Environmental DNA metabarcoding reveals diverse phytoplankton assemblages and potentially harmful algal distribution along the urban coasts of Türkiye.

Marine phytoplankton are widely used to monitor the state of the water column due to their rapid changes in response to environmental conditions. In this study, we aimed to investigate the coastal phytoplankton assemblages, including bloom-forming species using high-throughput sequencing of 18S rRNA genes targeting the V4 region and their relationship with environmental variables along the Istanbul coasts of the Sea of Marmara. A total of 118 genera belonging to six phyla were detected. Among them, Dinoflagellata (36) and Bacillariophyta (26) were represented with the highest number of genera. According to the relative abundance of DNA reads, the most abundant taxa were Dinoflagellata_phylum (18.1%), Emiliania (8.4%), Biecheleria (8.4), and Noctiluca (8.1%). The ANOSIM test showed that there was a significant temporal difference in the assemblages, while the driving environmental factors were pH, water temperature, and salinity. According to the TRIX index, the trophic state of the coasts was highly mesotrophic and eutrophic. In addition, 45 bloom-forming and HAB taxa were detected and two species of Noctiluca and Emiliania, which frequently cause blooms in the area, were recorded in high abundance. Our results provide insight into the phytoplankton assemblages along the urbanized coastlines by analysing the V4 region of 18S rRNA. This data can support future studies that use both traditional methods and metabarcoding, employing various primers and targeting different genes and regions.

Development and application of a whole genome amplicon sequencing method for infectious salmon anemia virus (ISAV).

Infectious salmon anemia (ISA) is an infectious disease primarily affecting farmed Atlantic salmon, Salmo salar, which is caused by the ISA virus (ISAV). ISAV belongs to the Orthomyxoviridae family. The disease is a serious condition resulting in reduced fish welfare and high mortality. In this study, we designed an amplicon-based sequencing protocol for whole genome sequencing of ISAV. The method consists of 80 ISAV-specific primers that cover 92% of the virus genome and was designed to be used on an Illumina MiSeq platform. The sequencing accuracy was investigated by comparing sequences with previously published Sanger sequences. The sequences obtained were nearly identical to those obtained by Sanger sequencing, thus demonstrating that sequences produced by this amplicon sequencing protocol had an acceptable accuracy. The amplicon-based sequencing method was used to obtain the whole genome sequence of 12 different ISAV isolates from a small local epidemic in the northern part of Norway. Analysis of the whole genome sequences revealed that segment reassortment took place between some of the isolates and could identify which segments that had been reassorted.

Microbiota Association and Profiling of Gingival Sulci and Root Canals of Teeth with Primary or Secondary/Persistent Endodontic Infections.

INTRODUCTION: Microbiota associated with primary endodontic infection (PEI) and secondary/persistent endodontic infection (SPEI) must be characterized to elucidate pathogenesis in apical periodontitis and bacterial biomarkers identified for diagnostic and therapeutic applications. METHODS: This study analyzed the microbial community profiles of root canals and gingival sulci (sulcus-E) for teeth with PEI (n = 10) or SPEI (n = 10), using the Illumina MiSeq platform. Bacterial samples from gingival sulci (sulcus-C) of healthy contralateral teeth served as controls. RESULTS: There were 15 phyla, 177 genera, and 340 species identified. The number and diversity of bacteria in root canals did not differ significantly between PEI and SPEI. Proteobacteria, Firmicutes, Fusobacteria, Bacteroidetes, and Actinobacteria were the dominant phyla in both groups. At the genus level, Lancefieldella, Bifidobacterium, Stomatobaculum, and Schaalia were enriched in root canals with SPEI. Of significance, Lancefieldella was observed in both root canals and sulcus-E of teeth with SPEI. At the species level, Neisseria macacae, Streptococcus gordonii, Bifidobacterium dentium, Stomatobaculum longum, and Schaalia odontolytica were increased significantly in root canals with SPEI compared to PEI. Oribacterium species, Streptococcus salivarius, Lancefieldella parvula, Prevotella denticola, and Oribacterium asaccharolyticum were more abundant in sulcus-E of teeth with SPEI compared to PEI. CONCLUSIONS: There were distinctive and differing predominant bacterial species associated with the root canals and gingival sulci between teeth with PEI and SPEI. Specific bacteria identified in sulcus-E and root canals of teeth with SPEI could serve as noninvasive diagnostic biomarkers for detecting SPEI.

