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2021 ◽  
Author(s):  
Sergei Shalygin ◽  
Omar Holguin

Abstract The toxin producing cyanobacterium Microcystis sp. was collected in the mid October 2020 from the shallow waters of Snow Lake (New Mexico, USA). This species caused a visible bloom consisting of the pale green irregular macro colonies. Mass spectral analysis of the biomass revealed the presence of 4 derivatives of microcystin in that bloom: MC-LR (in the water and biomass), MC-RR (in biomass), MC-LY (in biomass), and MC-YR (in biomass).Next-generation sequencing allowed the retrieval of two Microcystis sequences in the bloom; which are molecular benchmarks for toxic Microcystis that may be used in future monitoring studies. Light microscopy provided evidence for the taxonomic affiliation of the found morphotype as Microcystis flos-aquae (Wittrock) Kirchner. However, molecular sequencing and the present situation in cyanobacterial taxonomy prevented affiliation of our morphotype to Microcystis flos-aquae, justifying following name – Microcystis sp. Confocal microscopy was used to determine the distribution of the cell content utilizing 3D stereo imaging. Emission spectra analysis identified the pigment composition and pigment distribution within the cells. SEM revealed 3D arrangement of the cells in the colonies, texture of the surface of the cells (perhaps dehydrated collapsed polysaccharides), F-layer and pili-like structures. Additionally, SEM/EDS analysis confirmed the F-layer using elemental composition analysis, which showed sulfur in the F-layer – typical element for that structure. Through the use of AFM, we analyzed the texture of the cell's surface and confirmed pili-like structures.


Author(s):  
L.V. Stelmakh ◽  
◽  
I.M. Mansurova ◽  

The possibility of using cultures of Black Sea planktonic microalgae of different taxonomic affiliation to assess the quality of the aquatic environment based on the assessment of their functional state is shown. The research was carried out on the diatom Phaeodactylum tricornutum, three dinoflagellates species Prorocentrum cordatum, Prorocentrum pusillum and Gyrodinium fissum, as well as the coccolithopho-ride Emiliania huxleyi. It was found that the waters of the Sevastopol Bay in the period from May to August 2021 in 50% of cases had a weak inhibitory effect on the growth of the tested species. In other cases, algae growth was either stimulated or the effect of pollution on cultures was not revealed. The need for using several types of algae in carrying out complex work on water biotesting of the coastal are-as of the Black Sea is highlighted.


2021 ◽  
Vol 10 (1) ◽  
pp. 31
Author(s):  
Alina Matsvay ◽  
Marina Dyachkova ◽  
Ivan Mikhaylov ◽  
Daniil Kiselev ◽  
Anna Say ◽  
...  

Discovery and study of viruses carried by migratory birds are tasks of high importance due to the host’s ability to spread infectious diseases over significant distances. With this paper, we present and characterize the first complete genome sequence of atadenovirus from a tern bird (common tern, Sterna hirundo) preliminarily named tern atadenovirus 1 (TeAdV-1). TeAdV-1 genome is a linear double-stranded DNA molecule, 31,334 base pairs which contain 30 methionine-initiated open reading frames with gene structure typical for Atadenovirus genus, and the shortest known inverted terminal repeats (ITRs) within the Atadenovirus genus consisted of 25 bases. The nucleotide composition of the genome is characterized by a low G + C content (33.86%), which is the most AT-rich genome of known avian adenoviruses within Atadenovirus genus. The nucleotide sequence of the TeAdV-1 genome shows high divergence compared to known representatives of the Atadenovirus genus with the highest similarity to the duck atadenovirus 1 (53.7%). Phylogenetic analysis of the protein sequences of core genes confirms the taxonomic affiliation of the new representative to the genus Atadenovirus with the degree of divergence from the known representatives exceeding the interspecies distance within the genus. Thereby we proposed a novel TeAdV-1 to be considered as a separate species.


