MiSeq High-throughput Sequencing Technology Research Articles

Microbiome Flora and Metabolomics Analysis of Mung Bean Sour Liquid in Luoyang, China

In order to reveal the fermentation microflora and fermentation metabolites of traditional mung bean sour liquid (MBSL) in Luoyang area, China, this experiment was sampled from four administrative districts of Luoyang, and volatile metabolites and non-targeted metabolites were detected and analyzed by HS-SPME-GC-MS and LC-MS, and bacterial and fungal sequencing were analyzed by Illumina MiSeq high-throughput sequencing technology. And the correlation between microorganisms and metabolites was conducted. The results showed that 42 volatiles were detected in four MBSL samples named Jianxi (JX), Liujia (Liu), LiJia (LJ), Majia (MJ), with 11 identical volatile flavor subtances, and the highest content of esters was found in JX, Liu, and LJ, and the highest content of acids was found in MJ. A total of 1703 non-targeted metabolites were identified, and there were more types of amino acids, carbohydrates, fatty acids and their complexes, flavonoids, carbonyl compounds, and organic acids, accounting for 40.93%. High-throughput sequencing results showed that there were nine bacterial and fungal genera with an average abundance of more than 1%, and the dominant genera mainly belonged to lactic acid bacteria and yeast. The composition of dominant genera was different in different workshop samples, and the abundance of fungal genera differed greatly. Among the volatile substances, Methyleugenol, a volatile component, was related to more bacteria, and ketones and hydrocarbons may be more closely associated with bacteria. Acetic acid and Oxalic acid may be more closely related to fungi, while some esters were more closely related to both fungal and bacterial genera. For non-target metabolites, amino acid and alcohol metabolites may be more influenced by bacteria, and organic acids and flavonoids may be more influenced by fungi.

Diversity and Functional Insights into Endophytic Fungi in Halophytes from West Ordos Desert Ecosystems.

Arid desert regions are among the harshest ecological environments on Earth. Halophytes, with their unique physiological characteristics and adaptability, have become the dominant vegetation in these areas. Currently, research on halophytes in this region is relatively limited, particularly concerning studies related to their root endophytic fungi, which have been rarely reported on. Therefore, investigating the diversity and composition of endophytic fungi in halophytes is crucial for maintaining ecological balance in such an arid environment. This study focuses on eight representative angiosperm halophytes from the West Ordos Desert in China (including Nitraria tangutorum, Salsola passerina, Suaeda glauca, Reaumuria trigyna, Reaumuria kaschgarica, Limonium aureum, Apocynum venetum, and Tripolium vulgare), utilizing Illumina MiSeq high-throughput sequencing technology combined with soil physicochemical factor data to analyze the diversity, composition, and ecological functions of their root-associated fungal communities. Ascomycota dominated the fungal composition in most halophytes, particularly among the recretohalophytes, where it accounted for an average of 88.45%, while Basidiomycota was predominant in Suaeda glauca. A Circos analysis of the top 10 most abundant genera revealed Fusarium, Dipodascus, Curvularia, Penicillium, and other dominant genera. Co-occurrence network analysis showed significant differences in fungal networks across halophyte types, with the most complex network observed in excreting halophytes, characterized by the highest number of nodes and connections, indicating tighter fungal symbiotic relationships. In contrast, fungal networks in pseudohalophytes were relatively simple, reflecting lower community cohesiveness. Redundancy analysis (RDA) and Mantel tests demonstrated that soil factors such as organic matter, available sulfur, and urease significantly influenced fungal diversity, richness, and evenness, suggesting that soil physicochemical properties play a critical role in regulating fungal-plant symbiosis. Functional predictions indicated that endophytic fungi play important roles in metabolic pathways such as nucleotide biosynthesis, carbohydrate degradation, and lipid metabolism, which may enhance plant survival in saline-alkaline and arid environments. Furthermore, the high abundance of plant pathogens and saprotrophs in some fungal communities suggests their potential roles in plant defense and organic matter decomposition. The results of this study provide a reference for advancing the development and utilization of halophyte endophytic fungal resources, with applications in desert ecosystem restoration and halophyte cultivation.

