Effects of planting patterns plastic film mulching on soil temperature,moisture, functional bacteria and yield of winter wheat in the Loess Plateau of China

The yield of winter wheat is hindered by drought and low temperature in the Loess Plateau of China.Two common mulching methods to conserve soil moisture,ridge furrows with plastic film mulching (RP) and flat soil surfaces with plastic film mulching (FP) are helpful for wheat production.Our previous study indicated that FP could improve wheat yield more effectively than RP,but the reason remains unclear.The effect of mulching method on functional bacteria also needs to be further studied.In this study,winter wheat was employed to evaluate the impacts of mulching method on soil temperature,moisture content,microorganisms and grain yield.The results showed that FP had a warming effect when the soil temperature was low and a cooling effect when the temperature was too high.However,the ability to regulate soil temperature in the RP method was unstable and varied with year.The lowest negative accumulated soil temperature was found in the FP treatment,which was 20–89 and 43–99%lower than that of the RP and flat sowing with non-film mulching control (NP) treatments,respectively.Deep soil moisture was better transferred to topsoil for wheat growth in the FP and RP treatments than the NP treatment,which made the topsoil moisture in the two treatments (especially FP) more sufficient than that in the NP treatment during the early growing stage of wheat.However,due to the limited water resources in the study area,there was almost no difference between treatments in topsoil water storage during the later stage.The wheat yield in the FP treatment was significantly higher,by 12–16and 23–56%,respectively,than in the RP and NP treatments.Significant positive correlations were observed among the negative accumulated soil temperature,spike number and wheat yield.The Chao1 and Shannon indices in the RP treatment were 17 and 3.9%higher than those in the NP treatment,respectively.However,according to network relationship analysis,the interspecific relationships of bacteria were weakened in the RP treatment.Phosphorus solubilizing,ammonification and nitrification bacteria were more active in the RP than in the FP treatment,and microbes with nitrate reduction ability and plant pathogens were inhibited in the RP treatment,which improved nutrient availability and habitat for wheat.

Optimization of Fermentation and Product Collection Process of the Functional Bacteria for Bioremediation of Shrimp Culture Environment

In order to implement industrial production of selected functional bacteria for bioremediation of shrimp culture environment, the fermentation conditions of the three functional bacteria, which have high ability in degrading organic pollutants at the bottom of shrimp ponds, were studied. The results showed that the favorable fermentation medium （per L） was 25 g of peptone, 5 g of yeast extract, and 0.2 g of ferric phosphate, and the initial pH value of the medium was 8.0. The optimum fermentation time was 20 h. The optimum stirring way was stirring one hour after one hour. Iso-electric point sedimentation collecting method was the most efficient and economic method to collect the bacteria cells after fermentation, with the optimum sediment pH of 3.67, 4.02, and 3.40 for the strains Lt7222, Gy7018 and Lt7511,respectively. It was also indicated that the survival and reproducing ability of the bacterial cells were not affected by the sedimentation process.

Abundance,Diversity and Functional Potentials of Planktonic Bacteria and Microeukaryotes in the Coral-Reef System of Xisha Islands,China

Corals influence microorganisms within the surrounding seawater,yet the diversities and functions of seawater bacteria and microeukaryotes in coral-reef systems have not been well addressed.We collected 40 seawater samples in outer coral reef flats and semi-closed inner lagoons from the surface,middle and bottom layers in the pristine coral-reef system of Xisha Islands,South China Sea.We detected the abundance,composition and distribution of bacteria and microeukaryotes using flow cytometry,qPCR and high throughput sequencing techniques,and profiled the potential ecological roles based on the information of 16S and 18S rDNA sequencing.In terms of flow cytometry,Prochlorococcus dominated the autotrophs with cell abundance ranging from 5.8×10^(2)to 5.44×10^(3)cells mL−1 seawater.Based on qPCR,the 16S rDNA copies were much higher in coral reef flats than in lagoons(P=0.003).The bacterial communities held significantly lower diversity in bottom waters compared with surface and middle waters(P<0.05),which were dominated by SAR11,Flavobacteriales,and Synechococcus.Alveolata represented most of the microeukaryotic communities with Dinophyceae and Syndiniales well represented in all samples.Neither bacterial nor microeukaryotic community exhibited distinct layer or niche pattern,however,Haptophyta and Picozoa decreased with depth and SAR 86,MAST-3 and Picozoa were enriched in lagoons(P<0.05).To adapt the nutrient-poor and organic matter-rich environment,bacterial nitrogen fixation and assimilatory/dissimilatory nitrate reduction were active in the system,and mixotrophy was the most important trophic strategy among microeukaryotes.The study highlighted the ecological adaptability of seawater microbes to the unique coral-reef environments.

