Differences In Bacterial Community Structure Research Articles

Effects of different dietary energy levels on growth performance, meat quality and nutritional composition, rumen fermentation parameters, and rumen microbiota of fattening Angus steers.

This study investigates the effects of varying energy levels in diets on Black Angus steers, focusing on growth performance, muscle composition, rumen microbial community, and their interrelationships. Twenty-seven Black Angus steers, aged approximately 22 months and weighing 520 ± 40 kilograms, were randomly divided into three groups: low-energy (LE), medium-energy (ME), and high-energy (HE). Each group consisted of nine individuals. The steers were fed diets with energy levels of 6.657 MJ/kg (LE), 7.323 MJ/kg (ME), and 7.990 MJ/kg (HE) following a 14-day pre-feeding period, with a subsequent 90-day main experimental phase. After the 90-day feeding period, both the HE and ME groups exhibited significantly higher average daily weight gain (ADG) compared to the LE group (p < 0.05). The feed-to-weight ratios were lower in the HE and ME groups compared to the LE group (p < 0.05). The HE group showed significantly higher crude fat content in the longissimus dorsi muscle compared to the LE group (p < 0.05), with total fatty acid content in the muscle surpassing that in the ME and LE groups (p < 0.05). As dietary energy levels increased, the diversity of the rumen microbial community decreased (p < 0.05), and significant differences in bacterial community structure were observed between the LE and HE groups (p < 0.05). The results suggest that higher dietary energy levels enhance growth performance and alter muscle composition in Black Angus steers, while also influencing the rumen microbial community. This study contributes to understanding optimal dietary strategies for finishing Angus cattle to improve beef quality, economic returns, and the development of standardized production procedures.

Abstract 2808: Levels of isobutyric acid from gut butyrate-producing taxa are associated to Delta-24-RGDOX efficacy against malignant glioma

Abstract Glioblastoma (GBM) is the most aggressive malignant primary brain tumor worldwide. Current standard-of-care treatments allow for a median survival of 12 to 18 months. GBM has a poor survival prognosis, observing less than 6% of patients surviving 5 years post-diagnosis. Among recent treatment advancements, the oncolytic adenovirus Delta-24-RGDOX armed with the T-cell activator OX40L is promising. Studies have unveiled a relationship between the gut microbiome and high levels of short-chain fatty acids (SCFA), such as isobutyric and propionic acid, to immunotherapy response. Changes in the gut microbiome and metabolome associated to viroimmunotherapy efficacy remain unclear. Here, we assessed the gut microbial changes in addition to isobutyric and propionic acid levels regarding viroimmunotherapy efficacy. Immunocompetent C57BL/6 mice were intracranially implanted GL261-5 GBM cells and received intratumoral injections of PBS (control) or Delta-24-RGDOX. A naïve group with no tumor nor treatment was also included. Fecal pellets were collected at three different time points: (1) before tumor implantation, (2) before treatment, and (3) 14 days after the first dose of treatment. Genomic DNA was isolated with the QIAGEN DNeasy Powersoil Pro Kit from fecal pellets (n=75), followed by sequencing with the Illumina platform of the 16S ribosomal RNA V4 region. Quality assessment of the sequences was executed in QIITA. Bacterial community analysis with a sequencing depth of 1,470 reads, while using the taxonomic database SILVA, was followed downstream with QIIME2 and R. Metabolic profiling of SCFA of the fecal pellets was performed through Gas Chromatography. Results showed significant differences in bacterial community structure of viroimmunotherapy-treated mice with survival of &amp;gt;100 days compared to controls (ANOSIM p-value=0.006). Alpha diversity metrics showed significant differences in richness between the naive and tumor-implanted mice of the PBS (KW p-value=0.049) and Delta-24-RGDOX (KW p-value=0.019) groups, highlighting that tumor presence alters the gut microbiota. Additionally, viroimmunotherapy-treated mice with survival of &amp;gt;100 days had a significant increase of Lactobacillus and the butyrate-producing bacterias Erysipelatoclostridium and Ruminococcaceae. Also, we found significantly higher levels of isobutyric acid and lower levels of propionic acid in viroimmunotherapy-treated mice with survival of &amp;gt;100 days (p-value&amp;lt;0.05). These findings suggest that butyrate-producing bacteria coupled with higher levels of isobutyric acid may be important in the efficacy of Delta-24-RGDOX. This highlights the microbial and metabolic changes associated with oncolytic viral therapy efficacy. Sponsored by an award within The University of Puerto Rico/UT MD Anderson Cancer Center Partnership for Excellence in Cancer Research Grant (2U54CA096297-17). Citation Format: Natalie M. Meléndez-Vázquez, Xuejun Fan, Juan Fueyo, Candelaria Gomez-Manzano, Filipa Godoy-Vitorino. Levels of isobutyric acid from gut butyrate-producing taxa are associated to Delta-24-RGDOX efficacy against malignant glioma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2808.

