Plant-associated microbes play a crucial role in host growth, health, and stress resistance. Host plants significantly influence the assembly of their microbial communities. To examine the influence of plant provenance on bacterial composition and plant growth promoting (PGP) properties, we compared readily culturable bacteria isolated from the root interior and rhizosphere of Tripterygium wilfordii Hook f., a woody Chinese medicinal plant, across three provenances grown in different regions. Regardless of the host growing environment, the abundance of endophytic bacterial colonies followed the trend: Fujian provenances > Hunan provenances > Hubei provenances. A total of 227 isolates were classified into 21 genera from the root interior and 40 genera from the rhizosphere, with Pseudomonas and/or Bacillus as the dominant genera. The taxonomic composition varied across plant provenances and host growing environments. Plants from the same provenance but cultivated in different locations exhibited greater similarity in their endophytic bacterial composition. The majority of the assayed strains displayed one or more PGP traits. Local plants harbored a higher proportion of PGP strains than non-local plants. Our findings indicate that plant provenance significantly influences the composition of root-associated culturable bacteria, particularly endophytic communities. Plants in their native environments may recruit PGP bacteria to enhance their fitness.

针对有机磷农药废水的处理,本研究通过对牡蛎壳粉末(Oyster shell photocatalyst,OSP)进行TiO2负载,制备出Zn/TiO2-牡蛎壳光催化剂(Zn/TiO2-OSP).在此基础之上,对光催化材料的形貌结构与光学性能进行表征,并探究其对有机磷农药废水的降解性能.结果表明,所制备的Zn/TiO2-OSP材料检测出TiO2的衍射峰,并在478 cm-1处出现Ti-O的伸缩振动峰,同时EDS中也检测出Ti的信号,证明了 TiO2的成功负载.此外,对于初始浓度10mg·L-1的两种有机磷废水,Zn/TiO2-OSP对敌敌畏的降解效率可达100％,对辛硫磷的降解率达到90.1％;光催化剂降解效果与光照时间、溶液初始浓度及催化剂用量等显著相关,具有较好的光催化活性,且多次回收再利用后仍保持良好的稳定性,降解中间产物对水生环境微生物的毒害效应也较小.另外,两种废水中均未检测出由有机磷降解而生成的磷酸盐,说明Zn/TiO2-OSP在光催化降解有机磷的同时也能吸附水体中的磷酸盐.

A lanthanum-modified magnetic oyster shell (La-Fe-OSP) was prepared by magnetization and lanthanum loading, and then its properties and phosphorus removal capability were studied. The results showed that La-FeOSP was magnetic, and the specific surface area and porosity increased remarkably compared with those before modification. La-Fe-OSP achieved a removal rate greater than 90% for various phosphate solutions (10-100 mg L-1) and could be successfully recycled by applying a magnetic field. The phosphorus adsorption process of La-Fe-OSP could be characterized by a pseudo-second order model and Langmuir model and displayed intraparticle diffusion properties. La-Fe-OSP could maintain the novel adsorption performance within the pH range of 3.0-8.0, and its adsorption capability was negligibly affected by coexisting ions and dissolved organic matter (DOM) in water. Moreover, the maximum phosphorus removal rates of La-Fe-OSP for the overlying water and the pore water were 96.4% and 41%, respectively. In addition, La-Fe-OSP application also slightly changed the order of various phosphorus forms in sediment and promoted the transformation of easily released iron-bound P (Fe-P) to hardly released occluded P (Oc-P). After five successive cycles, La-Fe-OSP still obtained 85.1% phosphate removal efficiency and thus showed excellent application prospects.

为了解雷公藤内生真菌的雷公藤甲素合成能力以及内生真菌间互作对雷公藤甲素合成的影响,本试验从雷公藤中筛选出1株产雷公藤甲素的内生真菌NS-1,鉴定为Fusarium nisikadoi;通过NS-1与其它内生真菌共培养,发现青霉菌属(Penicilliumn)内生真菌NS-8能够显著促进NS-1的雷公藤甲素合成(P<0.05),是对照的1.6倍.以此为基础,通过制备和添加NS-8菌丝体提取物和发酵液诱导子,进一步研究内生真菌NS-8诱导子对NS-1雷公藤甲素合成的影响.结果表明,NS-8发酵液诱导子促进了NS-1的糖消耗速率,提高了NS-1生物量和培养液pH值,明显促进了NS-1胞外雷公藤甲素的积累,最高含量是对照的4.2倍;NS-8菌丝体提取物诱导子对培养液pH值的影响不显著,NS-1糖消耗速率略有下降,对NS-1生长有一定的抑制作用,胞外雷公藤甲素含量低于对照.两种诱导子对NS-1胞内雷公藤甲素合成均未呈现明显的促进作用.因此,NS-8主要通过其代谢产物强化NS-1雷公藤甲素的合成.

