Fungal Sequences Research Articles

Microbial community assembly during aging of food waste-derived hydrochar: Key bacterial guilds mediate nutrient dynamics

Hydrochar aging may mitigate the adverse effects of direct hydrochar application on plant growth. However, little is known about the strategies for accelerating aging process and the microbiological mechanisms involved. This study explored the effects of three aging strategies, including the addition of straw and efficient-degrading microorganisms, on the aging processes of food waste-derived hydrochar, and identified the key microbial drivers. The bacterial and fungal sequencing was performed to estimate the species composition in hydrochar at different aging periods (i.e., day 1, 7, 14 and 35). The results showed that the addition of straw and microbial inoculum improved the maximum reaction temperature by 13%, and shortened the aging time by ∼30%. Three bacterial guilds, mainly including Bacillus-like species, were identified that showed significant correlations with the nitrogen and phosphorus dynamics during aging. This study demonstrates the feasibility of manipulating key microbial guilds artificially to achieve efficient harmless-treatment of hydrochar.

Quantification of the dark fungal taxon Cryptomycota using qPCR.

Fungi are present in a wide variety of natural environments, and in the last years, various studies have shown that they are quite abundant in aquatic ecosystems. In addition, a whole new highly diverse phylum, the Cryptomycota, was discovered. Nevertheless, research on aquatic fungi and a detailed evaluation of their functions and distribution are still sparse. One of the main reasons is a limitation in reliable identification and quantification methods. To bridge part of the research gap, this study aims to implement a quantitative PCR method to detect and quantify the newly discovered phylum. We developed and validated a Cryptomycota-specific qPCR primer pair targeting the 5.8S region that detects the majority of Cryptomycota, but Microsporidia. The resulting amplicon is 102 bp long. We used different environmental samples to evaluate the primer pair, various fungal sequences as negative control and positive control sequences. Obtained amplicons were sequenced using Illumina, and the obtained ASVs were all classified as Cryptomycota. The qPCR method works reliably and specifically for the quantification of Cryptomycota in environmental samples.

Consecutive Fertilization-Promoted Soil Nutrient Availability and Altered Rhizosphere Bacterial and Bulk Fungal Community Composition

Fertilization is an important measure to quickly supplement the soil nutrients required for plantation productivity. However, the response patterns of the microbial community and functional taxa in Larix plantation root, rhizosphere, and bulk soil to short-term and consecutive fertilization have rarely been reported. In this study, we assessed Larix root, rhizosphere, and bulk soil microbial community on days 0, 5, 15, and 30 after the first inorganic fertilization and after three consecutive years of fertilization. The bacterial 16S and fungal ITS high-throughput sequencing technology were used to monitor changes in microbial community composition and potential functional groups, as well as changes in soil nutrient content and enzyme activity to evaluate the status of plantation soil productivity. Consecutive fertilization treatment significantly increased the available nitrogen, phosphorus, and potassium (NPK) content and soil enzyme activity. The nonmetric multidimensional scaling (NMDS) and analysis of similarities (ANOSIM) results showed that there were significant differences in microbial community composition in root samples, rhizosphere soil, and bulk soil samples. The dominant microbial taxa were different between root and soil microbial community composition. Consecutive fertilization treatment had little effect on endophytic microbial community but significantly increased the abundance of Gaiellales in rhizosphere soil and Mortierella in bulk soil. The redundancy analysis (RDA) and co-occurrence network analyses showed that Gaiellales and Mortierellales had significant positive correlations with soil nutrient content and enzyme activity. The fungal functional group compositions were significantly affected by consecutive fertilization treatment and the proportions of ectomycorrhizal and saprotroph significantly decreased, but the proportion of endophyte significantly increased in bulk soil samples. Our results suggested that consecutive fertilization may promote soil nutrient availability by increasing the abundance of Gaiellales and Mortierella. Consecutive fertilization maintained the balance of the soil microbiota under Larix plantation and had a positive effect on promoting soil nutrient availability. This study provided a theoretical basis for consecutive fertilization to promote soil nutrient availability through specific microbial groups.