Comparative microbiome analysis of beef cattle, the feedyard environment, and airborne particulate matter as a function of probiotic and antibiotic use, and change in pen environment.

Intensive beef cattle production systems are frequently implicated as a source of bacteria that can be transferred to nearby humans and animals via effluent water, manure used as fertilizer, or airborne particulate matter. It is crucial to understand microbial population dynamics due to manure pack desiccation, antibiotic usage, and antibiotic alternatives within beef cattle and their associated feedyard environment. Understanding how bacterial communities change in the presence of antibiotics can also improve management practices for reducing the spread of foodborne bacteria. In this study, we aimed to compare the microbiomes within cattle feces, the feedyard environment and artificially produced airborne particulate matter as a function of pen change and treatment with tylosin or probiotics. We utilized 16S rRNA sequencing to compare bacterial communities among sample types, study days, and treatment groups. Bacterial community diversity varied as a function of sampling day and pen change (old or new) within fecal and manure pack samples. Manure pack samples from old pens and new pens contained diverse communities of bacteria on days 0 and 84; however, by day 119 of the study these taxonomic differences were less evident. Particulate matter samples exhibited significant differences in community diversity and predominant bacterial taxa compared to the manure pack they originated from. Treatment with tylosin did not meaningfully impact bacterial communities among fecal, environmental, or particulate matter samples; however, minor differences in bacterial community structure were observed in feces from cattle treated with probiotics. This study was the first to characterize and compare microbial communities within feces, manure pack, and airborne particulate matter from the same location and as a function of tylosin and probiotic treatment, and pen change. Although fecal and environmental samples are commonly used in research studies and other monitoring programs to infer public health risk of bacteria and antimicrobial resistance determinants from feedyard environments, our study suggests that these samples may not be appropriate to infer public health risk associated with airborne particulate matter.

Eimeria infections of plateau pika altered the patterns of temporal alterations in gut bacterial communities.

Intestinal parasites, such as Eimeria, are common among plateau pika (Ochotona curzoniae). The gut microbiome is an essential driver of the host response to gastrointestinal parasites. However, the effects of intestinal protozoal parasites on the temporal variations in the gut microbiome and behavioral and physiological activities remain unknown. Our study conducted treatments involving experimental feeding of pika with Eimeria oocysts or anticoccidia under laboratory conditions to focus on the parasite-associated alterations in gut bacterial communities, host behavioral activity, physiology, and host-bacteria relationships. The results showed insignificant differences in bacterial community structures among treatments on the basis of Bray-Curtis distance metrics, whereas the patterns of temporal alterations in the bacterial communities were changed by the treatments. Bacterial alpha diversities did not vary with the treatments, and experimental feeding with Eimeria slowed down the decrement rate of alpha diversity. Furthermore, few bacterial members were significantly changed by the treatments-only the genus Ruminococcus and the species Ruminococcus flavefaciens, which were associated with energy metabolism. Experimental feeding with Eimeria modified the temporal variations in the bacterial members, including a lower loss rate of the relative abundance of the dominant families Muribaculaceae and Ruminococcaceae in the group with Eimeria experimental feeding. Moreover, a shifting energy trade-off was suggested by the parasite-induced increments in thyroid hormones (triiodothyronine and tetraiodothyronine) and decrements in exploration behavior in the group with Eimeria feeding. However, we did not detect specific connections between gut bacterial communities and pika behaviors and physiology in terms of energy trade-offs. Further in-depth research is needed to examine the role of Eimeria-modified differences in the gut bacteria of plateau pika.