The effect of iron deficiency anemia and black stain on the microbial community of dental plaque in young children with early childhood caries

Objective: To analyze the effect of Iron deficiency anemia (IDA) and Black stain (BS) on the microbial community of dental plaque. Methods: A total of 136 preschool children aged 3 to 6 years old from 12 kindergartens in Shinan District and Shibei District of Qingdao City were investigated by using a cluster sampling method from April to May 2019. They were divided into two groups based on oral examination: the early childhood caries (ECC) group and the caries-free (CF) group. According to whether they had IDA and BS, they were further divided into four groups: the IDA with caries (IDA-ECC) group, the non-IDA with caries (NIDA-ECC) group, the BS without caries (BS-CF) group and the non-BS without caries (NBS-CF) group. The gingival plaque of the study subjects was collected. The 16S rRNA gene was sequenced by using Illumina MiSeq high-throughput sequencing technology. The composition, community structure and different bacteria genera of the microbial communities between the groups were compared and analyzed. Potential biomarkers within each group were further identified by linear discriminant analysis of effect size (LEfSe). Results: The 136 children were aged (5.11±0.87) years old, with 80 boys (58.82%). There were statistically significant differences in the microbial composition, structure and function of oral plaque between the ECC and CF groups (P<0.05). There were statistically significant differences in the microbial richness and diversity of oral plaque between the IDA-ECC and NIDA-ECC groups (P<0.05). There was no significant difference in microbial diversity index between the BS-CF and NBS-CF groups (P>0.05). The LEfSe analysis results showed that 41, 31 and 9 taxa with different relative abundance were identified between the ECC and CF groups, IDA-ECC and NIDA-ECC groups, and BS-CF and NBS-CF groups, respectively. Conclusion: IDA and BS have an effect on the microecological diversity and microbial community function of oral plaque in young children with early childhood caries.

Structure and Function of Soil Bacterial Communities in the Different Wetland Types of the Liaohe Estuary Wetland.

Soil bacterial communities play a crucial role in the functioning of estuarine wetlands. Investigating the structure and function of these communities across various wetland types, along with the key factors influencing them, is essential for understanding the relationship between bacteria and wetland ecosystems. The Liaohe Estuary Wetland formed this study's research area, and soil samples from four distinct wetland types were utilized: suaeda wetlands, reed wetlands, pond returning wetlands, and tidal flat wetlands. The structure and function of the soil bacterial communities were examined using Illumina MiSeq high-throughput sequencing technology in conjunction with the PICRUSt analysis method. The results indicate that different wetland types significantly affect the physical and chemical properties of soil, as well as the structure and function of bacterial communities. The abundance and diversity of soil bacterial communities were highest in the suaeda wetland and lowest in the tidal flat wetland. The dominant bacterial phyla identified were Proteobacteria and Bacteroidota. Furthermore, the dominant bacterial genera identified included RSA9, SZUA_442, and SP4260. The primary functional pathways associated with the bacterial communities involved the biosynthesis of valine, leucine, and isoleucine, as well as lipoic acid metabolism, which are crucial for the carbon and nitrogen cycles. This study enhances our understanding of the mutual feedback between river estuary wetland ecosystems and environmental changes, providing a theoretical foundation for the protection and management of wetlands.

Effects of Intercropping of Sisal and Three Different Leguminous Plants on Soil Bacterial Diversity

Intercropping is widely utilised in agricultural production to enhance land use efficiency because of its benefits, such as heightened crop productivity and optimised resource utilisation. We investigated the effects of Pinto peanut/sisal (HST), Stylo/sisal (strT) and Grona styracifolia/sisal (JqT) intercropping systems on soil bacterial communities compared with sisal continuous cropping (CK) by using Illumina MiSeq high-throughput sequencing technology. The intercropping system significantly increased the total nitrogen (TN), soil pH and soil moisture levels and decreased the levels of available phosphorus (AP) and available potassium (AK). Minimal variations were observed in Shannon’s and Simpson’s diversity indices between the monoculture and intercropping systems as well as among different intercropping systems. The most abundant phyla observed within the four groups were Proteobacteria, Acidobacteria, Cyanobacteria and Bacteroidetes. At the phylum level, the relative abundances of Proteobacteria, Acidobacteria, Cyanobacteria and Bacteroidetes were 37.37–54.35%, 10.54–21.21%, 3.46–20.43% and 2.15–5.67%, respectively. Compared with ZCK, StrT, JqT and HST treatments led to higher abundance of Cyanobacteria (from 3.46% to 20.43%, 11.37% and 16.58%, respectively) and Bacteroidetes (from 2.15% to 5.67%, 5.21% and 5.10%, respectively). The results of the linear discriminant analysis of effect sizes demonstrated notable variations in the relative abundance of bacterial taxa among various intercropping systems. The dominant categories of the genus in strT and JqT groups were Blastocatellia and Blastocatellaceae-Subgroup4, while Firmicutes was the dominant category of the genus in the HST group. The structure of bacterial communities did not vary between intercropping and monoculture systems. The findings indicated that the impact of the intercropping system on the bacterial community structure was not contingent on the specific intercropping patterns employed.