Comparative metabarcoding and biodiversity of gut-associated fungal assemblages of Dendroctonus species (Curculionidae: Scolytinae).

The genus Dendroctonus is a Holarctic taxon composed of 21 nominal species; some of these species are well known in the world as disturbance agents of forest ecosystems. Under the bark of the host tree, these insects are involved in complex and dynamic associations with phoretic ectosymbiotic and endosymbiotic communities. Unlike filamentous fungi and bacteria, the ecological role of yeasts in the bark beetle holobiont is poorly understood, though yeasts were the first group to be recorded as microbial symbionts of these beetles. Our aim was characterize and compare the gut fungal assemblages associated to 14 species of Dendroctonus using the internal transcribed spacer 2 (ITS2) region. A total of 615,542 sequences were recovered yielding 248 fungal amplicon sequence variants (ASVs). The fungal diversity was represented by 4 phyla, 16 classes, 34 orders, 54 families, and 71 genera with different relative abundances among Dendroctonus species. The α-diversity consisted of 32 genera of yeasts and 39 genera of filamentous fungi. An analysis of β-diversity indicated differences in the composition of the gut fungal assemblages among bark beetle species, with differences in species and phylogenetic diversity. A common core mycobiome was recognized at the genus level, integrated mainly by Candida present in all bark beetles, Nakazawaea, Cladosporium, Ogataea, and Yamadazyma. The bipartite networks confirmed that these fungal genera showed a strong association between beetle species and dominant fungi, which are key to maintaining the structure and stability of the fungal community. The functional variation in the trophic structure was identified among libraries and species, with pathotroph-saprotroph-symbiotroph represented at the highest frequency, followed by saprotroph-symbiotroph, and saprotroph only. The overall network suggested that yeast and fungal ASVs in the gut of these beetles showed positive and negative associations among them. This study outlines a mycobiome associated with Dendroctonus nutrition and provides a starting point for future in vitro and omics approaches addressing potential ecological functions and interactions among fungal assemblages and beetle hosts.

Investigating the inoculum dynamics of Cladosporium on the surface of raspberry fruits and in the air.

Raspberry production is under threat from the emerging fungal pathogenic genus Cladosporium. We used amplicon-sequencing, coupled with qPCR, to investigate how fruit age, fruit location within a polytunnel, polytunnel location and sampling date affected the fruit epiphytic microbiome. Fruit age was the most important factor impacting the fungal microbiome, followed by sampling date and polytunnel location. In contrast, polytunnel location and fruit age were important factors impacting the bacterial microbiome composition, followed by the sampling date. The within-tunnel location had a small significant effect on the fungal microbiome and no effect on the bacterial microbiome. As fruit ripened, fungal diversity increased and the bacterial diversity decreased. Cladosporium was the most abundant fungus of the fruit epiphytic microbiome, accounting for nearly 44% of all fungal sequences. Rotorod air samplers were used to study how the concentration of airborne Cladosporium inoculum (quantified by qPCR) varied between location (inside and outside the polytunnel) and time (daytime vs. nighttime). Quantified Cladosporium DNA was significantly higher during the day than the night and inside the polytunnel than the outside. This study demonstrated the dynamic nature of epiphytic raspberry fruit microbiomes and airborne Cladosporium inoculum within polytunnels, which will impact disease risks on raspberry fruit.

Exploring the diversity, bioactivity of endophytes, and metabolome in Synsepalum dulcificum.