Optimized Composition of Functional Bacteria for Bioremediation of Sediment Environment of Shrimp Culture

After the single-strain abilities of organic-pollutant-degrading bacteria in bioremediation of sediment environment of shrimp culture are determined, the multi- strain degrading effect of the compositions of different strains is measured. The results indicate that the multi-strains groups have higher degrading ability than the single -strain groups. Three-strain groups are better than two-strain groups, and four-strain groups are better than three-strain groups and five-strain groups, the groups composed of strains Lt7222, Lt7511, Fc6308 and Gy7018 has the best degrading effect, the CODMn removal rate is 73.2 % in 66 h, and gets to 82.7 % in 114 h, 30 % higher than that of the best single-strain group; Groups of Lt7222, Lt7511, Lt7451 and Gy7018 are the second, whose CODMn removal rate is 82.1 % in 114 h. It is suggested that multi-species bacteria be used as functional bacteria in bioremediation of mariculture environment.

Preclinical safety,effectiveness evaluation,and screening of functional bacteria for fecal microbiota transplantation based on germ-free animals

Fecal microbiota transplantation(FMT),also known as fecal bacterial therapy,is a treatment option that can quickly reconstruct the normal composition of intestinal microbes,and it has a good therapeutic effect on Clostridium difficile infection,as well as on other microecological disorders.However,the causal mechanism of FMT efficacy remains to be clarified,its safety is a major problem,and the standardization and acceptability of FMT need to be improved.This review summarizes its current research status and potential research areas that need to be strengthened,and proposes to clarify the safety of FMT and the causal relationship between FMT and therapeutic effectiveness based on germ-free animals.Meanwhile,the research system is combined with multiomics technology to screen the effective bacteria in FMT,and develop standard,safe,effective and controllable flora of FMT.

Screening of Starch-degrading Strains in Bagasse and Identification of Strains s2g5-1 and s3g4-8

[Objective]The study aimed to screen the starch-degrading bacterium in bagasse and carry on the identification of strains s2g5-1 and s3g4-8.[Method]By using a variety of selective media,varieties of starch degrading bacterium were isolated from the sugar cane bagasse form different stages of natural fermentation,then,primary screening and secondary screening were performed.[Result] Starch-degrading strains s2g5-1 and s3g4-8 were screened,and they were identified as Bacillus amyloliquefaciens according to their morphological,physiological,biochemical and molecular characteristics.[Conclusion]The research provided theoretical basis for factory application of bagasse.

Combined probiotic bacteria promotes intestinal epithelial barrier function in interleukin-10-gene-deficient mice

AIM: To investigate the protective effects of combinations of probiotic (Bifico) on interleukin (IL)-10-gene-deficient (IL-10 KO) mice and Caco-2 cell monolayers.

The diversity and potential function of endophytic bacteria isolated from Kobreasia capillifolia at alpine grasslands on the Tibetan Plateau, China

A total of 50 endophytic bacterial isolates were obtained from Kobreasia capillifolia at alpine grasslands in the Eastern Qilian Mountains on the Tibetan Plateau in China. Based on the sequencing and phylogenetic analysis of 16 S r DNA genes, all isolates phylogenetically related closely to Bacillus, Acinetobacter, Stenotrophomonas, Brevundimonas, Arthrobacter, Curtobacterium, Paenibacillus, Plantibacter, Promicromonospora, Serratia, and Microbacterium, among which Bacillus was the predominant genus（47.8% of the total number of endophytic isolates）. These isolates possessed different biological functions. In 50 endophytic bacteria, 42 isolates produced indole acetic acid（IAA） on King medium. There were seven isolates showing potency of mineral phosphate solubilization in Pikovaskaia＇s（PKO） liquid medium. Seven isolates exhibited antagonistic effect against Fusarium avenaceum, Colletotrichum coccodes and Phoma foveata. This was the first report on diversity and plant growth promotion of endophytic bacteria from K. capillifolia on alpine grassland in the Eastern Qilian Mountains, Chain. It is essential for revealing the relationship among plant, microorganism, and the special environment because the potential function of endophytic bacteria made a contribution to the interactions of plants and endophytic bacteria.

