In order to elucidate community structures and dynamic changes of culturable symbiotic fungal colony in roots of Quercus mongolica,the symbiotic fungi in roots of young Q.mongolica at different ages were isolated directly.The isolated fungi were identified based on the morphological characteristics of colony and molecular analysis.The results were as follows:(1)A total of 249 fungal strains were isolated from the roots of young Q.mongolica,18 species belonging to 15 genera,8 families,7 orders,5 classes and 2 phyla were recognized.Among them,two species belonged to Basidiomycetes and 16 species belonged to Ascomycota.Pezicula pruinosa was the species with the highest isolation frequency(81.93％),followed by Dactylonectria torresensis(4.02％),Ilyonectria robusta(2.01％)and Atrocalyx nordicus(2.01％).(2)Significant differences in species and quantities of symbiotic fungi demonstrated in different ages of young Quercus mongolica,with the highest frequency of isolation occurring in the 4-5 years old(44.98％)followed by the triennial(29.32％),biennial(19.68％)and annual(6.02％).To sum up,culturable symbiotic fungi in the roots of young Q.mongolica on Liupan Mountain are highly diverse.Species and quantities of isolates vary at different ages of trees,the diversity increases with the growth of tree,and Pezicula pruinosa is the most dominant culturable symbiotic fungi in roots of young Quercus mongolica.The results provide the reference for further investigating symbiotic fungal resources and exploring the microbial symbiotic mechanism of Q.mongolica in adapting to local environment.

The organic pollution generated during production and processing in the mining area seriously endangers the ecological security of the surrounding environment. In this study, degradation of alpha-nitroso-beta-naphthol (alpha N beta N), a typical organic flotation reagent in mining area, by using steel converter slag (SCS) as a low-cost catalyst was reported for the first time. The results showed that SCS + H2O2 could effectively remove alpha N beta N from water solutions. In the system used in this study, more than 98.8 % of alpha N beta N could be removed within 60 min. Based on the analysis of the experimental results, the synergistic mechanism of radical and non-radical pathways was proposed. The radical pathway mainly consisted of center dot OH radical oxidation, while the non-free radical pathway consisted of O-1(2) and electron transfer. Fe, bridging OH and terminal OH on the surface of SCS were the active sites for H2O2 activation. The removal performance of the system was not affected by common coexisting ions, and showed strong anti-interference ability. After 4 times repeated use, the removal efficiency still reached more than 83 %. HPLC-MS was used to analyze the intermediate products, while the changes in their toxicity effects were analyzed by microcalorimetry for the first time. The results showed that the system could effectively reduce the ecotoxicity of a water solution containing alpha N beta N. This study provides not only a new strategy for treating organic pollution in mining areas, but also a new idea for the green cycle development of industry and mining from the perspective of "treat the wastes with wastes".

The microbiome and metabolic processes occurring in the soil of the moss crust-soil continuum contribute to drive biogeochemical cycles. In this study, soil chemical properties of soil which was attached to bryophyte (BRS) and soil which was dropped from bryophyte (BBS) were analyzed. Differences in microbial species composition, metabolic pathways and related genes of these two different soil types were also analyzed. The results showed that the total organic carbon (TOC), total nitrogen (TN) and ammonium nitrogen (NH4+-N) content of BRS were significantly higher than those of BBS. The dominant phylum in the soil microbiome of the moss crust-soil continuum was Actinobacteria. Genes and metabolic pathways related to the carbon, nitrogen, phosphorus, and sulfur cycle differed between BRS and BBS. The carbon sequestration capacity of BRS was higher than that of BBS. The relative abundance of napA, narH and narI genes involved in denitrification and dissimilatory nitrate reduction in the BRS microbiome was significantly higher than that in the BBS microbiome, while the relative abundance of nasA, NR and nirA genes involved in assimilatory nitrate reduction in the BRS soil microbiome was significantly lower than that in the BBS soil microbiome. The relative abundance of glpQ genes encoding glycerophosphodiester phosphodiesterase in the BRS microbiome was significantly higher than that in the BBS microbime, while the relative abundance of pstS, pstA, pstC, pstB genes responsible for phosphate-specific transport systems in the BRS microbiome was significantly lower than that in the BBS microbiome. The abundance of the assimilatory sulfate-reducing metabolic pathway in the BRS microbiome was significantly higher than that in the BBS microbiome, while the dissimilatory sulfate-reducing metabolic pathway in the BRS microbiome was significantly lower than that in the BBS microbiome. The study found that the microbiome in the soil which was attached to bryophyte plays a more important role in the accumulation of soil nutrients in the Tengger Desert through biodiversity and metabolic activity.