Effects of Trichoderma harzianum on Growth and Rhizosphere Microbial Community of Continuous Cropping Lagenaria siceraria

This study analyzed the effects of Trichoderma harzianum on the growth of continuous cropping Lagenaria siceraria and the physical and chemical properties of rhizosphere soil and microbial community structure, using Illumina Miseq (PE300) high-throughput sequencing technology along with physiological and biochemical detection. The results indicated that after applying T. harzianum, the growth of L. siceraria was significantly promoted, with increases in plant height, fresh weight, and dry weight of 21.42%, 24.5%, and 4.5%, respectively. The pH of the rhizosphere soil decreased from 7.78 to 7.51, while the electrical conductivity, the available phosphorus, the available potassium, and the total nitrogen were markedly higher compared to the control group and increased by 13.95%, 22.54%, 21.37%, and 16.41%, respectively. The activities of catalase and sucrase in the rhizosphere increased by 18.33% and 61.47%, and the content of soil organic carbon (SOC) increased by 27.39%, which indicated that T. harzianum could enhance soil enzyme activity and promotes the transformation of organic matter. The relative abundance of beneficial bacteria such as Pseudomonas increased, while the relative abundance of harmful fungi such as Fusarium and Podosphaera decreased significantly.

Changes in the microbial community structure and diversity during the electricity generation process of a microbial fuel cell with algal-film cathode

Abstract A two-chamber microbial fuel cell (MFC) with algal-film cathode was constructed. It showed good electric-generating performance with three electric-generating stages: start-up, development, and stable. An average output voltage reached ~0.412 V during the stable period. A maximum power density during continuous operation was 19.76 mW/m2. Bacterial samples were collected from the anode in the three stages (A1, A2, and A3), and their community structure and diversity were analyzed using Illumina MiSeq high-throughput sequencing technology. A total of 4238 operational taxonomic units were identified based on the number of taxa. At the phylum level, Proteobacteria and Bacteroidetes played a dominant role in the three stages and increased significantly during electricity generation. Compared with A1, the relative abundances of Proteobacteria in A2 and A3 increased by 23.30% and 32.06%, respectively, whereas those of Bacteroidetes in A2 and A3 increased by 5.56% and 14.50%, respectively. At the genus level, there were differences in the composition of bacterial communities among the three stages. Acinetobacter and Chlorobium became the dominant genera in A2, replacing Nitrospira and norank_f__Saprospiraceae in A1, and Sphingobacterium and Ochrobactrum became the dominant genera in A3. According to the sample cluster and principal component analyses, A1 was clustered into one class, and A2 and A3 were clustered into a second class. This work revealed bacterial community succession at the anode of an algal-film cathode MFC during the electricity generation process, which provides a theoretical basis for the subsequent promotion of electricity generation by algal-film cathode MFCs.