Tauroursodeoxycholic acid(TUDCA)improves intestinal barrier function associated with TGR5-MLCK pathway and the alteration of serum metabolites and gut bacteria in weaned piglets

Background:Tauroursodeoxycholic acid(TUDCA),a hydrophilic bile acid,is the main medicinal component of bear bile and is commonly used to treat a variety of hepatobiliary diseases.Meanwhile,TUDCA has been shown to modulate the intestinal barrier function and alleviate DSS-induced colitis in mice.However,the effect of TUDCA on the intestinal barrier of weaned piglets remains largely unclear.Methods:The weaned piglets and porcine IPEC-J2 intestinal epithelial cells were used to investigate the effects of TUDCA on intestinal barrier function in weaned piglets and explore the possible underlying mechanisms.In vivo,72 healthy weaned piglets were randomly allocated into 2 groups according to their gender and body weight,and piglets were fed the basal diet with 0(control,CON)and 200 mg/kg TUDCA for 30 d,respectively.Three female and three male piglets reflecting the average bodyweight were slaughtered in each group and samples were collected.In vitro,IPEC-J2 cells were subjected to 100μmol/L TUDCA to explore the possible underlying mechanisms.Results:Our results demonstrated that dietary TUDCA supplementation significantly reduced the diarrhea incidence of weaned piglets,possibly attributing to the TUDCA-enhanced intestinal barrier function and immunity.In addition,TUDCA supplementation altered serum metabolites and the relative abundance of certain gut bacteria,which might contribute to the improved intestinal barrier function.Furthermore,the in-vitro results showed that TUDCA improved the E.coli-induced epithelial barrier impairment of IPEC-J2 cells and increased Takeda G-coupled protein receptor 5(TGR5)protein expression.However,knockdown of TGR5 and inhibition of myosin light chain kinase(MLCK)pathway abolished the TUDCA-improved epithelial barrier impairment in E.coli-treated IPEC-J2 cells,indicating the involvement of TGR5-MLCK in this process.Conclusions:These findings showed that TUDCA improved intestinal barrier function associated with TGR5-MLCK pathway and the alteration of serum metabolites and gut bacteria in weaned piglets,suggesting the potential application of TUDCA in improving gut health in piglet production.

Partial function prediction of sulfate-reducing bacterial community from the rhizospheres of two typical coastal wetland plants in China

Sulfate-reducing bacteria(SRB)are ubiquitous anaerobic microorganisms that play signifi cant roles in the global biogeochemical cycle.Coastal wetlands,one of the major habitats of SRB,exhibit high sulfate-reducing activity and thus play signifi cant roles in organic carbon remineralization,benthic geochemical action,and plant-microbe interactions.Recent studies have provided credible evidence that the functional rather than the taxonomic composition of microbes responds more closely to environmental factors.Therefore,in this study,functional gene prediction based on PacBio single molecular real-time sequencing of 16S rDNA was applied to determine the sulfate-reducing and organic substrate-decomposing activities of SRB in the rhizospheres of two typical coastal wetland plants in North and South China:Zostera japonica and Scirpus mariqueter.To this end,some physicochemical characteristics of the sediments as well as the phylogenetic structure,community composition,diversity,and proportions of several functional genes of the SRB in the two plant rhizospheres were analyzed.The Z.japonic a meadow had a higher dissimilatory sulfate reduction capability than the S.mariqueter-comprising saltmarsh,owing to its larger proportion of SRB in the microbial community,larger proportions of functional genes involved in dissimilatory sulfate reduction,and the stronger ability of the SRB to degrade organic substrates completely.This study confi rmed the feasibility of applying microbial community function prediction in research on the metabolic features of SRB,which will be helpful for gaining new knowledge of the biogeochemical and ecological roles of these bacteria in coastal wetlands.

