Relative Abundance Of Proteobacteria Research Articles

Combined Aerobic Fermentation of Maricultural and Agricultural Solid Waste: Physicochemical Property and Bacterial Community Structure

The large-scale production of maricultural solid waste is not used effectively and has a significant impact on the environment. However, there is no report on the utilization of solid waste in mariculture of maricultural and agricultural solid waste. At present, aerobic composting is a simple and feasible means of waste resource utilization, but it also seriously pollutes the environment. This paper studied the change of physical and chemical properties (T1: solid waste + straw, T2: solid waste + cow dung + straw, T3: solid waste + cow dung + straw + 5% biochar, T4: solid waste + chicken dung + cow dung + straw + 5% biochar) and microbial succession in the composting process (T4: solid waste + chicken dung + cow dung + straw + 5% biochar) and the effect of decomposed products on seed growth. The results showed that the mixed compost of various materials had a good regulating effect on the physical and chemical indexes, and the highest temperature could reach 69.4 °C. Biochar could extend the high temperature period by 1–2 days. The germination indexes of seeds treated with T1–T4 were 75%, 80%, 81%, and 94%, respectively. Through the change of the seed germination index, it could be seen that the bacterial community structure changed significantly during composting. The Chao 1 index and Shannon index showed that the bacterial abundance and diversity index increased and then decreased. The analysis of the bacterial community structure showed that Proteobacteria and Acinetobacter were the main bacteria in composting, and the relative abundance of Proteobacteria was 81.9% at the phyla level. Acinetobacter and Pseudoxanthomonas were the main bacteria in the process of composting. Acinetobacter was the dominant bacteria in the heating stage, with an abundance of 67.2%.

Effects of 17β-Estradiol Pollution on Microbial Communities and Methane Emissions in Aerobic Water Bodies.

17β-Estradiol (E2) is a widely present trace pollutant in aquatic environments. However, its impact on microbial communities in aerobic lake waters, which are crucial for methane (CH4) production, remains unclear. This study conducted an E2 contamination experiment by constructing laboratory-simulated aerobic microecosystems. Using 16S rRNA high-throughput sequencing, the effects of E2 on bacterial and archaeal communities were systematically examined. Combined with gas chromatography, the patterns and mechanisms of E2's impact on CH4 emissions in aerobic aquatic systems were uncovered for the first time. Generally, E2 contamination increased the randomness of bacterial and archaeal community assemblies and weakened microbial interactions. Furthermore, changes occurred in the composition and ecological functions of bacterial and archaeal communities under E2 pollution. Specifically, two days after exposure to E2, the relative abundance of Proteobacteria in the low-concentration (L) and high-concentration (H) groups decreased by 6.99% and 4.01%, respectively, compared to the control group (C). Conversely, the relative abundance of Planctomycetota was 1.81% and 1.60% higher in the L and H groups, respectively. E2 contamination led to an increase in the relative abundance of the methanogenesis functional group and a decrease in that of the methanotrophy functional group. These changes led to an increase in CH4 emissions. This study comprehensively investigated the ecotoxicological effects of E2 pollution on microbial communities in aerobic water bodies and filled the knowledge gap regarding aerobic methane production under E2 contamination.

Comparing root-associated microbial communities in Tamarix ramosissima across three Xinjiang basins, China

Analyzing the root-associated microbial communities in desert plants during different seasons may provide a valuable understanding of how desert plants adapt to climate change in harsh environments. Hence, we selected root-associated microbial communities (bacteria and fungi) of Tamarix ramosissima from three regions (Cele, CL; Turpan, TLF; Mosuowan, MSW), focusing on three compartments: root endosphere (RE), rhizosphere soil (RS), and bulk soil (BS). Results indicated that the relative abundance of Actinobacteriota, Proteobacteria, and Ascomycota of root bacteria and fungi taxa was higher the in three compartments (RE, RS, and BS). In the CL region, there was a decline in the relative abundance of Proteobacteria within the RE followed by RS and BS during the autumn. During both summer and autumn, the relative abundance of Ascomycota declined with increasing sampling distance (from the TLF to the MSW to the CL) in the BS. Furthermore, in spring, the bacterial (BS) and fungal (BS) Chao1 and ACE index decreased in TLF compared to the MSW region. However, MSW had a higher bacterial Chao1 and Shannon index of the RE (in summer) and RS (in autumn) than the CL area. Overall, in spring, summer, and autumn, root-associated bacterial and fungal communities across various regions (CL, TLF, and MSW) were more responsive to climate and soil factors than plant nutrients. This research provides compelling theoretical evidence advocating for the restoration of degraded vegetation within arid environments, underscoring the critical significance of judicious plant management practices in these regions.