Stable composition of gut microbiome in the Asian ladybeetle Coccinella septempunctata reared on natural and artificial diets

The Asian ladybeetle, Coccinella septempunctata, is an important insect of predatory natural enemy, which has a strong control effect and application prospects for aphids, whiteflies, mealybugs, and other small-sized pests of agriculture and forestry crops. Gut microbiota composition posed impacts on development of insects. In order to clarify the effect of artificial feed feeding on the intestinal microbial species and structure of C. septempunctata, we compared the intestinal microbial flora of C. septempunctata reared on bean aphids and artificial food for 15 days. Results show that Proteobacteria was the dominant component in all groups at phylum level, Rhodobacter, Methylovigula, Burkholderia, and Bradyrhizobium were the dominant bacteria among all groups at genus level. As to the differences in bacterial community structure and diversity, there is no significant difference between Shannon index and Simpson index, the principal components analysis of the bacterial communities, and the samples were roughly distributed in different regions. After 15 days of feeding, artificial diet did not significantly reduce the microbial diversity of the gut of C. septempunctata compared to the aphid group, and there was no significant effect on the abundance of dominant flora in the gut of C. septempunctata, C. septempunctata gut has a similar core microbiota. This study clarifies the effects in intestinal microbial diversity and composition structure of the C. septempunctata with artificial diet, and provides a theoretical basis for understanding the intestinal microorganisms and optimizating the artificial diet of C. septempunctata.

Impact of different sulfur sources on the structure and function of sulfur autotrophic denitrification bacteria

Nitrate pollution in surface water has become a significant environmental concern. Sulfur autotrophic denitrification (SAD) technology is gaining attention for its cost-effectiveness and efficiency in nitrate removal. This study aimed to investigate the structure and function of sulfur autotrophic denitrification microbial communities in systems using sodium thiosulfate (Group A) and elemental sulfur (Group B) as the sole electron donors. Metagenomic amplicon sequencing and physicochemical analysis were performed to examine the microbial communities. The results revealed that on day 13, the nitrate nitrogen removal rate in Group A was significantly higher (89.2%) compared to Group B (74.4%). The dominant genus in both Groups was Thiobacillus, with average abundances of 34.15% and 16.34% in Groups A and B, respectively. β-diversity analysis based on species level showed significant differences in bacterial community structure between the two Groups (P < 0.001). Group A exhibited a greater potential for nitrate reduction and utilized both thiosulfate and elemental sulfur (P < 0.01) compared to Group B. This study provides a sufficient experimental basis for improving the start-up time and operating cost of SAD system through sulfur source switching and offers new prospects for in-depth mechanistic analysis.

Community structure and niche differentiation of endosphere bacterial microbiome in Camellia oleifera.

Understanding the changes in bacterial community structure in different microenvironments of Camellia oleifera is essential to better explore the benign interaction between beneficial microorganisms and plants. Using Camellia oleifera trees, a Chinese wooden oil plant as a model ecosystem, we characterized the archaeal and bacterial microbiome across five different tissue-level niches using 16S rRNA gene analyses. Our research indicates that the diversity of Camellia oleifera endophytic bacterial communities is highly dependent on the plant compartment. The species replacement process (69.90%) is the dominant factor in the differences in bacterial community structure. The dominant bacteria phyla (Proteobacteria, Acidobacteria, Actinobacteria, Bacteroidetes, Firmicutes, Chloroflexi, and Verrucomicrobia) of Camellia oleifera show a significant plant compartment (roots, stems, leaves, fruits) enrichment effects. A variety of bacteria (Hymenobacter, Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium, Mesorhizobium, Bradyrhizobium, Bacillus, Ochrobactrum, Pantoea, Pseudomonas, etc.) with nitrogen-fixed potentials are enriched in Camellia oleifera tissue. In addition, the hub bacterial groups of Camellia oleifera are Nitrospira, Haemophilus, Staphylococcus, Ruminiclostridium, and Ochrobactrum. They are widespread colonization in various tissues with a low relative abundance and may play an important role in the nitrogen cycle, host life promotion, and plant defense. This study provides a holistic understanding of the endosphere bacterial community structure, which is one of the most complete ecological niche-level analyses of Camellia oleifera. These results provide a scientific theoretical basis for an in-depth discussion of plant-endosphere microbial interaction and better exploration of benign interaction of beneficial microorganisms and plants.IMPORTANCEMicroorganisms inhabited various tissues of plants and play a key role in promoting plant growth, nutritional absorption, and resistance. Our research indicates that the diversity of Camellia oleifera endophytic bacterial communities is highly dependent on the plant compartment. Proteobacteria, Acidobacteria, Actinobacteria, Bacteroidetes, Firmicutes, Chloroflexi, and Verrucomicrobia are dominant bacteria phyla. The tissues of Camellia oleifera contain various bacteria with nitrogen fixation potential, host life promotion, and plant defense. This study provides a scientific theoretical basis for an in-depth discussion of plant-endosphere microbial interaction and better exploration of benign interaction of beneficial microorganisms and plants.