Geochip-based analysis of microbial functional genes diversity in rutile bio-desilication reactor

Biological desilication process is an effective way to remove silicate from rutile so that high purity rutile could be obtained. However, little is known about the molecular mechanism of this process. In this work, a newly developed rutile bio-desilication reactor was applied to enrich rutile from rough rutile concentrate obtained from Nanzhao rutile mine and a comprehensive high through-put functional gene array(Geo Chip 4.0) was used to analyze the functional gene diversity, structure and metabolic potential of microbial communities in the biological desilication reactor. The results show that TiO2 grade of the rutile concentrate could increase from 78.21% to above 90% and the recovery rate could reach to 96% or more in 8-12 d. The results also show that almost all the key functional genes involved in the geochemical cycling process, totally 4324 and 4983 functional microorganism genes, are detected in the liquid and ore surface, respectively. There are totally 712 and 831 functional genes involved in nitrogen cycling for liquid and ore surface samples, respectively. The relative abundance of functional genes involved in the phosphorus and sulfur cycling is higher in the ore surface than liquid. These results indicate that nitrogen, phosphorus and sulfur cycling are also present in the desiliconization process of rutile. Acetogenesis genes are detected in the liquid and ore surface, which indicates that the desiliconizing process mainly depends on the function of acetic acid and other organic acids. Four silicon transporting genes are also detected in the sample, which proves that the bacteria have the potential to transfer silicon in the molecule level. It is shown that bio-desilication is an effective and environmental-friendly way for enrichment of rough rutile concentrate and presents an overview of functional diversity and structure of desilication microbial communities, which also provides insights into our understanding of metabolic potential in biological desilication reactor ecosystems.

Ability of lactulose breath test results to accurately identify colorectal polyps through the measurement of small intestine bacterial overgrowth

BACKGROUND While colorectal polyps are not cancerous,some types of polyps,known as adenomas,can develop into colorectal cancer over time.Polyps can often be found and removed by colonoscopy;however,this is an invasive and expensive test.Thus,there is a need for new methods of screening patients at high risk of developing polyps.AIM To identify a potential association between colorectal polyps and small intestine bacteria overgrowth(SIBO)or other relevant factors in a patient cohort with lactulose breath test(LBT)results.METHODS A total of 382 patients who had received an LBT were classified into polyp and non-polyp groups that were confirmed by colonoscopy and pathology.SIBO was diagnosed by measuring LBTderived hydrogen(H)and methane(M)levels according to 2017 North American Consensus recommendations.Logistic regression was used to assess the ability of LBT to predict colorectal polyps.Intestinal barrier function damage(IBFD)was determined by blood assays.RESULTS H and M levels revealed that the prevalence of SIBO was significantly higher in the polyp group than in the non-polyp group(41%vs 23%,P<0.01;71%vs 59%,P<0.05,respectively).Within 90 min of lactulose ingestion,the peak H values in the adenomatous and inflammatory/hyperplastic polyp patients were significantly higher than those in the non-polyp group(P<0.01,and P=0.03,respectively).In 227 patients with SIBO defined by combining H and M values,the rate of IBFD determined by blood lipopolysaccharide levels was significantly higher among patients with polyps than those without(15%vs 5%,P<0.05).In regression analysis with age and gender adjustment,colorectal polyps were most accurately predicted with models using M peak values or combined H and M values limited by North American Consensus recommendations for SIBO.These models had a sensitivity of≥0.67,a specificity of≥0.64,and an accuracy of≥0.66.CONCLUSION The current study made key associations among colorectal polyps,SIBO,and IBFD and demonstrated that LBT has moderate potential as an alternative noninvasive screening tool for colorectal polyps.

Magnetotactic Bacteria Algorithm for Function Optimization

Magnetotactic bacteria is a kind of polyphyletic group of prokaryotes with the characteristics of magnetotaxis that make them orient and swim along geomagnetic field lines. A magnetotactic bacteria optimization algorithm(MBOA) inspired by the characteristics of magnetotactic bacteria is researched in the paper. Experiment results show that the MBOA is effective in function optimization problems and has good and competitive performance compared with the other classical optimization algorithms.