Intensive Citrus Cultivation Suppresses Soil Phosphorus Cycling Microbial Activity

Soil microbes are key drivers in regulating the phosphorus cycle. Elucidating the microbial mineralization process of soil phosphorus-solubilizing bacteria is of great significance for improving nutrient uptake and yield of crops. This study investigated the mechanism by which citrus cultivation affects the soil microbial acquisition strategy for phosphorus by measuring the abundance of the phoD gene, microbial community diversity and structure, and soil phosphorus fractions in the soils of citrus orchards and adjacent natural forests. The results showed that citrus cultivation could lead to a decrease in soil pH and an accumulation of available phosphorus in the soil, with a content as high as 112 mg·kg-1, which was significantly higher than that of natural forests (3.7 mg·kg-1). Citrus cultivation also affected the soil phosphorus fractions, with citrus soil having higher levels of soluble phosphorus (CaCl2-P), citrate-extractable phosphorus (Citrate-P), and mineral-bound phosphorus (HCl-P). The phosphorus fractions of natural forest soils were significantly lower than those of citrus soils, whereas the phoD gene abundance and alkaline phosphatase activity were significantly higher in natural forest soils than in citrus soils. High-throughput sequencing results showed that the Shannon diversity index of phosphate-solubilizing bacteria in citrus soils was 4.61, which was significantly lower than that of natural forests (5.35). The microbial community structure in natural forests was also different from that of citrus soils. In addition, the microbial community composition of phosphate-solubilizing bacteria in citrus soils was also different from that of natural forests, with the relative abundance of Proteobacteria being lower in natural forest soils than in citrus soils. Therefore, citrus cultivation led to a shift of soil microbial acquisition strategy for phosphorus, with external phosphorus addition being the main strategy in citrus soils, whereas microbial mineralization of organic phosphorus was the main strategy in natural forest soils to meet their growth requirements.

Effect of Polyethylene Microplastics on the Microbial Community of Saline Soils

Mulching to conserve moisture has become an important agronomic practice in saline soil cultivation, and the effects of the dual stress of salinity and microplastics on soil microbes are receiving increasing attention. In order to investigate the effect of polyethylene microplastics on the microbial community of salinized soils, this study investigated the effects of different types (chloride and sulphate) and concentrations (weak, medium, and strong) of polyethylene (PE) microplastics (1% and 4% of the dry weight mass of the soil sample) on the soil microbial community by simulating microplastic contamination in salinized soil environments indoors. The results showed that:PE microplastics reduced the diversity and abundance of microbial communities in salinized soils and were more strongly affected by sulphate saline soil treatments. The relative abundance of each group of bacteria was more strongly changed in the sulphate saline soil treatment than in the chloride saline soil treatment. At the phylum level, the relative abundance of Proteobacteria was positively correlated with the abundance of fugitive PE microplastics, whereas the relative abundances of Bacteroidota, Actinobacteriota, and Acidobacteria were negatively correlated with the abundance of fugitive PE microplastics. At the family level, the relative abundances of Flavobacteriaceae, Alcanivoracaceae, Halomonadaceae, and Sphingomonasceae increased with increasing abundance of PE microplastics. The KEGG metabolic pathway prediction showed that the relative abundance of microbial metabolism and genetic information functions were reduced by the presence of PE microplastics, and the inhibition of metabolic functions was stronger in sulphate saline soils than in chloride saline soils, whereas the inhibition of genetic information functions was weaker than that in chloride saline soils. The secondary metabolic pathways of amino acid metabolism, carbohydrate metabolism, and energy metabolism were inhibited. It was hypothesized that the reduction in metabolic functions may have been caused by the reduced relative abundance of the above-mentioned secondary metabolic pathways. This study may provide a theoretical basis for the study of the effects of microplastics and salinization on the soil environment under the dual pollution conditions.