Hepatic transcriptome, transcriptional effects and antioxidant responses in Poecilia vivipara exposed to sanitary sewage.

Aquatic environments are subject to threats from multiple human activities, particularly through the release of untreated sanitary sewage into the coastal environments. These effluents contain a large group of natural or synthetic compounds referred to as emerging contaminants. Monitoring the types and quantities of toxic substances in the environment, especially complex mixtures, is an exhausting and challenging task. Integrative effect-based tools, such as biomarkers, are recommended for environmental quality monitoring programs. In this study, fish Poecilia vivipara were exposed for 24 and 96 h to raw untreated sewage diluted 33 % (v/v) in order to identify hepatic genes to be used as molecular biomarkers. Through a de novo hepatic transcriptome assembly, using Illumina MiSeq, 54,285 sequences were assembled creating a reference transcriptome for this guppy species. Transcripts involved in biotransformation systems, antioxidant defenses, ABC transporters, nuclear and xenobiotic receptors were identified and evaluated by qPCR. Sanitary sewage induced transcriptional changes in AhR, PXR, CYP2K1, CYP3A30, NQO1, UGT1A1, GSTa3, GSTmu, ST1C1, SOD, ABCC1 and SOX9 genes from liver of fish, particularly after 96 h of exposure. Changes in hepatic enzyme activities were also observed. The enzymes showed differences in fish exposed to both periods, while in the gills there was a prevalence of significant results after 96 h. The observed differences were associated to gender and/or to sewage exposure. The obtained results support the use of P. vivipara as sentinel and model organism for ecotoxicological studies and evidence the importance of understanding the differential responses associated to gender.

Uncovering the microbial diversity of Czech Republic archives: A study of metabolically active airborne microbes.

Despite the diligent efforts of libraries, archives, and similar institutions to preserve cultural monuments, biodeterioration continues to pose a significant threat to these objects. One of the main sources of microorganisms responsible for the biodeterioration process is the presence of airborne microorganisms. Therefore, this research aims to monitor and compare outcomes of both culture-dependent (utilising various cultivation strategies) and culture-independent approaches (RNA-based sequencing) to identifying metabolically active airborne microorganisms in archives in the Czech Republic. Through this study, several species that have the potential to pose risks to both cultural heritage objects and the health of institution employees were found. Additionally, the efficacy of different cultivation media was demonstrated to be varied across archive rooms, highlighting the necessity of employing multiple cultivation media for comprehensive analyses. Of noteworthy importance, the resuscitating-promoting factor (Rpf) proved to be a pivotal tool, increasing bacterial culturability by up to 30% when synergistically employed Reasoner's 2A agar (R2A) and R2A + Rpf media. Next, the study emphasises the importance of integrating both culture-dependent and culture-independent approaches. The overlap between genera identified by the culture-dependent approach and those identified also by the culture-independent approach varied from 33% to surpassing 94%, with the maximum alignment exceeding 94% in only one case. Our results highlight the importance of actively monitoring and assessing levels of microbial air contamination in archives to prevent further deterioration of cultural heritage objects and to promote improved conditions for employees in archives and similar institutions.

16S-Metagenomic data profiling of the bacterial community in ready-to-eat vegetable salads sold in Kampala, Uganda.

This article presents a dataset on bacterial community structure associated with Ready-to-eat (RTE) vegetable salads sold in Kampala City, Uganda. The Illumina Miseq sequencing of 16S rRNA gene amplicon unveiled the bacterial communities and generated a metagenomic library from RTE vegetable salads to understand the diversities and distribution. The metagenome contained a total of 23,805 sequences with 35,420 Taxonomic units (OTUs). Metagenome sequence information is obtainable at NCBI under the Bioproject assigned accession number PRJNA1064313. Taxonomic hits distribution from VSEARCH analysis at phylum level classification of NN-3 discovered predominantly Proteobacteria (65.34%) followed by Firmicutes (31.60%) and Bacteroidota (0.14%). Deinococcota (0.01%) and Planctomycetota (0.01%) were also detected. Also, VSEARCH-assisted analysis of NN-4 detected a higher prevalence of Firmicutes (65.68%) than Proteobacteria (33.25%), while Bacteroidota (0.04%) indicating the presence of contaminants of faecal sources.

