Effects of land-use patterns on soil microbial diversity and composition in the Loess Plateau,China

In the Loess Plateau of China,land-use pattern is a major factor in controlling underlying biological processes.Additionally,the process of land-use pattern was accompanied by abandoned lands,potentially impacting soil microbe.However,limited researches were conducted to study the impacts of land-use patterns on the diversity and community of soil microorganisms in this area.The study aimed to investigate soil microbial community diversity and composition using high-throughput deoxyribonucleic acid(DNA)sequencing under different land-use patterns(apricot tree land,apple tree land,peach tree land,corn land,and abandoned land).The results showed a substantial difference(P<0.050)in bacterial alpha-diversity and beta-diversity between abandoned land and other land-use patterns,with the exception of Shannon index.While fungal beta-diversity was not considerably impacted by land-use patterns,fungal alpha-diversity indices varied significantly.The relative abundance of Actinobacteriota(34.90%),Proteobacteria(20.65%),and Ascomycota(77.42%)varied in soils with different land-use patterns.Soil pH exerted a dominant impact on the soil bacterial communities'composition,whereas soil available phosphorus was the main factor shaping the soil fungal communities'composition.These findings suggest that variations in land-use pattern had resulted in changes to soil properties,subsequently impacting diversity and structure of microbial community in the Loess Plateau.Given the strong interdependence between soil and its microbiota,it is imperative to reclaim abandoned lands to maintain soil fertility and sustain its function,which will have significant ecological service implications,particularly with regards to soil conservation in ecologically vulnerable areas.

Mitigation of N_(2)O emissions in water-saving paddy fields:Evaluating organic fertilizer substitution and microbial mechanisms

Water-saving irrigation strategies can successfully alleviate methane emissions from rice fields,but significantly stimulate nitrous oxide(N_(2)O)emissions because of variations in soil oxygen level and redox potential.However,the relationship linking soil N_(2)O emissions to nitrogen functional genes during various fertilization treatments in water-saving paddy fields has rarely been investigated.Furthermore,the mitigation potential of organic fertilizer substitution on N_(2)O emissions and the microbial mechanism in rice fields must be further elucidated.Our study examined how soil N_(2)O emissions were affected by related functional microorganisms(ammonia-oxidizing archaea(AOA),ammonia-oxidizing bacteria(AOB),nirS,nirK and nosZ)to various fertilization treatments in a rice field in southeast China over two years.In this study,three fertilization regimes were applied to rice cultivation:a no nitrogen(N)(Control),an inorganic N(Ni),and an inorganic N with partial N substitution with organic manure(N_(i)+N_(o)).Over two rice-growing seasons,cumulative N_(2)O emissions averaged 0.47,4.62 and 4.08 kg ha^(−1)for the Control,Ni and N_(i)+N_(o)treatments,respectively.In comparison to the Ni treatment,the N_(i)+N_(o)fertilization regime considerably reduced soil N_(2)O emissions by 11.6%while maintaining rice yield,with a lower N_(2)O emission factor(EF)from fertilizer N of 0.95%.Nitrogen fertilization considerably raised the AOB,nirS,nirK and nosZ gene abundances,in comparison to the Control treatment.Moreover,the substitution of organic manure for inorganic N fertilizer significantly decreased AOB and nirS gene abundances and increased nosZ gene abundance.The AOB responded to N fertilization more sensitively than the AOA.Total N_(2)O emissions significantly correlated positively with AOB and nirS gene abundances while having a negative correlation with nosZ gene abundance and the nosZ/nirS ratio across N-fertilized plots.In summary,we conclude that organic manure substitution for inorganic N fertilizer decreased soil N_(2)O emissions primarily by changing the soil NO_(3)^(−)-N,pH and DOC levels,thus inhibiting the activities of ammonia oxidation in nitrification and nitrite reduction in denitrification,and strengthening N_(2)O reduction in denitrification from water-saving rice paddies.