Aridification alters the diversity of airborne bacteria in drylands of China

Dryland ecosystems, which vary sensitively to drought owing to climate change and human activities, frequently cause large-scale aeolian dispersal of terrestrial-mineral and biological particles. To date, very few studies have focused on the atmosphere-land exchange of bacteria in drylands. To understand the bacterial transport from the terrestrial environment to the atmosphere over drylands, soil and aerosol samples were collected at 19 sites in arid and semi-arid regions across drylands of China in the summer of 2017. The 16S rRNA gene sequencing revealed that the bacterial diversity in the atmosphere was significantly lower than that in terrestrial ecosystems for all the collected samples. Moreover, bacterial diversity in the atmosphere increases in arid regions compared to semi-arid regions, while those of the terrestrial environment were maintained regardless of the region. Additionally, the terrestrial bacterial sources contributed to the airborne bacteria more significantly in arid regions than those in semi-arid regions (accounting for 10.0 ± 1.1% and 3.5 ± 1.1%, respectively). The arid conditions tended to enhance the atmospheric emissions of Chloroflexi, while the members of Bacteroidetes were dominant in both the atmospheres of the semi-arid and arid regions. The differences in bacterial community structures between the terrestrial and atmospheric ecosystems are thought to depend on the ground surface characteristics such as vegetation and terrestrial substrates. Meteorological drought may alter terrestrial characteristics, which regulate airborne bacterial dispersal from dryland to its downwind regions, suggesting that more attention should be paid to the bacterial roles in the biology-health-climate process in the future.

Analysis of bacterial community structure and taste quality of different colored high-temperature Daqu in the Xiangyang region, China

In this study, the differences in bacterial community structure and taste quality among the three different colored high-temperature Daqu (HTD) produced by Enterprise-A were investigated. Furthermore, these HTD were compared to HTD produced by local Enterprise-B. The results revealed yellow HTD of Enterprise-A showed significantly higher bacterial richness and diversity (P < 0.05). The dominant bacterial genera were Bacillus (27.09%), Lentibacillus (21.28%), Kroppenstedtia (12.68%), Thermoactinomyces (8.83%). The electronic tongue detection showed that black HTD presented significantly higher taste attributes, such as sourness, astringency, and bitter aftertaste (P < 0.05). Highly significant positive correlations between Bacillus with umami and saltiness were observed (P < 0.01), while a highly significant negative correlation was found between Bacillus and sourness (P < 0.01). Furthermore, the PCoA and cluster analysis revealed that the three colored HTD samples from the same enterprise were closer to each other. Finally, 84 bacterial strains were isolated from the HTD of Enterprise-A using pure culture methods, including B. amyloliquefaciens, B. licheniformis, Caldibacillus hisashii, and Pediococcus acidilactici. This study provides a greater understanding of the quality of HTD from Enterprise-A and reveals that the production process employed by different enterprises has a greater impact on the microbial community structure of HTD, compared to the differences in temperature during fermentation.

Gut microbiome in men with chronic prostatitis/chronic pelvic pain syndrome: profiling and its predictive significance.