Mining activities will produce a large amount of active tailings accumulation, resulting in heavy metal pollution, which can greatly change the evolutionary direction of surrounding soil microorganisms and affect the biogeochemical cycle process. However, little is known about the effects of heavy metal concentration gradients on microbial communities and the mechanisms of microbial community evolution in active tailings environments. Herein, we collected soil samples around active lead-zinc tailings including uncontaminated and contaminated soils, by 16S rRNA gene sequencing to gain insight into soil microbial community structure and evolutionary direction under copper (Cu) concentration gradient stress. Investigation of tailings and surrounding soil found that the Cu concentration gradient was the main factor responsible for the significant differences in microbial community diversity and composition. Actinobacteria, Proteobacteria, Acidobacteriota dominated the original microbial community and continued changes in the microbial community were observed along the copper concentration gradient, revealing that copper induced the microbial community dominated by Proteobacteria to the Thermoplasma and Methylation bacteria-dominated microbial community evolution. We also found that 10 - 30 mg/Kg Cu can promote the abundance of microbial community but 50 mg/Kg Cu greatly reduces its abundance, which observed across different microbial phyla. Co-occurrence network analysis and functional prediction were performed, and a hypothesis was proposed that the microbial community could resist heavy metal stress by adjusting metabolic strategies. This study deepened the understanding of heavy metals contamination in an active tailings, and the microbial community succession with Cu concentration gradients and provided theoretical guidance for bioremediation of heavy metals pollution from active tailings.

[背景]青海云杉(Picea crassifolia)是中国特有植物,具有极高的生态价值,是西北地区重要的森林更新树种和荒山造林树种,其生长发育及其抗逆性与根系共生真菌多样性密切相关.[目的]从青海云杉根系分离并鉴定定殖的可培养共生真菌,阐明青海云杉根系可培养共生真菌的种类组成,为共生真菌在青海云杉育苗、造林及生态恢复的应用研究提供依据.[方法]采用根段直接分离培养法,对青海云杉根系共生真菌进行分离培养,描述菌落形态特征.结合rDNA ITS序列分析的方法,对分离的真菌进行鉴定.[结果]从青海云杉根系中分离获得65株真菌,隶属1门4纲8目13科16属18种,均属于子囊菌门(Ascomycota);属水平上,以瓶头霉属(Phialocephala)分离频率最高,占分离菌株总数的31％;种水平上,以Phialocephala lagerbergi分离频率最高(22％),Cadophora interclivum、Pleotrichocladium opacum、福廷瓶头霉(Phialocephala fortinii)和Alfoldi sp.次之,分别为18％、17％、9％和9％.从不同发育阶段的青海云杉根系分离得到的共生真菌的种类和数量不同,其中幼树阶段分离频率最高(52％),幼苗阶段次之(28％),成树阶段最低(20％).[结论]宁夏贺兰山青海云杉根系可培养的共生真菌种类丰富,其种类和数量在植株不同发育阶段差异较大.本实验分离的真菌种类均为青海云杉中首次获得.本研究结果是以往相关研究的重要补充,为进一步挖掘青海云杉根系共生真菌资源、探索青海云杉适应本地高寒与干旱逆境的共生微生物组作用机制奠定了基础.