2021 ◽  
Vol 48 ◽  
pp. 109-116
Author(s):  
Liudmila Stelmakh ◽  
Nela Kovrigina ◽  
Tatiana Gorbunova

For the degrees of toxicity assessment within the Black Sea surface coastal waters near Sevastopol, laboratory experiments were performed on three marine microalgae species culture’s growth in water sampled on the three stations of the region from May to December 2020. The study has indicated, that in the majority of cases, insignificant inhibiting influences of the waters to diatom Phaeodactylum tricornutum Bohlin and insignificant stimulated effect to dinoflagellates Prorocentrum сordatum (Ostenfeld) J.D.Dodge and Gyrodinium fissum (Levander) Kofoid & Swezy were observed. Rarely this effect was characterized as chronic or subacute. The concentration levels of both stable and unstable forms of organic substances in the studied waters were estimated. The results of the testing of the water to determine its contamination using microalgae and analysis of the organic substances concentration levels in them, allowed the conclusion that the studied area should be classified as episodically polluted. Justification for the necessity to use several microalgae species of different taxonomic affiliation when performing marine water biotesting is provided in this study.


2021 ◽  
Author(s):  
Qinggeer BORJIGIN ◽  
Bizhou ZHANG ◽  
Xiaofang Yu ◽  
Julin Gao ◽  
Xin ZHANG ◽  
...  

Abstract A lignocellulolytic microbial consortium holds promise for the in situ biodegradation of crop straw and the comprehensive and effective utilization of agricultural waste. In this study, we applied metagenomics technology to comprehensively explore the metabolic functional potential and taxonomic diversity of the microbial consortia CS (cultured on corn stover) and FP (cultured on filter paper).Analyses of the metagenomics taxonomic affiliation data showed considerable differences in the taxonomic composition and functional profile of the microbial consortia CS and FP. The microbial consortia CS primarily contained members from the genera Pseudomonas, Stenotrophomonas, Achromobacter, Dysgonomonas, Flavobacterium and Sphingobacterium, as well as Cellvibrio, Azospirillum, Pseudomonas, Dysgonomonas and Cellulomonas in FP. The COG and KEGG annotation analyses revealed considerable levels of diversity. Further analysis determined that the CS consortium had an increase in the acid and ester metabolism pathways, while carbohydrate metabolism was enriched in the FP consortium. Furthermore, a comparison against the CAZy database showed that the microbial consortia CS and FP contain a rich diversity of lignocellulose degrading families, in which GH5, GH6, GH9, GH10, GH11, GH26, GH42, and GH43 were enriched in the FP consortium, and GH44, GH28, GH2, and GH29 increased in the CS consortium. The degradative mechanism of lignocellulose metabolism by the two microbial consortia is similar, but the annotation of quantity of genes indicated that they are diverse and vary greatly. The lignocellulolytic microbial consortia cultured under different carbon conditions (CS and FP) differed substantially in their composition of the microbial community at the genus level. The changes in functional diversity were accompanied with variation in the composition of microorganisms, many of which are related to the degradation of lignocellulolytic materials. The genera Pseudomonas, Dysgonomonas and Sphingobacterium in CS and the genera Cellvibrio and Pseudomonas in FP exhibited a much wider distribution of lignocellulose degradative ability.


Author(s):  
C. Belyaeva

Air-aerosol pollen of plants can influence the results of climatotherapy and elimination therapy of respiratory allergic diseases. The diversity of the flora, the poorly studied prevalence and etiology of pollinosis on the Southern coast of the Crimea determine the need for aeropalinological studies of this region to optimize the treatment and rehabilitation of patients with respiratory sensitization. Objective To determine the content of plant pollen in the air, to develop a calendar of palination of plants in the Yalta resort, to identify periods that are potentially unfavorable for the stay of patients with pollen sensitization on the Southern coast of the Crimea. Material and methods Plant pollen in the air was determined gravimetrically. The taxonomic affiliation was identified and the amount of pollen deposited on the glass-traps in the coastal and foothill areas of Yalta city was calculated. The data obtained were averaged over the city as a whole. Results In 2011-2013, 19 pollen taxa were identified in the air of the resort, including 10 with sensitizing properties. Of these, cypress pollen accounted for 49.7% of the average annual amount, deciduous trees with allergenic pollen 4.7%, cereals and weeds 1.6% each. 79.0% of pollen was recorded in spring, 7.7% in summer, 8.6% in autumn, 4.7% in winter. In the air of the coastal area of the city, 2.2 times less pollen was detected than in the air of the foothill. Three waves of plants pollination were revealed: winter-spring pollination of trees and shrubs, late spring pollination of cereals, summer-autumn pollination of weeds. The calendar of pollination of plants of the Yalta resort has been developed. Conclusion The greatest risk of sensitization and exacerbation of respiratory allergies in the Yalta resort is created by cypress pollen in March April. The most favorable for the treatment and rehabilitation of patients with respiratory allergies is the coastal area of the resort. The developed plant pollination calendar allows predicting unfavorable aeropalinological periods, optimizing the treatment and rehabilitation of patients with pollen sensitization at the Yalta resort.