To investigate the difference in gut microbiome composition between patients with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) and healthy controls, and to assess the potential of gut microbiota as predictive markers for CP/CPPS risk. The present study included 41 CP/CPPS patients and 43 healthy controls in China. Fecal specimen data were obtained and analysed using 16S rRNA gene sequencing. Alpha and beta-diversity indices, relative microbiome abundances, cluster analysis, and linear discriminant analysis effect size (LEfSe) were employed. Microbial biomarkers were selected for the development of a diagnostic classification model, and the functional prediction was conducted using PICRUSt2. Alpha-diversity measures revealed no statistically significant difference in bacterial community structure between CP/CPPS patients and controls. However, significant differences were observed in the relative abundances of several bacterial genera. Beta-diversity analysis revealed a distinct separation between the two groups. Significant inter-group differences were noted at various taxonomic levels, with specific bacterial genera being significantly different in abundance. The LEfSe analysis indicated that three bacterial species were highly representative and seven bacterial species were low in CP/CPPS patients as compared to the control group. A diagnostic model for CP/CPPS based on microbial biomarkers exhibited good performance. PICRUSt2 functional profiling indicated significant differences in the development and regeneration pathway. Significant differences in the gut microbiome composition were found between groups. The study provided a novel diagnostic model for CP/CPPS based on microbiota, presenting promising potential for future therapeutic targets and non-invasive diagnostic biomarkers for CP/CPPS patients.

Distribution of bacterial community structures on human scalp hair shaft in relation to scalp sites.

Bacterial community structure on the human skin is specific to each individual and varies among different body sites. In this study, we investigated differences in bacterial community structure among 5 hair sampling sites and among 12 individuals. Significant differences were found between individuals in terms of alpha diversity and relative abundance of major bacterial phyla and genera, whereas no differences were found between hair sampling sites. The principal coordinate analysis plots of within-individual group tended to converge individually, whereas those of within-hair sampling site group did not cluster. In addition, weighted UniFrac analysis showed that the individual-based category was a statistically significant category but not the scalp hair sampling site-based category. These results suggest that the distribution of bacterial community structures on scalp hair shafts within individuals was relatively steady, even when the scalp hair sampling site was different.

Identification of significant live bacterial community shifts in different reclaimed waters during ozone and chlorine disinfection

Ozone and chlorine are the most widely used disinfectants for water and wastewater disinfection. They play important role in microbial inactivation but could also pose a considerable selection effect on the microbial community of reclaimed water. Classical culture-based methods that rely on the assessment of conventional bacterial indicators (e.g., coliform bacteria) could hardly reflect the survival of disinfection residual bacteria (DRB) and hidden microbial risks in disinfected effluents. Hence, this study investigated the shifts of live bacterial community during ozone and chlorine disinfection in three reclaimed waters (i.e., two secondary effluents and one tertiary effluent), adopting Illumina Miseq sequencing technology in combination with a viability assay, propidium monoazide (PMA) pretreatment. Notably, statistical analyses of Wilcoxon rank-sum test confirmed the existance of distinct differences in bacterial community structure between samples with or without PMA pretreatment. On the phylum level, Proteobacteria commonly dominated in three undisinfected reclaimed waters, while ozone and chlorine disinfection posed varied effects on its relative abundance among different influents. On the genus level, ozone and chlorine disinfection significantly changed the bacterial composition and dominant species in reclaimed waters. Specifically, the typical DRB identified in ozone disinfected effluents were Pseudomonas, Nitrospira and Dechloromonas, while for chlorine disinfected effluents, Pseudomonas, Legionella, Clostridium, Mycobacterium and Romboutsia were recognized as typical DRB, which call for much attention. The Alpha and Beta diversity analysis results also suggested that different influent compositions greatly affected the bacterial community structure during disinfection processes. Since the experiments in present study were conducted in a short period and the dataset was relatively limited, prolonged experiment under different operational conditions are needed in future to illustrate the potential long-term effects of disinfection on the microbial community structure. The findings of this study could provide insights into microbial safety concern and control after disinfection for sustainable water reclamation and reuse.