为了研究干旱胁迫下内生真菌对青贮玉米幼苗生长的影响并筛选可以提高青贮玉米幼苗抗旱性的菌株,开展盆栽试验,将分离自西鄂尔多斯荒漠强旱生孑遗植物四合木、沙冬青、绵刺等植物根系的8株内生真菌和1株内生真菌模式种印度梨形孢,以灌根的方式分别接种到青贮玉米幼苗根系,镜检侵染率后,采用PEG6000模拟重度干旱胁迫培养2周,测定青贮玉米幼苗生理生化指标并计算抗旱系数,利用主成分分析法综合评价内生真菌对青贮玉米幼苗抗旱性的影响.结果表明:所有菌株均能侵入青贮玉米根系形成共生,但侵染率存在差异;在未接菌(E-)组的非胁迫和胁迫植株之间,地上部分鲜重、叶相对含水量、叶绿素含量、根体积、根表面积、根鲜重、根干重、根干物质含量、Pro含量、MDA含量、CAT活性、SOD活性、POD活性等13个指标存在显著差异,基于13个生理指标的主成分分析表明,只有Am04、Tm36、Tm02、印度梨形孢等4株内生真菌可提高青贮玉米幼苗抗旱性,并以菌株Am04最优;而Pm53、Tm30、Pm38、Pm06、Pm57等5株内生真菌并未提高青贮玉米幼苗抗旱性;且侵染率和大多数抗旱性生理指标之间无相关性.因此,不同内生真菌对青贮玉米幼苗抗旱性具有不同程度影响,其中菌株Am04较其他菌株更有利于提高青贮玉米幼苗抗旱能力.

Lycium ruthenicum Murr. (L. ruthenicum) is a valuable medicinal source with a high content of anthocyanin. Most of the previous study were focused on the regulation process of anthocyanin biosynthesis in fruit development, the mechanism of anthocyanin accumulation in L. ruthenicum seedlings has rarely been reported. In the present study, anthocyanin accumulation in L. ruthenicum seedlings induced by salt stress was studied, and the expression of LrMYB1 and phytohormone abscisic acid (ABA) played a role in this process. Our results showed that LrMYB1 was stimulated by salt stress, and the expression of LrMYB1 also had a positive correlation with the expression of LrDFR and LrANS, which play key roles in anthocyanin biosynthesis in L. ruthenicum, suggesting that LrMYB1 is a critical regulator in anthocyanin biosynthesis. Compared with the wild-type seedlings, LrMYB1 RNA interference lines accumulated less anthocyanins under salt stress, which confirmed the role of LrMYB1 in anthocyanin biosynthesis in the L. ruthenicum seedlings response to salt stress. Furthermore, ABA content was sharply increased in L. ruthenicum seedlings after 1/2 days of salt stress. Exogenous ABA could also stimulate the expression of LrMYB1 and structural genes in anthocyanin biosynthesis pathway but could not induce more anthocyanin biosynthesis and structural gene upregulation in the LrMYB1 RNA interference lines. These results may imply that ABA could induce anthocyanin biosynthesis under salt stress by upregulating LrMYB1. This study provides valuable insights into the molecular mechanisms of anthocyanin biosynthesis in L. ruthenicum seedlings and extend the understanding of the regulatory mechanism of MYB transcription factor and ABA on anthocyanin accumulation in L. ruthenicum. We provide new details regarding the molecular mechanism by which ABA participate in anthocyanin biosynthesis via modulate the expression of LrMYB1 in Lycium ruthenicum Murr. seedlings response to salt stress.

为筛选降解胆固醇、发酵酸乳、定植胃肠道的乳酸菌优良菌株,通过邻苯二甲醛法测定菌株体外降胆固醇能力,感官评价和质构仪测定降解菌株发酵酸乳能力,菌株在酸溶液、胆盐溶液、人工模拟胃液、人工模拟胰液中存活率考察胃肠道耐受性,筛选获得优良菌株,基于16SrDNA序列鉴定优良菌株.结果表明,250株供试菌株中只有8株胆固醇的降解率在40％以上,其中降解率最高的菌株"青A16"达54.64％,其发酵酸乳的感官评分和大多数质构指标值也最高,在4种体外模拟胃肠道溶液中存活率均达到了 40％以上,分子生物学鉴定为耐久肠球菌.菌株"青A16"可作为开发功能性酸乳候选发酵菌株.

