lipolytica growth by nitrogen, phosphorus, sulfur or magnesium, and an addition of iron, activating aconitate hydratase, a key enzyme of isocitrate synthesis. Another regulatory approach capable to shift acid formation to a predominant ICA synthesis is the use of inhibitors (itaconic and oxalic acids), which blocks the conversion of isocitrate at the level of isocitrate lyase. It is recommended to cultivate Y. lipolytica VKM Y-2373 under nitrogen deficiency conditions with addition of 1.5 mg/L iron and 30 mM itaconic acid. Such optimized nutrition medium provides 70.6 g/L ICA with a ratio between ICA and citric acid (CA) equal 4:1, a mass yield (YICA) of 1.25 g/g and volume productivity (QICA) of 1.19 g/L·h.

scholarly journals Effect of Metabolic Regulators and Aeration on Isocitric Acid Synthesis by Yarrowia lipolytica Grown on Ester-Aldehyde Fraction

Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 283
Author(s):  
Svetlana V. Kamzolova ◽  
Igor G. Morgunov
Keyword(s):  
Yarrowia Lipolytica ◽  
Itaconic Acid ◽  
Isocitrate Lyase ◽  
Nitrogen Deficiency ◽  
Carbon Sources ◽  
Acid Synthesis ◽  
Aconitate Hydratase ◽  
Isocitric Acid ◽  
Metabolic Regulators ◽  
Putative Mechanism

Isocitric acid (ICA) has found wide application in medicine as a promising compound with powerful antioxidant activity to combat oxidative stress. In the known microbiological processes of ICA production by non-conventional yeast Yarrowia lipolytica, the pure carbon sources are commonly used. ICA can be also synthetized by Y. lipolytica from ester-aldehyde fraction (EAF)-waste of the ethanol production process. A highly effective method of ICA production from EAF based on regulation of key enzymes (aconitate hydratase and isocitrate lyase) by metabolic regulators (iron and itaconic acid) and aeration was developed. It is recommended to cultivate Y. lipolytica VKM Y-2373 under nitrogen deficiency conditions, a high aeration (60% of air saturation), an addition of 15 mM itaconic acid, and 2.4 mg/L iron. Under optimal conditions, Y. lipolytica VKM Y-2373 produced 83 g/L ICA with isocitrate to citrate ratio of 4.1:1 and mass yield of 1.1 g/g. The putative mechanism of ICA overproduction from EAF by Y. lipolytica was suggested.

scholarly journals Fermentation Conditions and Media Optimization for Isocitric Acid Production from Ethanol by Yarrowia lipolytica

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Svetlana V. Kamzolova ◽  
Roman V. Shamin ◽  
Nadezda N. Stepanova ◽  
Grigorii I. Morgunov ◽  
Julia N. Lunina ◽  
...  
Keyword(s):  
Yarrowia Lipolytica ◽  
Isocitrate Lyase ◽  
Krebs Cycle ◽  
Growth Period ◽  
Energy Yield ◽  
Good Growth ◽  
Acid Inhibitor ◽  
Isocitric Acid ◽  
Nutrition Medium ◽  
Key Enzyme

Isocitric acid exists in the form of four stereoisomers, of which only the threo-Ds-form (ICA) is a natural active compound, an intermediate of Krebs cycle, and suitable for nutritional and pharmaceutical use. In this paper, we propose a method for ICA production from ethanol by yeast Yarrowia lipolytica. The effects of temperature, pH of the medium, and aeration on the growth of the producer Y. lipolytica VKM Y-2373 and synthesis of ICA were studied. An optimal fermentation regime, which ensures a good growth of the producer and directed synthesis of the target product, was determined. The producer is advised to carry out cultivation at 29°C and various pH of the medium and the oxygen concentration (pH 5 and pO2 20–25% (of saturation) during the growth period and pH 6 and pO2 50–55% (of saturation) during the acid formation) on a nutrient medium containing an increased content of zinc (0.6 mg/L), iron (1.2 mg/L), and 30 mM itaconic acid (inhibitor of isocitrate lyase—the key enzyme of ICA metabolism) should also be introduced into the nutrition medium. Such fermentation production mode provides 90.5 g/L ICA with process selectivity of 80%, mass yield (YICA) of 0.77 g/g, and energy yield (ηICA) of 0.278 g/g.