Characterization of Microplastic Surface Bacterial Community Structure and Prediction of Ecological Risk in Poyang Lake, China

In recent years, the environmental pollution of microplastics in Poyang Lake has received increasing attention. Baisha Lake of Poyang Lake was selected as the study area, and samples of water and sediments of Baisha Lake and the microplastics therein were collected, and the polymer types of microplastics were identified as polyethylene (PE), polyester (PET), polypropylene (PP), and polystyrene (PS) using Fourier infrared spectroscopy. We also analyzed the structural composition of bacterial communities in water, in sediments, and on microplastic surfaces using 16S high-throughput sequencing. The species richness and diversity of bacteria on the microplastic surfaces were lower than those in the surrounding water and sediments. The results of NMDS analysis showed that the bacterial community structures on the microplastic surfaces differed greatly from those in the surrounding sediments and water. The bacterial community composition in water and sediment differed from that on the microplastic surfaces, and the dominant bacterial phyla on the microplastic surfaces were Proteobacteria and Bacteroidota, and their relative abundance on the microplastic surfaces was higher than that in sediment. The relative abundance of Proteobacteria was higher than that in water. The relative abundances of Bacteroidota and Actinobacteriota were significantly lower than that of water. Massilia and Pseudomonas were the dominant genera on the microplastic surfaces, and their relative abundances were significantly higher than those in the surrounding water and sediments. BugBase phenotype prediction revealed that the relative abundance of contains mobile elements, biofilm formation, potential pathogenicity, and stress tolerance phenotypes of microplastic bacterial communities were significantly higher than those of the surrounding water and sediments. The results revealed that microplastics may have contributed to the spread of harmful bacteria, including pathogenic bacteria, and increased the potential pathogenicity of bacterial communities. Additionally, microplastic surface bacterial communities had higher phenotypes of mobile gene element content. Revealing the potential harm of microplastic pollution to wetland ecology at the micro level may provide a scientific reference for maintaining the ecological stability of wetlands.

Effects of luteolin supplementation on growth, histology, antioxidant capacity, non−specific immunity and intestinal microbiota of the red swamp crayfish (Procambarus clarkii)

To investigate the effects of luteolin (LUT) on the growth, antioxidant capacity, non−specific immunity and intestinal microbiota of red swamp crayfish (Procambarus clarkii), 300 individual crayfish (4.17 ± 0.50 g average body weight and 50.19 ± 1.40 mm average body length) were randomly divided into five groups and fed with LUT doses of 0 mg/kg (CG), 50 mg/kg (LG50), 100 mg/kg (LG100), 300 mg/kg (LG300), and 500 mg/kg (LG500) for 8 weeks, respectively. Firstly, the results demonstrated that the survival and growth performance were significantly improved in all LUT added groups compared to the control (CG group), with no significant differences in hepatosomatic index, feed coefficient and muscle components, and the crayfish in LG100 group showed the maximal survival rate (SR) and specific growth rate (SGR) (P < 0.05). Secondly, histological observations displayed that the hepatopancreas and intestine tissues were not impacted in the LUT−supplemented groups, and the length of intestinal folds was significantly increased in LG100 and LG300 groups. Thirdly, LG50, LG100, and LG300 groups produced significantly increased hepatopancreatic antioxidant enzyme activities and hemolymph immune indicators compared with the control. In all experimental groups, malondialdehyde (MDA) contents were significantly reduced, as were aspartate aminotransferase and alanine aminotransferase activities. Lastly, dietary LUT specifically improved the structure and optimized the function of the gut microbiota. Compared to the control, the LG100 group displayed a significant increase in the index of Chao1 and Observed species, an increase in the relative abundance of Proteobacteria and Actinobacteria, a decrease in the ratio of Bacteroidetes to Firmicutes, and an increase in the abundance of Thermomonas, Turicibacter, Bdellovibrio and Enterococcus. PICRUSt analysis demonstrated a significant improvement in the KEGG pathway associated with isoflavone biosynthesis in the LG group. In conclusion, the present study confirms that dietary supplementation with 50−300 mg/kg LUT favors growth, non−specific immunity and antioxidant function in P. clarkii, with optimal additions ranging from 102−165 mg/kg. Furthermore, it optimized gut microbiota function, suggesting that LUT can be used as a potential feed additive for P. clarkii. These findings provide new insights for crayfish’s healthy culture.