[背景]黑沙蒿是我国北方沙漠地区分布广泛、抗旱性能优良的固沙灌木,对稳定沙漠地区生态系统有至关重要的作用.[目的]内生菌在植物生命过程中扮演着重要角色,认识植物生长发育阶段幼嫩和成熟组织内生菌群的结构变化,对于理解菌群间的相互作用及保护宿主植物抵御生物和非生物胁迫具有积极意义.[方法]以宁夏拉巴湖林场黑沙蒿为研究对象,对其嫩枝和成熟枝木质化相关指标进行测定并对其内生菌群落进行高通量测序分析.[结果]黑沙蒿茎枝不同发育阶段木质素和纤维素差异显著,嫩枝内生细菌、真菌的多样性高于成熟枝,具有更多的OTU;成熟枝则通过木质素、纤维素的积累,表现出较高的环境适应能力;随着黑沙蒿茎枝的不断发育,内生真菌群落变化较为明显,优势门出现未识别真菌菌门替代子囊菌门的趋势.[结论]黑沙蒿茎枝不同发育阶段对植物微生物组的组装有深刻的影响,内生细菌和真菌微生物组在植物发育的不同阶段起着不同的生态作用.本研究揭示了黑沙蒿茎枝发育过程中内生细菌、真菌群落结构的差异,为荒漠地区生态恢复提供理论参考.

本实验以来源于自制酸奶、泡菜、酵头等特色发酵食品的49株乳酸菌为候选菌株,分光光度法测定菌株体外降解草酸盐能力和模拟胃肠道耐受性,主成分分析法评价各菌株发酵酸乳特性.结果表明,9株菌草酸盐降解率在70％以上,最高达86.96％;其中,菌株"四川郫县A1"、菌株"鄂温克"、菌株"鲁青6"在pH3.0酸溶液、人工模拟胃液、胆盐溶液、人工模拟肠液存活率均在50％以上;菌株"鲁青6"和菌株"鄂温克"发酵酸乳的感官评价、持水力、酸度、后酸度、破裂力、硬度、胶粘性、内聚力、咀嚼性、弹性等特性均较优;16S rDNA序列分析表明,菌株"鲁青6"为食窦魏斯氏菌,菌株"鄂温克"为副干酪乳杆菌.菌株"鲁青6"和菌株"鄂温克"既能高效降解草酸盐,又能耐受胃肠道环境,同时在酸乳中发酵特性优良,可作为功能酸乳开发候选菌株.

蛋白质在植物细胞内的定位是了解蛋白质功能、 基因调控和蛋白质-蛋白质相互作用的关键.近年来随着各种蛋白质亚细胞定位方法的快速发展和技术的不断提升,蛋白质亚细胞定位实现了高通量、活体动态研究.本文总结了植物蛋白质亚细胞定位的常用技术,以及常用细胞器特异性标记的研究进展,并对此领域研究的发展前景做出了展望.

探究根腐病病原菌侵染对宁夏枸杞根区土壤丛枝菌根真菌(arbuscular mycorrhizal fungi,AMF)群落组成的影响,为后续开展应用AMF防控宁夏枸杞根腐病奠定基础.从宁夏银川、宁夏中宁和甘肃靖远采集宁夏枸杞健康和根腐病发病植株根系和土壤样品,采用湿筛倾析法和AMF定殖染色法探究3个样地根区土壤AMF的孢子组成、密度和根系菌根侵染率以及AMF多样性与土壤理化因子间的相关性.结果显示,宁夏枸杞健康植株受根腐病病原菌入侵后,孢子密度、总侵染率和总球囊霉素含量不发生变化,中宁样地易提取球囊霉素含量显著升高;不同样地宁夏枸杞健康植株和发病植株根区土壤AMF群落组成差异显著(R2=0.875,P=0.001);中宁样地和靖远样地优势属种发生变化,但银川样地不变.根腐病发生改变宁夏枸杞根区土壤AMF群落结构,会引起银川样地AMF的α-多样性升高,但对中宁样地和靖远样地α-多样性无影响;AMF孢子密度、种丰度和总侵染率与土壤理化性质存在相关性,但土壤理化性质不影响AMF物种多样性,影响AMF定殖.