Disruption of genes for the enhanced biosynthesis of α-ketoglutarate in Corynebacterium glutamicum

2012 ◽  
Vol 58 (3) ◽  
pp. 278-286 ◽  
Author(s):  
Jae-Hyung Jo ◽  
Hye-Young Seol ◽  
Yun-Bom Lee ◽  
Min-Hong Kim ◽  
Hyung-Hwan Hyun ◽  
...  
Keyword(s):  
Corynebacterium Glutamicum ◽  
Biosynthetic Pathway ◽  
Isocitrate Lyase ◽  
Glutamate Synthase ◽  
Flask Culture ◽  
Control Strain ◽  
Enhanced Production ◽  
Key Enzyme ◽  
Microbial Strains ◽  
Glyoxylate Pathway

The development of microbial strains for the enhanced production of α-ketoglutarate (α-KG) was investigated using a strain of Corynebacterium glutamicum that overproduces of l-glutamate, by disrupting three genes involved in the α-KG biosynthetic pathway. The pathways competing with the biosynthesis of α-KG were blocked by knocking out aceA (encoding isocitrate lyase, ICL), gdh (encoding glutamate dehydrogenase, l-gluDH), and gltB (encoding glutamate synthase or glutamate-2-oxoglutarate aminotransferase, GOGAT). The strain with aceA, gltB, and gdh disrupted showed reduced ICL activity and no GOGAT and l-gluDH activities, resulting in up to 16-fold more α-KG production than the control strain in flask culture. These results suggest that l-gluDH is the key enzyme in the conversion of α-KG to l-glutamate; therefore, prevention of this step could promote α-KG accumulation. The inactivation of ICL leads the carbon flow to α-KG by blocking the glyoxylate pathway. However, the disruption of gltB did not affect the biosynthesis of α-KG. Our results can be applied in the industrial production of α-KG by using C. glutamicum as producer.

scholarly journals The Gluconeogenic Enzyme Fructose-1,6-Bisphosphatase Is Dispensable for Growth of the Yeast Yarrowia lipolytica in Gluconeogenic Substrates

2008 ◽  
Vol 7 (10) ◽  
pp. 1742-1749 ◽  
Author(s):  
Raquel Jardón ◽  
Carlos Gancedo ◽  
Carmen-Lisset Flores
Keyword(s):  
Yarrowia Lipolytica ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Isocitrate Lyase ◽  
Carbon Sources ◽  
Subcellular Fractionation ◽  
Fructose 1,6 Bisphosphatase ◽  
Genes Encoding ◽  
Key Enzyme ◽  
Gluconeogenic Enzyme ◽  
Fructose 1,6 Bisphosphate

ABSTRACT The genes encoding gluconeogenic enzymes in the nonconventional yeast Yarrowia lipolytica were found to be differentially regulated. The expression of Y. lipolytica FBP1 (YlFBP1) encoding the key enzyme fructose-1,6-bisphosphatase was not repressed by glucose in contrast with the situation in other yeasts; however, this sugar markedly repressed the expression of YlPCK1, encoding phosphoenolpyruvate carboxykinase, and YlICL1, encoding isocitrate lyase. We constructed Y. lipolytica strains with two different disrupted versions of YlFBP1 and found that they grew much slower than the wild type in gluconeogenic carbon sources but that growth was not abolished as happens in most microorganisms. We attribute this growth to the existence of an alternative phosphatase with a high Km (2.3 mM) for fructose-1,6-bisphosphate. The gene YlFBP1 restored fructose-1,6-bisphosphatase activity and growth in gluconeogenic carbon sources to a Saccharomyces cerevisiae fbp1 mutant, but the introduction of the FBP1 gene from S. cerevisiae in the Ylfbp1 mutant did not produce fructose-1,6-bisphosphatase activity or growth complementation. Subcellular fractionation revealed the presence of fructose-1,6-bisphosphatase both in the cytoplasm and in the nucleus.