Diversity and Ecological Functions of Fungal Communities in Tangchi Hot Spring in Lujiang (China)

Hot springs contain many microorganisms, and a great deal of research has been conducted on the bacteria in hot springs but less on the fungi. Microbial diversity research in hot springs will help to further develop and utilize the microbial resources from hot springs. This is the first study to analyze the fungal diversity and ecological functions in Tangchi hot spring (China). In this paper, the fungal ITS sequences in the water samples of Tangchi hot spring were sequenced by Illumina MiSeq high-throughput sequencing technology and bioinformatically analyzed to explore the fungal diversity and ecological functions in the hot spring. The results revealed that the dominant fungal phylum was Ascomycota, followed by Basidiomycota, Chytridiomycota, and Olpidiomycota, and the dominant fungal genera were Rhizophydium, Aureobasidium, Rhodotorula, and Sclerotinia in Tangchi hot spring. The FUNGuild functional analysis results revealed that the dominant guilds in Tangchi hot spring were plant pathogens followed by the undefined saprotroph and the animal endosymbiont–animal pathogen–endophyte–plant pathogen–undefined saprotroph. This study can fill the gap in people’s understanding of fungal resources and offer theoretical support for understanding the fungal diversity and fungal resource development and utilization in Tangchi hot spring.

Comparison of Bacterial Community Composition in Gut of Chinese Mitten Crabs from Three Distinct Rivers in Korea

The Chinese mitten crab (CMC) also known as Eriocheir sinensis has great significance in the aquaculture industry. The bacterial communities inhabiting the CMC’s gut may differ depending on the host habitat and can aid in their normal biological functioning. These microbes are also known to have certain effects on their flavor. In this study, we utilized MiSeq high-throughput sequencing technology to explore the diversity of bacterial communities in the gut of CMCs from three different geographical locations in Korea: the Geum (GD), Han (HD), and Tamjin (TD) rivers. Although most of the environmental parameters were similar at the three sites, significant differences in conductivity (CDS), dissolved oxygen (DO), and salinity were observed. The results show that CMCs sampled from these locations exhibited distinct microbial composition and abundance. For example, the genus Candidatus Hepatoplasma displayed significantly higher abundance in CMCs from HD than those in the other locations, suggesting nutritional stress. Similarly, the crabs collected from TD showed a higher abundance of pathogenic Helicobacter than those from HD and GD sites. We also observed differences in the amino acid, nucleotide, and lactic acid concentrations between different tissues such as the muscle, hepatopancreas, and testis of CMCs. However, only small differences were observed when these characteristics were compared in CMCs from different locations. Our results offer important insights into the intestinal bacterial composition in CMCs which in turn may help in designing better culturing strategies for these important species of crabs.

High-throughput sequencing-based analysis of the composition and diversity of the endophyte community in roots of Stellera chamaejasme

Stellera chamaejasme (S. chamaejasme) is an important medicinal plant with heat-clearing, detoxifying, swelling and anti-inflammatory effects. At the same time, it is also one of the iconic plants of natural grassland degradation in northwest China, playing a key role in the invasion process. Plant endophytes live in healthy plant tissues and can synthesize substances needed for plant growth, induce disease resistance in host plants, and enhance plant resistance to environmental stress. Therefore, studying the root endophytes of S. chamaejasme is of great significance for mining beneficial microbial resources and biological prevention and control of S. chamaejasme. This study used Illumina MiSeq high-throughput sequencing technology to analyze the composition and diversity of endophytes in the roots of S. chamaejasme in different alpine grasslands (BGC, NMC and XGYZ) in Tibet. Research results show that the main phylum of endophytic fungi in the roots of S. chamaejasme in different regions is Ascomycota, and the main phyla of endophytic bacteria are Actinobacteria, Proteobacteria and Firmicutes (Bacteroidota). Overall, the endophyte diversity of the NMC samples was significantly higher than that of the other two sample sites. Principal coordinate analysis (PCoA) and permutational multivariate analysis of variance (PERMANOVA) results showed significant differences in the composition of endophytic bacterial and fungal communities among BGC, NMC and XGYZ samples. Co-occurrence network analysis of endophytes showed that there were positive correlations between fungi and some negative correlations between bacteria, and the co-occurrence network of bacteria was more complex than that of fungi. In short, this study provides a vital reference for further exploring and utilizing the endophyte resources of S. chamaejasme and an in-depth understanding of the ecological functions of S. chamaejasme endophytes.

