Optimization of dextran production from Leuconostoc strains isolated from different dairy products from Ouargla region Algeria

Leuconostoc (Ln) sp. belongs to a group of lactic acid bacteria, which has the capacity to produce dextran (an exopolysaccharides) in the presence of su-crose. dextran is industrially important, it was the first microbial exopolysac-charide affirmed for commercial use. This study aimed to optimize the pro-duction of the synthesized dextran by Ln strains species isolated from differ-ent dairy products. Morphological, cultural, physiological and biochemical characteristics were employed to identify 23 isolated strains. We have identi-fied the species: Ln. gelidum, Ln. carnosum, Ln. citreum, Ln. fallax, Ln. mesen-teroides subsp mesenteroides, Ln. mesenteroides subsp dextranicum, Ln. mesenteroides subsp cremoris. 20 strains had the capacity to produce dex-tran from sucrose. The precipitation and quantification of EPS on MRSs (Mark rogosa et sharpe sucrose) medium revealed a difference between the strains, by the total sugars assay method, the amount of EPS varied between 0.63 ± 0.19 and 2.41 ± 0.17 g / L of strains LnF70 and LnC1 (isolated from goat's milk), respectively. The dextran production from MRSs medium was better than from liquid MSE. The optimization of production on MRSs medi-um with different concentration of glucose, yeast extract and sucrose showed that the strains had good production with a concentration of 2% glucose, 0.3% yeast extract and 10% sucrose.

Isolation and determination of Vibrio spp. pathogen from hemorrhagic disease in Sciaenops ocellatus in cage culture

In this study, 18 strains of Vibrio bacteria were identified from 27 samples of Red drum fish (Sciaenops ocellatus) suffering from the haemorrhagic disease from cage culture in Vietnam. The bacterial strains were identified with the 16S rRNA sequencing method and checked for morphological, physiological, and biochemical characteristics by using the API 20E KIT. Twelve strains of V. alginolyticus, three strains of V. fluvialis, and three strains of V. orientalis were recorded. All Vibrio strains have gene similarities with those on the gene bank ranging from 98 to 100%. The biochemical characteristics of these 18 isolates were similar. These bacteria are susceptible to tetracycline and doxycycline and entirely resistant to ampicillin, amoxicillin, and erythromycin.

Application of Reflectance Indices for Remote Sensing of Plants and Revealing Actions of Stressors

Environmental conditions are very changeable; fluctuations in temperature, precipitation, illumination intensity, and other factors can decrease a plant productivity and crop. The remote sensing of plants under these conditions is the basis for the protection of plants and increases their survivability. This problem can be solved through measurements of plant reflectance and calculation of reflectance indices. Reflectance indices are related to the vegetation biomass, specific physiological processes, and biochemical compositions in plants; the indices can be used for both short-term and long-term plant monitoring. In our review, we considered the applications of reflectance indices in plant remote sensing. In Optical Methods and Platforms of Remote Sensing of Plants, we briefly discussed multi- and hyperspectral imaging, including descriptions of multispectral and hyperspectral cameras with different principles and their efficiency for the remote sensing of plants. In Main Reflectance Indices, we described the main reflectance indices, including vegetation, water, and pigment reflectance indices, as well as the photochemical reflectance index and its modifications. We focused on the relationships of leaf reflectance and reflectance indices to plant biomass, development, and physiological and biochemical characteristics. In Problems of Measurement and Analysis of Reflectance Indices, we discussed the methods of the correction of the reflectance indices that can be used for decreasing the influence of environmental conditions (mainly illumination, air, and soil) and plant characteristics (orientation of leaves, their thickness, and others) on their measurements and the analysis of the plant remote sensing. Additionally, the variability of plants was also considered as an important factor that influences the results of measurement and analysis.

Cold Acclimation Affects Physiological and Biochemical Characteristics of Betula platyphylla S. under Freezing Stress