Visualization Analysis of the Impact of Rubber Agroforestry Ecosystem on Soil Microbial Community

Rubber agroforestry systems positively impact soil microbial communities. This study employed a bibliometric approach to explore the research status, hotspots, and development trends related to these effects. Using CiteSpace software, we visually analyzed research literature from the Web of Science (WOS) core database, spanning 2004 to 2024. The focus was on the impact of rubber agroforestry ecosystems on soil microbial communities. The results indicate significant attention from Chinese researchers, who have published numerous influential papers in this field. Authors Liu Wenjie have contributed the most papers, although no stable core author group exists. The Chinese Academy of Sciences is the leading research institution in terms of publication volume. While there is close collaboration between different institutions and countries, the intensity of researcher cooperation is low. The most cited literature emphasizes soil nutrients and structure in rubber agroforestry, laying a foundation for soil microorganism studies. Most cited journals are from countries like Netherlands and the United Kingdom. Key research areas include the effects of rubber intercropping on soil microbial communities, agroforestry management, and soil health. Research development can be divided into three stages: the initial stage (2010-2015), the development stage (2015-2020), and the mature stage (2020-2024). Current studies show that rubber intercropping and rubber-based agroforestry systems enhance soil microbial communities, positively impacting soil health. This paper provides a theoretical basis for the sustainable development of rubber agroforestry systems and improved management plans. Future research could explore the effects of species composition on soil microbiological characteristics and develop methods for species interactions. An in-depth study of the soil microbial community’s structure and function, and its relationship with rubber trees, is crucial. Developing effective, rationally designed rubber agroforestry systems and underground soil microbiome technology will promote sustainability and improve plantation productivity.

Dietary supplementation of bilberry anthocyanin on growth performance,intestinal mucosal barrier and cecal microbes of chickens challenged with Salmonella Typhimurium

Background Anthocyanins(AC)showed positive effects on improving the intestinal health and alleviating intestinal pathogen infections,therefore,an experiment was conducted to explore the protective effects of supplemented AC on Salmonella-infected chickens.Methods A total of 240 hatchling chickens were randomly allocated to 4 treatments,each with 6 replicates.Birds were fed a basal diet supplemented with 0(CON,and ST),100(ACL)and 400(ACH)mg/kg of AC for d 60,and orally challenged with PBS(CON)or 10^(9) CFU/bird(ST,ACL,ACH)Salmonella Typhimurium at d 14 and 16.Results(1)Compared with birds in ST,AC supplementation increased the body weight(BW)at d 18 and the average daily gain(ADG)from d 1 to 18 of the Salmonella-infected chickens(P<0.05);(2)AC decreased the number of Salmonella cells in the liver and spleen,the contents of NO in plasma and inflammatory cytokines in ileal mucosa of Salmonella-infected chickens(P<0.05);(3)Salmonella infection decreased the ileal villi height,villi height to crypt depth(V/C),and the expression of zonulaoccludins-1(ZO-1),claudin-1,occludin,and mucin 2(MUC2)in ileal mucosa.AC supplementation relieved these adverse effects,and decreased ileal crypt depth(P<0.05);(4)In cecal microbiota of Salmonella-infected chickens,AC increased(P<0.05)the alpha-diversity(Chao1,Pd,Shannon and Sobs indexes)and the relative abundance of Firmicutes,and decreased(P<0.05)the relative abundance of Proteobacteria and Bacteroidota and the enrichment of drug antimicrobial resistance,infectious bacterial disease,and immune disease pathways.Conclusions Dietary AC protected chicken against Salmonella infection via inhibiting the Salmonella colonization in liver and spleen,suppressing secretion of inflammatory cytokines,up-regulating the expression of ileal barrier-related genes,and ameliorating the composition and function of cecal microbes.Under conditions here used,100 mg/kg bilberry anthocyanin was recommended.

Metagenomic analysis reveals hidden links between gut microbes and habitat adaptation among cave and surface dwelling Sinocyclocheilus species