为了解烟草内生菌的烟碱降解机制,以一株具有高效烟碱降解功能的内生菌G16为对象,通过降解培养及代谢产物分析,对其烟碱降解特征进行研究.结果表明,该菌株经鉴定为Rhizobium sp.G16,在烟碱培养基中的生长符合Slogistic模型,烟碱对G16菌株的最大生长抑制浓度为4000 mg/L;G16菌株的烟碱降解受到pH、接种量及烟碱浓度的影响,其降解过程可采用一级动力学模型进行描述;对G16菌株降解烟碱的中间代谢产物进行分析,发现主要为尼古丁提林、3-(3,4-dihydro-2H-pyrrol-5-yl)pyridine、脱甲基尼古丁、2,3-联吡啶、可铁宁等物质.

[目的]雷公藤甲素是雷公藤主要药用活性成分之一,具有抗肿瘤、免疫抑制和抗炎等多种作用.应用植物细胞培养技术生产雷公藤甲素具有重要意义,而诱导子是提高植物细胞培养中次生代谢产物积累的有效途径之一.研究通过探究非生物和生物诱导子对雷公藤悬浮细胞中雷公藤甲素积累的影响,以期提高雷公藤甲素产量,为雷公藤悬浮细胞规模化生产雷公藤甲素等药用活性物质提供基础.[方法]以水杨酸(SA)、LaCl3以及雷公藤内生真菌NS-5、NS-17作为诱导子,研究不同类型及不同浓度诱导子添加对雷公藤悬浮细胞中雷公藤甲素积累及细胞活力、细胞生长、总糖消耗、PAL活性的影响.[结果]SA、LaCl3和内生真菌NS-5、NS-17诱导子均可促进雷公藤悬浮细胞培养物中雷公藤甲素的积累.非生物诱导子的效应大小受其浓度的影响,0.1 mg/L的SA诱导作用最好,可提高细胞活力,促进细胞生长,总糖消耗增加,升高PAL活性,雷公藤甲素产量最高是对照的3.5倍.随着浓度的降低,LaCl3对雷公藤甲素的诱导作用增强,20 mg/L LaCl3诱导下的最高含量是对照的2.0倍,同时20 mg/L LaCl3也提高了PAL活性和总糖消耗,但对细胞活力和细胞生长影响不大.内生真菌诱导子的效应大小即与诱导子种类和添加时间有关.细胞培养第4天添加NS-5、NS-17菌丝体提取物,第8天添加任一内生真菌诱导子均提高了雷公藤甲素的积累,其中NS-5菌丝体提取物的诱导效果相对最强,细胞培养第8天添加时雷公藤甲素产量最高,是对照的2.4倍,但雷公藤甲素的积累与细胞生长及PAL活性无明显的关联.[结论]诱导子的添加能够提高雷公藤悬浮细胞中雷公藤甲素的积累,诱导效应的大小与诱导子种类、添加浓度及添加时间有关.本研究中的0.1 mg/L SA、20 mg/L LaCl3及内生真菌NS-5菌丝体提取物显示了良好的诱导效果,在利用细胞培养技术进行雷公藤甲素生产中具有较好的应用前景.

为了解决烟草上部烟叶中烟碱含量偏高的行业问题以及应对烟碱污染的环境治理,从福建三明烟区的烟草植株中筛选得到1株具有高效降烟碱特性的内生菌Y5,对其生长、降烟碱特性以及代谢途径进行研究.结果表明:该菌株能够以烟碱为唯一碳源、氮源.经菌株形态和16S rDNA序列分析,菌株属于假单胞菌属(Pseudomonas sp.).利用Slogistic模型对菌株生长情况拟合得到菌株Y5的生长延迟期为7.5h,最大比生长速率μmax为0.0396 h-1.烟碱浓度为0.5～2.0g·L-1时菌株生长良好;pH为5.0～8.0时菌株具有较高的降解活性;接种量对菌株最终的降解率无显著影响.该菌株在烟碱浓度为0.5g·L-1的无机盐培养基中,15 h内能够基本完全降解烟碱.菌株Y5降解烟碱的中间产物主要为尼古提林、脱甲基尼古丁、可铁宁、3-丙酰基吡啶和5-pyridin-3-yloxolan-2-one等物质,与已报道的假单胞菌属的吡咯烷途径不同.

