Toshkhon Gulyamova

• Head of Laboratory at Institute of Microbiology, Chinese Academy of Sciences

Data on endophytic fungi Aspergillus niger FF152S and Cladosporium sp. HT207 producing brown-black pigment are presented. The pigment was extracted from fungal biomass, purified, characterized, and identified. Physico-chemical characteristics showed solubility in alkali, discoloration in oxidizing agents, and insolubility in organic solvents and wa...

Recently, there has been increased interest in melanins, representatives of the class of condensed polyphenols that find wide practical applications in various industries. In this study, melanin was isolated from the endophytic fungus Cladosporium sp.-HT207 , and a polymer nanocomposite was developed based on melanin, using carboxymethylcellulose a...

Obesity is one of the globally widespread diseases, accompanied by hypertension, hyperlipidemia, atherosclerosis, and type II diabetes. The most effective therapeutic approach for treating obesity is the inhibition of pancreatic lipase (PL). Eight isolates of endophytic fungi were obtained from Viola odorata growing in the park areas of Tashkent, U...

Search for pancreatic lipase (PL) inhibitors is essential for obesity and associated chronic disease therapy. PL inhibitors significantly reduce enzyme activity and prevent the absorption and hydrolysis of triglycerides into free fatty acids. This study provides new evidence of screening PL inhibitory activity of 15 endophytic fungi from 6 medicina...

Search for pancreatic lipase (PL) inhibitors is essential for obesity and associated chronic disease therapy. PL inhibitors significantly reduce enzyme activity and prevent the absorption and hydrolysis of triglycerides into free fatty acids. This study provides new evidence of screening PL inhibitory activity of 15 endophytic fungi from 6 medicina...

Halophytes play an essential role in ecosystems, forming plant mass and seed material in salinization and water scarcity conditions, and have unique mechanisms that allow them to survive in regions where other crops cannot exist. This ability of halophyte plants is due, among other things, to endophytic microorganisms inhabiting various organs and...

The microbial diversity of soil and plant samples selected from the Aral Sea region was studied in the autumn-winter period. It total 43 mycelial fungi including 22 soil isolates and 21 endophytes from two halophytes were obtained into a pure culture. The isolates were able to grow in the presence of 5 up to 15% salt concentrations. The identific...

The auxin-synthesizing activity of endophytic fungi from desert halophyte plants Aeluropus litoralis, Halocnemum strobilaceum, Climacoptera crassa, Suaeda heterophylla were studied. In addition, screening of indole-3-acetic acid (IAA) was carried out at the cultivation of endophytes in the presence of 10% NaCl. All isolates produced IAA, but the hi...

This study reports the diversity of cultivable endophytic bacteria associated with yellow iris (Iris pseudacorus L.) by using 16S rRNA gene analysis and their plant beneficial traits. The 16S rRNA sequence similarities of endophytic bacteria isolated from the leaves and roots of yellow iris showed that the isolates belonged to the genera Staphyloco...

The influence of the total extract of Vinca rosea on fermentation of endophytic fungi Aspergillus amstelodami-VR177L and Penicillium concavoradulozum-VE89L, producing vinca alkaloids was studied. It shown that the plant extract has a positive effect on the growth, level of vinblastine and antibacterial activity of the associated endophyte Aspergill...

The component composition of the secondary metabolites Aspergillus egypticusHT-166S isolated from stem of Heliánthus tuberósusplant, which has the ability to strongly inhibit the activity of pancreatic α-amylase, was studied. Qualitative analysis of phytocompounds showed that among metabolites there wereterpenoids, tannins, flavonoids, glycosides,...

Composition of statins produced by Aspergillus terreus 20 indigenous strain in submerged fermentation (SmF) has been studied. Identification of statin compounds in fungal extracts by LC-MS-MS analysis revealed 6 polyketide metabolites: lovastatin (LV) in lactone, acid and methyl ester forms, pravastatin (PV), monacolin L (ML) and simvastatin (SV)....

Lovastatin production by Aspergillus terreus indigenous strains in submerged (SmF) and solid state fermentations (SSF) have been studied. To evaluate the ability to produce lovastatin various cultivation media and substrates have been used. The obtained data showed good lovastatin yield by A. terreus 4 and A. terreus 20 both in SmF and SSF. At subm...