2021 ◽  
Author(s):  
Susheel Bhanu Busi ◽  
Laura de Nies ◽  
Paraskevi Pramateftaki ◽  
Massimo Bourquin ◽  
Tyler J. Kohler ◽  
...  

Background: Antimicrobial resistance (AMR) is a universal phenomenon whose origins lay in natural ecological interactions such as competition within niches, within and between micro- to higher-order organisms. However, the ecological and evolutionary processes shaping AMR need to be better understood in view of better antimicrobial stewardship. Resolving antibiotic biosynthetic pathways, including biosynthetic gene clusters (BGCs), and corresponding antimicrobial resistance genes (ARGs) may therefore help in understanding the inherent mechanisms. However, to study these phenomena, it is crucial to examine the origins of AMR in pristine environments with limited anthropogenic influences. In this context, epilithic biofilms residing in glacier-fed streams (GFSs) are an excellent model system to study diverse, intra- and inter-domain, ecological crosstalk. Results: We assessed the resistomes of epilithic biofilms from GFSs across the Southern Alps (New Zealand) and the Caucasus (Russia) and observed that both bacteria and eukaryotes encoded twenty-nine distinct AMR categories. Of these, beta-lactam, aminoglycoside, and multidrug resistance were both abundant and taxonomically distributed in most of the bacterial and eukaryotic phyla. AMR-encoding phyla included Bacteroidota and Proteobacteria among the bacteria, alongside Ochrophyta (algae) among the eukaryotes. Additionally, BGCs involved in the production of antibacterial compounds were identified across all phyla in the epilithic biofilms. Furthermore, we found that several bacterial genera (Flavobacterium, Polaromonas, etc.) including representatives of the superphylum Patescibacteria encode both ARGs and BGCs within close proximity of each other, thereby demonstrating their capacity to simultaneously influence and compete within the microbial community. Conclusions: Our findings highlight the presence and abundance of AMR in epilithic biofilms within GFSs. Additionally, we identify their role in the complex intra- and inter-domain competition and the underlying mechanisms influencing microbial survival in GFS epilithic biofilms. We demonstrate that eukaryotes may serve as AMR reservoirs owing to their potential for encoding ARGs. We also find that the taxonomic affiliation of the AMR and the BGCs are congruent. Importantly, our findings allow for understanding how naturally occurring BGCs and AMR contribute to the epilithic biofilms mode of life in GFSs. Importantly, these observations may be generalizable and potentially extended to other environments which may be more or less impacted by human activity.


Author(s):  
N. V. Ilyukhina ◽  
A. Yu. Kolokolova ◽  
M. Yu. Kolokolov

Dehydrated pitted apricots are widely used as a ready meal ingredient, which renders control of their quality and safety a relevant issue. Pitted apricots are rich in sugars, moisture and organic acids that serve a good medium for microorganisms. Therefore, these products require presale processing. Microwave treatment proved effective for the processing of raw and finished food products. Its impact on microorganisms depends on variant criteria, including taxonomic affiliation, total counts, dielectric cell properties and the treatment dose. The research aimed to study death kinetics in the native dried apricot surface microflora and its growth during subsequent storage. In this respect, we have studied the microwave treatment impact on dried apricot surface microflora depending on treatment dose and determined the residual microflora growth rate during subsequent storage. The doses of 120, 180 and 240 kJ at a 200 W radiation power have been shown to reduce baseline contamination of dehydrated pitted apricots by three orders of magnitude. Statistical kinetics analyses demonstrated a retarded surface microflora growth during subsequent storage. Microwave doses of 120–240 kJ (accounting for ±0.4 lg CFU/g error) exhibited a similar microflora dynamics in subsequent storage. The exposure of dried apricots to a lowest microwave field of 120 kJ ensured stability of the product microbiological dynamics.