Altered microbiome of serum exosomes in patients with acute and chronic cholecystitis.

This study aimed to investigate the differences in the microbiota composition of serum exosomes from patients with acute and chronic cholecystitis. Exosomes were isolated from the serum of cholecystitis patients through centrifugation and identified and characterized using transmission electron microscopy and nano-flow cytometry. Microbiota analysis was performed using 16S rRNA sequencing. Compared to patients with chronic cholecystitis, those with acute cholecystitis exhibited lower richness and diversity. Beta diversity analysis revealed significant differences in the microbiota composition between patients with acute and chronic cholecystitis. The relative abundance of Proteobacteria was significantly higher in exosomes from patients with acute cholecystitis, whereas Actinobacteria, Bacteroidetes, and Firmicutes were significantly more abundant in exosomes from patients with chronic cholecystitis. Furthermore, functional predictions of microbial communities using Tax4Fun analysis revealed significant differences in metabolic pathways such as amino acid metabolism, carbohydrate metabolism, and membrane transport between the two patient groups. This study confirmed the differences in the microbiota composition within serum exosomes of patients with acute and chronic cholecystitis. Serum exosomes could serve as diagnostic indicators for distinguishing acute and chronic cholecystitis.

Effects of bile acids supplementation in feed on digestive capacity, antioxidant capacity, lipid metabolism, and intestinal microorganisms in Yellow River carp (Cyprinus carpio)

This study investigated the effects of adding bile acids (BA) to the feed on several biological aspects of Yellow River carp (Cyprinus carpio). The experimental design covered four groups, namely, CT, BA1, BA2, and BA3, fed diets containing 0 mL/kg, 0.1 mL/kg, 1.0 mL/kg, and 10.0 mL/kg of BA, respectively, and the Yellow River carp with an initial body weight of 46.13±0.74 g were fed for 28 days. The results revealed that BA increased trypsin and lipase activities, positively influencing growth performance. Additionally, it enhanced the activity of intestinal antioxidant-related enzymes and the expression of related genes. Meanwhile, our findings suggested that the addition of BA might restrict hepatic lipid deposition by inhibiting lipogenesis-related genes and stimulating lipolysis-related genes. Furthermore, BA significantly altered the intestinal microorganisms' flora structure, leading to a decrease in the relative abundance of Proteobacteria.

Exploring of gut microbiota features in dyslipidemia and chronic coronary syndrome patients undergoing coronary angiography.

Chronic coronary syndrome (CCS) has a high mortality rate, and dyslipidemia is a major risk factor. Atherosclerosis, a cause of CCS, is influenced by gut microbiota dysbiosis and its metabolites. The objective of this study was to study the diversity and composition of gut microbiota and related clinical parameters among CCS patients undergoing coronary angiography and dyslipidemia patients in comparison to healthy volunteers in Thailand. CCS patients had more risk factors and higher inflammatory markers, high-sensitivity C-reactive protein (hs-CRP) than others. The alpha diversity was lower in dyslipidemia and CCS patients than in the healthy group. A significant difference in the composition of gut microbiota was observed among the three groups. The relative abundance of Proteobacteria, Fusobacteria, Enterobacteriaceae, Prevotella, and Streptococcus was significantly increased while Roseburia, Ruminococcus, and Faecalibacterium were lower in CCS patients. In CCS patients, Lachnospiraceae, Peptostreptococcaceae, and Pediococcus were positively correlated with hs-CRP. In dyslipidemia patients, Megasphaera was strongly positively correlated with triglyceride (TG) level and negatively correlated with high-density lipoprotein cholesterol (HDL-C). The modification of gut microbiota was associated with changes in clinical parameters involved in the development of coronary artery disease (CAD) in CCS patients.