Synsepalum dulcificum exhibits high edible and medicinal value; however, there have been no reports on the exploration of its endophyte resources. Here, we conducted analyses encompassing plant metabolomics, microbial diversity, and the biological activities of endophytic metabolites in S. dulcificum. High-throughput sequencing identified 4,913 endophytic fungal amplicon sequence variants (ASVs) and 1,703 endophytic bacterial ASVs from the roots, stems, leaves, flowers, and fruits of S. dulcificum. Fungi were classified into 5 phyla, 24 classes, 75 orders, 170 families, and 313 genera, while bacteria belonged to 21 phyla, 47 classes, 93 orders, 145 families, and 232 genera. Furthermore, there were significant differences in the composition and content of metabolites in different tissues of S. dulcificum. Spearman's correlation analysis of the differential metabolites and endophytes revealed that the community composition of the endophytes correlated with plant-rich metabolites. The internal transcribed spacer sequences of 105 isolates were determined, and phylogenetic analyses revealed that these fungi were distributed into three phyla (Ascomycota, Basidiomycota, and Mucoromycota) and 20 genera. Moreover, 16S rDNA sequencing of 46 bacteria revealed they were distributed in 16 genera in three phyla: Actinobacteria, Proteobacteria, and Firmicutes. The antimicrobial activities (filter paper method) and antioxidant activity (DPPH and ABTS assays) of crude extracts obtained from 68 fungal and 20 bacterial strains cultured in different media were evaluated. Additionally, the α-glucosidase inhibitory activity of the fungal extracts was examined. The results showed that 88.6% of the strains exhibited antimicrobial activity, 55.7% exhibited antioxidant activity, and 85% of the fungi exhibited α-glucosidase inhibitory activity. The research suggested that the endophytes of S. dulcificum are highly diverse and have the potential to produce bioactive metabolites, providing abundant species resources for developing antibiotics, antioxidants and hypoglycemic drugs.

Endophytic fungi in buckwheat seeds: exploring links with flavonoid accumulation.

Buckwheat is a famous edible and medicinal coarse cereal which contain abundant of bioactive flavonoids, such as rutin. In this study, the composition and diversity of endophytic fungi in eight different buckwheat seeds were analyzed by high-throughput sequencing of ITS rDNA. Results showed that, the fungal sequences reads were allocated to 272 OTUs, of them, 49 OTUs were shared in eight buckwheat seeds. These endophytic fungi could be classified into 6 phyla, 19 classes, 41 orders, 79 families, 119 genera, and 191 species. At genus level, Alternaria sp. was the domain fungal endophyte. Besides, fungal endophytes belonged to the genera of Epicocum, Cladosporium, Botrytis, Filbobasidium, Stemphylium, and Vishniacozyma were highly abundant in buckwheat seeds. The total flavonoids and rutin contents in tartary buckwheat cultivars (CQ, XQ, CH, K2) were much higher than those in common buckwheat cultivars (HT, T2, T4, T8). For tartary buckwheat cultivars, the total flavonoids and rutin contents were ranging from 2.6% to 3.3% and 0.9% to 1.3%, respectively. Accordingly, the tartary buckwheat samples displayed stronger antioxidant activity than the common buckwheat. Spearman correlation heat map analysis was successfully found that certain fungal species from the genera of Alternaria, Botryosphaeria, Colletorichum and Diymella exhibited significant positive correlation with flavonoids contents. Results of this study preliminary revealed the fungi-plant interaction relationship at secondary metabolite level, and could provide novel strategy for increasing the flavonoids accumulation of buckwheat seeds, as well as improving their quality.

Influence of weeding methods on rhizosphere soil and root endophytic microbial communities in tea plants.

