The microbial community mediated biogeochemical cycles play important role in global C-cycle and display a sensitive response to environmental changes. Limited information is available on microbial ...composition and functional diversity controlling biogeochemical cycles in the riverine environment. The Ganga River water and sediment samples were studied for environmental gene tags with reference to carbohydrate metabolism, photoheterotrophy and chemolithotrophy using high throughput shotgun metagenomic sequencing and functional annotation. The diversity of environmental gene tags specific microbial community was annotated against reference sequence database using Kaiju taxonomic classifier. The metagenomic analyses revealed that the river harbored a broad range of carbohydrate and energy metabolism genes. The in-depth investigation of metagenomic data revealed that the enzymes associated with reverse TCA cycle, Calvin-Benson cycle enzyme RuBisCO, starch and sucrose metabolism genes were highly abundant. The enzymes associated with sulfur metabolism such as EC:2.7.7.4 (sulfate to ammonium per sulfate), EC:1.8.1.2, EC:1.8.7.1 (sulfite to H2S) were prevalent in both the class of samples. The principal component analysis of the functional profiles revealed that the water and sediment samples were clustered distinctly suggesting that both the sites had variable abundance of functional genes and associated microbiota. The taxonomic classification showed abundance of Proteobacteria, Actinobacteria and Bacteroidetes phyla. Also, the metagenomic study showed the presence of purple sulfur bacteria viz. Thiodictyon, Nitrosococcus and purple non-sulfur bacteria viz. Bradyrhozobium and Rhodobacter. The study demonstrates that the Ganga River microbiome has prevalence of functional genes involved in carbohydrate anabolism and catabolism, and CO2 fixation with great prospects in cellulose and sulfide degrading enzyme production and characterization.
•River Ganga harbored broad range of carbohydrate and energy metabolism genes.•Enzymes involved in reverse TCA, Calvin-Benson cycle enzyme RuBisCO were prevalent.•Sulfur metabolism enzymes such as EC:2.7.7.4 and EC:1.8.1.2 were prevalent river.•Proteobacteria, Actinobacteria and Bacteroidetes were the highly abundant phyla.•Various purple sulfur and purple non sulfur bacteria were also detected.
Drylands are areas under continuous degradation and desertification frequently covered by cyanobacterial biocrusts. Several studies have indicated that soil microorganisms contribute to nutrient ...cycling. Nevertheless, little is still known about how those could potentially be participating according to their taxonomic groups. In addition, biocrust-associated communities still remain largely unexplored at taxonomic and functional levels and, therefore, biotechnologically underexploited in comparison with other terrestrial ecosystems. This work aimed at revealing the ecological and biotechnological potential of soil communities using a shotgun sequencing approach in cyanobacterial-colonised biocrusts in the Tabernas Desert regarding the cycles of carbon, nitrogen, phosphorus, iron, sulfur, and potassium. The abundance and successful adaptation of major groups Rubrobacter and Conexibacter was explained by the presence of metabolic diversity regarding glycolytic and CO2 fixation pathways but also by exhibiting a rich pool of hydrolytic enzymes. Besides, Rubrobacter representatives might potentially be driving sulfate mineralisation. Others, such as Caulobacter representatives, were also suggested to have a potential key role in K+ uptake. Furthermore, iron uptake was found to potentially be mediated via synthesis and release of siderophores, mostly derived from pseudomonads. Importantly, this work revealed a meaningful biotechnological niche in which the recovery of novel isolates is a very desirable step forward for the industry and a step forward in unwrapping the potential role of those microorganisms in soil restoration as well as in the functioning of arid soils as CO2 sinks.
•Rubrobacter and Conexibacter members present a rich pool of hydrolytic enzymes.•Major groups Rubrobacter and Conexibacter exhibit Calvon-Benson-Basshan cycle.•Rubrobacter representatives might be driving sulfate mineralisation.•Caulobacter representatives are suggested to have a potential key role in K+ uptake.•Conexibacter, Rubrobacter and Caulobacter isolates would be desirable for industry.