Lovastatin is a natural statin with a cholesterol-lowering effect. In nature, this compound is synthesized by some species of filamentous fungi. Amongst them, fungi from the genus Aspergillus have gained special interest as potential producers of this statin. Previously, 30 halotolerant strains belonging to this genus were isolated, whose lovastati...

Natural statins are fungal secondary metabolites produced by fermentation. These compounds are competitive inhibitors of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, the rate-limiting enzyme in cholesterol biosynthesis. They significantly reduce the risk of heart diseases associated with hypercholesterolemia. Moreover, statins prevent stroke an...

Studies of so-called “black yeasts,” which are excedingly interesting due to their exclusive ability to synthesize melanin, have comparatively recently begun. Melanin has recently been used successfully in medicine, pharmaceutics, and the agricultural industry [1-4]. Our goal was to isolate and study certain properties of the pigment of the local s...

Enzymatic response of cotton resistant variety C-5621 and susceptible variety Ak-kurgan-2 on action of pathogenic fungus Verticillium dahliae was studied. It was established that resistant variety C-5621 considerably exceeds susceptible variety Ak-kurgan-2 by all studied enzymes except amylase. Comparative analysis of distribution of specific enzym...

Strains of halophilic bacteria from samples of Barsakelmes saline soil were screened for ability to synthesize carotinoid pigments. An active strain that accumulated β-carotene as the main pigment was selected. The β-carotene was shown to be identical to the standard pigment.

Cobalamins are cobalt containing corrinoid compounds. At present, cobalamins are widely used in medicine, food industry, and agriculture. Commercial production of these compounds is based on microbial synthesis. Bacteria from Propionibacterium genus are considered as potential producers of cobalamins. Previously, we obtained a cobalt-resistant stra...

Vitamin B12 (cobalamin) is cobalt containing tetrapyrollic compound. Industrial production of this vitamin is based on microbial synthesis using mostly mutant strains of propionic acid bacteria. The aim of the present study was the determination of the influence of Co2+ ions on cobalamin synthesizing activity of Propionibacterium avidum and its cob...

It has been shown that the yeast S. cerevisiae has the ability to synthesize nicotinic acid and NAD from 3-methylpyridine. Fractionation of intracellular yeast proteins established that the fraction of molecular weight 65–90 kDa had the highest activity for transformation of pyridine derivatives into nicotinate. HPLC showed that, in addition to nic...

A method of adaptation to cobalt nitrate at high concentrations allowed us to isolate 46 strains of propionic acid bacteria Propionibacterium acidipropionici, resistant to excessive amounts of Co2+ in the medium. Studies of these strains revealed cultures that were most potent in synthesizing vitamin B12. The yield of vitamin B12 was increased 3 ti...

In nature, cobalamins are synthesized only by bacteria. The complexity of the molecular structure of these compounds underlies the difficulty of their chemical synthesis. At present, only two main microbial producers are used in industrial production of cobalamins. For instance, Pseudomonas denitrificans is successfully used to produce vitamin B12...

Vitamin B12 is a cobalt-containing complex compound, which is synthesized in nature only by bacteria. The diverse biochemical functions of this vitamin in the human organism are the basis for its use in the treatment of several diseases, for example, anemia, hepatitis, and cirrhosis. According to the literature data, the natural metabolism of propi...

The activities of nuclear enzymes involved in NAD+ metabolism in Saccharomyces cerevisiae strain 913a-1 and its mutant 110 previously selected as an NAD+ producer were investigated. The presence of extracellular nicotinamide increased the total NAD+ pool in the cells and increased [3H]nicotinic acid incorporation; however, NAD+ concentration in iso...

Vitamin B12 is widely used in the treatment of various diseases, including arthritis and different types of anemia. Currently, this vitamin is produced only by microbiological fermentations using bacteria. Propionic acid bacteria are considered as the main producers of cobalamins. In this study, several strains of propionic acid bacteria were isola...

The functional status of nuclei of Fusarium sambucinum was investigated under stimulation of NAD synthesis by exogenous nicotinamide. An increase in the intracellular concentration of NAD with a concurrent decline in its nuclear pool was caused by an enhanced turnover and utilization of nuclear NAD for ADP-ribosylation of proteins. A rise in ADP-ri...