Structure and diversity of bacterial communities in the water column of three reservoirs in Yun-Gui Plateau, China

ABSTRACT Plateau reservoirs are considered vulnerable and sensitive to eutrophication under global warming and land use changes. We investigated the structure, diversity, and gene functions of bacterial communities in 3 reservoirs in Yun-Gui Plateau. We assumed the bacterial community structures were different among these 3 plateau reservoirs because of differences in trophic status. We found an insignificant difference in bacterial community structure among the reservoirs but a varying relative abundance of components in the community. Proteobacteria and Cyanobacteria were the most abundant phyla. Alpha diversity, as indicated by Simpson, Shannon, and evenness indexes, were similar in the 3 reservoirs, but richness was different. Hongfeng Reservoir exhibited the lowest heterogeneity, as indicated by the beta diversity. Analysis of gene functions suggested that amino acid metabolism and membrane transport were important and reflected the multiple roles of bacteria in biogeochemical processes. This study provided information about the bacterial community structure in reservoirs of Yun-Gui Plateau and analysis of the effects of environmental factors. Bacterial communities show little variation among reservoirs due to exposure to similar environmental conditions, and differences in trophic status were not a strong driver of community structure changes.

Relation analysis of bacterial community in soils of coal mines with potential ecological risk from heavy metals

Coal consumption increases consistently, and heavy metal contamination in soils surrounding coal mines has been a severe environmental issue. Investigation of the relations of the bacterial community in soils of coal mines with potential ecological risk from heavy metals is essential for better understanding the impact of coal production on ecosystem health. In this study, soils surrounding two coal mines in a typical coal industry city of China were sampled, and heavy metals (Cd, Cr, Ni, Cu, Zn, As, and Pb) were quantified together with an in-depth evaluation of bacterial community based on high-throughput sequencing. The individual and overall ecological risk from heavy metals were estimated, and their relations with the identified seven core bacteria were analyzed. For soils surrounding both coal mines, in phylum level, five dominant bacterial taxa (Proteobacteria, Acidobacteriota, Actinobacteria, Firmicutes, and Bacteroidota) were identified, and their differences in relative abundance were clearly revealed, even if the differences between the two mines were not significant. When evaluated in genus level, apparent differences in bacterial community structure and complexity were found. The soils with higher potential ecological risk showed relatively lower complexity for the bacterial community. Seven core bacteria were identified, and negative relations of their relative abundance with the individual and overall ecological risk from heavy metals were revealed. Two families (Halomonadaceae and Aeromonadaceae) and two genera (Oceanisphaera and Ignatzschineria) were found more sensitive to both the individual risk from arsenic and the overall risk from all heavy metals, suggesting their possibility as indicators of soil contamination by these metal elements. Different from these, Rhizobiaceae revealed a positive relation with the overall risk value, implying their strong tolerance to heavy metals and, therefore, possible effect in bioremediation and phytoremediation of heavy metal contaminated soils. These findings have great reference value for better understanding the impacts of heavy metal contamination induced by coal production.

Antibiotics affected the bacterial community structure and diversity in pore water and sediments with cultivated Phragmites australis in a typical Chinese shallow lake.

The migration of antibiotics and bacterial communities between sediments and pore water occurring in the lake, which is affected by aquatic vegetation. However, the differences in bacterial community structure and biodiversity between pore water and sediments with plants in lakes under antibiotic stress are still poorly understood. We collected pore water and sediments in both wild and cultivated Phragmites australis regions in the Zaozhadian (ZZD) Lake to explore the characteristics of the bacterial community. Our results showed that the diversity of bacterial community in sediment samples were significantly higher than those in pore water samples in both P. australis regions. Due to higher antibiotic levels in sediments from the cultivated P. australis region, the composition of bacterial communities showed a difference, which reduced the relative abundance of dominant phyla in pore water and increased that in sediments. The higher bacterial variations in pore water could be explained by sediment in the cultivated P. australis region than that in wild P. australis region, therefore plant cultivation might change the source-sink pattern between sediments and pore water. The dominant factors shaping the bacterial communities in the wild P. australis region pore water or sediment were NH4-N, NO3-N, and particle size, while cultivated P. australis region pore water or sediment were oxytetracycline, tetracycline, etc. The findings of this work indicates that the antibiotic pollution caused by planting activities has a greater impact on the bacterial community, which will provide a reference for the use and management of antibiotics in lake ecosystems.

