Academy of Sciences Republic of Uzbekistan

An extremely thermophilic chemolithoautotrophic strain Uz 6-8 was isolated from a hot spring in the Navoi region (Uzbekistan). Cells of strain Uz 6-8 were motile straight rods, non-spore-forming, 0.4–0.5 μm in diameter and 1.0−1.75 μm in length, with a gram-negative cell wall structure and a single lateral flagellum. The cells grew chemolithoautotrophically under aerobic conditions on thiosulfate or hydrogen in the medium containing NaHCO3, with CO2 in the gas phase. Nitrate was used as an electron acceptor during anaerobic growth on formate or hydrogen. The major fatty acids were saturated C18:0 and C20:0 with a cyclopropane moiety. The G+C content of the DNA was 47.5 mol %. Phylogenetic analysis based on comparison of 120 conserved proteins, DNA−DNA hybridization results (in silico), and genomic indices ANI and AAI indicated that Uz 6-8 belonged to a new species of the genus Pampinifervens (Aquificaceae). The name Pampinifervens navoyensis sp. nov. is proposed, with the type strain P. navoyensis Uz 6-8ᵀ. The genome contains the genes encoding the Arnon cycle, two uptake hydrogenases, and enzymes for formate oxidation, nitrate reduction, denitrification, and thiosulfate oxidation.

The aim of this study was to obtain culturable bacterial isolates, which are resistant to heat and salt stress, from saline soil samples enriched with plant residues, collected in the coastal zone of Lake Aydarkul (Uzbekistan). When all the 21 isolates, belonging to the family Bacillaceae, obtained in a cultivation medium with 60 g/L salinity, were tested for the ability to degrade plant polysaccharides, such as pectin and hemicellulose (xylan), the new isolate, Niallia sp. M35, was selected as the most interesting for application in plant residues hydrolysis under salt stress. The strain was actively growing on citrus pectin and birchwood xylan, degrading 46 ± 9 and 71 ± 5% of added polysaccharides, respectively. Genome sequencing revealed a very broad spectrum of carbohydrate-active enzymes (CAZymes), including 96 glycosyl hydrolases, as well as two extracellular polysaccharide lyases of families 8 and 11. Complete pathways of rhamnogalacturonan and xylan degradation were revealed in the M35 genome. Moreover, this isolate possessed the complete genomic potential for the mineralization of other polysaccharides. Overall, our data indicate that Niallia sp. M35 exhibits versatile metabolic and degradation potential useful not only for various biotechnological applications but also representing an important resource for the recycling of plant residues, thereby increasing the fertility of saline soils typically depleted in organic matter.

The study examines the synthesis and color characteristics of Co-containing ceramic pigments in the CoO-ZnO-SiO2 system. Pigments were prepared from Zn(NO3)2·6H2O, Co(NO3)2·6H2O, and quartz sand (SiO2) by solid-state firing in air at 1050-1250 °C. X-ray diffraction confirmed willemite-type Zn₂SiO₄ as the main phase; at 1050 °C secondary phases (Co2SiO4, α-SiO2, and traces of ZnO) were detected, while their contribution decreased markedly with increasing temperature, indicating near-complete willemite formation at 1250 °C. Diffuse reflectance colorimetry (CIELAB, D65/10°) showed progressive darkening and saturation of the blue–violet color with temperature (L* 58.57→33.43; b* -38.35→-48.65; C* 39.15→49.25) with an almost constant hue angle. The most stable and intense coloration was achieved at 1250 °C (ΔE* vs 1250 °C: 27.17 at 1050 °C and 9.78 at 1150 °C).

This article presents the results of studying the morphological and biochemical properties of Lactobacillus bacteria Lacticaseibacillus paracasei 36/1 and Lacticaseibacillusparacasei 30/1, as well as the characteristics of optimal conditions for vacuum freeze-drying and effective protectants for preserving the industrially valuable properties of lactobacilli included in “AS-Probionorm”. As a result of the morphological analysis, strains 30/1 and 36/1 were identified as Gram-positive, asporogenous, rod-shaped, non-spore-forming, facultatively anaerobic bacteria belonging to the phylum Firmicutes, class Bacilli, order Lactobacillales, family Lactobacillaceae, genus Lactobacillus. Protectant No. 1 (7% sucrose; 1.5% gelatin; 7% skimmed milk powder) was determined to be the optimal protective medium for lyophilization, as it allows the number of viable cells to remain at the same level before and after drying. The lactic acid bacterial strains are resistant to bile, since the decrease in viable cell count when grown on a medium containing 3% bile is minor and amounts to one order of magnitude. В данной статье представлены результаты изучения морфологических и биохимических свойств бактерий рода Lactobacillus, Lacticaseibacillus paracasei 36/1 и Lacticaseibacillus paracasei 30/1, а также приведены характеристики оптимальных условий вакуумной сублимационной сушки и эффективных протекторов для сохранения производственно-ценных свойств лактобактерий, входящих в состав «АС-Пробионорм». В результате морфологического исследования штаммы 30/1 и 36/1 определены как грамположительные, аспорогенные, палочковидные, неспорообразующие, факультативно анаэробные бактерии типа Firmicutes, класса Bacilli, порядка Lactobacillales, семейства Lactobacillaceae, рода Lactobacillus. Оптимальной защитной средой для лиофильного высушивания определен протектор №1 (7% сахарозы; 1,5% желатина; 7% сухого обезжиренного молока), который позволяет сохранить количество жизнеспособных клеток до и после высушивания на одном уровне. Штаммы молочнокислых бактерий устойчивы к желчи, так как снижение титра жизнеспособных клеток при росте на среде с 3% желчи незначительно и составляет один порядок.