生物炭对微塑料污染下普通白菜生长和土壤细菌群落结构的影响

采用盆栽试验,以四季小白菜为试材,研究了施用生物炭对不同微塑料类型(PP、PE、PVC)污染下普通白菜生长、土壤细菌群落结构和丰度的影响,并进行了功能预测分析。结果表明,微塑料污染对普通白菜鲜质量和叶片数有抑制作用,施用生物炭对微塑料污染下的普通白菜鲜质量、株高和根长均有促进作用。微塑料及其与生物炭共存处理显著增加了土壤细菌丰度,其中PER处理土壤细菌丰度最大;PE、PVC及其与生物炭共存处理均显著促进土壤细菌Chao1指数和ACE指数增加。在门水平上,放线菌门、变形菌门、绿弯菌门、厚壁菌门、酸杆菌门为优势类群;微塑料及其生物炭共存处理促进了放线菌门相对丰度的增加,抑制了变形菌门、酸杆菌门相对丰度。土壤p H以及有机碳、铵态氮、硝态氮、速效钾含量是土壤细菌群落结构变化的主要影响因素。PICRUSt分析表明,施用生物炭提高了微塑料污染下土壤新陈代谢、环境信息处理和有机系统等有益细菌代谢通路的相对丰度。综上,施用生物炭对微塑料污染下土壤微生物影响较大,但其影响程度因微塑料类型而异。

玉米种植改变了引黄灌区盐渍化土壤细菌多样性与功能

为了明确植物修复对盐渍化土壤细菌群落结构及多样性的影响,本文对宁夏引黄灌区盐渍化土壤玉米种植地根际和非根际土壤以及荒地土壤细菌多样性、群落结构及功能、细菌群落与环境因子之间的相关关系等进行研究。结果表明:玉米种植能够增加盐渍化土壤细菌物种数(OTU, Operational Taxonomic Unit)和多样性,各土壤细菌总物种数和特有物种数(OTU)从高到低依次为:非根际土壤>根际土壤>荒地土壤;土壤细菌多样性(即ACE指数、Chao1指数、Simpson指数与Shannon指数)由大到小均依次为:根际土壤>非根际土壤>荒地土壤, 3种土壤细菌多样性之间差异不显著。玉米种植改变了盐渍化土壤细菌群落结构和功能多样性,玉米种植显著提高了变形菌门(Proteobacteria)与放线菌门(Actinobacteria)两种优势菌门的相对丰度;丛毛单胞菌属(Comamonadaceae)、丝状菌属(Hyphomircobiales)和根瘤菌属(Rhizobiaceae)为3种土壤组间差异贡献最大的物种;玉米种植增加了盐渍化土壤中细菌参与新陈代谢功能与遗传信息处理功能物种的相对丰度,且有效磷、全磷、速效氮、全盐和pH是影响二级功能相对丰度的重要因子。玉米种植后其根际和非根际土壤细菌群落在生态位上与荒地之间存在明显分异。种植玉米修复盐渍化土壤能够改变土壤细菌群落结构、功能和多样性,对改善盐渍化土壤微环境,促进盐渍化土壤微生物功能发挥和盐渍化土壤种植结构优化具有重要意义。

益生菌基因组学在乳酸菌筛选和功能评价中的应用

乳杆菌和双歧杆菌是益生菌筛选的主要微生物类群,在促进人类、动物甚至植物健康方面都有重要的应用价值,被广泛应用于多种功能性食品、动物饲料和微生物菌肥。然而,这些细菌对宿主健康产生积极影响的分子机制还远未完全了解。另外,传统的益生菌筛选技术主要依靠表型和生理生化特性的测定以及随机对照试验,这些方法不仅耗时、费力,而且数据难以重复。不同研究小组之间数据难以共享,不能实现菌株有益特性的均一性和标准化验证,严重制约了益生菌科学研究的发展和菌株的产业化开发利用。基于新的测序技术和强大的计算机分析方法,被称为益生菌基因组学新学科的出现,允许研究者在短时间内通过筛选大量的生物学和基因组数据,显著提高益生菌筛选的效率和准确性。本文综述了通过基因组数据的分析,帮助人们高效、快速地确定益生菌,开辟益生菌新功能的评价途径。总结益生菌基因组学在阐明益生特性功效评价的分子基础等方面的最新研究成果,以期为扩展研究人员对这些有益微生物生物学的认知,揭示益生菌促进健康特性的分子机制提供新视角。