Intestinal microbes are closely related to vital host functions such as digestion and nutrient absorption,which play important roles in enhancing host adaptability.As a natural“laboratory”,caves provide an outstanding model for understanding the significance of gut microbes and feeding habits in the habitat adaptability of hosts.However,research on the relationship between gut microbes,feeding habits,and the adaptability of troglobites remains insufficient.In this study,we compared the characteristics of the intestinal microbes of Sinocyclocheilus cavefish and surface fish and further established the relationship between intestinal and habitat microbes.Furthermore,we conducted environmental DNA(eDNA)(metabarcoding)analysis of environmental samples to clarify the composition of potential food resources in the habitats of the Sinocyclocheilus cavefish and surface fish.Results showed that the structure of the Sinocyclocheilus gut microbes was more related to ecological type(habitat type)than phylogenetic relationships.While horizontal transfer of habitat microbes was a source of gut microbes,hosts also showed strong selection for inherent microbes as dominant microorganisms.Differences in the composition and structure of gut microbes,especially dominant microbes,may enhance the adaptability of the two Sinocyclocheilus fish types from the perspectives of food intake,nutrient utilization,and harmful substance metabolism,suggesting that food resources,predation patterns,intestinal flora,digestive and absorptive capacity,and feeding habits and preferences are linked to habitat adaptability.These results should facilitate our understanding of the significance of fish gut microbes to habitat adaptation and provide a new perspective for studying the adaptive mechanisms of cavefish.

Vaginal microbes confounders and implications on women's health

The vagina has diverse vaginal microbes(Vm).A disturbance in the delicate balance maintained in Vm is linked to women's obstetrical and reproductive tract problems.Vaginal microbes play an essential role in protecting the health of the female reproductive tract by alleviating gynecological infection.However,Vm profiling has many confounders that need to be addressed during sampling,including age,race,pregnancy,medical illness,and smoking.Vm profiling improves reproduction odds,may serve as a marker for genital malignancies and have a therapeutic application in menopausal women and women with cervical cancers.

Overview of microbes in hypertension

High blood pressure(BP),known as hypertension,is a major contributing factor to the development of cardiovascular disease.The development and pathogenesis of hypertension involve a wide array of factors including genetics,environment,hormones,hemodynamics,and inflammation.There is a significantly positive association between higher levels of colonization by Aggregatibacter actinomycetemcomitans,Porphyromonas gingivalis,Tannerella forsythia,and Treponema denticola(etiologic bacterial burden)below the gum line,and the presence of hypertension.The use of antibiotics during pregnancy,which is likely indicative of bacterial infections severe enough to require antibiotic treatment,is associated with a slight increase in average arterial BP.Cytomegalovirus infection is a risk factor for heightened arterial BP and acts as a co-factor in the development of aortic atherosclerosis.The relationship between hypertension and coronavirus disease 2019 involves endothelial dysfunction and dysregulation of the renin-angiotensin system.The effects of gut microbiota on BP,whether beneficial or harmful,are influenced by multiple factors including genetics,epigenetics,lifestyle choices,and antibiotic usage.These variables collectively contribute to overall BP levels and the control of hypertension.Several reports have examined the BP levels of patients infected with the Zika virus.In regions with a high incidence of nasopharyngeal carcinoma,hypertension has been linked to a higher risk of Epstein-Barr virus reactivation.Also,a potential causal link has been found between malaria and elevated BP.Also,the elevated prevalence of hypertension among dengue patients during their initial visit suggests that relying solely on BP measurements to predict severe infection may not be clinically reliable.

Research on the Jilin Oilfield Field Trials of Microbial Enhanced Oil Recovery

This paper describes the experience of Jilin oilfield trials for Microbial Enhanced Oil Recovery (MEOR). A new technique to identify microbes with DNA for MEOR has been established, and useful microbes selected for use in field trials. Behaviors of bacteria activated in the reservoir, oil recovery and water cut, and the viscosity of crude oil produced through huff & puff testing and flooding with molasses-injection tests, have been investigated in situ. CJF-002, which produces biopolysaccharide, is the best among the microbes used for field trials, as it can use molasses as nutrient and produce a small quantity of CO2 and a mass of water-insoluble biopolymer. The metabolic behavior in the reservoir showed that CJF-002 had a good potentiality for MEOR.

The microbial content of unexpired pasteurized milk from selected supermarkets in a developing country

