Large-Scale Production of Isocitric Acid Using Yeast with Further Down-Stream Purification.

Isocitric acid (ICA) refers to a group of promising regulators of energy metabolism which has antistress, antihypoxic, and antioxidant activities. In this paper, we reported a process of ICA production from rapeseed oil using yeast VKM Y-2373 in a 500-L fermentor. The producer synthesized 64.

Effect of Nitrogen Concentration on the Biosynthesis of Citric Acid, Protein, and Lipids in the Yeast .

yeast is well known to be able to synthesize citric acid (CA) in large amounts. This study deals with CA biosynthesis, the production of biomass, as well as the accumulation and composition of proteins and lipids in VKM Y-2373 grown in media with glucose at different concentrations of ammonium sulfate (from 2 to 10 g/L). It was found that these concentrations of nitrogen source are limiting for the growth of and that nitrogen deficiency is the main cause of CA excretion.

Optimization of medium composition and fermentation conditions for α-ketoglutaric acid production from biodiesel waste by Yarrowia lipolytica.

This work demonstrates the ability of the yeast Yarrowia lipolytica cultivated on biodiesel waste to synthesize α-ketoglutaric acid with a minimal content of pyruvic acid as the main byproduct. The key factor promoting the microbial production of α-ketoglutaric acid from the waste is a strong deficiency of thiamine in the cultivation medium. The production of α-ketoglutaric acid by the yeast can be regulated by changing the concentration of nitrogen, iron, zinc, copper, and manganese in the medium, as well as by pH medium and the aeration rate.

Microbiological Production of Isocitric Acid from Biodiesel Waste and Its Effect on Spatial Memory.

Within this work, the microbial synthesis of (2,3)-isocitric acid (ICA), a metabolite of the nonconventional yeast , from biodiesel waste, has been studied. The selected strain VKM Y-2373 synthesized ICA with citric acid (CA) as a byproduct. This process can be regulated by changing cultivation conditions.

Microbial production of (2R,3S)-isocitric acid: state of the arts and prospects.

(2R,3S)-isocitric acid has long been used only as a specific biochemical reagent. However, there is ever increasing evidence that it can also be used as an original promising substance for prevention and treatment of some diseases. The review considers the results of longtime research in our laboratory and the data of other researchers related to microbial synthesis of (2R,3S)-isocitric acid, derivation and selection of active microbial producers, development of their cultivation conditions, as well as the results of study of the mechanism of acid overproduction, and regulation of enzymes involed in this process.

Biosynthesis of isocitric acid in repeated-batch culture and testing of its stress-protective activity.

Biosynthesis of Ds(+)-threo-isocitric acid from ethanol in the Yarrowia lipolytica batch and repeated-batch cultures was studied. Repeated-batch cultivation was found to provide for a good biosynthetic efficiency of the producer for as long as 748 h, probably due to maintenance of high activities of enzymes involved in the biosynthesis of isocitric acid. Under optimal repeated-batch cultivation conditions, the producer accumulated 109.

Biosynthesis of pyruvic acid from glycerol-containing substrates and its regulation in the yeast Yarrowia lipolytica.

The ability of different yeasts to synthesize pyruvic acid (PA) from glycerol-containing substrates has been studied. The selected strain Yarrowia lipolytica VKM Y-2378 synthesized PA with α-ketoglutaric acid (KGA) as a byproduct. The content of KGA greatly depended on cultivation conditions.

Fermentation Conditions and Media Optimization for Isocitric Acid Production from Ethanol by .

Isocitric acid exists in the form of four stereoisomers, of which only the -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 . The effects of temperature, pH of the medium, and aeration on the growth of the producer VKM Y-2373 and synthesis of ICA were studied.

Investigation of the effect of biologically active threo-Ds-isocitric acid on oxidative stress in Paramecium caudatum.