Author(s):  
Т.В. ФЕДОСЕНКО ◽  
Л.К. ПАЦЮК ◽  
В.В. КОНДРАТЕНКО ◽  
Ю.Ю. УСАНОВА

При применении инновационных способов производства пищевых продуктов, например ультразвуковой кавитационной обработки, для управления параметрами ультразвукового воздействия необходима предварительная информация об исходных свойствах обрабатываемой среды – теплопроводности, плотности, вязкости, дисперсности, поверхностном натяжении, которой, особенно для пищевых продуктов, пока еще недостаточно. Цель настоящей работы – экспериментально установить влияние температуры на величину коэффициента поверхностного натяжения образцов овощных пюре из моркови, тыквы и кабачков, изготовленных на оборудовании технологического стенда по классической технологии. Из образцов предварительно удаляли дисперсную фазу центрифугированием с фактором разделения 8000 g. Супернатант фильтровали через складчатый бумажный обеззоленный фильтр и для образцов фильтрата определяли коэффициент поверхностного натяжения сталагмометрическим методом по ГОСТ 33276–2015 в сравнении с водой. Плотность пюре устанавливали пикнометрическим методом. Для определения влияния температуры на величину поверхностного натяжения образцы овощного пюре нагревали на водяной бане до 25 и 35°С. Установлено, что для всех исследованных образцов овощных пюре величина коэффициента поверхностного натяжения практически в два раза превышает значение аналогичного показателя для воды. Для математического описания зависимости коэффициента поверхностного натяжения от температуры в образцах овощных пюре использовали эмпирическую формулу Катаямы–Гуггенгейма. Установлено, что изменение коэффициента поверхностного натяжения овощных пюре под влиянием температуры практически не зависит от таксономической принадлежности исходного сырья и начальной текучести продукта. Поэтому при практическом использовании установленную зависимость необходимо исследовать отдельно для каждого вида овощного пюре. Зависимости коэффициентов поверхностного натяжения образцов кабачкового и морковного пюре от температуры практически идентичны. Наиболее выражено влияние температуры на коэффициент поверхностного натяжения тыквенного пюре, что указывает на очевидную необходимость стабилизации температуры технологического процесса для сохранения условий, не выходящих за границы оптимума его реализации. When using innovative methods of food production, for example ultrasonic cavitation treatment, to control the parameters of ultrasonic exposure, preliminary information about the initial properties of the treated medium – thermal conductivity, density, viscosity, dispersion, surface tension is necessary. The purpose of this work is to experimentally establish the effect of temperature on the value of the surface tension coefficient of samples of vegetable purees from carrots, pumpkins and zucchini made on the equipment of the technological stand. The dispersed phase was previously removed from the samples by centrifugation with a separation factor of 8000 g. The supernatant was filtered through a folded paper decontaminated filter and the surface tension coefficient was determined for the filtrate samples by the stalagmometric method according to GOST 33276–2015 in comparison with water. The density of the puree was set pycnometrically. To determine the effect of temperature on the value of surface tension, samples of vegetable puree were heated in a water bath to 25 and 35°C. It was found that for all the studied samples of vegetable purees, the value of the surface tension coefficient is almost twice the value of the same indicator for water. The Katayama–Guggenheim empirical formula was used to mathematically describe the dependence of the surface tension coefficient on the temperature in the samples of vegetable purees. It is established that the change in the surface tension coefficient of vegetable purees under the influence of temperature practically does not depend on the taxonomic affiliation of the raw material and the initial fluidity of the product. Therefore, in practical use, the established dependence should be investigated separately for each type of vegetable puree. The temperature dependences of the surface tension coefficients of zucchini and carrot puree are almost identical. The influence of temperature on the surface tension coefficient is most pronounced in pumpkin puree, which indicates the obvious need to stabilize the temperature of the technological process in order to maintain conditions that do not exceed the optimal limits of its implementation.


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