为探究内生真菌与内生细菌对雷公藤(Tripterygium wilfordii)的生长和次生代谢产物积累的相互作用,用内生真菌NS33、NS6和内生细菌LG3、LY1单独或跨界联合接种雷公藤,对雷公藤的生长和雷公藤甲素、雷公藤红素合成进行了研究.结果表明,单独或混合培养的菌株具有分泌铁载体、吲哚乙酸(IAA)和溶磷能力,对种子萌发、芽伸长和根系活力有显著促进作用.接种菌株NS33、NS6、NS6-LG3和NS6-LY1均显著促进了雷公藤组培苗的生长.单独或联合接种菌株均能显著提高雷公藤组培苗雷公藤甲素和雷公藤红素的积累,其中NS33-LG3和LG3的作用最显著.菌株NS33与LG3能够协同促进IAA的分泌、小麦幼苗根系活力和雷公藤红素的积累;菌株NS6与LY1协同提高了雷公藤组培苗的高度、质量和雷公藤红素的积累.因此,内生真菌与内生细菌联合接种对雷公藤生长和次生代谢产物积累具有一定的协同效应,显示出实际应用潜力.

A magnet zirconium modified oyster shell powder material was prepared by magnetization and addition of soluble zirconium salt, and then its properties and phosphorus removal capability were studied. The results showed that the modified material was magnetic, and the specific surface area and porosity increased remarkably compared with that before modification. The phosphorus adsorption amount of oyster shell also increased from 4.5 mg·g-1 to 46.5 mg·g-1, and the modified oyster shell can be successfully recycled by applying a magnetic field. The adsorption kinetics study showed that the whole phosphorus adsorption process included two stages of rapid adsorption and equilibrium adsorption. In addition, the modified oyster shell mainly adsorbed the soluble phosphate (SRP) in water. Compared with the interstitial water, the modified oyster shell exhibited a more obvious inhibition effect on the phosphorus release of the overlying water. The modified material might promote the transformation of the easily released iron-bound P (Fe⁃P) to the hard released sequestered P (Oc⁃P), and reduce the concentration of easily released exchanged P ( Ex⁃P) . The above mentioned results indicate that the magnet zirconium-modified oyster shell can be used as an efficient phosphorus removal adsorbent for the eutrophication treatment.

通过热聚合法制备不同比例Cu掺杂g-C3N4复合光催化材料,利用XRD、SEM/EDX、FT-IR、UV-Vis DRS、PL、XPS等技术对复合材料的形貌结构和光学性能进行表征,研究了复合材料对藻细胞的光催化灭活效果.结果表明,Cu掺杂改性可有效促进g-C3N4材料表面光生电子-空穴的分离,增强其对可见光的利用率,进而提升其光催化效率;随着Cu掺杂比例的增大,Cu-C3N4对藻细胞的灭活效果则越好.进一步研究发现,H2O2和·O2-是Cu-C3N4光催化灭藻过程中起主要作用的活性物质,会损伤藻细胞的形态结构、抗氧化酶系统和光合系统,导致藻细胞大量死亡.

以一株耐锌细菌S3为研究对象,对其菌体及其胞外聚合物(EPS)的Zn2+吸附特征进行研究.结果表明,菌株S3属于鞘氨醇杆菌属(Sphingobacterium),其序列与S.caeni相似性达到99％.Zn2+对菌株S3生长的最小抑制浓度为500 mg·L-1左右.S3活性菌体对Zn2+的吸附率明显高于非活性菌体,且活性菌体实现吸附平衡的时间稍长.参与S3菌体Zn2+吸附过程的官能团主要有缔合O-H、N-H和多糖的C-O.菌体EPS对Zn2+的吸附率随时间延长逐渐增大,在80 min达到吸附平衡.S3菌体及EPS对Zn2+的吸附过程均可采用准二级动力学模型进行描述.

为探究内生细菌对宿主植物光合作用的影响机制,以雷公藤(Tripterygiun wilfordii)组培苗为材料,研究了单独和混合接种内生细菌对光合作用参数和叶绿素荧光参数的影响.结果表明,接种菌株LY3+LJ3、LG6+LY3、LJ3+LJ12及LJ3显著提升了净光合速率(Pn)(P<0.05),相比对照分别提高了81.6％、71.4％、67.3％ 和18.4％,而其余接种处理则降低了Pn或无明显影响.接种LG6+LY3的气孔导度(Gs)和蒸腾速率(Tr)显著下降(P<0.05),光系统潜在活性(Fv/F0)则显著上升(P<0.05).接种LJ3+LJ12的情况相反,Gs、胞间CO2浓度(Ci)和Tr显著升高(P<0.05),最大光化学效率(Fv/Fm)、Fv/F0和最大荧光(Fm)则显著下降(P<0.05);接种LY3+LJ3显著升高了Gs和Tr(P<0.05),其余指标无明显变化.与单独接种相比,混合接种LG6+LY3、LJ3+LJ12、LY3+LJ3对宿主光合作用具有协同促进作用.可见,不同的内生菌对光合作用的影响机制不同,LG6+LY3主要通过调节叶绿素荧光改善光合速率,气孔因素的改善是LJ3+LJ12提升光合速率的主要原因.