Screening of Anti-mycobacterial Phytochemical Compounds for Potential Inhibitors against Mycobacterium Tuberculosis Isocitrate Lyase

2019 ◽  
Vol 19 (8) ◽  
pp. 600-608 ◽  
Author(s):  
Ashish Tiwari ◽  
Akhil Kumar ◽  
Gaurava Srivastava ◽  
Ashok Sharma
Keyword(s):  
Binding Energy ◽  
Virtual Screening ◽  
Md Simulation ◽  
Isocitrate Lyase ◽  
Docking Study ◽  
High Morbidity ◽  
Average Binding Energy ◽  
Ic50 Value ◽  
Key Enzyme ◽  
Potential Inhibitors

Conclusion:Phytochemical based anti-mycobacterial compound can further developed into effective drugs against persistence tuberculosis with lesser toxicity and side effects.Results:Docking and MD simulation studies of top hit compounds have identified shinjudilactone (quassinoid), lecheronol A (pimarane) and caniojane (diterpene) as potential MtbICL inhibitors.Methods:Virtual screening, molecular docking and MD simulation study has been integrated for screening of phytochemical based anti-mycobacterial compounds. Docking study of reported MtbICL inhibitors has shown an average binding affinity score -7.30 Kcal/mol. In virtual screening, compounds exhibiting lower binding energy than calculated average binding energy were selected as top hit compounds followed by calculation of drug likeness property. Relationship between experimental IC50 value and calculated binding gibbs free energy of reported inhibitors was also calculated through regression analysis to predict IC50 value of potential inhibitors.Background and Introduction:Tuberculosis (TB) is a leading infectious disease caused by Mycobacterium tuberculosiswith high morbidity and mortality. Isocitrate lyase (MtbICL), a key enzyme of glyoxylate pathway has been shown to be involved in mycobacterial persistence, is attractive drug target against persistent tuberculosis.

scholarly journals The assimilation of carbon by Chloropseudomonas ethylicum

1968 ◽  
Vol 106 (3) ◽  
pp. 615-622 ◽  
Author(s):  
A G Callely ◽  
N. Rigopoulos ◽  
R. C. Fuller
Keyword(s):  
Carbon Dioxide ◽  
Phosphate Buffer ◽  
Citrate Synthase ◽  
Isocitrate Lyase ◽  
Fumarate Hydratase ◽  
Malate Synthase ◽  
Nutritional Requirements ◽  
Aconitate Hydratase ◽  
Oxoglutarate Dehydrogenase ◽  
Ribulose Diphosphate Carboxylase

1. The enzymes in ultrasonically prepared extracts of Chloropseudomonas ethylicum were studied to elucidate how this organism assimilates acetate and carbon dioxide and why it cannot grow with either of these two compounds alone. 2. Such extracts can (i) convert acetate and oxaloacetate into α-oxoglutarate, (ii) convert oxaloacetate into succinyl-CoA, (iii) convert phosphopyruvate into 3-phosphoglyceraldehyde and (iv) interconvert phosphopyruvate and pyruvate via oxaloacetate. 3. Pyruvate kinase, α-oxoglutarate dehydrogenase, ribulose diphosphate carboxylase, isocitrate lyase and malate synthase were not detected. 4. It is difficult to detect aconitate hydratase, fumarate hydratase and citrate synthase in extracts of the organism ultrasonically treated in tris buffer; to demonstrate these enzymes extracts should be prepared in phosphate buffer containing 2-mercaptoethanol. 5. Provided that this organism can synthesize pyruvate from acetate and carbon dioxide, the enzymes detected are sufficient to account for the nutritional requirements of this organism.