Characteristics of the Rhizospheric AMF Community and Nutrient Contents of the Dominant Grasses in Four Microhabitats of the Subalpine Zone in Northwestern Yunnan, China

At the southeastern periphery of the Tibetan Plateau, the subalpine ecosystem hosts grasses as some of the most substantial species. However, the community and function of arbuscular mycorrhizal fungi (AMF) around the rhizospheres of grasses in the subalpine zone are still poorly understood. In the present study, 28 soils and 11 species of dominant grasses collected from four microhabitats (shrubland, grassland, woodland, and forest) in the subalpine zone of northwestern Yunnan, China, were used to investigate the AMF community by Illumina MiSeq high-throughput sequencing technology as well as nutrient contents. Among the four microhabitats, the maximum soil nutrient levels around the rhizospheres of grasses were observed in woodland. The nitrogen, phosphorus, and potassium concentrations in Dactylis glomerata shoots were significantly higher than those in the other 10 grass species. The AMF diversity of grassland in summer was substantially greater than that of the other three microhabitats (p &lt; 0.05). Discrepancies were observed within a given plant species across microhabitats; for example, in summer, the nitrogen concentration in the shoot of Iris tectorum in woodland was significantly higher than that in both forest and shrubland (p &lt; 0.05). A total of eight genera were detected in the AMF communities, which were dominated by Glomus, with a relative abundance of 45.4–94.4% in summer and 60.5–84.3% in winter. Moreover, the abundance of Glomus was significantly positively correlated with the content of alkali-hydrolyzable nitrogen in soil and nitrogen in grasses according to the Mantel test. As a critical nutrient element in soil, nitrogen is beneficial for plant growth. Thus, these results provide a better understanding of the resilience of soil AMF community and the ecological adaptability of grasses in the subalpine ecosystems of northwestern Yunnan.

Response of Carbon-Fixing Bacteria to Patchy Degradation of the Alpine Meadow in the Source Zone of the Yellow River, West China.

This study aims to enlighten our understanding of the distribution of soil carbon-fixing bacteria (cbbL-harboring bacteria) and their community diversity in differently degraded patches at three altitudes. MiSeq high-throughput sequencing technology was used to analyze the soil carbon-fixing bacteria community diversity of degraded patches and healthy meadow at three altitudes. Redundancy analysis (RDA) and structural equation model (SEM) were used to analyze the correlation and influence path between environmental factors and carbon-fixing bacteria. The results showed that degradation reduced the relative abundance of Proteobacteria from 99.67% to 95.57%. Sulfurifustis, Cupriavidus, and Alkalispirillum were the dominant genera at the three altitudes. Hydrogenophaga and Ectothiorhodospira changed significantly with altitude. RDA results confirmed that available phosphorus (AP) was strongly and positively correlated with Proteobacteria. AP and total nitrogen (TN) were strongly and positively correlated with Hydrogenophaga. Grass coverage and sedge aboveground biomass were strongly and positively correlated with Sulfurifustis and Ectothiorhodospira, respectively. Elevation adversely affected the relative abundance of dominant carbon-fixing bacteria and diversity index by reducing the coverage of grass and soil volumetric moisture content (SVMC) indirectly, and also had a direct positive impact on the Chao1 index (path coefficient = 0.800). Therefore, increasing the content of nitrogen, phosphorus and SVMC and vegetation coverage, especially sedge and grass, will be conducive to the recovery of the diversity of soil carbon-fixing bacteria and improve the soil autotrophic microbial carbon sequestration potential in degraded meadows, especially in high-altitude areas.

Decrease in beneficial bacteria and increase in harmful bacteria in Gastrodia seedlings and their surrounding soil are mainly responsible for degradation of Gastrodia asexual propagation.

Asexual reproduction of Gastrodia elata Bl. f. glauca S. chow (GeB) produces degeneration with increasing number of GeB. Therefore, we analyzed the microorganisms of GeB seedlings and surrounding soil by Illumina Miseq high-throughput sequencing technology. In this study, Illumina Miseq high-throughput sequencing technology was applied to analyze the types and quantities of GeB seedlings and surrounding soil microorganisms in the first to third generations of asexual reproduction, isolated and identified the dominant strains of GeB in the first to third generations and screened the antagonistic bacteria of its pathogenic fungi, and evaluated the effects of beneficial bacteria on the production performance of seedlings planted with GeB. With an increase in the number of asexual reproductive generations, the number of pathogenic fungi and bacteria in GeB seedlings and the surrounding soil increased, and the number of beneficial fungi and bacteria decreased. Pseudomonas sp., Agrobacterium rhizomes, and Herbaspirillum hiltneri were isolated and identified in the first generation, and Trichoderma harzianum, Penicillium viridiatum, Fusarium oxysporum, and Novosphingobium sp. Were isolated and identified in the third generation. Antagonistic strains of the three pathogenic bacterial strains were screened. In conclusion, beneficial bacteria significantly improved the production performance of asexual reproductive seedlings planted with GeB. In conclusion, our findings suggested that the microorganisms of GeB seedlings and the surrounding soil change as the number of generations of GeB reproduction increases, disrupts the microecological balance of surrounding soil and endophytic microbiomes.This study provides a theoretical basis for the degradation of asexual reproduction in GeB.