Warming and increased precipitation alter soil carbon cycling in a temperate desert steppe of Inner Mongolia

Abstract Warming and precipitation are key global change factors driving soil carbon (C) dynamics in terrestrial ecosystems. However, the effects of warming and altered precipitation on soil microbial diversity and functional genes involved in soil C cycling remain largely unknown. We investigated the effects of warming and increased precipitation on soil C cycling in a temperate desert steppe of Inner Mongolia using metagenomic sequencing. We found that warming reduced plant richness, Shannon–Wiener and Simpson index. In contrast, increased precipitation significantly influenced Shannon–Wiener and Simpson index. Warming reduced soil microbial species by 5.4% while increased precipitation and warming combined with increased precipitation led to increases in soil microbial species by 23.3% and 2.7%, respectively. The relative abundance of Proteobacteria, which involve C cycling genes, was significantly increased by warming and increased precipitation. Warming significantly reduced the abundance of GAPDH (Calvin cycle) and celF (cellulose degradation) while it enhanced the abundance of glxR (lignin degradation). Increased precipitation significantly enhanced the abundance of pgk (Calvin cycle), coxL (carbon monoxide oxidation), malZ (starch degradation), and mttB (methane production). Moreover, a wide range of correlations among soil properties and C cycling functional genes was detected, suggesting the synergistic and/or antagonistic relationships under scenario of global change. These results may suggest that warming is beneficial to soil C storage while increased precipitation negatively affects soil C sequestration. These findings provide a new perspective for understanding the response of microbial communities to warming and increased precipitation in the temperate desert steppe.

Effects of host identity on the gut microbiota: A comparative study on three microtinae species.

Gut microbiota exert an immense effect on host health and host environmental adaptation. Furthermore, the composition and structure of gut microbiota are determined by the environment and host genetic factors. However, the relative contribution of the environment and host genetic factors toward shaping the structure of gut microbiota has been poorly understood. In this study, we characterized the fecal microbial communities of the closely related voles Neodon fuscus, Lasiopodomys brandtii, and L. mandarinus after caged feeding in the laboratory for 6 months, through high-throughput sequencing and bioinformatics analysis. The results of pairwise comparisons of N. fuscus vs. L. brandtii and L. mandarinus vs. L. brandtii revealed significant differences in bacterial diversity and composition after domestication. While 991 same operational taxonomic units (OTUs) were shared in three voles, there were 362, 291, and 303 species-specific OTUs in N. fuscus, L. brandtii, and L. mandarinus, respectively. The relative abundances of Proteobacteria and Prevotella, which are reported to be enriched in high-altitude populations, were significantly higher in high-altitude N. fuscus than in low-altitude L. brandtii after domestication. Firmicutes, which produce various digestive enzymes for energy metabolism, and Spirochaetes, which can degrade cellulose, were found in higher abundance in subterranean L. mandarinus than thatin L. brandtii which dwells on the earth surface. Our findings showed that some components of gut microbiota still maintained dominance even when different host species are reared under the same environmental conditions, suggesting that these bacteria are substantially influenced by host factors.

Metagenomics reveals the variations in functional metabolism associated with greenhouse gas emissions during legume-vegetable rotation process

Legume-based rotation is commonly recognized for its mitigation efficiency of greenhouse gas (GHG) emissions. However, variations in GHG emission-associated metabolic functions during the legume-vegetable rotation process remain largely uncharacterized. Accordingly, a soybean-radish rotation field experiment was designed to clarify the responses of microbial communities and their GHG emission-associated functional metabolism through metagenomics. The results showed that the contents of soil organic carbon and total phosphorus significantly decreased during the soybean-radish process (P < 0.05), while soil total potassium content and bacterial richness and diversity significantly increased (P < 0.05). Moreover, the predominant bacterial phyla varied, with a decrease in the relative abundance of Proteobacteria and an increase in the relative abundance of Acidobacteria, Gemmatimonadetes, and Chloroflexi. Metagenomics clarified that bacterial carbohydrate metabolism substantially increased during the rotation process, whereas formaldehyde assimilation, methanogenesis, nitrification, and dissimilatory nitrate reduction decreased (P < 0.05). Specifically, the expression of phosphate acetyltransferase (functional methanogenesis gene, pta) and nitrate reductase gamma subunit (functional dissimilatory nitrate reduction gene, narI) was inhibited, indicating of low methane production and nitrogen metabolism. Additionally, the partial least squares path model revealed that the Shannon diversity index was negatively correlated with methane and nitrogen metabolism (P < 0.01), further demonstrating that the response of the soil bacterial microbiome responses are closely linked with GHG-associated metabolism during the soybean-radish rotation process. Collectively, our findings shed light on the responses of soil microbial communities to functional metabolism associated with GHG emissions and provide important insights to mitigate GHG emissions during the rotational cropping of legumes and vegetables.