Cold and freezing stress is one of the most harmful environmental stresses, especially in temperate and subtropical areas, that adversely affects plant growth, development, and yield production. Betula platyphylla Sukaczev, also known as white birch, is one of the most valuable, important, and widely distributed tree species in East Asia. This study explored the effects of cold acclimation (CA) in reducing the destructive effect of freezing stress in B. platyphylla seedlings. We measured the physiological and biochemical characteristics of B. platyphylla seedlings, such as chlorophyll content, electrolyte leakage (EL), malondialdehyde (MDA), antioxidant enzymes (such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT)), and proline content before and after freezing stress to observe the contribution of CA in reducing the detrimental effects of freezing stress. The results showed that CA increased physiological and biochemical characteristics of B. platyphylla seedlings before and after freezing stress, except for chlorophyll content. Antioxidant enzymes were significantly positively correlated with proline, MDA, and EL content, and negatively correlated with chlorophyll content. Moreover, histochemical detection (H2O2 and O2−) and cell death were revealed to be induced by cold stress in B. platyphylla seedlings. Furthermore, it was revealed that increased time and decreased temperature of the CA process significantly influenced the physiological and biochemical parameters. Overall, the CA process significantly reduced the detrimental effects of freezing stress compared to the control treatment in B. platyphylla seedlings. Taken together, these findings provide beneficial information toward understanding the mechanism of CA and freezing stress in B. platyphylla. Furthermore, the substantial activity of physiological and biochemical results could be used as selection criteria for screening time and temperature points of cold/freezing stress in further omics analyses. In addition, the combination of current study results, further omics analyses, and genetic engineering techniques directly contribute to sustainable forest management systems, tree plantations, and conservation of tree species, especially non-cold/non-freezing tolerant tree species.

The low-volume technology of Fitopyramida type and the potential of tomato hybrids of various commodity groups

Качество урожая томатов обусловливается физиологическими и биохимическими характеристиками плодов, которые зависят от условий, обеспечивающих рост и развитие растений. Для создания этих условий производителям необходимо искать современные экологически дружественные и эффективные способы производства. Гидропонная система «Фитопирамида» обеспечивает рациональное использование пространства с наибольшим количеством растений на единицу площади за счет многоярусных установок. Технология «Фитопирамида» – альтернативное решение для получения экологически безопасных органических продуктов при одновременном снижении потребления воды, удобрений и пестицидов. Исследования проводили в 2020–2021 годах во ВНИИО – филиале ФГБНУ ФНЦО (д. Верея Московской области). Растения выращивали в поликарбонатной теплице ООО «Фитопирамида», площадь выращивания – 326,4 м2, общая площадь – 460 м2. В испытании участвовали 11 гибридов томатов с разным уровнем скороспелости и различных товарных групп. Растения томата формировали в один стебель, еженедельно проводили подкручивание, удаление пасынков, при формировании первой кисти регулярно удаляли нижние листья. Формировали на 3–4 кисти. Для лучшего завязывания плодов в теплице использовали шмелей. Опыт проводили в четырехкратной повторности, общее количество опытных единиц достигло 44. Определяли всхожесть (%) на 10 сутки от посева, общую продуктивность (г/куст), среднюю массу одного плода (г). Среди индетерминантных крупноплодных гибридов F1 Румяный шар был лучшим вариантом, подходящим для технологии «Фитопирамида» (его продуктивность достигала 1936,27 г/куст, а масса плода – 140,10 г). Из группы детерминантных раннеспелых гибридов выделился F1 Капитан, продуктивность которого достигала 1751,58 г/ куст, а масса плода – 86,84 г. Гибрид F1 Афродита был с точки зрения производства наименее пригоден для гидропоники. Гидропонное производство дает возможность повысить качество и продуктивность сельхозкультур, а также решать экологические проблемы, что позволит повысить конкурентоспособность такого типа производства, обеспечит экономию ресурсов и увеличит его доходность. The quality of the tomato harvest is determined by the physiological and biochemical characteristics of the fruit, which depend on the conditions that ensure the growth and development of plants. To ensure these conditions, manufacturers need to look for modern environmentally friendly and efficient production methods. The Fitopyramida hydroponic system ensures the rational use of the space with the largest number of plants per unit area due to multi-tiered installations. Fitopyramida technology is an alternative solution for obtaining environmentally friendly organic products, while reducing the consumption of water, fertilizers and pesticides. The research was carried out in 2020–2021 at the All-Russian Research Institute of Vegetable Growing – branch of Federal Scientific Centre of Vegetable Growing (Vereya village, Moscow region). The plants were grown in a polycarbonate greenhouse of Fitopyramida LLC, the cultivation area is 326.4 m2, the total area is 460 m2. The test involved 11 tomato hybrids with different levels of precocity and different product groups. Tomato plants were formed into one stem, twisting and removal of stepsons were carried out weekly, and the lower leaves were regularly removed during the formation of the first brush. They were formed into 3–4 brushes. Bumblebees were used for better fruit tying in the greenhouse. The experiment was carried out four times, the total number of experimental units reached 44. Germination (%) on the 10th day from sowing, total productivity, g/bush, average weight of one fruit (g) were determined. Among the indeterminate large-fruited F1 hybrids, the Rumyanyi shar was the best hybrid suitable for the Fitopyramida technology (its productivity reached 1936.27 g/plant, and the fruit weight was 140.10 g). F1Kapitan stood out from the group of determinant early-maturing hybrids, whose productivity reached 1751.58 g/plant, and the fruit weight was 86.84 g. The F1Afrodita hybrid was the least suitable for hydroponics from the point of view of production. Hydroponic production makes it possible to improve the quality and productivity of agricultural crops, as well as solve environmental problems, which will increase the competitiveness of this type of production, ensure resource savings and increase its profitability.

