The effects of the short-term application of Ascophyllum nodosum-fermented seaweed fertilizer on the bacterial community, soil nitrogen contents, and plant growth in maize rhizosphere soil were evaluated. The changes in the bacterial community composition and nitrogen contents including those of total nitrogen (TN), nitrate nitrogen (NO3--N) and ammonium nitrogen (NH4+-N) in rhizosphere soils in response to treatment with seaweed fertilizer were determined. Furthermore, soil enzymatic activity and crop biomass were analyzed. The relative abundance of the dominant phyla varied regularly with fertilization, and bacterial α-diversity was apparently influenced by seaweed fertilizer amendment. The TN contents of all soil samples decreased gradually, and the NO3--N and NH4+-N contents of the soils treated with seaweed fertilizer were much higher than those of the control soils. Similarly, the enzymatic activities of dehydrogenase, nitrite reductase, urease, and cellulase in the soil were significantly increased on day 3, day 8, and day 13 after the application of seaweed fertilizer to the maize rhizosphere soil. However, there was no difference in the activity of soil sucrase between the treatment group and the control group. In this study, the growth of maize seedlings was confirmed to be greatly promoted by the utilization of seaweed fertilizer. These results deepen our understanding of plant-microbe interactions in agroecosystems and should benefit the wide use of seaweed fertilizer in sustainable agricultural production.

• MeSH
• Ascophyllum chemie   MeSH
• Bacteria klasifikace   MeSH
• biomasa MeSH
• dusík analýza   MeSH
• fylogeneze MeSH
• kukuřice setá růst a vývoj   mikrobiologie   MeSH
• mikrobiota * MeSH
• mořské řasy chemie   MeSH
• průmyslová hnojiva analýza   MeSH
• půda chemie   MeSH
• půdní mikrobiologie MeSH
• rhizosféra * MeSH
• vývoj rostlin MeSH
• zemědělství metody   MeSH
• Publikační typ
• časopisecké články MeSH

Biogeochemical processes and ecosystemic functions are mostly driven by soil microbial communities. However, most methods focus on evaluating the total microbial community and fail to discriminate its active fraction which is linked to soil functionality. Precisely, the activity of the microbial community is strongly limited by the availability of organic carbon (C) in soils under arid and semi-arid climate. Here, we provide a complementary genomic and metaproteomic approach to investigate the relationships between the diversity of the total community, the active diversity and ecosystem functionality across a dissolved organic carbon (DOC) gradient in southeast Spain. DOC correlated with the ecosystem multifunctionality index composed by soil respiration, enzyme activities (urease, alkaline phosphatase and β-glucosidase) and microbial biomass (phospholipid fatty acids, PLFA). This study highlights that the active diversity (determined by metaprotoemics) but not the diversity of the whole microbial community (evaluated by amplicon gene sequencing) is related to the availability of organic C and it is also connected to the ecosystem multifunctionality index. We reveal that DOC shapes the activities of bacterial and fungal populations in Mediterranean semi-arid soils and determines the compartmentalization of functional niches. For instance, Rhizobales thrived at high-DOC sites probably fuelled by metabolism of one-C compounds. Moreover, the analysis of proteins involved in the transport and metabolism of carbohydrates revealed that Ascomycota and Basidiomycota occupied different nutritional niches. The functional mechanisms for niche specialization were not constant across the DOC gradient.

• MeSH
• biodiverzita * MeSH
• pentacyklické triterpeny MeSH
• půda chemie   MeSH
• půdní mikrobiologie * MeSH
• uhlík chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Španělsko MeSH

The increasing use of silver nanoparticles (AgNPs) due to their well-known antimicrobial activity, has led to their accumulation in soil ecosystems. However, the impact of environmental realistic concentrations of AgNPs on the soil microbial community has been scarcely studied. In this work, we have assessed the impact of AgNPs, that mimic real concentrations in nature, on tropical soils cultivated with Coffea arabica under conventional and organic management systems. We evaluated the biomass, extracellular enzyme activities, and diversity of the soil microbial community, in a microcosm experiment as a function of time. After seven days of incubation, we found an increase in microbial biomass in an AgNPs-concentration-independent manner. In contrast, after 60-day-incubation, there was a decrease in Gram+ and actinobacterial biomass, in both soils and all AgNPs concentrations. Soil physico-chemical properties and enzyme activities were not affected overall by AgNPs. Regarding the microbial community composition, only some differences in the relative abundance at phylum and genus level in the fungal community were observed. Our results suggest that environmental concentrations of AgNPs affected microbial biomass but had little impact on microbial diversity and may have little effects on the soil biogeochemical cycles mediated by extracellular enzyme activities.