Artesunate Alleviates Kidney Fibrosis in Type 1 Diabetes with Periodontitis Rats via Promoting Autophagy and Suppression of Inflammation.

To explore the effect of periodontal disease on the progression of diabetic kidney disease (DKD), to observe the effects of artesunate (ART) intervention on periodontal and kidney tissues in type 1 diabetic rats with periodontitis, and to explore the possibility of ART for the treatment of DKD. Rat models of diabetes mellitus, periodontitis, and diabetes mellitus with periodontitis were established through streptozotocin (STZ) intraperitoneal injection, maxillary first molar ligation, and P. gingivalis ligation applied sequentially. Ten weeks after modeling, ART gavage treatment was given for 4 weeks. Immunohistochemistry, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and Western blot were used to investigate the inflammatory factors, fibrogenisis, autophagy-related factors, and proteins in periodontal and kidney tissues, and 16S rDNA sequencing was used to detect the changes in dental plaque fluid and kidney tissue flora. Compared to the control group, the protein expression levels of transforming growth factor β1 (TGF-β1) and COL-IV in the periodontal disease (PD) group were increased. The protein expression of TGF-β1, Smad3, and COL-IV increased in the DM group and the DM + PD group, and the expression of TGF-β1, Smad3, and COL-IV was upregulated in the DM + PD group. These results suggest that periodontal disease enhances renal fibrosis and that this process is related to the TGF-β1/Smad/COL-IV signaling pathway. Among the top five dominant bacteria in the kidney of the DM + PD group, the abundance of Proteobacteria increased most significantly, followed by Actinobacteria and Firmicutes with mild increases. The relative abundance of Proteobacteria, Actinobacteria, and Firmicutes in the kidney tissues of DM and PD groups also showed an increasing trend compared with the CON group. Proteobacteria and Firmicutes in the kidney of the PD group and DM + PD group showed an increasing trend, which may mediate the increase of oxidative stress in the kidney and promote the occurrence and development of DN. Periodontal disease may lead to an imbalance of renal flora, aggravate renal damage in T1DM, cause glomerular inflammation and renal tubulointerstitial fibrosis, and reduce the level of autophagy. ART delays the process of renal fibrosis by inhibiting the TGF-β-Smad signaling pathway.

Antibiotic alters host's gut microbiota, fertility, and antimicrobial peptide gene expression vis-à-vis ampicillin treatment on model organism Drosophila melanogaster.

Antibiotics are commonly used to treat infectious diseases; however, persistence is often expressed by the pathogenic bacteria and their long-term relative effect on the host have been neglected. The present study investigated the impact of antibiotics in gut microbiota (GM) and metabolism of host. The effect of ampicillin antibiotics on GM of Drosophila melanogaster was analyzed through deep sequencing of 16S rRNA amplicon gene. The dominant phyla consisted of Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria, Planctomycetes, Chloroflexi, Euryarchaeota, Acedobacteria, Verrucomicrobia, and Cyanobacteria. It was found that the composition of GM was significantly altered on administration of antibiotics. On antibiotic treatments, there were decline in relative abundance of Proteobacteria and Firmicutes, while there were increase in relative abundance of Chlorophyta and Bacteroidota. High abundance of 14 genera, viz., Wolbachia, Lactobacillus, Bacillus, Pseudomonas, Thiolamprovum, Pseudoalteromonas, Vibrio, Romboutsia, Staphylococcus, Alteromonas, Clostridium, Lysinibacillus, Litoricola, and Cellulophaga were significant (p ≤ 0.05) upon antibiotic treatment. Particularly, the abundance of Acetobacter was significantly (p ≤ 0.05) declined but increased for Wolbachia. Further, a significant (p ≤ 0.05) increase in Wolbachia endosymbiont of D. melanogaster, Wolbachia endosymbiont of Curculio okumai, and Wolbachia pipientis and a decrease in the Acinetobacter sp. were observed. We observed an increase in functional capacity for biosynthesis of certain nucleotides and the enzyme activities. Further, the decrease in antimicrobial peptide production in the treated group and potential effects on the host's defense mechanisms were observed. This study helps shed light on an often-overlooked dimension, namely the persistence of antibiotics' effects on the host.