Polyethylene mulch is a kind of inorganic mulch widely used in agriculture. The effects of plastic mulch debris on the structure of plant soil and root growth have been fully studied, but their effects on endophytic microbial communities have not been explored to a large extent. In this study, High-throughput sequencing of bacterial 16S rRNA genes and fungal ITS region sequences were used to analyze microbial community structure and composition in rhizosphere soil and root endophytic of tea plant under three different weeding methods: polyethylene mulching, hand weeding and no weeding (CK). The results showed that the weeding methods had no significant effect on the rhizosphere and root endophytic microbial abundance, but the rhizosphere bacterial structure covered by polyethylene mulch was significantly different than hand weeding and CK. The rhizosphere fungal diversity was also significantly higher than the other two analyzed treatments. The community abundance of rhizosphere microorganisms Acidobacteria, Candidatus Rokubacteria and Aspergillus covered by polyethylene mulch decreased significantly, whereas Bradyrhizobium, Solirubrobacterales and Alphaproteobacteria increased significantly. The abundance of bacteria Ktedonobacter, Reticulibacter, Ktedonosporobacter and Dictyobacter communities covered by polyethylene mulch was significantly changed, and the abundance of Fusarium and Nitrobacteraceae was significantly increased. Rhizosphere dominant bacteria were negatively correlated with soil available nitrogen content, while dominant fungi were significantly correlated with soil pH, total nitrogen and total potassium. Polyethylene mulch forms an independent micro-ecological environment. At the same time, the soil nutrient environment was enriched by affecting the nitrogen cycle, and the composition of microbial community was affected. This study elucidated the effects of polyethylene mulch on soil microbial community in tea garden and provided a new theoretical understanding for weed management.

Microbiology of Big Soda Lake, a multi-extreme meromictic volcanic crater lake in the Nevada desert.

Big Soda Lake, Nevada, is a multi-extreme meromictic lake, whose hypersaline hyperalkaline bottom waters feature permanent anoxia and high concentrations of arsenic, sulphide and ammonia. These properties make Big Soda Lake-and the adjacent Little Soda Lake-a fascinating system for exploring life's boundaries, discovering novel microbial taxa and identifying biotechnologically useful strains. To date, the taxonomic diversity and metabolic capabilities of microorganisms in this system remain largely unknown. Here, we fill this gap using microbiome surveys across the Big and Little Soda Lake water columns, including 16S rRNA sequencing, fungal ITS2 sequencing and gene- and genome-resolved metagenomics. We accompany these surveys with measurements of salinity, pH, temperature, oxygen, ammonium and ammonia concentrations. Our analyses reveal rich bacterial communities, taxonomically and functionally differentiated along Big Soda Lake's oxycline and, to lesser extent, between lakes. Fungal communities were dominated by a small number of families, while nearly no archaea were detected. Pathways related to perchlorate reduction, anoxygenic phototrophy, fermentation, dissimilatory metabolism of arsenite/arsenate, sulphur compounds, nitrogen compounds and hydrogen, were particularly prevalent. A total of 129 high-quality bacterial and archaeal metagenome-assembled genomes (completeness ≥ 80%, contamination ≤ 5%) were recovered, yielding insight into the taxonomic distribution of microbial metabolic pathways.

The Diverse Mycorrizal Morphology of Rhododendron dauricum, the Fungal Communities Structure and Dynamics from the Mycorrhizosphere.

It is generally believed that mycorrhiza is a microecosystem composed of mycorrhizal fungi, host plants and other microscopic organisms. The mycorrhiza of Rhododendron dauricum is more complex and the diverse morphology of our investigated results displays both typical ericoid mycorrhizal characteristics and ectomycorrhizal traits. The characteristics of ectendoomycorrhiza, where mycelial invade from the outside into the root cells, have also been observed. In order to further clarify the mycorrhizal fungi members and other fungal communities of R. dauricum mycorrhiza, and explore the effects of vegetation and soil biological factors on their community structure, we selected two woodlands in the northeast of China as samples-one is a mixed forest of R. dauricum and Quercus mongolica, and the other a mixed forest of R. dauricum, Q. mongolica, and Pinus densiflor. The sampling time was during the local growing season, from June to September. High-throughput sequencing yielded a total of 3020 fungal amplicon sequence variants (ASVs), which were based on sequencing of the internal transcribed spacer ribosomal RNA (ITS rRNA) via the Illumina NovaSeq platform. In the different habitats of R. dauricum, there are differences in the diversity of fungi obtained from mycorrhizal niches, and specifically the mycorrhizal fungal community structure in the complex vegetation of mixed forests, where R. dauricum is found, exhibits greater stability, with relatively minor changes over time. Soil fungi are identified as the primary source of fungi within the mycorrhizal niche, and the abundance of mycorrhizal fungi from mycorrhizal niches in R. dauricum is significantly influenced by soil pH, organic matter, and available nitrogen. The relationship between soil fungi and mycorrhizal fungi from mycorrhizal niches is simultaneously found to be intricate, while the genus Hydnellum emerges as a central genus among mycorrhizal fungi from mycorrhizal niches. However, there is currently a substantial gap in the foundational research of this genus, including the fact that mycorrhizal fungi from mycorrhizal niches have, compared to fungi present in the soil, proven to be more sensitive to changes in soil moisture.