丛枝菌根真菌（arbuscular mycorrhizal fungi,AMF）对植物营养吸收和生态系统功能具有重要作用。宁夏枸杞作为西北地区重要的经济、生态乡土植物,其根系AMF占据独特的生态位而具有特殊的功能。基于扩增子高通量测序技术,揭示不同品种和不同产区宁夏枸杞根系AMF多样性,为宁夏枸杞AMF菌剂开发奠定基础。收集"宁杞7号"、"宁杞9号"、"蒙杞1号"、"蒙杞2号"4个宁夏枸杞品种,宁夏中宁、甘肃靖远、宁夏海原、内蒙古乌拉特4个产区宁夏枸杞主栽品种"宁杞7号"根系和鲜果样品,采用AMF特异性引物进行PCR扩增,然后Illumina Miseq测序,比较分析AMF多样性;同时测定鲜果中多糖、总黄酮、甜菜碱等有效成分含量,相关性分析与有效成分含量有关的AMF。所有样品中共出现3个目3个科3个属49个AMF OTUs,球囊霉属是所有样品的优势属;Glomus.sp.VTX00113是所有样品共有种,也是"宁杞7号"、"蒙杞1号"和"蒙杞2号"品种以及"海原"产区和"甘肃"产区的优势种,但"宁杞9号"优势种为Glomus.sp.VTX00156,"内蒙古"产区和"中宁"产区的优势种分别为未鉴定出的球囊霉菌unclassified O TU32和unclassified O TU39。不同品种之间α-多样性指数有显著差异,"宁杞7号"最高,"蒙杞2号"最低;产区之间α-多样性指数无显著差异。在种水平,Glomus.sp.VTX00113在4个产区中所占比例存在显著性差异（P＜0.001）,但4个品种间无显著性差异种。品种间AMF群落β-多样性无显著差异（P=0.123）,产区间β-多样性差异显著（P=0.001）;果实多糖含量与AMF无相关性,Glomus.sp.VTX00113与甜菜碱含量显著正相关,unclassified O TU14仅在不同品种样品中与甜菜碱含量显著负相关,Glomus.sp.VTX00393仅在不同品种样品中与总黄酮含量显著正相关,Glomus.sp.VTX00247仅在不同产区样品中与总黄酮含量显著正相关。品种影响宁夏枸杞根系AMF群落α-多样性、优势种,但不影响β-多样性,产区影响β-多样性、优势种,不影响α-多样性指数;AMF与枸杞果实甜菜碱、总黄酮含量相关,与多糖含量无相关性。

枸杞徒长枝是枸杞种植过程中的废弃物,但富含与枸杞子类似的营养成分和药用成分,将其开发为青贮饲料可以变废为宝.乳酸菌是青贮的关键菌种,从青贮原料上筛选的乳酸菌具有更好的适应性.采用MRS+CaCO3平板从枸杞枝叶上分离乳酸菌,筛选生长快、产酸能力强的菌株,作为添加菌剂应用于枸杞徒长枝青贮,评价青贮品质及测定有效成分含量,筛选适合青贮宁夏枸杞徒长枝的优良乳酸菌.结果表明:从枸杞枝叶上共分离到15株溶解圈大而明显的乳酸菌,其中GJ2、GJ8、GJ18生长较快、产酸能力较强;以菌株GJ8为添加菌剂青贮枸杞徒长枝,粗蛋白、粗灰分、酸性洗涤纤维、中性洗涤纤维、可溶性碳水化合物、氨态氮、乳酸、干物质等营养成分和枸杞多糖、甜菜碱、黄酮等有效成分的含量及感官评价综合最优;16S rDNA序列分析表明,GJ8菌株为乳酸片球菌.GJ8可作为开发宁夏枸杞徒长枝专用青贮菌剂候选菌株.