Application of Rice Straw Inhibits Clubroot Disease by Regulating the Microbial Community in Soil.

Straw return is an effective agricultural management practice for alleviating soil sickness, but only a few studies have focused on the incorporation of straw with deep plowing and rotary tillage practices in vegetable production. To determine the effects of rice straw return on Chinese cabbage clubroot, a field experiment for three consecutive years in the same area was performed. Soil microbial high-throughput sequencing, quantitative real-time polymerase chain reaction (PCR) and other methods were used to detect Chinese cabbage plant growth, clubroot occurrence, soil chemical properties and soil microbial diversity and abundance. The results showed that straw addition could significantly reduce the clubroot disease incidence. Through Illumina Miseq sequencing, the diversity of the fungi decreased obviously. The relative abundance of the phyla Proteobacteria and Firmicutes was strikingly reduced, while that of Chloroflexi was significantly increased. Redundancy analysis suggests that soil properties may also affect the soil microbial composition; changes in the microbial structure of bacteria and fungi were associated with the available phosphorus. In conclusion, the continuous addition of rice straw can promote the growth and control the occurrence of clubroot, which is closely related to the microbial composition, and the inhibition effect is proportional to the age of addition.

Responses of soil microbiome to copper-based materials (nano and bulk) for agricultural applications: An indoor-mesocosm experiment.

The foreseen increasing application of copper-based nanomaterials (Cu-NMs), replacing or complementing existing Cu-agrochemicals, may negatively impact the soil microbiome. Thus, we studied the effects on soil microbiome function and composition of nano copper oxide (nCuO) or copper hydroxide NMs in a commercial (Kocide®3000) or a lab-synthetized formulation (nCu(OH)2) or bulk copper hydroxide (Cu(OH)2-B), at the commonly recommended Cu dose of 50 mg(Cu)kg-1 soil. Microbial responses were studied over 28 days in a designed indoor mesocosm. On day-28, in comparison to non-treated soil (CT), all Cu-treatments led to a reduction in dehydrogenase (95% to 68%), arylsulfatase (41% to 27%), and urease (40% to 20%) activity. There was a 32% increase in the utilization of carbon substrates in the nCuO-treatment and an increased abundance of viable bacteria in the nCu(OH)2-treatment (75% of heterotrophic and 69% of P-solubilizing bacteria). The relative abundance of Acidobacteria [Kocide®3000, nCuO, and Cu(OH)2-B treatments] and Flavobacteriia [nCu(OH)2-treatment] was negatively affected by Cu exposure. The abundance of Cu-tolerant bacteria increased in soils treated with Kocide®3000 (Clostridia) and nCu(OH)2 (Gemmatimonadetes). All Cu-treated soils exhibited a reduced abundance of denitrification-related genes (0.05% of nosZ gene). The DTPA-extractable pool of ionic Cu(II) varied among treatments: Cu(OH)2-B > Kocide®3000 âˆ¼ nCuO>nCu(OH)2, which may explain changes on the soil microbiome composition, at the genera and OTU levels. Thus, our study revealed that Cu-materials (nano and bulk) influence the soil microbiome with implications on its ecological role. It highlights the importance of assessing the impact of Cu-materials under dynamic and complex exposure scenarios and emphasizes the need for specific regulatory frameworks for NMs.

Characterization of bacterial diversity and screening of cellulose-degrading bacteria in the gut system of Glenea cantor (Fabricius) larvae.

The intestinal bacteria of longhorn beetles would be ideal targets for pest control and lignocellulosic resources by destroying or exploiting their cellulose-degrading function. This article aims to investigate the diversity and community structure of intestinal bacteria the oligophagous longhorn beetle Glenea cantor. Additionally, it seeks to identify the presence of lignocellulose-degrading bacteria in the gut, and explore their role in consuming host kapok trees Bombax malabaricum. In this study, the bacterial community from G. cantor was examined by Illumina sequencing of 16S ribosomal RNA (rRNA) targeting the V3 and V4 regions. A total of 563,201 valid sequences and 814 OTUs were obtained. The dominant phyla were Proteobacteria, and the dominant genera were Acinetobacter and Lactococcus. The analysis of microbial diversity revealed a high bacterial diversity in the samples, with the gut bacteria playing a crucial role in the physiological activities of the host, particularly, 9 genera of intestinal bacteria with cellulose degradation function were found, highlighting their vital role in cellulose degradation. Five strains of cellulose-degrading bacteria, belonging to the genus Pseudomonas, were obtained from the intestinal tract of G. cantor larvae using traditional isolation and culture techniques as well as 16S rDNA sequencing. Among these strains, A4 exhibited a cellulase activity of 94.42 ± 0.42 U/mL, while A5 displayed the highest filter paper enzyme activity of 127.46 ± 3.54 U/mL. These results offered valuable insights into potential targets for pest control through internal attack digestion and cellulose-degrading bacteria in longhorn beetles.