Fungal Communities Associated with Siricid Wood Wasps: Focus on Sirex juvencus, Urocerus gigas, and Tremex fuscicornis.

We investigated the diversity and occurrence of wood wasps in Lithuania and determined communities of associated fungi. Trapping of wood wasps resulted in three different species, including Sirex juvencus, Urocerus gigas, and Tremex fuscicornis. Fungal culturing from adult females of T. fuscicornis mainly resulted in fungi from the genera Penicillium and Trichoderma. High-throughput sequencing of ITS2 rDNA resulted in 59,797 high-quality fungal sequences, representing 127 fungal OTUs. There were 93 fungal OTUs detected in U. gigas, 66 in S. juvencus, and 10 in T. fuscicornis. The most common fungi were Fusarium sporotrichioides (63.1% of all fungal sequences), Amylostereum chailletii (14.9%), Penicillium crustosum (7.8%), Microascus sp. 2261_4 (5.0%), and Pithoascus ater (2.1%). Among these, only A. chailletii was found in all three insect species with the highest relative abundance in U. gigas (15.2%), followed by S. juvencus (7.7%), and the lowest in T. fuscicornis (0.3%) (p < 0.0003). Correspondence analysis of fungal communities showed a distant placement of different species of wood wasps, indicating that fungal communities in each of these were largely different. In conclusion, the study showed that the economically important tree pathogen A. chailletii was among the most common fungal OTUs vectored by siricid wood wasps.

The influence of a soil amendment on the abundance and interaction of arbuscular mycorrhizal fungi with arable soils and host winter wheat.

Arbuscular mycorrhizal (AM) fungi have been shown to be associated with an estimated 70 % of vascular terrestrial plants. Such relationships have been shown to be sensitive to soil disturbance, for example, tillage in the preparation of a seed bed. From the application of arable soil management, AM fungal populations have been shown to be negatively impacted in abundance and diversity, reducing plant growth and development. The present study aims to utilise two sources (multipurpose compost and a commercial inocula) of mycorrhizal fungi for the amendment of arable soils supporting Zulu winter wheat under controlled conditions and quantify plant growth responses. A total of nine fields across three participating farms were sampled, each farm practicing either conventional, reduced, or zero tillage soil management exclusively. Soil textures were assessed for each sampled soil. Via the employment of AM fungal symbiosis quantification methods, AM fungi were compared between soil amendments and their effects on crop growth and development. The present study was able to quantify a mean 6 cm increase to crop height (P<0.001), 10 cm reduction to root length corresponding with a 2.45-fold increase in AM fungal arbuscular structures (P<0.001), a 1.15-fold increase in soil glomalin concentration corresponding to a 1.26-fold increase in soil carbon, and a 1.32-fold increase in the relative abundance of molecular identified AM fungal sequences for compost amended soils compared to control samples. Mycorrhizal inocula, however, saw no change to crop height or root length, AM fungal arbuscules were reduced by 1.43-fold, soil glomalin was additionally reduced by 1.55-fold corresponding to a reduction in soil carbon by 1.31-fold, and a reduction to relative AM fungal species abundance by 1.26-fold. The present study can conclude the addition of compost as an arable soil amendment is more beneficial for the restoration of AM fungi beneficial to wheat production and soil carbon compared to the addition of a commercial mycorrhizal inocula.

