Biocrust diazotrophs and bacteria rather than fungi are sensitive to chronic low N deposition.

Anthropogenic long-term nitrogen (N) deposition may dramatically impact biocrusts due to the overarching N limitation of soil biota in deserts. Even low levels of N may reach a critical loading threshold altering biocrust constituents and function. To identify the impact of chronic and continuous low levels of N deposition on biocrusts, we created a realistic gradient mirroring anthropogenic N addition rate (2:1 NH : NO rates: 0.

A bias away from Th2 in amniotic fluid is involved in preeclampsia.

Inflammatory cytokines contribute to the pathophysiology of preeclampsia. However, whether the imbalance of Th1/Th2 cytokines in amniotic fluid is associated with preeclampsia is not well defined. In the present study, we collected peripheral blood and amniotic fluid from normal pregnancy (n = 25) and preeclampsia (n = 22) at last trimester during cesarean section.

The safty profile of blood salvage applied for collected blood with amniotic fluid during cesarean section.

Background: The guidelines of National Health Service(NHS, the United Kingdom) recommended for use in obstetrics at increased risk of bleeding, requiring two suction devices to reduce amniotic fluid contamination, however, when comes to massive hemorrhage, it is may difficult to operate because the complex operation may delay time. The aim of the study was to detect the effect of amniotic fluid recovery on intraoperative cell salvage in obstetrics and provide evidence for clinical applications.

Method: Thirty-four patients undergoing elective cesarean section were randomly divided into two groups.

Freeze-thaw cycles change the physiological sensitivity of Syntrichia caninervis to snow cover.

Spring, especially the freeze-thaw season, is considered the key period for the growth and carbon sequestration of desert mosses. It is not clear how the change in environment water and temperature affects the physiological characteristics of desert mosses in freeze-thaw season. In this study, the effects of water and freeze-thaw cycles on the physiological characteristics of Syntrichia caninervis were assessed by manipulating the increase or removal of 65% snow and changes in the freeze-thaw cycles.

Population Genomics Insights into Adaptive Evolution and Ecological Differentiation in Streptomycetes.

Deciphering the genomic variation that represents microevolutionary processes toward species divergence is key to understanding microbial speciation, which has long been under debate. Streptomycetes are filamentous bacteria that are ubiquitous in nature and the richest source of antibiotics; however, their speciation processes remain unknown. To tackle this issue, we performed a comprehensive population genomics analysis on residing in different habitats and with a worldwide distribution and identified and characterized the foundational changes within the species.

Phylogenetic relationships in the family Streptomycetaceae using multi-locus sequence analysis.

The family Streptomycetaceae, notably species in the genus Streptomyces, have long been the subject of investigation due to their well-known ability to produce secondary metabolites. The emergence of drug resistant pathogens and the relative ease of producing genome sequences has renewed the importance of Streptomyces as producers of new natural products and resulted in revived efforts in isolating and describing strains from novel environments. A previous large study of the phylogeny in the Streptomycetaceae based on 16S rRNA gene sequences provided a useful framework for the relationships among species, but did not always have sufficient resolution to provide definitive identification.

Prophylactic Melatonin Attenuates Isoflurane-Induced Cognitive Impairment in Aged Rats through Hippocampal Melatonin Receptor 2 - cAMP Response Element Binding Signalling.

Melatonin exerts many physiological effects via melatonin receptors, among which the melatonin-2 receptor (MT ) plays a critical role in circadian rhythm disorders, Alzheimer's disease and other neurological disorders. A melatonin replacement strategy has been tested previously, and MT was a critical target during the process. cAMP response element binding (CREB) is an essential transcription factor for memory formation and could be involved in MT signalling.

Widespread interspecies homologous recombination reveals reticulate evolution within the genus Streptomyces.

Homologous recombination is increasingly being recognized as a driving force in microbial evolution. However, recombination in streptomycetes, a rich source of diverse secondary metabolites, particularly among different species, remains minimally investigated. In this study, the largest sample of Streptomyces species to date, consisting of 142 type strains spanning the genus, with available sequences of 16S rRNA, atpD, gyrB, recA, rpoB and trpB genes, were collected and subjected to a comprehensive population genetic analysis to generate an overall estimate of the level of Streptomyces interspecies genetic exchange and its effect on the evolution of this genus.

Taxonomic evaluation of species in the Streptomyces hirsutus clade using multi-locus sequence analysis and proposals to reclassify several species in this clade.