Objective:To determine the presence and levels of microbes in unexpired pasteurized milk from randomly selected supermarkets in Kingston,Jamaica.Methods:The quantitative study used a stratified random sampling technique in the selection of the 20 representative milk samples from six(6) supermarkets.Microbiological tests such as methylene blue reduction,standard plate count(SPC),coliform plate count(CPC),purity plate culture,gram staining and biochemical tests were performed to examine the microbes in purchased unexpired pasteurized milk.Results:One sample(BCr016) had a pH of 4.0.a rancid odour and curdled appearance.It decolourized within one hour during the methylene blue reduction test and was classified as class 4 milk.Seven of the samples were sterile with no microbe growth on the plate count agar and violet red bile salt agar(VRBA).The milk samples that appeared to be safe for consumption were all 10,11,12 and 13 days before expiration.The VRBA sample BCr016,had a colony count of 13 400 CFU/ mL.There was the presence of Escherichia coli in sample LCr021 which had a standard plate count of 1 580 SPC/mL and a coliform count of 500 CFU/mL.Enterobacter sp.was present in colonies from BCr016 and all the other milk samples.Conclusions:Unacceptable levels of Entembacter spp.and Escherichia coli were found in most of the samples.Effective measures to ensure safe milk for human consumption such as the phosphatase test and methylene blue reduction test should be routinely performed on each batch of milk processed by dairy plants.

Relationship between Microbial Activity and the Formation of Polymetallic Concretions in the Central Pacific Ocean

Using the concept of the interactive water rock- microbe system of ocean floor, the microbialmineralization of ocean-floor polymetallic concretions in the central Pacific Ocean has been studied for the firsttime. Through the correlation and study of the microbial activity and formation mechanism of polymetallicconcretions, the microbial and chemical processes for. transforming mineralizing materials and the observationand determination of the concentration of mineralizing material in the system and the variation ofenvironmental parameters, this paper reveals the reaction rate and evolutionary direction of mineralizing com-ponents caused by microbial activity, expounds the microbial mineralization mechanism and formation modelof polymetallic concretions from the angle of microbial geochemical action, and suggests a threefold division ofthe microbial mineralization stages

Research Progress of Soil Microbiology

This paper aims at summarized the research progress of soil microbes,in amount of soil microbes including bacteria,fungi and actinomycetes,soil microbial biomass,including microbial biomass carbon,microbial biomass nitrogen and microbial biomass phosphorus,function of microbial and screening and application of beneficial microorganisms etc.,and future research are discussed combined with our project team for many years of work.

Effects of Urbanization on the Quantity Changes of Microbes in Urban-to-rural Gradient Forest Soil

Three typical rural-suburban-urban artificial wetlands Pinus elliottii forest in Nanchang City were selected as research objects to mensurate the soil nutrient content.And the annual average values and seasonal changes of microbes in forest soil were analyzed.The results showed that soil bulk density,total phosphorus （TP） and pH increased,while soil organic carbon （SOC）,total nitrogen （TN） declined with rural-to-urban gradient.At different eco-boundary,annual average values showed that actinomycetes quantity bacteria quantity fungi quantity.Total microbe number was urban suburb rural areas.The number of bacteria and fungi was urban suburbs rural areas,but the number of actinomycetes was suburb urban rural areas.Eco-boundary,season and microbes actinomycetes and fungi reached an extreme significant level （P 0.001）.Bacteria in soil at different eco-boundary had significant effects,but season had no significant effect on bacteria.Eco-boundary and season had a very significant interaction on actinomycetes and fungi （P 0.001）,but they had no significant interaction on bacteria （P 0.05）.Eco-boundary showed significantly positive correlation with actinomycetes and fungi （P 0.001）,but season had no significant corelation with microbes.In conclusion,urbanization process caused the physical-chemical properties changes of forest soil and affected the amount of soil microbes obviously.

Fecal microbiota transplantation broadening its application beyond intestinal disorders

Intestinal dysbiosis is now known to be a complication in a myriad of diseases.Fecal microbiota transplantation(FMT),as a microbiota-target therapy,is arguably very effective for curing Clostridium difficile infection and has good outcomes in other intestinal diseases.New insights have raised an interest in FMT for the management of extra-intestinal disorders associated with gut microbiota.This review shows that it is an exciting time in the burgeoning science of FMT application in previously unexpected areas,including metabolic diseases,neuropsychiatric disorders,autoimmune diseases,allergic disorders,and tumors.A randomized controlled trial was conducted on FMT in metabolic syndrome by infusing microbiota from lean donors or from self-collected feces,with the resultant findings showing that the lean donor feces group displayed increased insulin sensitivity,along with increased levels of butyrate-producing intestinal microbiota.Case reports of FMT have also shown favorable outcomes in Parkinson's disease,multiple sclerosis,myoclonus dystonia,chronic fatigue syndrome,and idiopathic thrombocytopenic purpura.FMT is a promising approach in the manipulation of the intestinal microbiota and has potential applications in a variety of extra-intestinal conditions associated with intestinal dysbiosis.