African swine fever virus NAM P1/95 is a mixture of genotype I and genotype VIII viruses.

African swine fever virus causes a lethal hemorrhagic disease of domestic pigs. The NAM P1/1995 isolate was originally described as B646L genotype XVIII; however, full genome sequencing revealed that this assignment was incorrect.

Temporal changes in ewe vaginal microbiota throughout gestation.

Introduction: Numerous factors are known to influence reproductive efficiency in ewes, but few studies have investigated the potential role of vaginal microbiota in sheep reproductive success. The objective of this study was to thoroughly characterize the ewe vaginal microbiota throughout the course of pregnancy. Methods: Vaginal samples were collected from 31 pregnant Hampshire and Hampshire X Suffolk crossbred ewes on a weekly basis from pre-breeding to pregnancy testing and then biweekly until just after lambing. To characterize the vaginal microbial communities, DNA was extracted and 16S rRNA gene Illumina MiSeq amplicon sequencing was performed. Results and Discussion: Alpha diversity metrics indicated an increase in species richness, evenness, and overall diversity throughout gestation. Distinct shifts in the bacterial communities were observed during gestation and were segregated into three periods: early gestation, a transitional period and mid/late gestation. During early gestation, Actinobacillus, Histophilus, and unclassified Leptotrichiaceae were found in greater relative abundance. During the transitional period, a population shift occurred characterized by increasing relative abundance of Streptococcus and Staphylococcus. During mid/late gestation, Staphylococcus, Streptococcus, and Ureaplasma had the greatest relative abundance. These shifts in the microbial population throughout the ewe's gestation are likely related to hormonal changes triggered by the growing conceptus, specifically increasing blood concentration of progesterone. The transitional period shift in vaginal microbial communities potentially aligns with the placental take-over of progesterone production from the corpus luteum at approximately day 50 after conception (gestational week 7). Understanding the observed variability of the vaginal microbiota throughout pregnancy will allow for future comparison of ewes that did not become pregnant or had abnormal pregnancies, which could lead to the discovery of potential bacterial biomarkers for pregnancy outcome; this understanding could also lead to development of probiotics to improve sheep reproductive success.

Diversity of soil fungi from sacred groves of Kerala, India revealed by comparative metagenomics analysis using illumina sequencing.

The diversity, composition, and abundance of soil fungi from three sacred groves in Kerala, namely Iringole kavu of Ernakulam District, Kollakal Thapovanam of Alappuzha District, and Poyilkavu of Kozhikode District were analysed using Metagenomics analysis and Illumina sequencing. A total of 30,584, 78,323, and 55,640 reads were obtained from these groves, respectively. Ascomycota constitutes over 96% of the total fungi, making it the most abundant phylum, followed by Mortierellomycota, Basidiomycota, Chytridiomycota, and Rozellomycota. These phyla were subdivided into 20 classes, 40 orders, 83 families, 119 genera, and 135 species, while 1269 OTUs remained unidentified at the species level. Eurotiomycetes predominates the class, while the genus Talaromyces from the family Trichomaceae dominates the genera. Neocarmospora falciformis, Trichoderma lixii, and Candida ethanolic are the most abundant fungal species. Diversity analysis shows that Kollakal Thapovanam is rich in fungal species, while Poyilkavu is rich in biodiversity, with a high degree of dominance. Several species were found only in a particular grove and were absent in others and vice-versa, indicating high fungal specificity. Therefore, fungi have to be preserved in their original habitat. The Principal Coordinate Analysis revealed that each grove is distinct highlighting the importance of preserving the unique diversity of each sacred grove. In conclusion, this research provides valuable information about the soil fungal genera in their natural habitat. It emphasizes the need for more systematic research to understand the actual diversity and ecological role of fungi in sacred groves. This study is the first of its kind to analyse and compare soil fungal diversity in sacred groves using the metagenomics approach.