Previous phylogenetic analysis of species of the genus Streptomyces based on 16S rRNA gene sequences resulted in a statistically well-supported clade (100 % bootstrap value) containing eight species that exhibited very similar gross morphology in producing open looped (Retinaculum-Apertum) to spiral (Spira) chains of spiny- to hairysurfaced, dark green spores on their aerial mycelium. The type strains of the species in this clade, specifically Streptomyces bambergiensis, Streptomyces cyanoalbus, Streptomyces emeiensis, Streptomyces hirsutus, Streptomyces prasinopilosus and Streptomyces prasinus, were subjected to multi-locus sequence analysis (MLSA) utilizing partial sequences of the housekeeping genes atpD, gyrB, recA, rpoB and trpB to clarify their taxonomic status. The type strains of several recently described species with similar gross morphology, including Streptomyces chlorus, Streptomyces herbaceus, Streptomyces incanus, Streptomyces pratens and Streptomyces viridis, were also studied along with six unidentified green-spored Streptomyces strains from the ARS Culture Collection.

Effects of simulated microgravity and spaceflight on morphological differentiation and secondary metabolism of Streptomyces coelicolor A3(2).

As well-known antibiotic-producing and filamentous bacteria, streptomycetes can be an ideal model to study the effects of microgravity on microbial development and antibiotic production. In this study, the model organism Streptomyces coelicolor A3(2) was exposed to simulated microgravity (SMG) on a rotating clinostat and microgravity (μg) on the Shenzhou-8 spacecraft. The strain exhibited some similar responses under both conditions.

Population genetic analysis of Streptomyces albidoflavus reveals habitat barriers to homologous recombination in the diversification of streptomycetes.

Examining the population structure and the influence of recombination and ecology on microbial populations makes great sense for understanding microbial evolution and speciation. Streptomycetes are a diverse group of bacteria that are widely distributed in nature and a rich source of useful bioactive compounds; however, they are rarely subjected to population genetic investigations. In this study, we applied a five-gene-based multilocus sequence analysis (MLSA) scheme to 41 strains of Streptomyces albidoflavus derived from diverse sources, mainly insects, sea, and soil.

Activation of the canonical nuclear factor-κB pathway is involved in isoflurane-induced hippocampal interleukin-1β elevation and the resultant cognitive deficits in aged rats.

Although much recent evidence has demonstrated that neuroinflammation contributes to volatile anesthetic-induced cognitive deficits, there are few existing mechanistic explanations for this inflammatory process. This study was conducted to investigate the effects of the volatile anesthetic isoflurane on canonical nuclear factor (NF)-κB signaling, and to explore its association with hippocampal interleukin (IL)-1β levels and anesthetic-related cognitive changes in aged rats. After a 4-h exposure to 1.

Classification of Streptomyces phylogroup pratensis (Doroghazi and Buckley, 2010) based on genetic and phenotypic evidence, and proposal of Streptomyces pratensis sp. nov.

The Streptomyces phylogroup pratensis (Doroghazi and Buckley, 2010) contains isolates obtained from grassy fields, as well as Streptomyces flavogriseus ATCC 33331 and strain CGMCC 4.1868. This latter strain was received as Streptomyces griseoplanus but was subsequently found to be mislabeled, and S.

Femtoliter-scale patterning by high-speed, highly scaled inverse gravure printing.

Pattern printing techniques have advanced rapidly in the past decade, driven by their potential applications in printed electronics. Several printing techniques have realized printed features of 10 μm or smaller, but unfortunately, they suffer from disadvantages that prevent their deployment in real applications; in particular, process throughput is a significant concern. Direct gravure printing is promising in this regard.

Streptomyces bullii sp. nov., isolated from a hyper-arid Atacama Desert soil.

A Streptomyces strain isolated from a hyper-arid Atacama Desert soil was characterised using a polyphasic taxonomic approach. The strain, designated C2(T), had chemical and morphological properties typical of the genus Streptomyces. The isolate formed a branch in the Streptomyces 16S rRNA gene tree together with the type strain of Streptomyces chromofuscus and was also loosely related to Streptomyces fragilis NRRL 2424(T).

Streptomyces chlorus sp. nov. and Streptomyces viridis sp. nov., isolated from soil.

Two actinomycete strains, BK125(T) and BK199(T), isolated from a hay meadow soil sample were investigated to determine their taxonomic position using a polyphasic approach. The isolates produced greenish-yellow and light green aerial mycelium on oatmeal agar, respectively. They contained anteiso-C15 : 0, iso-C15 : 0 and C16 : 0 as the major fatty acids, and MK-9 (H6) and MK-9 (H8) as the predominant isoprenoid quinones.