本研究将雷公藤内生细菌菌株Pseudomonas chlororaphis LG6、Pantoea ananatis LY3、Bacillus cereus group LJ3、Bacillus cereus group LJ12及其组合分别以活菌、灭活菌体粗提物和菌液的形式添加到悬浮细胞培养体系中,通过检测悬浮细胞的重量、细胞活力以及培养液的pH、电导率、可溶性糖和NO3-含量,分析了内生细菌对雷公藤悬浮细胞生长状况的影响.结果显示,内生细菌活菌对悬浮细胞生长的影响较大,菌株LY3、LJ3、LJ12、LY3+LJ12及LG6+LY3+LJ3+LJ12活菌对悬浮细胞的鲜重具有促进作用,菌株LY3和大部分混合菌株的活菌降低了培养液的pH,多数内生菌株活菌提高了培养液的电导率,内生菌株活菌的添加使培养液的可溶性糖含量发生了较大变化,并明显提高了培养液中的NO3-含量.灭活菌体粗提物和菌液的添加对细胞鲜重的增加多表现为抑制作用.

In this study,the adsorption characteristics of two bacteria strains isolated from biofouling layer of MBR and interaction between bacteria and polypropylene (PP) microfiltration membrane were studied by using the thermodynamic method and the interfacial adsorption theory.The results show that the surfaces of A.veronii M4 strain and PP membrane exhibited obviously hydrophobic properties,however,A.caviae N25 had a hydrophilic surface.The motility of A.veronii M4 strain was higher than that of A.caviae N25.In addition,both of the two bacteria and PP membrane surfaces were negatively charged and displayed the typical electron donor characteristics.The Lewis acid-base interactions of both bacterium-membrane systems occupied a dominant position among the various interfacial interaction energy components.According to the XDLVO theory,the total interfacial interaction energy of two systems was negative,which indicates the adsorption potentials of both strains to the PP membrane.Compared with the A.caviae N25-PP membrane system,the A.veronii M4-PP membrane combination had the relative lower (negatively greater) interfacial interaction energy,which suggeste that A.veronii M4 might be favored to the PP membrane.Moreover,the results of the static adsorption results demonstrate that the quantity of A.veronii M4 adsorbed on PP membrane was significantly higher than that of A.caviae N25.The adsorption process of both bacterium-membrane systems could be described by the pseudo-second-order kinetics equation.

In this study,two endophytic fungi,Fusarium oxysporum NS33 and Penicillium steckii NS6,and two endophytic bacteria,Enterobacter cloacae sub sp LG3 and Serratia marcescens LY1,isolated from Tripterygium wilfordii,and their combinations were co-cultured with T.wilfordii cells,respectively.The growth and physiobiochemical properties of T.wilfordii suspension cells were studied in the various co-culture systems.The results showed that in the early stage of co-culture all the single strain promoted the T.wilfordii cell growth and the NS6 strain exhibited the most significant effect,however,during the late period all the endophytic strains and their combinations acted a negative role on the plant cell growth.When T.wilfordii cells were co-cultured with the two endophytic fungi and the strain combinations,the pH values of supernatants increased obviously,but for the T.wilfordii cells and LY1 strain co-culture system,the pH values decreased.In addition,the sugar consumption of supernatants was the highest when T.wilfordii cells were co-cultured with the mixed strains,and the soluble protein content was enhanced as the strains were inoculated singly.The activities of POD,CAT and SOD of T.wilfordii cells were influenced by the endophytes.Compared with the control,the single strain inoculation made T.wilfordii cells exhibited the higher activities of POD and CAT and the lower MDA content.

This study investigated the effects of different explants, culture media and pH on induction of Tripterygium wilfordii callus. And then physiological and biochemical properties and triptolide accumulation in the callus were further analyzed. The results indicated that, to induce T. wilfordii callus, the best explants were tender leaves of tissue culture seedlings, the most suitable medium was MS, and the optimal pH values ranged from 5.8 to 6.1. The activities of SOD and POD both reached the maximum at the middle stage (4th week) and the end (8th week) of the callus growth period, when MDA content and PAL activity showed relatively low values. At the stationary growth phase, SOD and POD had low activities, while MDA content and PAL activity were high. As to triptolide content in the callus of different explants, the root callus and the leaf callus shared similar levels, significantly higher than the stem callus. The callus produced higher triptolide amount at the latter stage ( 6th to 8th week) of the growth period.