Serpentoviruses Exhibit Diverse Organization and ORF Composition with Evidence of Recombination.

Serpentoviruses are a subfamily of positive sense RNA viruses in the order Nidovirales, family Tobaniviridae, associated with respiratory disease in multiple clades of reptiles. While the broadest viral diversity is reported from captive pythons, other reptiles, including colubrid snakes, turtles, and lizards of captive and free-ranging origin are also known hosts. To better define serpentoviral diversity, eleven novel serpentovirus genomes were sequenced with an Illumina MiSeq and, when necessary, completed with other Sanger sequencing methods. The novel serpentoviral genomes, along with 57 other previously published serpentovirus genomes, were analyzed alongside four outgroup genomes. Genomic analyses included identifying unique genome templates for each serpentovirus clade, as well as analysis of coded protein composition, potential protein function, protein glycosylation sites, differences in phylogenetic history between open-reading frames, and recombination. Serpentoviral genomes contained diverse protein compositions. In addition to the fundamental structural spike, matrix, and nucleoprotein proteins required for virion formation, serpentovirus genomes also included 20 previously uncharacterized proteins. The uncharacterized proteins were homologous to a number of previously characterized proteins, including enzymes, transcription factors, scaffolding, viral resistance, and apoptosis-related proteins. Evidence for recombination was detected in multiple instances in genomes from both captive and free-ranging snakes. These results show serpentovirus as a diverse clade of viruses with genomes that code for a wide diversity of proteins potentially enhanced by recombination events.

Diversity of Endophytes of Actinidia arguta in Different Seasons.

The seasonal changes in environmental conditions can alter the growth states of host plants, thereby affecting the living environment of endophytes and forming different endophytic communities. This study employs Illumina MiSeq next-generation sequencing to analyze the 16SrRNA and ITS rDNA of endophytes in 24 samples of Actinidia arguta stem tissues across different seasons. The results revealed a high richness and diversity of endophytes in Actinidia arguta, with significant seasonal variations in microbial community richness. This study identified 897 genera across 36 phyla for bacteria and 251 genera across 8 phyla for fungi. Notably, 69 bacterial genera and 19 fungal genera significantly contributed to the differences in community structure across seasons. A distinctive feature of coexistence in the endophytic community, both specific and conservative across different seasons, was observed. The bacterial community in winter demonstrated significantly higher richness and diversity compared to the other seasons. Environmental factors likely influence the optimal timing for endophyte colonization. Solar radiation, temperature, precipitation, and relative humidity significantly impact the diversity of endophytic bacteria and fungi. In addition, seasonal variations show significant differences in the nutritional modes of fungal endophytes and the degradation, ligninolysis, and ureolysis functions of bacterial endophytes. This study elucidates the potential role of endophytes in assisting Actinidia arguta in adapting to seasonal changes and provides a theoretical basis for further exploration of functional microbial strains.

Functional and structural responses of a halophilic consortium to oily sludge during biodegradation.

Biotreatment of oily sludge and the involved microbial communities, particularly in saline environments, have been rarely investigated. We enriched a halophilic bacterial consortium (OS-100) from petroleum refining oily sludge, which degraded almost 86% of the aliphatic hydrocarbon (C10-C30) fraction of the oily sludge within 7 days in the presence of 100 g/L NaCl. Two halophilic hydrocarbon-degrading bacteria related to the genera Chromohalobacter and Halomonas were isolated from the OS-100 consortium. Hydrocarbon degradation by the OS-100 consortium was relatively higher compared to the isolated bacteria, indicating potential synergistic interactions among the OS-100 community members. Exclusion of FeCl2, MgCl2, CaCl2, trace elements, and vitamins from the culture medium did not significantly affect the hydrocarbon degradation efficiency of the OS-100 consortium. To the contrary, hydrocarbon biodegradation dropped from 94.1 to 54.4% and 5% when the OS-100 consortium was deprived from phosphate and nitrogen sources in the culture medium, respectively. Quantitative PCR revealed that alkB gene expression increased up to the 3rd day of incubation with 11.277-fold, consistent with the observed increments in hydrocarbon degradation. Illumina-MiSeq sequencing of 16 S rRNA gene fragments revealed that the OS-100 consortium was mainly composed of the genera Halomonas, Idiomarina, Alcanivorax and Chromohalobacter. This community structure changed depending on the culturing conditions. However, remarkable changes in the community structure were not always associated with remarkable shifts in the hydrocarbonoclastic activity and vice versa. The results show that probably synergistic interactions between community members and different subpopulations of the OS-100 consortium contributed to salinity tolerance and hydrocarbon degradation.