Staklokeramika, 70 godina od otkrića Kurajica, Stanislav
Kemija u industriji; časopis kemičara i tehnologa Jugoslavije,
11/2023, Letnik:
72, Številka:
11-12
Journal Article
Recenzirano
Odprti dostop
Ove će se godine navršiti 70 godina od otkrića staklokeramike. Tim povodom u ovom je članku dan sveobuhvatan opis ovog materijala i njegovog napretka od otkrića do danas. Objašnjeno je što je ...staklokeramika te ukazano na rast interesa i komercijalni uspjeh ovog materijala. Opisan je proces priprave staklokeramike, a posebna pozornost posvećena je ulozi nukleatora te procesu nukleacije i rasta. Navedeni su čimbenici koji presudno utječu na svojstva staklokeramike poput kristalne faze, njenog udjela, sastava preostale staklene faze i mikrostrukture. Zahvaljujući utjecaju navedenih čimbenika moguće je pripraviti različite vrste staklokeramike, s različitim kristalnim fazama i morfologijama te posljedično različitim svojstvima, prikladne za različite namjene. Predstavljeni su najvažniji sustavi i vrste staklokeramike, opisana su i objašnjena njihova svojstva i navedene namjene, a spomenuti su i nazivi najvažnijih robnih marki komercijalne staklokeramike. U zaključku je dano viđenje perspektive ovog materijala te vrste staklokeramike i područja primjene u kojima je napredak najizvjesniji.
This year will be the 70th anniversary of the discovery of glass-ceramics. On this occasion, a review paper presenting this material and its progress from discovery to the present day is given. It is explained what glass-ceramic is and pointed out to the growth of interest in this material and its commercial success. The process of preparing glass-ceramics is described, while special attention is paid to the role of nucleating agents and the process of nucleation and growth. Factors that decisively affect the properties of glass-ceramics, such as the crystalline phase, its proportion, the composition of the remaining glass phase and the microstructure, are listed. Owing to the influence of the mentioned factors, it is possible to prepare different types of glass-ceramics, with different crystal phases and morphologies and consequently different properties, suitable for different purposes. The most important systems and types of glass-ceramics are presented, their properties and uses are described and explained. The names of the most important brands of commercial glass-ceramics are also mentioned. In the conclusion, a view of the perspective of this material, glass-ceramic types and areas of application in which the progress is most certain is given.
Understanding the dynamics of soil microbial communities and the factors that affect those dynamics is crucial for comprehending the processes affecting soil fertility in agricultural ecosystems. ...Here, we used shotgun DNA sequencing to characterise 29 soil microbial communities in flooded paddies in China's Yangtze River Basin, and comparatively analysed the composition and function of microbial communities with 132 communities from North and South America's rainfed cropland. We hypothesised that soil microbial community diversity and functional composition are predominantly determined by edaphic properties and land-use history, rather than by spatial distance and climate. We revealed significant differences in taxonomic structure and functional composition among the microbial communities collected from a 2000 km transect along the Yangtze River and found that taxonomic diversity and genomic functional composition of the soil microbial communities were predominantly defined by soil pH. The significant correlation between soil pH and microbial community diversity can be extended to soils from different continents. Microbial communities in flooded paddies in China differed significantly from those in rainfed croplands in North and South America, while the communities from rainfed croplands in North and South America were similar despite their significant differences in geographic distance. Together with available evidence, our results suggest that soil microbial diversity is controlled primarily by edaphic variables rather than by climate, which differs fundamentally from the global biogeography of macro-organisms. The predominant element of soil properties (soil pH in particular) and the response of particular taxa to changing pH provides insight for the selection of agronomic practice. Agronomic practice and fertilisation may change soil pH and therefore alter soil microbial diversity and composition, which could have an impact on soil nutrient supply in agricultural ecosystems.