Bacterial Diversity Analysis of Chaozhou Sauerkraut Based on High-Throughput Sequencing of Different Production Methods

In this study, high-throughput sequencing technology was used to analyze the bacterial diversity of sauerkraut produced at home and in factories in Chaozhou. The differences in bacterial community structure among different sauerkraut samples were studied by diversity analysis and heat map analysis, and the dominant bacterial genera were analyzed. The results showed that 54 phyla and 622 genera were identified from 10 Chaozhou sauerkraut samples. The bacterial community structures of Chaozhou sauerkraut produced by five factories were similar, and the dominant bacterial genera were the same, which were Lactobacillus, Pediococcus and Weissella. The dominant genus in the sauerkraut samples produced by three families was similar to that in samples produced by the factories. However, the samples from two other families were quite different, and there may be environmental pollution. The samples may also contain possible pathogenic microorganisms such as Pseudomonas and Vibrio. Overall, there were still some differences in the bacterial community structure of Chaozhou sauerkraut factory-produced and household-handmade samples. To the best of our knowledge, this paper is the first to compare the bacterial diversity of homemade and factory-produced Chaozhou sauerkraut, laying the foundation for further research on Chaozhou sauerkraut.

Characteristics of bacterial community structure and diversity in overlying water and sediments with Lotus in the Baiyangdian Lake, China

Bacterial communities in water and sediments are important decomposers of lake ecosystem. However, the differences in bacterial community structure and biodiversity in overlying water and sediments covered by aquatic plants such as Lotus in lake ecosystems are still poorly understood. Here we collected paired overlying water and sediments in the Baiyangdian (BYD) Lake to explore their characteristics of bacterial community. Our results showed that bacterial diversity indices such as Sobs, Shannon, Simpsoneven and Phylogenetic diversity in sediment samples were significantly higher than those in overlying water samples, which were mainly affected by ofloxacin (OFL), dissolved oxygen and pH in the overlying water, while norfloxacin (NOR), OFL and sulfapyridine (SPD) in sediments. Dominant phyla across all overlying water samples were Actinobacteriota (36.65%), Proteobacteria (29.12%) and Patescibacteria (17.01%), while Proteobacteria (20.97%), Chloroflexi (19.56%) and Actinobacteriota (13.37%) in all sediment samples. Source Tracker results showed that about 6.59 ± 1.9% of the variations in bacterial community in sediments could be attributed to the contribution of the overlying water bacterial community, which is higher than that of sediments to the overlying water bacterial community. The dominant factors shaping the bacterial communities in the overlying water were NOR, dissolved organic carbon (DOC) and total phosphorus, while in sediments were NOR, OFL and DOC. It is suggested that antibiotics (especially NOR) may have a substantial effect on bacterial community rather than interaction of environmental compartments (overlying water and sediments), and would help to improve the understanding of bacteria transfer and coalescence in a shallow lake ecosystem.

Effect of Deep Vertical Rotary Tillage on Soil Bacterial Community Diversity and Microbial Network Structure in Cultivated Land

The aim of this study was to understand the effect of deep vertical rotary tillage on the diversity and structural distribution of a soil bacterial community in cultivated land, as well as the interactions between microbial ecological molecular network and species. In this study, the cultivated soil under different tillage methods in the Yellow River diversion irrigation area in Ningxia was selected as the research object, and two treatments were set up, namely, deep vertical rotary tillage (DVRT) and conventional tillage (CT). Then, Illumina MiSeq technology was used to analyze the molecular ecological network of soil bacterial community under different tillage methods in the Ningxia Yellow River irrigation area. The results showed that DVRT significantly increased the contents of total organic carbon (TOC), total nitrogen (TN), alkali-hydrolyzed nitrogen (AN), total phosphorus (TP), available phosphorus (AP), and total potassium (TK) in the 0-20 cm soil layer compared with those in the CT treatment. Compared with those in the CT treatment, DVRT significantly increased the contents of TOC, TN, TP, AP, TK, and available potassium (AK) in the 20-40 cm soil layer. DVRT treatment significantly increased water content (WC) by 8.13%-13.30% and decreased pH and electrical conductivity (EC) by 4.51%-5.85% and 12.5%-13.33%, respectively. In different growth stages and soil layers of maize, the Shannon and Ace indices were increased in the DVRT treatments. The dominant bacterial phyla were:Actinobacteria, Proteobacteria, Chloroflexi, Acidobacteriota, and Gemmatimonadota. The results of bacterial community β diversity showed that DVRT and CT had significant differences in bacterial community structure. The redundancy analysis and Partial Mantel test results showed that pH, EC, and TP were the key environmental factors affecting the structural diversity of bacterial communities. Molecular ecological network analysis revealed that DVRT treatment microbial networks consisted of more functionally related microbial modules, and the topological roles of key microorganisms were different from those in the CT treatment. In conclusion, DVRT can enhance soil nutrients and WC in different soil layers, reduce pH and EC, improve soil bacterial community diversity and microbial network structure, and also enhance the potential ecosystem functions in cultivated soil.