The influence of moisture content on removal of H2S using the vermicompost biflter and analysis on microbial community

The utilization of biofilters provides a promising option, serving as an environment-friendly and economically beneficial strategy for waste gas abatement. In this study, the different moisture content of vermicompost with indigenous microorganisms as a filter bed material was evaluated for the performance of a biofilter in terms of hydrogen sulfide removal efficiencies and the bacterial dynamics. Maximum removal efficiency of hydrogen sulfide was conformed when the moisture content of the packing material was from 50% to 60%. By 16S rDNA gene-Illumina Miseq high-throughput sequencing technology, The Shannon and Simpon index of the vermicompost microbial community had significantly decreased after treating hydrogen sulfide. The predominant bacteria in vermicompost samples were Proteobacteria, Gemmatimonadetes, Bacteroidetes and Actinobacteria. Rhodanobacter and Mesorhizobium were isogenous with sulfur-oxidizing bacteria, which play a critical role in vermicompost biodegrading hydrogen sulfide.

Effects of microbial agent and microbial fertilizer input on soil microbial community structure and diversity in a peanut continuous cropping system

IntroductionThe soil harbors a diverse array of microorganisms, and these are essential components of terrestrial ecosystems. The presence of microorganisms in the soil, particularly in the rhizosphere, is closely linked to plant growth and soil fertility. ObjectiveThe primary objective of this study is to assess the potential advantages of integrating microbial inoculants with compound fertilizer in enhancing peanut yield. MethodsWe utilized Illumina MiSeq high-throughput sequencing technology to conduct our investigation. The experimental design consists of four treatment groups: compound fertilizers (CF), compound fertilizers supplemented with microbial agents (CF + MA), compound fertilizers supplemented with microbial fertilizers (CF + MF), and compound fertilizers supplemented with both microbial agents and microbial fertilizers (CF + MM). ResultsThe experimental results demonstrated a significant increase in peanut yield upon application of CF + MA, CF + MF, and CF + MM treatments. During the blossom stage and pod-setting stage, the soil's catalase, urease, and acid phosphatase activities were significantly increased in the CF + MA, and CF + MM treatments compared to the CF treatment. The application of CF + MA resulted in an increase in bacterial richness in the rhizosphere soil of peanuts, as indicated by the sequencing results. The application of CF + MA, CF + MF, and CF + MM resulted in a reduction of fungal diversity. Proteobacteria, Actinobacteria, and Acidobacteria were the dominant bacterial phyla, while Ascomycota and Basidiomycota were the dominant phyla in the fungal component of the rhizosphere soil microbiome across all experimental treatments. ConclusionMicrobial agents and fertilizers modify the peanut rhizosphere soil's microbial community structure, as per our findings. The abundance of potentially beneficial bacteria (Bradyrhizobium, Rhizobium, and Burkholderia) and fungi (Trichoderma and Cladophialophora) could increase, while pathogenic fungi (Penicillium and Fusarium) decreased, thereby significantly promoting plant growth and yield of peanut.