Relationship between gut microbiome and neurodevelopment in early life

To compare the differences in gut microbiome composition between children with good neurodevelopment and those with delayed neurodevelopment, and to analyze the relationship between gut microbiome and the neurodevelopment status of infants in early life. The mothers were included at the Second West China Hospital from November 2020 to April 2021. Their infant stools were collected on day 0 and day 90 after birth, and the follow-up questionnaires at the corresponding time points were completed. Additionally, the Ages and Stages Questionnaires-Third Edition(ASQ-3) were completed by mothers at 12 months of age. The structure and diversity of gut microbiota were examined by 16S rRNA sequencing, and the relationship between gut microbiome and ASQ-3 questionnaire scores in early life was analyzed. According to the ASQ-3 scores, mothers and infants into neurodevelopment good group(G group, n=18) and neurodevelopmental delay group(D group, n=10). Compared with the D group, the relative abundance of the Firmicutes was significantly higher in the G group at day 0(P&lt;0.05), while the level of the Proteobacteria was lower(P&lt;0.05). At day 90 after birth, the relative abundance of the Actinobacteria, Bifidobacteriaceae and Enterococcaceae was significantly higher in the G group(P&lt;0.05). In addition, alpha diversity was not statistically different between the two groups. Spearman&apos;s correlation analysis showed that Clostridiaceae of the postnatal day 0 infants was positively correlated with the communication domain score, but negatively associated with gross motor domain score in children at 12 months of age, whereas the relative abundance of Proteobacteria and Enterobacteriaceae of children at postnatal day 90 was negatively associated with communication development, while the relative abundance of Erysipelatoclostridiaceae showed a negative correlation with gross motor domain scores. The structure of the gut microbiome in early life between neurodevelopment good and delayed infants, and were associated with the development of communication and gross motor domain in infants at 12 months of age, suggesting that gut microbiome in early life may be related to the level of neurodevelopment in infants.

Bioaccessibility of lead and cadmium in soils around typical lead-acid power plants and their effect on gut microorganisms.

Potentially toxic elements (Pb and Cd) contamination of soil can adversely affect human health. Moreover, these metal ions interact with the gut microbiota after entering the human digestive system. Based on the physiologically based extraction test and the simulator of human intestinal microbial ecosystem, the bioaccessibility of Pb and Cd in soils contaminated with lead-acid power plants was assessed. The gastric stage exhibited the greatest average bioaccessibility of lead and cadmium (63.39% and 57.22%), followed by the small intestinal stage (6.86% and 36.29%); due to gut microorganisms, the bioaccessibility of lead and cadmium was further reduced in the colon stage (1.86% and 4.22%). Furthermore, to investigate soil contamination's effects on gut microbes, 16S rRNA high-throughput sequencing was used to identify the gut microbial species after the colon period. Due to Pb and Cd exposure, the relative abundance of Firmicutes and unidentified_Bacteria decreased, while the relative abundance of Proteobacteria, Synergistota, and Bacteroidota increased. The relationship between environmental factors and the number of microbial species in the gut was also examined using Spearman correlation analysis. Pb and Cd exposure has been found to affect the composition and structure of the gut microbiota.