Differences in bacterial community composition, structure and function between sediments in waterways and non-navigable channels in a plain river network area.

Bacterial communities greatly help maintain the balance of river ecosystems and are highly sensitive to changes in environmental conditions. Plain river network areas (PRNs) are characterized by dense river networks, low-lying terrain, and slow water flow, where the bottom sediment is frequently disturbed by ship navigation due to the limited water depth and width of waterways, providing a unique ecological niche for bacterial growth. Hence, understanding how bacterial communities in PRNs respond to changes in hydrodynamic conditions, physicochemical parameters, and pollutants under ship navigation is essential to maintaining the stability of inland waterway ecosystems. The Taihu Lake Basin, a typical PRN, was selected to explore the differences in bacterial community composition, structure and function between sediments in waterways (WS) and non-navigable channels (NS). The results indicate that the sediment from NS possessed more diverse and complex bacterial communities than WS. NMDS and ANOSIM analyses further verified the significant differences in bacterial community structure between WS and NS. Combined with LEfSe, we observed the highly differential taxonomy between WS and NS from phylum to order. Moreover, a comparison of beta diversity dissimilarity indices revealed that although species replacement dominated both the WS and NS beta-diversity patterns, species loss caused the differences in the overall beta diversity between them. Variance partitioning analysis revealed that physicochemical parameters (clay content, pH, ORP, and others) and ship traffic volume (STV) were the main driving factors for bacterial community distribution between WS and NS, while pollutants (heavy metals, perfluoroalkyl acids, and others) had a relatively minor influence. PICRUSt2 analysis revealed that the changes in pH, ORP, and STV under ship navigation might inhibit the bacterial ability to metabolize carbohydrates. The results reveal the comprehensive effects of ship navigation disturbance on sediment bacterial communities in the PRN and contribute to further understanding of inland waterway ecosystems.

Diversity of Bacterial Communities Associated with Solitary Bee Osmia excavata Alfken (Hymenoptera: Megachilidae)

Insect-associated microorganisms play important roles in the health and development of insects. This study aimed to investigate the similarities and differences in bacterial community structure and composition between the larval gut of Osmia excavata, nest soil, and brood provision from the nest tube. We sequenced larvae gut and their environments’ microorganisms of O. excavata from four locations based on full-length 16S rRNA gene amplicons. The results showed 156, 280, and 366 bacterial OTUs from gut, brood provision, and nest soil, respectively, and three groups shared 131 bacterial OTUs. In the gut, the top two dominant bacteria were Sodalis praecaptivus (68.99%), Lactobacillus micheneri (17.95%). In the brood provision, the top two dominant bacteria were S. praecaptivus (26.66%), Acinetobacter nectaris (13.05%), and in the nest soil, the two most abundant bacteria were Gaiella occulta (4.33%), Vicinamibacter silvestris (3.88%). There were significant differences in diversity between the brood provision groups and the nest soil groups, respectively. Three of the four locations did not differ for gut microbial diversity. Bacteria similar to other solitary bees also existed in the gut of the larvae. Results indicated when the habitat environments were similar, the bacterial community diversity of the gut of O. excavata was similar, despite significant differences among brood provisions and soils, respectively.