Utilisation of stored lipids during germination in dimorphic seeds of euhalophyte Suaeda salsa

2018 ◽  
Vol 45 (10) ◽  
pp. 1009 ◽  
Author(s):  
Yuanqin Zhao ◽  
Yanchun Ma ◽  
Qiang Li ◽  
Yang Yang ◽  
Jianrong Guo ◽  
...  
Keyword(s):  
Adverse Effect ◽  
Seed Germination ◽  
Isocitrate Lyase ◽  
Sugar Content ◽  
Soluble Sugar ◽  
Malate Synthase ◽  
Suaeda Salsa ◽  
Lyase Activity ◽  
Key Enzyme ◽  
Black Seeds

Utilisation of stored lipids plays an important role in germination of oil seeds. In the present study, key enzyme activity (lipase, isocitrate lyase and malate synthase) in lipid utilisation was determined during germination in dimorphic seeds of euhalophyte Suaeda salsa (L.) Pall. The results revealed that the percentage of germination were highest in intertidal brown seeds, followed by inland brown seeds and then inland black seeds moistened with 0 and 300 mM NaCl during early seed germination. The same trend was found in the activity of three enzymes and soluble sugar content when seeds were moistened with 0 and 300 mM NaCl for 3 h. Salinity reduced the activity of three enzymes in inland brown and black seeds in the initial 3 h, except that salinity had no adverse effect on isocitrate lyase activity of brown seeds. Salinity had no adverse effect on three enzymes in inland brown and black seeds in the initial 30 h, except that it decreased malate synthase activity of black seeds. Salinity had no effect on three enzymes in intertidal brown seeds in the initial 3 h and 30 h. In conclusion, high activity of these enzymes in brown seeds may play an important role in utilisation of stored lipids during their rapid seed germination.

NEW RECOMBINANT STRAINS OF Yarrowia lipolytica YEAST WITH OVEREXPRESSION OF ACONITATE HYDRATASE GENE TO OBTAIN ISOCITRIC ACID

2015 ◽  
pp. 35-41
Author(s):  
I. A. Laptev ◽  
N. A. Filimonova ◽  
R. K. Allayarov ◽  
S. V. Kamzolova ◽  
V. A. Samoilenko ◽  
...  
Keyword(s):  
Yarrowia Lipolytica ◽  
Aconitate Hydratase ◽  
Recombinant Strains ◽  
Isocitric Acid

Regulation of isocitrate metabolism in Chlamydomonas segnis

1977 ◽  
Vol 55 (16) ◽  
pp. 2178-2185 ◽  
Author(s):  
Samuel S. K. Foo ◽  
Samir S. Badour
Keyword(s):  
Isocitrate Dehydrogenase ◽  
Isocitrate Lyase ◽  
Nitrogen Deficiency ◽  
Competitive Inhibitor ◽  
Enzyme Preparations ◽  
Batch Cultures ◽  
Keto Acids ◽  
Effective Inhibition ◽  
Lyase Activity

Isocitrate lyase (EC 4.1.3.1) and isocitrate dehydrogenase (NADP+) (EC 1.1.1.42) activities were detected in cell-free extracts of Chlamydomonas segnis Ettl when the alga was grown photoautotrophically with 5% CO2 in air (v/v) at 11 klx. When the cultures were either bubbled with air (0.03% CO2), exposed to low light intensity (3 klx), or subjected to manganese or nitrogen deficiency, isocitrate lyase activity was undetectable. During growth in batch cultures provided with 5% CO2, the activity of the dehydrogenase was about 5–12 times greater than the lyase.Using partially purified (about 50-fold) enzyme preparations, isocitrate dehydrogenase (NADP+) showed greater affinity for isocitrate (Km = 0.008 mM) than did isocitrate lyase (Km = 0.1 mM). The dehydrogenase had Km values of 0.011 mM and 0.006 mM for NADP and Mn2+, respectively. Both enzymes were inhibited by α-ketoglutarate and oxalacetate at 1 mM, but the dehydrogenase was more sensitive to these two keto acids (68–79%) than the lyase (36%). Glycolate at 1 mM inhibited (36%) only the lyase, while glyoxylate had little effect. The dehydrogenase was subject to concerted inhibition by oxalacetate plus glyoxylate (Ki = 0.01 mM). This inhibition was competitive with respect to isocitrate, and preincubation of the enzyme with NADP in absence of isocitrate was necessary for effective inhibition. Each of NADPH (Ki = 0.06 mM) and ATP (Ki = 0.65 mM) was a non-competitive inhibitor (with respect to isocitrate) of isocitrate dehydrogenase (NADP+), and both nucleotides are suggested to be active in the in vivo regulation of isocitrate metabolism in C. segnis during photoautotrophy.

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