Effects of vegetation type on soil microbial community structure and catabolic diversity assessed by polyphasic methods in North China

Soil microbes play a major role in ecological processes and are closely associated with the aboveground plant community. In order to understand the effects of vegetation type on the characteristics of soil microbial communities, the soil microbial communities were assessed by plate counts, phospholipid fatty acid （PLFA） and Biolog microplate techniques in five plant communities, i.e., soybean field （SF）, artificial turf （AT）, artificial shrub （AS）, natural shrub （NS）, and maize field （MF） in Jinan, Shandong Province, North China. The results showed that plant diversity had little discernible effect on microbial biomass but a positive impact on the evenness of utilized substrates in Biolog microplate. Legumes could significantly enhance the number of cultural microorganisms, microbial biomass, and community catabolic diversity. Except for SF dominated by legumes, the biomass of fungi and the catabolic diversity of microbial community were higher in less disturbed soil beneath NS than in frequently disturbed soils beneath the other vegetation types. These results confirmed that high number of plant species, legumes, and natural vegetation types tend to support soil microbial communities with higher function. The present study also found a significant correlation between the number of cultured bacteria and catabolic diversity of the bacterial community. Different research methods led to varied results in this study. The combination of several approaches is recommended for accurately describing the characteristics of microbial communities in many respects.

Microbially induced deposition of barium phosphates and its ingredient,morphology and size under different pH values

A phosphate-mineralization microbe was used to induce barium phosphates precipitation, and the precipitates with different types were obtained under different pH values. The average crystallite size of the barium phosphates was calculated by particle size distribution curves, and the size of the products was 33.40, 29. 37, 24. 13, 47.76 and 96. 53 μm when the pH values of the mixed solution are 7, 8, 9, 10 and 11, respectively. The results of X-ray diffraction （XRD） show that the structures of the particles controlled by the mixed solution are mainly BaaPO4 when pH 〈 10; the barium phosphates are synthesized by biological deposition which is the mixture of BaHPO4 and Ba5 （PO4）3OH when pH = 10; when pH = 11, the barium phosphates are also the mixtures, which are Ba5 （PO4）3OH and BaNaPO4. The above results indicate that the phosphate-mineralization microbe can produce a certain enzyme which constantly hydrolyzes phosphate monoester in the mixed solution, and then PO4^3- ions are obtained.

Isolation,Screening and Identification of High-temperature Cellulolytic Microbes in Pig Manure

[Objective] The research aimed to lay the foundation for high-efficiency biological degradation microbial inoculums. [Method] under the 60℃ temperature the cellulolytic microbes in pig manure were isolated and determined the CMCase and Fpase,then proceeded the 16S rRNA gene analysis. [Result]The results showed that:BC1 and BC3 strains characterized higher carboxymethyl cellulose enzyme activity and higher filter paper activity,but their difference was small,then the 16S rDNA sequence of BC1 and BC3 strains were related to pseudomonas sp. (98% and 99% similarities,respectively).[Conclusion] the experiment laid foundation for high-efficiency biological heating agent.

Exploration of the key microbes and composition stability of microbial consortium GF-20 with efficiently decomposes corn stover at low temperatures

The microbial consortium GF-20(GF-20) can efficiently decompose corn stover at low temperatures. The present study explored the key microbes of GF-20 and evaluated different culture conditions on its composition stability to promote the utilization of corn stover decomposing microbes in low temperature regions. GF-20 was subcultured to the 15 th generation under different temperatures, pHs, carbon, and nitrogen sources. Then, the dynamics of fermenting pH, cellulose enzyme activities, carbohydrate concentration, and oxidation reduction potential were determined to estimate the degradation efficiency of corn stover with GF-20. Furthermore, the structural stability and functional microbes of GF-20 were identified on the basis of PCR-denaturing gradient gel electrophoresis(DGGE) profiling and principal component analysis. The results showed that the offspring of GF-20 subcultured under different temperatures(4–30°C) and pH(6.0–9.0) conditions maintained stable growth, decomposition function, and composition structure. Furthermore, consortia GF-20 had a stable composition structure, which induced GF-20 to secrete cellulose and promote substrate decomposition as corn stover and ammonium were used as sources of carbon and nitrogen, respectively. According to the PCR-DGGE profiles, the key strains of GF-20 were determined to be Bacillus licheniformis, Cellvibrio mixtus subsp. mixtus, Bacillus tequilensis, Clostridium populeti, and Clostridium xylanolyticum.