The effect of biologically active form (threo-Ds-) of isocitric acid (ICA) on oxidative stress was studied using the infusorian Paramecium caudatum stressed by hydrogen peroxide and salts of some heavy metals (Cu, Pb, Zn, and Cd). ICA at concentrations between 0.5 and 10 mM favorably influenced the infusorian cells with oxidative stress induced by the toxicants studied.

Metabolic peculiarities of the citric acid overproduction from glucose in yeasts Yarrowia lipolytica.

Comparative study of 43 natural yeast strains belonging to 20 species for their capability for overproduction of citric acid (CA) from glucose under nitrogen limitation of cell growth was carried out. As a result, natural strain Yarrowia lipolytica VKM Y-2373 was selected. The effect of growth limitation by biogenic macroelements (nitrogen, phosphorus, or sulfur) on the CA production by the selected strain was studied.

Application of organic acids for plant protection against phytopathogens.

The basic tendency in the field of plant protection concerns with reducing the use of pesticides and their replacement by environmentally acceptable biological preparations. The most promising approach to plant protection is application of microbial metabolites. In the last years, bactericidal, fungicidal, and nematodocidal activities were revealed for citric, succinic, α-ketoglutaric, palmitoleic, and other organic acids.

Biosynthesis of pyruvic acid from glucose by Blastobotrys adeninivorans.

The ability of taxonomically different yeasts to synthesize pyruvic acid (PA) from glucose was studied. The study showed that many yeasts are able to produce PA from glucose under the condition of growth limitation by thiamine. This ability was found in the yeast Blastobotrys adeninivorans for the first time.

The effect of oxalic and itaconic acids on threo-Ds-isocitric acid production from rapeseed oil by Yarrowia lipolytica.

The effect of oxalic and itaconic acids, the inhibitors of the isocitrate lyase, on the production of isocitric acid by the wild strain Yarrowia lipolytica VKM Y-2373 grown in the medium containing rapeseed oil was studied. In the presence of oxalic and itaconic acids, strain Y. lipolytica accumulated in the medium isocitric acid (70.

Production of technical-grade sodium citrate from glycerol-containing biodiesel waste by Yarrowia lipolytica.

The production of technical-grade sodium citrate from the glycerol-containing biodiesel waste by Yarrowia lipolytica was studied. Batch experiments showed that citrate was actively produced within 144 h, then citrate formation decreased presumably due to inhibition of enzymes involved in this process. In contrast, when the method of repeated batch cultivation was used, the formation of citrate continued for more than 500 h.

Physiologo-biochemical characteristics of citrate-producing yeast Yarrowia lipolytica grown on glycerol-containing waste of biodiesel industry.

In this study, physiologo-biochemical characteristics of citrate-producing yeast Yarrowia lipolytica grown on glycerol-containing waste of biodiesel industry were studied by an investigation of growth dynamics, the consumption of glycerol, and the fatty acid fractions from waste as well as by measuring the activities of enzymes involved in the metabolism of waste. It was shown that Y. lipolytica realizes concurrent uptake of glycerol and the fatty acid fractions during conversion of glycerol-containing waste, although glycerol was utilized at a higher rate than fatty acids.

The production of succinic acid by yeast Yarrowia lipolytica through a two-step process.

The production of α-ketoglutaric acid by yeast Yarrowia lipolytica VKMY-2412 from ethanol and its subsequent chemical conversion to succinic acid (SA) were investigated. A highly effective and environmentally friendly process of α-ketoglutaric acid production was developed using a special pH-controlling strategy, in which the titration of the culture broth with KOH in the acid-formation phase was minimal, that allowed accumulation of only low amounts of inorganic wastes in the course of SA recovery. The culture broth filtrate containing α-ketoglutaric acid (88.

The peculiarities of succinic acid production from rapeseed oil by Yarrowia lipolytica yeast.

The process of succinic acid (SA) production represents the combination of microbial synthesis of α-ketoglutaric acid from rapeseed oil by yeast Yarrowia lipolytica VKM Y-2412 and subsequent decarboxylation of α-ketoglutaric acid by hydrogen peroxide to SA that leads to the production of 69.0 g l(-1) of SA and 1.36 g l(-1) of acetic acid.