Fungal communities and their correlation with the sensory quality of rice wine from the Xiaogan and Dazhou regions in China

In this study, we performed a comparative analysis of fungal communities and cultivable yeast isolates in rice wine from the Xiaogan and Dazhou regions using Illumina MiSeq high-throughput sequencing technology and traditional culture-dependent methods. And we further explored the correlation between the sensory quality and fungal communities in rice wine. The results demonstrated no significant difference (P > 0.05) in the abundance and diversity of fungal communities and cultivable yeast isolates between Xiaogan and Dazhou rice wine. The dominant fungal genera were Rhizopus and Saccharomyces, with Saccharomyces cerevisiae accounting for the greatest proportion of yeast isolates. The rice wine samples could be divided into two types based on the composition of fungal communities. Type 1 mainly contained Rhizopus and Saccharomyces, while type 2 mainly contained Rhizopus. Properties such as lightness, blueness-yellowness, methane levels, ethanol levels, organic sulfide content, and soluble solids content accounted for the main differences between the two types of rice wine. In addition, Candida and Clavispora showed a significant positive correlation (P < 0.05) with the aromatic substances in rice wine. The findings of the study enrich our understanding of traditional rice wine, providing meaningful information for the improvement and development of the traditional rice wine industry.

Differences in Fungal Communities in Different Material Cellar Sediments and Their Correlation with Environmental Factors

There are rich and diverse fungal communities in rainfall-cellar sediments. Fungi play a key role in the rainfall-cellar ecosystem as a bridge and link for material exchange between the rainfall-cellar ecosystem and the sediments. The changes in fungal community structure are usually closely related to the changes in environmental factors. The 16S rRNA gene Illumina MiSeq high-throughput sequencing technology was used to study the diversity and difference of fungal communities in the cellar sediments under two different catchment environments. The results revealed that the cellar sediments under the concrete catchment environment had higher diversity and richness of fungal communities than those under the loess land catchment environment. The dominant bacteria of the fungal communities under the two catchment environments were the same, namely Ascomycota, Basidiomycota, and Zygomycota, which constituted more than 90% of the abundance of the bacteria; however, the former had better homogeneity and stability. The indicator species based on LEfSe analysis demonstrated that Basidiobolales had the largest contribution to the diversity in the catchment environment of the loess land, and Mycosphaerella had the smallest contribution; Saccharomycetales contributed the most to the diversity in the concrete concentration environment, whereas Periconia contributed the least. The results of the co-occurrence network of the microbial community and environmental factors demonstrated that the positive relationship between fungi and environmental factors was stronger than the negative relationship. The research results have enhanced the understanding of the diversity of fungal communities in the cellar sediments and provided a reference for ensuring the drinking safety of rainwater harvesting cellar water for humans and livestock and improving the quality of cellar water.

Soil Bacterial Community Structure and Function Prediction of Millet/Peanut Intercropping Farmland in the Lower Yellow River

The objective of this study was to explore the microecological variability in farmland soil fertility in response to millet-peanut intercropping patterns by clarifying the effects of millet-peanut 4:4 intercropping on soil bacterial community structure and its diversity, as well as to provide a reference basis for promoting ecological restoration and arable land quality improvement in the lower Yellow River farmland. The Illumina MiSeq high-throughput sequencing technology and QIIME 2 platform were used to analyze the differences in bacterial community composition and their influencing factors in five soils[sole millet (SM), sole peanut (SP), intercropping millet (IM), intercropping peanut (IP), and millet-peanut intercropping (MP)] and to predict their ecological functions. The results showed that the α-diversity of intercropping soil bacterial communities differed from that of monocropping, though not significantly, whereas the β-diversity was significantly different (P<0.05). A total of 7081 ASVs were obtained from all soil samples, classified into 34 phyla, 109 orders, 256 class, 396 families, 710 genera, and 1409 species, of which 727 ASVs were shared, accounting for 24.5% to 27.8% in five soil species. The bacterial communities of millet-peanut intercropping and its monocropping soils were similar in phylum composition but varied in relative abundance. All five soils were dominated by the Actinobacteria, Proteobacteria, Acidobacteria, and Chloroflexi, with a relative abundance of 79.40%-81.33%. Soil organic carbon and alkaline nitrogen were the most important factors causing differences in the structures of the five soil bacterial communities at the phylum and genus levels, respectively. The PICRUSt functional prediction revealed that the relative abundance of primary functional metabolism was the largest (78.9%-79.3%), and the relative abundance of secondary functional exogenous biodegradation and metabolism fluctuated the most (CV=3.782%). In terms of the BugBase phenotype, the relative abundance of oxidative stress-tolerant bacteria increased in intercropping millet or peanut soils compared to that in the corresponding monocultures and significantly increased in intercropping millet soils compared to that in sole millet (P<0.05). Oxidative stress-tolerant, Gram-positive, and aerobic phenotypes were highly significantly positively correlated with each other (P<0.01), and all three showed highly significant negative correlations with potential pathogenicity and Gram-negative and anaerobic phenotypes (P<0.01). This showed that millet-peanut intercropping resulted in differences in soil bacterial community diversity, abundance, and metabolic functions and the possibility of reducing the occurrence of potential soil diseases. It can be used to regulate the soil microbiological environment to promote ecological restoration and sustainable development of farmland in the lower Yellow River.