Microbial population in rotten living body of Salix matsudana

The microbial population in rotten living body of Salix matsudana caused by Trametes suaveolens (L.) was researched. 11 bacteria species (1 species of Bacillus, 2 species of Clostridium and 8 species of non-brood-cell bacteria), 1 species of Actinomyces that belongs to Lavendulac, 8 species of fungi and 6 species of Trichoderma were isolated from rotten trunk. The hyphae of Trametes suaveolens mainly existed between rotten sections and discoioration sections. In over-rotten section and healthy section the fungi (Trametes suaveolens) were not isolated. The microbes that lived in the discoloration section were the most in kinds and number and they were the pioneer microbes of wood rotting. Only after they dwelled in wood and eIiminated its rot-resistance,could wood-rotting fungi invade wood and caused wood-rotting.

The commensal consortium of the gut microbiome is associated with favorable responses to anti-programmed death protein 1 (PD-1) therapy in thoracic neoplasms

Objective:Immune checkpoint inhibitors have revolutionized cancer therapy for multiple types of solid tumors,but as expected,a large percentage of patients do not show durable responses.Biomarkers that can predict clinical responses to immunotherapies at diagnosis are therefore urgently needed.Herein,we determined the associations between baseline gut commensal microbes and the clinical treatment efficiencies of patients with thoracic neoplasms during anti-programmed death protein 1(PD-1)therapy.Methods:Forty-two patients with advanced thoracic carcinoma who received anti-PD-1 treatment were enrolled in the study.Baseline and time-serial stool samples were analyzed using 16S ribosomal RNA gene sequencing.Tumor responses,patient progression-free survival,and overall survival were used to measure clinical outcomes.Results:The diversities of the baseline gut microbiota were similar between responders(n=23)and nonresponders(n=19).The relative abundances of the Akkermansiaceae,Enterococcaceae,Enterobacteriaceae,Carnobacteriaceae and Clostridiales Family XI bacterial families were significantly higher in the responder group.These 5 bacterial families acted as a commensal consortium and better stratified patients according to clinical responses(P=0.014).Patients with a higher abundance of commensal microbes had prolonged PFS(P=0.00016).Using multivariable analysis,the abundance of the commensal consortium was identified as an independent predictor of anti-PD-1 immunotherapy in thoracic neoplasms(hazard ratio:0.17;95%confidence interval:0.05–0.55;P=0.003).Conclusions:Baseline gut microbiota may have a critical impact on anti-PD-1 treatment in thoracic neoplasms.The abundance of gut commensal microbes at diagnosis might be useful for the early prediction of anti-PD-1 immunotherapy responses.

Soil microbial biomass and population in response to seasonal variation and age in Gmelina arborea plantations in south-western Nigeria

We investigated the Effects of plantation development, seasons, and soil depth on soil microbial indices in Gmelina arborea plantations in south-western Nigeria. Soil samples were obtained from the soil depths of 0-15 and 15-30 cm from plantations of six different ages during the rainy season, dry seasons, and their transitions. We used plate count and fumigation-extraction methods to determine microbe population and microbial biomass carbon （MB-C） and nitrogen （MB-N）, respectively. Plantation age did not affect microbial indices, implying a non-significant effect of plantation development on microbial communities. It could also imply that soil microbial indices had already stabilized in the sampled plantations. Seasonal variation and soil depth had significant effects on microbial indices. At 0-15 cm soil depth, mean MB-C increased from 50.74 μg·g^-1 during the peak of the dry season （i.e. March） to 99.58μg·g-1 during the peak of the rainy season （i.e. September）, while it increased from 36.22μg·.g^-1 to 75.31μg·.g^-1 at 15-30 cm soil depth between the same seasonal periods. Bacteria populations and MB-N showed similar increasing trends. Correlations between MB-C, MB-N, microbe populations, and rainfall were positive and linear. Significantly higher microbial activities took place in the plantations during the rainy season, increased with soil wetness, and decreased at greater soil depth.