Traditional methods may underestimate the microbial diversity. Metagenome analysis using whole genome sequencing allows quantification of the diversity more accurately and characterisation of the function of the mega-diverse soil microbial communities simultaneously. Using metagenome analysis on 141 soil microbial communities collected from global agriculture soil system with 32 from flooded paddies in China and 129 from rain-fed farmland in North and South America. We found that the significant correlation between soil pH and diversity of microbial communities can be extended to soils from different continents, which is fundamentally different from the diversity and community structure of macro-organisms. Moreover, we revealed that land use and cultivation history have shaped the taxonomic and functional composition in the soil microbial community. Our study deepens our understanding of the structure and function of the soil microbial community in general, and have particularly important implications in agricultural practice.
•Soil microbial diversity is controlled by soil pH in agricultural lands.•Microbial communities in flooded paddies differ from those in rainfed croplands.•Metagenome servers facilitate data archiving, sharing and comparative analysis.
Starting from the fact that in a microbial community even the concept of species is poorly defined and often debated, but closely related organisms tend to share a substantial amount of genomic ...sequences, together with a large number of physiological and biochemical properties, it was developed metagenomics. The discipline of metagenomics, defined as the genomic analysis of all microorganisms in a given niche environment, has evolved as an effort to find out more about the microbial diversity of natural environments, such as soil, seawater and the gastrointestinal tract of vertebrates and invertebrates. The purpose of this paper was to bring in front the discipline of metagenomics which will be used in many scientific areas in the future. Our paper represents a brief review of the literature available on the internet regarding the definition, description of metagenomics but also its possibilities of its application in ecology. Moreover, this paper contains the description of MG-RAST software as bioinformatics method that is suitable for usage of metagenomics in ecological studies.
Environmental microbiome studies rely on fast and accurate bioinformatics tools to characterize the taxonomic composition of samples based on the 16S rRNA gene. MetaGenome Rapid Annotation using ...Subsystem Technology (MG-RAST) and Quantitative Insights Into Microbial Ecology 2 (QIIME2) are two of the most popular tools available to perform this task. Their underlying algorithms differ in many aspects, and therefore the comparison of the pipelines provides insights into their best use and interpretation of the outcomes. Both of these bioinformatics tools are based on several specialized algorithms pipelined together, but whereas MG-RAST is a user-friendly webserver that clusters rRNA sequences based on their similarity to create Operational Taxonomic Units (OTU), QIIME2 employs DADA2 in the construction of Amplicon Sequence Variants (ASV) by applying an error model that considers the abundance of each sequence and its similarity to other sequences. Taxonomic compositions obtained from the analyses of amplicon sequences of DNA from swine intestinal gut and faecal microbiota samples using MG-RAST and QIIME2 were compared at domain-, phylum-, family- and genus-levels in terms of richness, relative abundance and diversity. We found significant differences between the microbiota profiles obtained from each pipeline. At domain level, bacteria were relatively more abundant using QIIME2 than MG-RAST; at phylum level, seven taxa were identified exclusively by QIIME2; at family level, samples processed in QIIME2 showed higher evenness and richness (assessed by Shannon and Simpson indices). The genus-level compositions obtained from each pipeline were used in partial least squares-discriminant analyses (PLS-DA) to discriminate between sample collection sites (caecum, colon and faeces). The results showed that different genera were found to be significant for the models, based on the Variable Importance in Projection, e.g. when using sequencing data processed by MG-RAST, the three most important genera were Acetitomaculum, Ruminococcus and Methanosphaera, whereas when data was processed using QIIME2, these were Candidatus Methanomethylophilus, Sphaerochaeta and Anaerorhabdus. Furthermore, the application of differential filtering procedures before the PLS-DA revealed higher accuracy when using non-restricted datasets obtained from MG-RAST, whereas datasets obtained from QIIME2 resulted in more accurate discrimination of sample collection sites after removing genera with low relative abundances (<1%) from the datasets. Our results highlight the differences in taxonomic compositions of samples obtained from the two separate pipelines, while underlining the impact on downstream analyses, such as biomarkers identification.