Comparative Analysis of Rhizosphere and Endosphere Fungal Communities in Healthy and Diseased Faba Bean Plants.

This study used the ITS approach based on Illumina MiSeq sequencing to assess the endosphere and rhizosphere fungal communities in healthy and diseased faba bean plants. The findings indicate that the most predominant phyla in all samples were Ascomycota (49.89-99.56%) and Basidiomycota (0.33-25.78%). In healthy endosphere samples, Glomeromycota (0.08-1.17%) was the only predominant phylum. In diseased endosphere samples, Olpidiomycota (0.04-1.75%) was the only predominant phylum. At the genus level, Penicillium (0.47-35.21%) was more abundant in rhizosphere soil, while Paraphoma (3.48-91.16%) was predominant in the endosphere roots of faba bean plants. Significant differences were observed in the alpha diversity of rhizosphere samples from different germplasm resources (p < 0.05). The fungal community structures were clearly distinguished between rhizosphere and endosphere samples and between healthy and diseased endosphere samples (p < 0.05). Saccharomyces was significantly enriched in diseased endosphere samples, whereas Apiotrichum was enriched in healthy endosphere samples. Vishniacozyma and Phialophora were enriched in diseased rhizosphere samples, while Pseudogymnoascus was enriched in healthy rhizosphere samples. Diseased samples displayed more strongly correlated genera than healthy samples. Saprotrophs accounted for a larger proportion of the fungal microbes in rhizosphere soil than in endosphere roots. This study provides a better understanding of the composition and diversity of fungal communities in the rhizosphere and endosphere of faba bean plants as well as a theoretical guidance for future research on the prevention or control of faba bean root rot disease.

Phylogeny and Fungal Community Structures of Helotiales Associated with Sclerotial Disease of Mulberry Fruits in China.

Mulberry fruit sclerotiniose is a prevalent disease caused by the fungal species Ciboria shiraiana, C. carunculoides, and Scleromitrula shiraiana of the order Helotiales, and severely affects the production of mulberry. However, these species have only been identified using morphological and rDNA-ITS sequence analyses, and their genetic variation is unclear. To address this, morphological and two-locus (ITS and RPB2) phylogenetic analyses were conducted using culture-dependent and independent methods for 49 samples from 31 orchards across four provinces in China. Illumina MiSeq sequencing was used to assess the fungal communities obtained from fruits varying in disease severity and color from an orchard in Wuhan. Conidial suspensions of C. shiraiana and C. carunculoides isolated from diseased fruits, diseased fruits affected with hypertrophy and pellet sorosis sclerotiniose, and mycelia of Sclerotinia sclerotiorum were determined to be pathogenic to the mulberry cultivar YSD10. However, fruits inoculated with S. sclerotiorum mycelia exhibited nontypical disease symptoms, and mycelia and conidia obtained from C. carunculoides and S. shiraiana strains were not pathogenic. Maximum parsimony and Bayesian analyses using the sequences of the assessed loci indicated species variability with no evidence of geographic specialization. Metagenomic analysis revealed that the diversity of fungal communities was reduced with disease progression. Furthermore, within a single fruit, the presence of two Ciboria spp. was detected. These results provide novel insights into Ciboria spp., revealing the secondary infections caused by conidia in diseased fruits, genetic variations of the pathogens, and the occurrence of coinfection. This improved understanding of fungal pathogens will aid in developing effective disease control strategies.

Patterns of bacterial communities in the rhizosphere and rhizoplane of alpine wet meadows.