土壤是植物定居的场所,也是植物-微生物互作的重要界面。古菌是土壤微生物重要组份,在碳、氮、硫、铁等元素的生物地球化学循环和植物的生长发育、适应生境中发挥重要作用。植物定居对土壤古菌群落的影响研究鲜有开展,孑遗植物在研究植物-微生物-环境互作中具有独特的优势。采用扩增子高通量测序技术,研究以荒漠孑遗植物四合木为建群种或优势种的四合木-红砂-珍珠-针茅群落、四合木-针茅群落和四合木群落等三种荒漠植物群落类型中,四合木根区土壤和光板地土体土壤古菌群落特征,揭示四合木定居对土壤古菌物种数量、多样性、群落组成及功能的影响。结果表明,荒漠孑遗植物四合木定居不仅增加了根区土壤古菌的物种数量,提高了根区土壤古菌群落多样性,而且改变了土壤古菌群落组成,减少了奇古菌门Nitrososphaeraceae科未分类的属氨氧化古菌（unclassified f N itrososphaeraceae）和暂定Nitrososphaera属氨氧化古菌（Candidatus Nitrososphaera）相对丰度,增加了Nitrososphaeraceae科暂定Nitrocosmicus属氨氧化古菌（Candidatus Nitrocosmicus）和广古菌门海洋古菌类群Ⅱ中未分类的属（norank o M arine G roup I I）相对丰度,广古菌门热原体纲未分类的属（unclassified c < sub>Thermoplasmata）相对丰度变化显著。植物群落演替对四合木根区土壤和光板地土体土壤古菌群落均无显著影响。Nitrososphaeraceae科氨氧化古菌是三种不同荒漠植物群落类型中土壤古菌的核心微生物组。四合木定居也显著改变土壤古菌群落的功能,减弱了高丰度功能,增强了低丰度功能,对有氧呼吸、核苷酸合成、氨基酸合成等途径影响显著。荒漠孑遗植物四合木定居改变了土壤古菌群落物种数量、多样性、组成、功能等特征。

Abandoned-growing branches are a waste of Lycium barbarum planting but contain abundant nutrients and medicinal ingredients. Using abandoned-growing branches of L. barbarum as a medicine additive silage is a way to turn waste into treasure. In this paper, molasses, bran, and corn flour were added as silage sugar sources and ‘Ya xin’, ‘Jun an jiao bao’, ‘Yijiayi,’ and ‘Nongfukang’ as commercial silage bacteria. By comparing the sensory evaluation scores, nutrient components, and medicinal components of the different sugar sources and microbial silages, we set out to find silage bacteria and sugar sources suitable for L. barbarum abandoned-growing branches silage. The results showed there were no significant differences in the content of acid detergent fiber, neutral detergent fiber, and ammonia nitrogen in the three kinds of sugar source silage (P > 0.05). The highest content of crude protein (1.18%), crude ash (12.77%), dry matter (30.5%), lactic acid (123.75 μg·g –1), polysaccharide (27.89 mg·g–1), betaine (6.47 mg·g–1), and total flavonoids (1.15 mg·g–1) added to molasses were significantly higher than those of the other two treatments (P < 0.05). There was no difference between the dry matter and ammonia nitrogen content of the four kinds of microbial agents and natural silage ( P > 0.05). However, crude protein (1.96%), acid detergent fiber (75.52%), neutral detergent fiber (73.86%), water-soluble carbohydrate (259.19 mg·g –1), lactic acid (145.82 μg·g–1), and polysaccharide (27.27 mg·g–1) content were the highest in natural silage (P < 0.05). Molasses was deemed to be the best sugar source, and natural silage is the best way of using the abandoned-growing branches of L. barbarum.

为探究宁夏枸杞叶内生细菌群落随生长变化动态及其影响因素,利用高通量测序技术分析宁夏枸杞幼叶、成熟叶和老叶3个典型生长时期叶内生细菌群落,并通过典范对应分析和方差分解分析探究气候因子代表的宿主植物生活环境、叶光合参数代表的宿主器官生理状态、叶内微生物生长可利用营养物质代表的植物体内内生菌生存微环境等三类环境因子对叶内生菌群落动态变化的影响.结果 表明:3个宁夏枸杞叶生长时期内生细菌共28个门、52个纲、118个目、249个科、503个属、738个种、978个OTUs,α多样性及丰富度以幼叶中最多,随着叶片生长而减少,至叶片成熟老化,保持在较低的水平;变形菌门γ-变形菌纲是3个生长时期枸杞叶片中的优势类群,但幼叶内生细菌中优势科属为黄单胞菌科食单胞菌属,成熟叶内生细菌优势科属为假单胞菌科假单胞菌属,老叶内生细菌优势科属为肠杆菌科泛菌属;成熟叶和老叶内生细菌OTU以继承前一个生长时期内生细菌OTU为主;叶内生细菌功能随叶片生长时期改变发生细微变化;不同生长时期影响叶内生细菌群落组成的环境因子不同,以叶内微生物生长可利用营养物质对宁夏枸杞叶内生细菌群落组成影响最大;宁夏枸杞叶内生细菌从各群落特征对不同叶生长时期内外环境变化做出响应,植物体内内生菌生存微环境是影响宁夏枸杞内生菌群落动态变化主要因素.