Alternative amplicon-PCR protocol for maximizing bacterial and fungal sequencing in low-biomass samples

Determining bacterial and fungal communities from low-biomass samples remains a challenge for high-throughput sequencing. Due to the low microbial load and host contamination, some sites, including the female upper reproductive tract and the lower respiratory tract, were even considered sterile until recent years. Despite efforts to improve sampling and DNA isolation protocols, some samples provide insufficient microbial DNA input for library preparation and sequencing. Herein, we propose an alternative amplicon-PCR protocol to be used in bacterial and fungal sequencing in low-biomass samples, targeting 16S-rDNA and the internal transcribed spacer region (ITS), respectively. Similar to a nested-PCR, we performed two sequential PCR reactions to maximise the target amplicon. We compared metagenomic results from the original Illumina protocol (Protocol 1 – P1) and the alternative one (Protocol 2 – P2), using a mock community and clinical samples with different microbial loads. Our findings showed no significant differences in data generated by P1 and P2, indicating that the second amplification round does not bias the microbiota diversity rates. Thus, the alternative protocol can be applied for low-biomass samples when the original protocol results in spurious output, preventing library preparation and sequencing.

Benzalkonium Chloride and Benzethonium Chloride Effectively Reduce Spore Germination of Ginger Soft Rot Pathogens: Fusarium solani and Fusarium oxysporum.

Ginger soft rot is a serious soil-borne disease caused by Fusarium solani and Fusarium oxysporum, resulting in reduced crop yields. The application of common chemical fungicides is considered to be an effective method of sterilization, and therefore, they pose a serious threat to the environment and human health due to their high toxicity. Benzalkonium chloride (BAC) and benzethonium chloride (BEC) are two popular quaternary ammonium salts with a wide range of fungicidal effects. In this study, we investigated the fungicidal effects of BAC and BEC on soft rot disease of ginger as alternatives to common chemical fungicides. Two soft rot pathogens of ginger were successfully isolated from diseased ginger by using the spread plate method and sequenced as F. solani and F. oxysporum using the high-throughput fungal sequencing method. We investigated the fungicidal effects of BAC and BEC on F. solani and F. oxysporum, and we explored the antifungal mechanisms. Almost complete inactivation of spores of F. solani and F. oxysporum was observed at 100 mg/L fungicide concentration. Only a small amount of spore regrowth was observed after the inactivation treatment of spores of F. solani and F. oxysporum in soil, which proved that BAC and BEC have the potential to be used as an alternative to common chemical fungicides for soil disinfection of diseased ginger.

Loop-Mediated Isothermal Amplification (LAMP): Potential Point-of-Care Testing for Vulvovaginal Candidiasis.

The aim of this study is to establish a loop-mediated isothermal amplification (LAMP) method for the rapid detection of vulvovaginal candidiasis (VVC). We developed and validated a loop-mediated isothermal amplification (LAMP) method for detecting the most common Candida species associated with VVC, including C. albicans, N. glabratus, C. tropicalis, and C. parapsilosis. We evaluated the specificity, sensitivity, positive predictive value (PPV), negative predictive value (NPV), and Kappa value of the LAMP method to detect different Candida species, using the conventional culture method and internal transcribed spacer (ITS) sequencing as gold standards and smear Gram staining and real-time Rolymerase Chain Reaction (PCR) as controls. A total of 202 cases were enrolled, of which 88 were VVC-positive and 114 were negative. Among the 88 positive patients, the fungal culture and ITS sequencing results showed that 67 cases (76.14%) were associated with C. albicans, 13 (14.77%) with N. glabratus, 5 (5.68%) with C. tropicalis, and 3 (3.41%) with other species. Regarding the overall detection rate, the LAMP method presented sensitivity, specificity, PPV, NPV, and Kappa values of 90.91%, 100%, 100%, 93.4%, and 0.919, respectively. Moreover, the LAMP had a specificity of 100% for C. albicans, N. glabratus, and C. tropicalis, with a sensitivity of 94.03%, 100%, and 80%, respectively. Moreover, the microscopy evaluation had the highest sensitivity, while the real-time PCR was less specific for C. albicans than LAMP. In addition, CHROMagar Candida was inferior to LAMP in detecting non-albicans Candida (NAC) species. Based on the cost-effective, rapid, and inexpensive characteristics of LAMP, coupled with the high sensitivity and specificity of our VVC-associated Candida detection method, we provided a possibility for the point-of-care testing (POCT) of VVC, especially in developing countries and some laboratories with limited resources.