Nitrogen starvation modulates the sensitivity of rhizobacterial community to drought stress in Stevia rebaudiana

Alterations in water regimes or nitrogen (N) availability lead to shifts in the assemblage of rhizosphere microbial community; however, how the rhizosphere microbiome response to concurrent changes in water and N availability remains largely unclear. Herein, we investigated the taxonomic and functional characteristics of rhizobacteria associated with stevia (Stevia rebaudiana Bertoni) under varying combinations of water and N levels. Community diversity and predicted functions of rhizobacteria were predominantly altered by drought stress, with N-starvation modulating these effects. Moreover, N fertilization simplified the ecological interactions within rhizobacterial communities and heightened the relative role of stochastic processes on community assembly. In terms of rhizobacterial composition, we observed both common and distinctive changes in drought-responsive bacterial taxa under different N conditions. Generally, the relative abundance of Proteobacteria and Bacteroidetes phyla were depleted by drought stress but the Actinobacteria phylum showed increases. The rhizobacterial responses to drought stress were influenced by N availability, where the positive response of δ-proteobacteria and the negative response of α- and γ-proteobacteria, along with Bacteroidetes, were further heightened under N starvation. By contrast, under N fertilization conditions, an amplified negative or positive response to drought were demonstrated in Firmicutes and Actinobacteria phyla, respectively. Further, the drought-responsive rhizobacteria were mostly phylogenetically similar, but this pattern was modulated under N-rich conditions. Overall, our findings indicate an N-dependent specific restructuring of rhizosphere bacteria under drought stress. These changes in the rhizosphere microbiome could contribute to enhancing plant stress tolerance.

Changes in Microbial Composition During the Succession of Biological Soil Crusts in Alpine Hulun Buir Sandy Land, China

Biological soil crusts (biocrusts) are considered “desert ecosystem engineers” because they play a vital role in the restoration and stability maintenance of deserts, including those cold sandy land ecosystems at high latitudes, which are especially understudied. Microorganisms participate in the formation and succession of biocrusts, contributing to soil properties’ improvement and the stability of soil aggregates, and thus vegetation development. Accordingly, understanding the composition and successional characteristics of microorganisms is a prerequisite for analyzing the ecological functions of biocrusts and related applications. Here, the Hulun Buir Sandy Land region in northeastern China—lying at the highest latitude of any sandy land in the country—was selected for study. Through a field investigation and next-generation sequencing (Illumina MiSeq PE300 Platform), our goal was to assess the shifts in diversity and community composition of soil bacteria and fungi across different stages during the succession of biocrusts in this region, and to uncover the main factors involved in shaping their soil microbial community. The results revealed that the nutrient enrichment capacity of biocrusts for available nitrogen, total nitrogen, total phosphorus, total content of water-soluble salt, available potassium, soil organic matter, and available phosphorus was progressively enhanced by the succession of cyanobacterial crusts to lichen crusts and then to moss crusts. In tandem, soil bacterial diversity increased as biocrust succession proceeded but fungal diversity decreased. A total of 32 bacterial phyla and 11 fungal phyla were identified, these also known to occur in other desert ecosystems. Among those taxa, the relative abundance of Proteobacteria and Cyanobacteria significantly increased and decreased, respectively, along the cyanobacterial crust–lichen–moss crust successional gradient. However, for Actinobacteria, Chloroflexi, and Acidobacteria their changed relative abundance was significantly hump-shaped, increasing in the shift from cyanobacterial crust to lichen crust, and then decreasing as lichen crust shifted to moss crust. In this process, the improved soil properties effectively enhanced soil bacterial and fungal community composition. Altogether, these findings broaden our understanding about how soil microbial properties can change during the succession of biocrusts in high-latitude, cold sandy land ecosystems.

Efficient nitrogen removal by multi-stage A/O mud membrane composite process with segmented influent: Performance and microbial community structure

In this paper, a multi-stage A/O mud membrane composite process with segmented influent was constructed for the first time and compared with the traditional activated sludge process and the multi-stage A/O pure membrane process with segmented influent. The nitrogen removal efficiency of the process under different influencing factors was studied. Under the optimum conditions, the highest removal rate of ammonia nitrogen can reach 99%, and the average removal rate of total nitrogen was 80%. The removal rate of COD in effluent reached 93%. The relative abundance of Proteobacteria was the highest in the multi-stage A/O mud membrane composite reactor with segmented influent. The community diversity and richness of activated sludge and biofilm in aerobic pool were the highest. Dechloromonas, Flavobacterium and Rhodobacter were dominant bacteria, and they were aerobic denitrifying bacteria that significantly contributed to the removal rate of ammonia nitrogen.