Effect of the quality of fat substrate on the dynamics of fatty acid utilization during biosynthesis of cephalosporin C

Influence of the quality of the fats used on their utilization in the process of cephalosporin C fermentation and accumulation was studied. A decrease in the level of all the fractions of the fatty acids was observed during the fermentation process. The antibiotic yield with the use of oxidized fats was lower. Treatment of the fats with gaseous nitrogen prevented their oxidation. It was supposed that the decreased yields of the antibiotic were associated with the influence of the oxidized fats on the biosynthetic processes.     

Effect of Transglutaminase on the Properties of Films Prepared from Chitosan and Gelatin

Applied Biochemistry and Microbiology - The production conditions were optimized, and the characteristics of biodegradable chitosan-gelatin films crosslinked with various microbial...     

Bacterial Cellulose as a Matrix for Microorganisms in Bioelectrocatalytic Systems

Applied Biochemistry and Microbiology - Bacterial cellulose (BC) produced by the Komagateibacter sucrofermentas VKPM B-11267 bacteria was used as a carrier for immobilization of acetic acid...     

Relation between ligninolytic and phospholipase activities in the fungus Lentinus tigrinus

Effect of hydrocortisone, NaF, and FeSO₄ on ligninolytic and phosphatase activity of the fungus Lentinus (Panus) tigrinus VKM F-3616D was investigated. Hydrocortisone and NaF were shown to inhibit the enzymes of the ligninolytic complex—laccase (EC 1.10.3.2), secretory peroxidase (EC 1.11.1.7), and Mn peroxidase (EC 1.11.1.13). FeSO₄ exhibited no significant effect on the activity of these enzymes. Decreased activity of the enzymes of the ligninolytic complex was associated with inhibition of the activity and changes in the substrate specificity of phospholipase A₂ (EC 3.1.1.4) in the presence of hydrocortisone of NaF. Cultivation of L. tigrinus in the presence of these compounds resulted in higher affinity of this enzyme to saturated fatty acids, while in the control and in the presence of FeSO₄ affinity to unsaturated fatty acids was higher.     

Optimizing the conditions of dextran synthesis by the bacterium Leuconostoc mesenteroides grown in a molasses-containing medium

Maximal dextran production (54-55 g/l) by the bacterium Leuconostoc mesenteroides strain V-2317D was observed in molasses-containing media in the presence of 17.5% glucose at pHinit 6.75. The beginning of dextran production depended on the amount of inoculate; maximum yield was observed at a shaker rate of 200 rpm. The dextran produced by L. mesenteroides grown in the molasses-containing medium was representative of three fractions differing in the molecular weight and composition: the high- (approximately 54.5%), medium- (approximately 27.9%), and low-molecular-weight (approximately 2.85%) fractions.     

Prediction of the three-dimensional structure of aflatoxin of Aspergillus flavus by homology modelling

Aflatoxins are polyketide-derived secondary metabolites produced by Aspergillus spp. The toxic effects of aflatoxins have adverse consequences for human health and agricultural economics. The aflR gene, a regulatory gene for aflatoxin biosynthesis, encodes a protein containing a zinc-finger DNA-binding motif. AFLR-Protein three-dimensional model was generated using Robetta server. The modeled AFLR-Protein was further optimization and validation using Rampage. In the simulations, we monitored the backbone atoms and the C-α-helix of the modeled protein. The low RMSD and the simulation time indicate that, as expected, the 3D structural model of AFLR-protein represents a stable folding conformation. This study paves the way for generating computer molecular models for proteins whose crystal structures are not available and which would aid in detailed molecular mechanism of inhibition of aflatoxin.     

Isolation and Characterization of the Strains Producing Bacterial Cellulose

Microbiology - Two new strains producing bacterial cellulose were isolated from the Kombucha and Tibicos symbiotic communities. Based on the 16S rRNA gene analysis and the morphological,...     

Investigation of fluorescence intensity and distribution of wheat leaf on exposure to temperature

It was established that exposure to extreme temperatures changed the distribution and intensity of fluorescence of pigments in the wheat leaf, which is likely related to the changes of both the leaf morphology and pigment state.