•Microbiome profiles obtained from QIIME2 showed higher alpha-diversity and lower beta-diversity than from MG-RAST.•Whole taxonomic compositions generated in MG-RAST led to more accurate discrimination between sample collection sites.•Removing low abundance taxa from QIIME2 compositions let to higher discrimination accuracy between sample collection sites.
An investigation of the adsorption equilibrium of carbon dioxide (CO2) and nitrogen (N2) and their mixtures on zeolites ZSM-5 and 13X is presented. Pure component isotherms are measured at five ...different temperatures in the range of 25 °C and pressures up to 10 bar, and the resulting data are described with an appropriate isotherm equation. Adsorption equilibrium of CO2/N2 mixtures was measured at two temperatures (25 °C and 45 °C) and three pressure levels (1.2 bar, 3 bar and 10 bar) using three feed gas compositions on both materials tested. The isotherms obtained from the pure component measurements are used to predict the binary data using two approaches: An empirical extension of the Sips isotherm and the application of ideal adsorbed solution theory (IAST). In the context of the binary CO2/N2 adsorption, it was found that for ZSM-5 the system behaves close to ideal over the whole range of pressure and temperature investigated here and thus is well described by the IAST prediction. On the other hand, our results demonstrate non-ideal behavior in the adsorbed phase with increasing pressure for zeolite 13X, thus motivating the use of real adsorbed solution theory (RAST) to accurately describe the binary adsorption data.
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•Pure component adsorption data of CO2 and N2 on ZSM-5 and 13X.•Binary adsorption equilibria of the CO2 and N2 mixture.•Non-ideal behavior of the CO2/N2 mixture in the adsorbed phase of 13X.•Proper description by ideal and real adsorbed solution theory.
Phages are complex biomolecular machineries that have to survive in a bacterial world. Phage genomes show many adaptations to their lifestyle such as shorter genes, reduced capacity for redundant DNA ...sequences, and the inclusion of tRNAs in their genomes. In addition, phages are not free-living, they require a host for replication and survival. These unique adaptations provide challenges for the bioinformatics analysis of phage genomes. In particular, ORF calling, genome annotation, noncoding RNA (ncRNA) identification, and the identification of transposons and insertions are all complicated in phage genome analysis. We provide a road map through the phage genome annotation pipeline, and discuss the challenges and solutions for phage genome annotation as we have implemented in the rapid annotation using subsystems (RAST) pipeline.
Istraživana je dinamika rasta ploda sorti: Springold, Redhaven, Suncrest i Fayette u ekološkim uvjetima Ravnih kotara. Breskve su uzgajane u obliku vretenastog grma na podlozi GF 677. Rezultati ...istraživanja predočeni su u tablicama i grafikonima. Rast ploda slijedi dvostruku sigmoidnu krivulju na kojoj su istaknute dvije faze bržeg rasta i jedna faza vrlo usporenog rasta. Prva faza brzog rasta traje oko 65 dana za sve četiri sorte. Druga faza rasta traje u sorte Springold 5 do 7 dana, u sorata Redhaven i Suncrest 28 dana, a u sorte Fayette 35 dana. Treća faza ponovnog bržeg rasta traje u sorata Springold i Redhaven 14 dana, u sorte Suncrest 21 dan, a u sorte Fayette 10 dana.
The dynamics of fruit growth of the varieties: Springold, Redhaven, Suncrest and Fayette in the ecological conditions of Ravni kotari were investigated. Peaches were grown in the form of a spindly bush on the rootstock GF 677. The results of the research are presented in tables and graphs. Fruit growth follows a double sigmoid curve, where two phases of faster growth and one phase of very slow growth are highlighted. The first phase of rapid growth lasts about 65 days for all four varieties. The second growth phase lasts 5 to 7 days in the Springold variety, 28 days in the Redhaven and Suncrest varieties, and 35 days in the Fayette varieties. The third phase of faster growth again lasts 14 days in the Springold and Redhaven varieties, 21 days in the Suncrest variety, and 10 days in the Fayette variety.
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