Effects of grazing prohibition on nirK- and nirS-type denitrifier communities in salt marshes.

Grazing prohibition is an effective management practice to restore salt marsh functioning. However, the effects of grazing exclusion on denitrifying microbial communities and their controlling factors in salt marshes remain unclear. In this study, we surveyed soil physicochemical properties and above- and below-ground biomass and using quantitative polymerase chain reaction and Illumina MiSeq high-throughput sequencing technology to determine the relative abundance, composition, and diversity of nitrite reductase nirS- and nirK-type denitrifying bacterial communities associated with grazing prohibition treatments and elevations. The abundance of nirS-type denitrifiers increased with grazing prohibition time, whereas the abundance of nirK-type denitrifiers remained unaltered. Moreover, nirS-type denitrifiers were more abundant and diverse than nirK-type denitrifiers in all treatments. Grazing prohibition significantly altered the operational taxonomic unit richness, abundance-based coverage estimator, and Chao1 indices of the nirS-type denitrifying bacterial communities, whereas it only minimally affected the structure of the nirK-type denitrifying bacterial community. The results imply that the nirS community, rather than nirK, should be the first candidate for use as an indicator in the process of salt marsh restoration after grazing prohibition. Substances of concern, total nitrogen, and salinity were the key environmental factors affecting the abundance and community composition of nirS and nirK denitrifiers. The findings of this study provide novel insights into the influence of the length of grazing prohibition and elevation on nirS- and nirK-type denitrifying bacterial community composition in salt marshes.

Evaluation and comparison of physicochemical properties, volatile substances, and microbial communities of leaf mustard (Brassica juncea var. multiceps) under natural and inoculated fermentation.

Due to the uncontrolled fermentation process and unstable quality of naturally fermented leaf mustard, inoculated fermentation is receiving more attention. Here, the physicochemical properties, volatile compounds, and microbial community in leaf mustard under natural fermentation (NF) and inoculated fermentation (IF) were analyzed and compared. The contents of total acid, crude fiber, and nitrite of leaf mustard were measured. Headspace-solid phase microextraction-gas chromatography-mass spectrometry and orthogonal projection on latent structure-discriminant analysis were used to analyze the differences of volatile compounds in NF and IF leaf mustard. Moreover, Illumina MiSeq high-throughput sequencing technology was employed to reveal the composition of microbiota. The results showed that the nitrite content in leaf mustard after IF (3.69mg/kg) was significantly lower than that after NF (4.43mg/kg). A total of 31 and 25 kinds of volatile components were identified in IF and NF, respectively. Among the detected compounds, 11 compounds caused the differences between IF and NF leaf mustard. The results of inter-group difference analysis showed that there were significant differences in fungal flora between IF and NF samples. Saccharomycetes, Kazachstania, and Ascomycota were the landmark microorganisms in IF leaf mustard and the landmark microorganisms in NF were Mortierellomycota, Sordariomycetes, and Eurotiomycetes. The abundance of probiotics (such as Lactobacillus) in IF leaf mustard (51.22%) was higher than that in NF (35.20%) and the abundance of harmful molds (such as Mortierella and Aspergillus) was opposite. Therefore, IF leaf mustard showed the potential to reduce the content of nitrite and harmful molds and increase the beneficial volatile compounds and probiotics. PRACTICAL APPLICATION: Leaf mustard of inoculated fermentation (IF) showed better fermented characteristics than natural fermentation in terms of lower nitrite content, greater beneficial volatile substances, and better potential for increasing probiotics and reducing harmful molds. These results provided a theoretical basis for IF leaf mustard and contributed to the industrial production of fermented leaf mustard.