• MeSH
• Bacteria klasifikace   účinky léků   enzymologie   genetika   MeSH
• bakteriální geny MeSH
• beta-glukosidasa chemie   MeSH
• biomasa MeSH
• kovové nanočástice toxicita   MeSH
• kyselá fosfatasa chemie   MeSH
• látky znečišťující půdu toxicita   MeSH
• mikrobiota účinky léků   MeSH
• půdní mikrobiologie MeSH
• RNA ribozomální 16S MeSH
• stříbro toxicita   MeSH
• ureasa chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

More than 40% of nosocomial infections are those of the urinary tract, most of these occurring in catheterized patients. Bacterial colonization of the urinary tract and catheters results not only in infection, but also various complications, such as blockage of catheters with crystalline deposits of bacterial origin, generation of gravels and pyelonephritis. The diversity of the biofilm microbial community increases with duration of catheter emplacement. One of the most important pathogens in this regard is Proteus mirabilis. The aims of this study were to identify and assess particular virulence factors present in catheter-associated urinary tract infection (CAUTI) isolates, their correlation and linkages: three types of motility (swarming, swimming and twitching), the ability to swarm over urinary catheters, biofilm production in two types of media, urease production and adherence of bacterial cells to various types of urinary tract catheters. We examined 102 CAUTI isolates and 50 isolates taken from stool samples of healthy people. Among the microorganisms isolated from urinary catheters, significant differences were found in biofilm-forming ability and the swarming motility. In comparison with the control group, the microorganisms isolated from urinary catheters showed a wider spectrum of virulence factors. The virulence factors (twitching motility, swimming motility, swarming over various types of catheters and biofilm formation) were also more intensively expressed.

• MeSH
• bakteriální adheze MeSH
• biofilmy růst a vývoj   MeSH
• faktory virulence metabolismus   MeSH
• infekce bakteriemi rodu Proteus mikrobiologie   MeSH
• infekce močového ústrojí mikrobiologie   MeSH
• katétrové infekce mikrobiologie   MeSH
• lidé MeSH
• lokomoce MeSH
• Proteus mirabilis izolace a purifikace   patogenita   fyziologie   MeSH
• ureasa metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The variations in the soil culturable bacterial communities and biochemical parameters of early successional soils from a receding glacier in the Tanggula Mountain were investigated. We examined low organic carbon (C) and nitrogen (N) contents and enzymatic activity, correlated with fewer bacterial groups and numbers in the glacier forefield soils. The soil pH values decreased, but the soil water content, organic C and total N significantly increased, along the chronosequence. The soil C/N ratio decreased in the early development soils and increased in the late development soils and it did not correlate with the soil age since deglaciation. The activities of soil urease, sucrase, protease, polyphenol oxidase, catalase, and dehydrogenase increased along the chronosequence. The numbers of culturable bacteria in the soils increased as cultured at 25°C while decreased at 4°C from younger soils to older soils. Total numbers of culturable bacteria in the soils cultured at 25°C were significantly positively correlated to the soil total N, organic C, and soil water content, as well as the activities of soil urease, sucrase, dehydrogenase, catalase, and polyphenol oxidase. We have obtained 224 isolates from the glacier forefield soils. The isolates were clustered into 28 groups by amplified ribosomal DNA restriction analysis (ARDRA). Among them, 27 groups and 25 groups were obtained from the soils at 25°C and at 4°C incubation temperatures, respectively. These groups are affiliated with 18 genera that belong to six taxa, viz, Actinobacteria, Gammaproteobacteria, Bacteroidetes, Firmicutes, Alphaproteobacteria, and Betaproteobacteria. The dominant taxa were Actinobacteria, Gammaproteobacteria, and Bacteroidetes in all the samples. The abundance and the diversity of the genera isolated at 25°C incubation temperature were greater than that at 4°C.

• MeSH
• Bacteria klasifikace   růst a vývoj   izolace a purifikace   metabolismus   MeSH
• bakteriální nálož MeSH
• časové faktory MeSH
• DNA bakterií chemie   genetika   MeSH
• DNA fingerprinting MeSH
• dusík analýza   MeSH
• enzymy analýza   MeSH
• fylogeneze MeSH
• koncentrace vodíkových iontů MeSH
• ledový příkrov * MeSH
• molekulární sekvence - údaje MeSH
• polymorfismus délky restrikčních fragmentů MeSH
• půda chemie   MeSH
• půdní mikrobiologie * MeSH
• sekvenční analýza DNA MeSH
• shluková analýza MeSH
• společenstvo * MeSH
• teplota MeSH
• uhlík analýza   MeSH
• voda analýza   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Čína MeSH