Effects of tillage practices on soil organic carbon, microbial community and necromass in a double rice cropping system

No-tillage (NT) can enhance the accumulation of soil organic carbon (SOC), thereby aiding in climate change mitigation and improving soil fertility. However, the relations of soil microbial abundance, composition, and necromass to SOC increase under NT are still unclear, limiting the knowledge of SOC stabilization. We performed a 5-year paddy field experiment in southern China including NT, reduced tillage (RT) and conventional tillage (CT). Soil microbial necromass C (MC, including fungal and bacterial necromass C, FC, and BC) were analyzed, as well as soil bacterial and fungal community composition. At a depth of 0–10 cm, NT increased FC (by 48.6 %–50.2 %, P < 0.05), BC (28.6 %–41.7 %), and MC (38.5 %–45.1 %, P < 0.05) but did not significantly alter the FC/BC and MC/SOC ratios. The increase rate of MC (NT vs. CT and RT) was 12.8–16.2 % higher than that of total SOC. Compared with 0–10 cm and 10–20 cm, the MC/SOC ratio was 12.5 %–14.1 % lower at 20–30 cm. Linear regression indicated significant positive correlations of SOC with MC, BC, and FC, whereas no significant correlation was found between bacterial (or fungal) α-diversity (expressed by Shannon index) and BC (or FC). The Random Forest Model showed that several important fungal and bacterial Amplicon Sequence Variants (ASVs) explained 14 %–73 % of the FC and BC variations. Therefore, the composition of the microbial community may play a pivotal role in driving the accumulation of MC. Short-term NT in rice paddies resulted in increased levels of both MC and SOC. Notably, the rate of increase in MC exceeded that of SOC, suggesting the potential for SOC stabilization.

Solitary Bees Host More Bacteria and Fungi on Their Cuticle than Social Bees.

Bees come into contact with bacteria and fungi from flowering plants during their foraging trips. The Western honeybee (Apis mellifera) shows a pronounced hygienic behavior with social interactions, while the solitary red mason bee (Osmia bicornis) lacks a social immune system. Since both visit the same floral resources, it is intriguing to speculate that the body surface of a solitary bee should harbor a more complex microbiome than that of the social honeybee. We compared the cuticular microbiomes of A. mellifera (including three European subspecies) and O. bicornis for the first time by bacterial 16S rRNA and fungal ITS gene-based high-throughput amplicon sequencing. The cuticular microbiome of the solitary O. bicornis was significantly more complex than that of the social A. mellifera. The microbiome composition of A. mellifera subspecies was very similar. However, we counted significantly different numbers of fungi and a higher diversity in the honeybee subspecies adapted to warmer climates. Our results suggest that the cuticular microbiome of bees is strongly affected by visited plants, lifestyle and adaptation to temperature, which have important implications for the maintenance of the health of bees under conditions of global change.

Mycoremediation of lead and cadmium by lignocellulosic enzymes of Pleurotus eryngii

This study aimed to investigate the ability of Pleurotus eryngii fungus to absorb lead and cadmium from industrial wastewater. After culturing the fungus on a potato dextrose agar (PDA) medium containing 0 (control), 150 mg L−1, 250 mg L−1, and 350 mg L−1 concentrations of lead and cademium for 30 days, the mycelia were isolated from the culture medium and their extracts were used to measure protein content and the activity of antioxidant enzymes. Also, heavy metal contents were analyzed by atomic absorption spectrometry using flame photometry. Results showed that the growth of mycelia was significantly affected by different concentrations of the two heavy metals. High tolerance of heavy metal pollution in the culture media and the ability to accumulate lead and cademium confirmed that Pleurotus eryngii is a favorable option for mycoremediation. Also, molecular studies for fungal sequencing were investigated using the trench method, the sequence of the fungus was recorded in the gene bank, and finally the fungus was identified in the study.