The combined contamination of nonferrous metal(loid) mining and smelting areas is a global issue, in need of urgent management. To our knowledge, this is the first report of microbial activities by microcalorimetry in specific nonferrous metal(loid) tailings with oligonutrition and high contents of toxic metal(loid)s. Dynamics of bacterial diversity were also characterized. Here we show that tailings had low microbial activities (P-max = 641-331 mu Wg(-1)), which were accelerated by the presence of dipotassium phosphate (P-max = 346-856 mu Wg(-1)), as measured by microcalorimetry. Frequent detection of S- and metal-resistant related genera and differences of Thiobacillus and Acidithiobacillus abundances indicated that the tailings were in an early stage of acidification. It has been further confirmed by the presence of a weak acid environment and secondary sulfur associated minerals, such as Sb2S3, FeAsS, FeS2, and CuFeS2. During the acidification process, phosphate, metal(loid)s, and microbial activity were correlated to the bacterial communities. It is suggested that the bacterial communities have metabolic capacities with a high potential for the use in management processes of multi-contaminated nonferrous metalliferous tailings. (C) 2019 Published by Elsevier Ltd.

Abandoned nonferrous metal(loid) tailings sites are anthropogenic, and represent unique and extreme ecological niches for microbial communities. Tailings contain elevated and toxic content of metal(loid)s that had negative effects on local human health and regional ecosystems. Microbial communities in these typical tailings undergoing natural attenuation are often very poorly examined. The diversity and inferred functions of bacterial communities were examined at seven nonferrous metal(loid) tailings sites in Guangxi (China), which were abandoned between 3 and 31 years ago. The acidity of the tailings sites rose over 31 years of site inactivity. Desulfurivibrio, which were always coupled with sulfur/sulfide oxidation to dissimilate the reduction of nitrate/nitrite, were specific in tailings with 3 years abandonment. However, genus beneficial to plant growth (Rhizobium), and iron/sulfur-oxidizing bacteria and metal(loid)-related genera (Acidiferrobacter and Acidithiobacillus) were specific within tailings abandoned for 23 years or more. The increased abundance of acid-generating iron/sulfur-oxidizing and metal(loid)-related bacteria and specific bacterial communities during the natural attenuation could provide new insights for understanding microbial ecosystem functioning in mine tailings. OTUs related to Sulfuriferula, Bacillus, Sulfurifustis, Gaiella, and Thiobacillus genera were the main contributors differentiating the bacterial communities between the different tailing sites. Multiple correlation analyses between bacterial communities and geochemical parameters indicated that pH, TOC, TN, As, Pb, and Cu were the main drivers influencing the bacterial community structures. PICRUSt functional exploration revealed that the main functions were related to DNA repair and recombination, important functions for bacterial adaptation to cope with the multi-contamination of tailings. Such information provides new insights to guide future metagenomic studies for the identification of key functions beyond metal-transformation/resistance. As well, our results offers novel outlooks for the management of bacterial communities during natural attenuation of multi-contaminated nonferrous metal(loid) tailings sites.

教书育人是教学活动的核心要求,如何充分发挥教学过程中的育人功能,是每一位教育工作者必须面对和思考的问题.科学史作为科学教育的重要资源,将其融入教学过程中,合理再现科学知识产生过程及科学家所做出的贡献,已达到培养科学精神与人文情怀兼备的合格人才.