Wet meadows, a type of wetland, are vulnerable to climate change and human activity, impacting soil properties and microorganisms that are crucial to the ecosystem processes of wet meadows. To decipher the ecological mechanisms and processes involved in wet meadows, it is necessary to examine the bacterial communities associated with plant roots. To gain valuable insight into the microbial dynamics of alpine wet meadows, we used Illumina MiSeq sequencing to investigate how environmental factors shape the bacterial communities thriving in the rhizosphere and rhizoplane of three plant species: Cremanthodium ellisii, Caltha scaposa, and Cremanthodium lineare. The most abundant bacterial phyla in rhizosphere and rhizoplane were Proteobacteria > Firmicutes > Actinobacteria, while Macrococcus, Lactococcus, and Exiguobacterium were the most abundant bacterial genera between rhizosphere and rhizoplane. The mantel test, network, and structure equation models revealed that bacterial communities of rhizosphere were shaped by total nitrogen (TN), soil water content (SWC), soil organic carbon (SOC), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), pH, however, rhizoplane bacterial communities exhibited varying results. The bacterial communities exhibited significant heterogeneity, with stochastic process predominating in both the rhizosphere and rhizoplane. PICRUSt2 and FAPROTAX analysis revealed substantial differences in key biogeochemical cycles and metabolic functional predictions. It was concluded that root compartments significantly influenced the bacterial communities, although plant species and elevation asserted varying effects. This study portrays how physicochemical properties, plant species, and elevations can shift the overall structure and functional repertoire of bacterial communities in alpine wet meadows.

Effect of chlorogenic acid grafted chitosan on microbiological compositions of sea bass (Lateolabrax japonicus) fillets: Dominant spoilage bacteria, inhibition activity and membrane damage mechanisms.

This study investigated the effect of chlorogenic acid grafted chitosan (CS-g-CA) on the microbiota composition of sea bass (Lateolabrax japonicus), isolated and identified the specific spoilage organisms (SSOs) in the late stage of refrigerated fillets and evaluation of their spoilage potential. Moreover, antibacterial activity and membrane damage mechanism of CS-g-CA against spoilage bacteria was also investigated. Illumina-MiSeq high throughput sequencing results showed that CS-g-CA retarded the growth of Pseudomonas spp., which largely contributed to delaying the quality degradation of sea bass during storage. Then nine spoilage bacteria were isolated and identified from the fillets at the end of storage and inoculated into sterile fish fillets to determine their spoilage capacity. Results showed that fish fillets inoculated with spoilage bacteria exhibited a significant increase in TVB-N, TBA and putrescine content and decreased sensory quality during storage. Subsequently, the inhibitory activity of CS-g-CA against spoilage bacteria was investigated and strains that were more sensitive to the CS-g-CA with a strong spoilage capacity were selected for the study of the inhibition mechanism. Results suggested that CS-g-CA had strong inhibitory activity and led to bacterial death through the mechanism of membrane damage. Overall, this study analyzed the effect of CS-g-CA on the preservation of fish fillets from a microbiological point of view to provide a reference for the anti-bacterial preservation of aquatic products.

Chemical fertilizer reduction combined with organic fertilizer affects the soil microbial community and diversity and yield of cotton.

Introduction: The soil microbial community plays an important role in modulating cotton soil fertility. However, the effects of chemical fertilizer combined with organic fertilizer on soil chemical properties, microbial community structure, and crop yield and quality in arid areas are still unclear. This study aimed to explore the effects of different organic fertilizers on soil microbial community structure and diversity and cotton growth and yield. Methods: High-throughput sequencing was used to study the soil bacteria and fungi in different growth stages of cotton. The field fertilization experiment had five treatments. Results: The results indicated that the treatments of chemical fertilizer reduction combined with organic fertilizer significantly increased soil available nitrogen and phosphorus in cotton field. There were significant differences in the abundance of the bacterial and fungal communities in the dominant phyla among the treatments. At the phyla level, there were not significantly different in the diversity of bacteria and fungi among treatments. There were significant differences in the composition and diversity of bacterial and fungal communities during the entire cotton growth period (p = 0.001). The rhizosphere bacterial and fungal community structure was significantly affected by soil TK, NH4+, AK, TP, AN, and NO3-. The different fertilization treatments strongly influenced the modular structure of the soil bacterial and fungal community co-occurrence network. A reduction in chemical fertilizer combined with organic fertilizer significantly improved cotton stem diameter and seed yield, and the effect of the biological organic fertilizer on plant growth and yield formation was greater than that of ordinary organic fertilizer. Discussion: This study provide a scientific and technical basis for the establishment of environmentally friendly green fertilization technology for cotton in arid areas and the promotion of sustainable development of cotton industry.