以Aeromonas veronii N8菌为对象,对菌体的性质及其吸附Zn2+特征进行研究.结果表明,Aeromonas veronii菌的生长周期在66 h左右,并且Zn2+对该菌的最低抑菌质量浓度为150 mg/L;N8菌体对Zn2+的吸附随时间的增加,吸附率逐渐增大,并且在90 min后达到吸附平衡.菌体的吸附率随菌体质量浓度的增加而变大,并随Zn2+质量浓度的增加而变小.吸附前、后扫描电镜及能谱分析(scanning electron microscope-energy dispersive X-ray,SEM-EDX)的表征结果显示,在菌体的细胞壁表面检测到Zn元素,说明Aeromonas veronii N8菌体对Zn2+具有一定的吸附作用.菌体的Zn2+吸附过程可采用Toth模型进行描述.

以Aeromonas veronii N8为研究对象,对其松散型胞外聚合物（LB-EPS）和紧密型胞外聚合物（TB-EPS）的性质及其吸Zn 2+ 特征进行了研究.结果表明,LB-EPS和TB-EPS具有不同的多糖及蛋白组成比例;与TB-EPS相比,LB-EPS的分子量分布范围较窄,但其平均分子量较大,TBEPS中含有一些LB-EPS不具有的富含芳香族氨基酸的蛋白质,而LB-EPS则含有少量TB-EPS不具有的腐殖酸类物质;1H NMR与XPS分析发现,两种EPS具有相似的结构与元素组成,但各元素在两者中的组成比例并不相同;LB-EPS和TB-EPS具有相似的Zn 2+ 吸附规律,经90 min后二者均能达到吸附平衡,但LB-EPS的吸附率一直大于TB-EPS,二者的吸附率则随着EPS浓度的增加而变大,并随着Zn 2+ 浓度的增加而变小;对比Zn 2+ 吸附前后,两种EPS中属于核酸、多糖与蛋白质在内的一些特征官能团的强度或位置则发生了一定的变化,表明这些特征峰在吸附过程具有不同的功能作用;而LB-EPS和TB-EPS的Zn 2+ 吸附过程则可分别采用Freundlich和Temkin模型进行描述.

In this study,in order to explore Al-tolerant and beneficial biological characteristics of rhizobac-teria from tea plant,three Al-tolerant rhizobacteria,T3,T6 and TJ3 were isolated screened from Camellia sinen-sis rhizospheric soils of tea plant,Camellia sinensis. The plant growth-promoting property and absorption to Al (Ⅲ) of the strains were studied by examining plant growth-promoting substances and conducting plate growth-promoting test and Al(Ⅲ) absorption experiment. The results showed that the three strains had showed good plant growth-promoting activities with ACC deaminase activities ranging from 0.048 to 0.196μM/( mg·min) , the maximum IAA secretion of 14.93 mg/L,and the positive nitrogen-fixation potential.Strains T3 and T6 were proved to have high capability to produce siderophore and phosphate solubilization. Stains T6 and TJ3 signifi-cantly increased the length of wheat radicule and hypocotyle.Stain T6 also facilitated the germination of wheat seeds.Al(Ⅲ) absorption test indicated that strains T6 and TJ3 had larger absorption capacity to Al(Ⅲ) than strain T3.The adsorption of strains T6 and TJ3 to Al(Ⅲ) reached the equilibrium after 60 min or so at pH 5. 0 and 30℃.Based on 16S rDNA molecular identity,strains T3,T6 and TJ3 shared the maximum sequence simi-larity with Burkholderia anthina,Burkholderia cepacia and Pseudomonas fluorescens,respectively. The isolated strains with high plant growth-promoting activities and large Al tolerance and Al absorption show prospect for development in practical application.

The synthetic wastewater was treated by a membrane bioreactor ( MBR ) . The membrane fouling of MBR was increasing with this bioreactor ’ s running and it had been unable to maintain the stability of the membrane flux at the 15th day. 37 dominant strains were isolated from membrane fouling layer,a strain of them was able to produce the acyl-homoserine lactones ( AHLs) . And the AHLs were the signal molecules of quorum sensing (QS) proved by the report bacterium of Chromobacterium violaceum 026. The further testing results of TLC and HPLC-MS/MS indicated the signal molecule produced by the strain N27 was C4-HSL. The N27 isolate was classified into Aeromonas hydrophila based on the phylogenetically identified result of 16S rDNA sequencing.