Isocitric acid production from rapeseed oil by Yarrowia lipolytica yeast.

Production of D S-threo-isocitric acid (ICA) by yeast meets serious difficulties since it is accompanied by a simultaneous production of citric acid (CA) in significant amounts that reduces the yield of desired product. In order to develop an effective process of ICA production, 60 yeast strains of different genera (Candida, Pichia, Saccharomyces, Torulopsis, and Yarrowia) were tested for their ability to produce ICA from rapeseed oil; as a result, wild-type strain Yarrowia lipolytica VKM Y-2373 and its mutant Y. lipolytica 704-UV4-A/NG50 were selected as promising ICA producers.

Enhanced α-ketoglutaric acid production and recovery in Yarrowia lipolytica yeast by effective pH controlling.

The replacement of chemical synthesis by environmentally friendly energy-efficient technologies for production of valuable metabolites is a principal strategy of developing biotechnological industry all over the world. In the present study, we develop a method for α-ketoglutaric acid (KGA) production from rapeseed oil with the use of Yarrowia lipolytica yeast. Sixty strains of Y.

The citric acid production from raw glycerol by Yarrowia lipolytica yeast and its regulation.

The optimal cultivation conditions ensuring the maximal rate of citric acid (CA) biosynthesis by glycerol-grown mutant Yarrowia lipolytica NG40/UV7 were found to be as follows: growth limitation by inorganic nutrients (nitrogen, phosphorus, or sulfur), 28 °C, pH 5.0, dissolved oxygen concentration (pO₂) of 50 % (of air saturation), and pulsed addition of glycerol from 20 to 80 g L⁻¹ depending on the rate of medium titration. Under optimal conditions of fed-batch cultivation, in the medium with pure glycerol, strain Y.

α-Ketoglutaric acid production from rapeseed oil by Yarrowia lipolytica yeast.

The possibility of using rapeseed oil as a carbon source for microbiological production of α-ketoglutaric acid (KGA) has been studied. Acid formation on the selective media has been tested in 26 strains of Yarrowia lipolytica yeast, and the strain Y. lipolytica VKM Y-2412 was selected as a prospective producer of KGA from rapeseed oil.

α-Ketoglutaric acid production by Yarrowia lipolytica and its regulation.

The yeast Yarrowia lipolytica VKM Y-2412 was selected as a prospective producer of α-ketoglutaric acid (KGA) from ethanol. The following peculiarities were found: (1) the intensive KGA production occurred only under the limitation of cell growth by thiamine and the excess of ethanol and nitrogen, (2) the production of KGA from ethanol required increased amount of zinc and iron ions, and (3) KGA production increased significantly with a high aeration at pH medium equal to 3.5.

Distribution of glyphosate and methylphosphonate catabolism systems in soil bacteria Ochrobactrum anthropi and Achromobacter sp.

Bacterial strains capable of utilizing methylphosphonic acid (MP) or glyphosate (GP) as the sole sources of phosphorus were isolated from soils contaminated with these organophosphonates. The strains isolated from MP-contaminated soils grew on MP and failed to grow on GP. One group of the isolates from GP-contaminated soils grew only on MP, while the other one grew on MP and GP.

Citric acid production from glycerol-containing waste of biodiesel industry by Yarrowia lipolytica in batch, repeated batch, and cell recycle regimes.

Yarrowia lipolytica A-101-1.22 produces high citric acid (112 g l(-1)) with a yield of 0.6 g g(-1) and a productivity of 0.

Chemically assisted microbial production of succinic acid by the yeast Yarrowia lipolytica grown on ethanol.

A new two-step process of production of succinic acid (SA) has been developed, which includes the microbial synthesis of alpha-ketoglutaric acid by the yeast Yarrowia lipolytica (step 1) and subsequent oxidation of the acid by hydrogen peroxide to SA (step 2). The maximum concentration of SA and its yield were found to be 63.4 g l(-1) and 58% of the ethanol consumed, respectively.