郑州市景观植物石楠叶际细菌群落结构及反硝化功能

采用16Sr RNA高通量测序技术分析叶际细菌群落多样性与丰富度,使用PICRUSt2软件基于基因测序结果对叶际细菌的氮代谢等功能基因进行预测,并测定叶际细菌的反硝化速率.结果显示,石楠植物叶际细菌以变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、拟杆菌门(Bacteroidetes)为优势菌门,以无色杆菌属(Achromobacter)、伯克霍尔德氏菌属(Burkholderia-Caballeronia-Paraburkholderia)、薄层菌属(Hymenobacter)为优势菌属,且同一地区的不同点位优势菌相同;同时发现石楠叶际细菌中存在无色杆菌属(Achromobacter)、马赛菌属(Massilia)和鞘氨醇单胞菌属(Sphingomonas)等具有反硝化功能的菌属;PICRUSt2功能基因预测叶际细菌6个一级功能层中以代谢功能为主,30个二级功能层中以膜转运功能为主;氮代谢功能基因中反硝化相关基因丰度最高,固氮相关基因丰度最低;测得叶际细菌反硝化速率为(22.2±1.7)~(33.2±4.7)μg/(g·h).

农田土壤中邻苯二甲酸酯降解功能细菌及其应用

本文综述了我国农田土壤PAEs污染特征,重点概述了PAEs降解功能菌株筛选、菌群构建及其应用策略.详细分析了细菌介导的PAEs降解的水解和开环裂解两个途径及参与其中的关键功能基因和酶,讨论了PAEs降解功能细菌在污染土壤中的应用、影响因素及可能存在的问题,并对该技术在消减农田土壤PAEs污染中的应用进行展望,以期为我国PAEs污染农田土壤功能细菌修复及农业生产安全提供理论和技术参考.

光合细菌对活性污泥微生物群落结构及功能的影响

构建光序批式反应器(PSBR)处理模拟生活污水,考察光合细菌投加量、pH值、光照强度和溶解氧(DO)对反应器污染物去除性能影响,通过16S r RNA测序技术揭示光合细菌对活性污泥微生物群落结构、功能和氮代谢通路的影响.结果表明:10%光合细菌投加通过促进微生物种间协调功能使PSBR系统CODCr、NH_(4)^(+)-N和TN去除率提高,pH值、光照强度和DO分别为7、5000lux和3mg/L时,PSBR脱氮性能最好.光合细菌提高了活性污泥微生物多样性和丰富度,Proteobacteria菌门和norank_f__Saprospiraceae菌属相对丰度增多.光合细菌促进部分参与硝化过程和反硝化过程的功能基因(amo、hao和nap)和酶(AMO、HAO和NAP)丰度增加,活性污泥的整体氮代谢潜力得到提升.

微生态制剂对非酒精性脂肪性肝炎患者临床作用的研究

目的 观察微生态制剂辅助治疗非酒精性脂肪性肝炎(NASH)患者的临床效果。方法 将我院2019年1月至2020年1月门诊及住院的诊断为NASH的102例患者纳入研究,随机分为对照组和治疗组。所有患者均通过结构化方案改变生活方式,采用饮食治疗和运动治疗相结合的策略。治疗组患者另外口服微生态制剂(枯草杆菌肠球菌二联活菌胶囊),比较两组患者治疗前后体质量指数、腰围、脂肪肝程度、肝酶、空腹血糖(FPG)、血脂指标、肿瘤坏死因子-α(TNF-α)、内毒素(LPS)水平。结果 治疗后两组患者体质量指数、腰围均明显降低,脂肪肝程度亦有明显好转,但治疗组与对照组无显著差异。空腹血糖、血清肝酶、血脂、TNF-α、LPS水平均低于治疗前,且治疗组与对照组亦有显著差异,差异均有统计学意义(P<0.05)。结论 微生态制剂枯草杆菌肠球菌二联活菌胶囊治疗NASH可显著改善脂肪肝程度及肝功能、血脂指标及降低内毒素、炎症因子等,值得临床推广应用。