Characterisation and functionalisation of chitosan nanoparticles as carriers for double-stranded RNA (dsRNA) molecules towards sustainable crop protection.

The need to minimise the impact of phytosanitary treatments for disease control boosted researchers to implement techniques with less environmental impact. The development of technologies using molecular mechanisms based on the modulation of metabolism by short dsRNA sequences appears promising. The intrinsic fragility of polynucleotides and the high cost of these techniques can be circumvented by nanocarriers that protect the bioactive molecule enabling high efficiency delivery to the leaf surface and extending its half-life. In this work, a specific protocol was developed aiming to assess the best methodological conditions for the synthesis of low-size chitosan nanoparticles (NPs) to be loaded with nucleotides. In particular, NPs have been functionalised with partially purified Green Fluorescent Protein dsRNAs (GFP dsRNA) and their size, surface charge and nucleotide retention capacity were analysed. Final NPs were also stained with FITC and sprayed on Nicotiana benthamiana leaves to assess, by confocal microscopy, both a distribution protocol and the fate of NPs up to 6 days after application. Finally, to confirm the ability of NPs to increase the efficacy of dsRNA interference, specific tests were performed: by means of GFP dsRNA-functionalised NPs, the nucleotide permanence during time was assessed both in vitro on detached wild-type N. benthamiana leaves and in planta; lastly, the inhibition of Botrytis cinerea on single leaves was also evaluated, using a specific fungal sequence (Bc dsRNA) as the NPs' functionalising agent. The encouraging results obtained are promising in the perspective of long-lasting application of innovative treatments based on gene silencing.

The Difference in Diversity between Endophytic Microorganisms in White and Grey Zizania latifolia.

The Zizania latifolia is usually infected by the obligate parasitic fungus Ustilago esculenta to form an edible fleshy stem which is an aquatic vegetable called Jiaobai in China. The infection by the teliospore (T) strain of U. esculenta induces Z. latifolia forming gray fleshy stems, while the mycelia-teliospore (MT) strain of U. esculenta induces white fleshy stems which are more suitable for edibility than gray fleshy stems. The mechanism of this phenomenon is still largely unknown. One of the possible causes is the diversity of endophytic microbial communities between these two fleshy stems. Therefore, we utilized fungal ITS1 and bacterial 16S rDNA amplicon sequencing to investigate the diversity of endophytic microbial communities in the two different fleshy stems of Z. latifolia. The results revealed that the α diversity and richness of endophytic fungi in white Z. latifolia were significantly greater than in gray Z. latifolia. The dominant fungal genus in both fleshy stems was U. esculenta, which accounted for over 90% of the endophytic fungi. The community composition of endophytic fungi in gray and white Z. latifolia was different except for U. esculenta, and a negative correlation was observed between U. esculenta and other endophytic fungi. In addition, the dominant bacterial genus in gray Z. latifolia was Alcaligenaceae which is also negatively correlated with other bacterium communities. Additionally, the co-occurrence network of white Z. latifolia was found to have a stronger scale, connectivity, and complexity compared to that of gray Z. latifolia. And the detected beneficial bacteria and pathogens in the stems of Z. latifolia potentially compete for resources. Furthermore, the function of endophytic bacteria is more abundant than endophytic fungi in Z. latifolia. This research investigated the correlation between the development of Z. latifolia fleshy stems and endophytic microbial communities. Our findings indicate that the composition of endophytic microbial communities is closely related to the type of Z. latifolia fleshy stems. This research also suggests the potential utilization of specific microbial communities to enhance the growth and development of Z. latifolia, thereby contributing to the breeding of Z. latifolia.