Streptomyces Pimoensis sp. nov., Isolated From the Taklimakan Desert in Xinjiang, China

A novel Streptomyces strain, designated TRM 75549T, was separated from a sample of sand in Pimo, Taklimakan desert, Xinjiang, North-West China. Phylogenetic analyses of the 16S rRNA gene sequences placed strain TRM75549T within the genus Streptomyces with the highest similarities to Streptomyces flavoviridis NBRC 12772T (98.76%). The whole-genome average nucleotide identity (ANI) value between strain TRM75549T and S. flavoviridis NBRC 12772T is 88.20%. Digital DNA-DNA hybridization (dDDH) value between strain TRM75549T and S. flavoviridis NBRC 12772T is 44.10%. They are well below the recommended 95-96% and 70% cut-off points for designated species respectively. A multi-locus sequence analysis of five house-keeping genes (atpD, gyrB, recA, rpoB and trpB) and phylogenomic analysis also illustrated that strain TRM75549T should be assigned to the genus Streptomyces. Strain TRM75549T contained MK-9 (H6) and MK-9 (H8) as predominant menaquinones. The diagnostic diamino acid of cell walls was identified as LL-diaminopimelic acid and Meso-diaminopimelic. The whole-cell sugar pattern of strain TRM 75549T consisted of mannose and glucose. The major fatty acids (>5%) were iso-C14:0, iso-C15:0, anteiso-C15:0, iso-C16:1H, iso-C16:0. The polar lipids were diphosphatidylglycerol, lysophosphatidylglycerol, phosphatidylethanolamine, phospholipids, phosphatidylglycerol, phosphatidylinositol, phosphatiylinositol mannosides and unidentified phospholipids. Strain TRM75549T could be differentiated from S. flavoviridis NBRC 12772T, based on physiological and biochemical characteristics. Based on the data from this polyphasic study presented above, strain TRM75549T is represent ative of a novel species of the genus Streptomyces, for which the name Streptomyces pimoensis sp. nov. is proposed. The type strain is TRM75549T (=CCTCC AA 2020054T=LMG 32221T ).

Dynamics of physiological and biochemical indicators of apricot cultivars under water stress

The results of the study of drought resistance of 4 cultivars Prunus armeniaca Lam bred in the Nikitsky Botanical Gardens are presented. The dynamics of indicators of the water regime of leaves, the content of photosynthetic pigments and phenolic compounds in them has been studied. As a result of the research, information was obtained on the physiological and biochemical characteristics of apricot against the background of adaptation to stressful conditions created by moisture deficit during the summer drought on the Southern Coast of the Crimea. Significant differences were revealed in the ability to retain moisture during wilting, the ability to restore tissue turgor after critical dehydration, the concentration of chlorophylls and phenolic substances in the cultivars of different resistance to water stress. The promising drought-resistant genotypes 'Professor Smykov' and 'Kazachok' have been identified, demonstrating a relatively high level of water-retaining forces of leaf tissues and reparation of the leaf surface area.

Aminipila luticellarii sp. nov., an anaerobic bacterium isolated from the pit mud of strong aromatic Chinese liquor, and emended description of the genus Aminipila

A novel mesophilic, aerotolerant anaerobic bacterium, designated JN-18T, was isolated from the pit mud of a strong aromatic Chinese liquor. According to a 16S rRNA gene sequence analysis, it had the highest sequence similarity to Aminipila butyrica DSM 103574T (95.69%). The G+C content of its genomic DNA was 43.39 mol%. The cells were Gram-stain-negative, slightly curved rods with flagella. Optimum growth was observed at 37 °C, pH 6.5 and without extra addition of NaCl. Strain JN-18Tutilized amino acids (l-alanine, l-arginine, l-asparagine, l-lysine, l-methionine, l-serine and l-threonine), malate and pyruvate, and used l-arginine and l-lysine to produce acetate, butyrate, H2, and CO2. The major cellular fatty acids of strain JN-18T were C14:0, C16:0 DMA and C18:1 cis-9 DMA. The carbohydrate composition of the cell wall predominantly included galactose, glucose and rhamnose. Based on its phylogenetic, phenotypic, physiological and biochemical characteristics, strain JN-18T was classified as a representative of a novel species within the genus Aminipila , for which the name Aminipila luticellarii sp. nov. is proposed. The type strain is JN-18T (=CCAM 412T=JCM 39126T).