Streptomyces erringtonii sp. nov. and Streptomyces kaempferi sp. nov., isolated from a hay meadow soil.

Two filamentous actinomycetes isolated from a hay meadow soil were provisionally assigned to the genus Streptomyces based on morphological features. The isolates were found to have chemical and morphological properties typical of the genus Streptomyces and formed distinct phyletic lines in the 16S rRNA gene tree. Isolate I36(T) was most closely related to Streptomyces glauciniger NBRC 100913(T) and isolate I37(T) to Streptomyces mirabilis NBRC 13450(T).

Streptomyces atacamensis sp. nov., isolated from an extreme hyper-arid soil of the Atacama Desert, Chile.

The taxonomic position of a Streptomyces strain isolated from an extreme hyper-arid soil sample collected from the Atacama Desert was determined using a polyphasic approach. The strain, isolate C60(T), had chemical and morphological features typical of members of the genus Streptomyces and formed a distinct phyletic line in the Streptomyces 16S rRNA gene tree, together with the type strain of Streptomyces radiopugnans. The two strains were distinguished readily using a combination of phenotypic properties and by a DNA-DNA relatedness value of 23.

Taxonomic evaluation of the Streptomyces hygroscopicus clade using multilocus sequence analysis and DNA-DNA hybridization, validating the MLSA scheme for systematics of the whole genus.

Streptomyces hygroscopicus and related species are the most well known candidate producers of antibiotics and many other industrially and agronomically important secondary metabolites in the genus Streptomyces. Multilocus sequence analysis (MLSA) has shown to be a powerful and pragmatic molecular method for unraveling streptomycete diversities. In this investigation, a multilocus phylogeny of 58 representatives of the S.

Streptomyces deserti sp. nov., isolated from hyper-arid Atacama Desert soil.

The taxonomic position of a Streptomyces strain isolated from a hyper-arid desert soil was established using a polyphasic approach. The organism had chemical and morphological properties typical of the genus Streptomyces and formed a phyletic line at the periphery of the Streptomyces coeruleorubidus subcluster in the 16S rRNA gene tree. DNA:DNA relatedness values between the isolate and its nearest phylogenetic neighbours, Streptomyces lomondensis NRRL 3252(T) and Streptomyces lusitanus NRRL B-12501(T) were 42.

Streptomyces herbaceus sp. nov., Streptomyces incanus sp. nov. and Streptomyces pratens sp. nov., isolated from the soil of a hay meadow.

The taxonomic positions of three streptomycetes isolated from a soil sample from a hay meadow were determined using a polyphasic approach. The isolates had chemical and morphological properties typical of the genus Streptomyces and, in phylogenetic analyses based on 16S rRNA gene sequences, formed a distinct subclade that was most closely related to the Streptomyces prasinus subclade. DNA-DNA relatedness studies showed that the novel strains belonged to three different genomic species.

Fluorescence in situ hybridization on plant extended chromatin DNA fibers for single-copy and repetitive DNA sequences.

The compactness of plant chromosomes and the structure of the plant cell wall and cytoplasm provide a great obstacle to fluorescence in situ hybridization (FISH) for single-copy or low-copy DNA sequences. Consequently, many new methods for improving spatial resolution via chromosomal stretching have been employed to overcome this technical challenge. In this article, a technique for extracting cell-wall free nuclei at mitotic interphase, then using these nuclei to prepare extended DNA fibers (EDFs) by the method of a receding interface, whereby slide-mounted chromatin produces EDFs in concert with gravity-assisted buffer flow, was adopted as a result of the low frequency of EDF damage produced by this procedure.

Genetic screening strategy for rapid access to polyether ionophore producers and products in actinomycetes.

Polyether ionophores are a unique class of polyketides with broad-spectrum activity and outstanding potency for the control of drug-resistant bacteria and parasites, and they are produced exclusively by actinomycetes. A special epoxidase gene encoding a critical tailoring enzyme involved in the biosynthesis of these compounds has been found in all five of the complete gene clusters of polyether ionophores published so far. To detect potential producer strains of these antibiotics, a pair of degenerate primers was designed according to the conserved regions of the five known polyether epoxidases.

Multilocus sequence analysis of Streptomyces griseus isolates delineating intraspecific diversity in terms of both taxonomy and biosynthetic potential.

Systematics can provide a fundamental framework for understanding the relationships and diversification of organisms. Multilocus sequence analysis (MLSA) has shown great promise for an elaborate taxonomic grouping of streptomycete diversity. To evaluate the practical significance of MLSA as a valuable systematic tool for streptomycetes, we examined six endophytic Streptomyces griseus isolates and two S.