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.

Effects of reclaimed water irrigation and nitrogen fertilization on the chemical properties and microbial community of soil

The ecological effect of reclaimed water irrigation and fertilizer application on the soil environment is receiving more attention.Soil microbial activity and nitrogen（N）levels are important indicators of the effect of reclaimed water irrigation on environment.This study evaluated soil physicochemical properties and microbial community structure in soils irrigated with reclaimed water and receiving varied amounts of N fertilizer.The results indicated that the reclaimed water irrigation increased soil electrical conductivity（EC）and soil water content（SWC）.The N treatment has highly significant effect on the ACE,Chao,Shannon（H）and Coverage indices.Based on a 16S ribosomal RNA（16S rRNA）sequence analysis,the Proteobacteria,Gemmatimonadetes and Bacteroidetes were more abundant in soil irrigated with reclaimed water than in soil irrigated with clean water.Stronger clustering of microbial communities using either clean or reclaimed water for irrigation indicated that the type of irrigation water may have a greater influence on the structure of soil microbial community than N fertilizer treatment.Based on a canonical correspondence analysis（CCA）between the species of soil microbes and the chemical properties of the soil,which indicated that nitrate N（NO3-–-N）and total phosphorus（TP）had significant impact on abundance of Verrucomicrobia and Gemmatimonadetes,meanwhile the p H and organic matter（OM）had impact on abundance of Firmicutes and Actinobacteria significantly.It was beneficial to the improvement of soil bacterial activity and fertility under 120 mg kg^-1 N with reclaimed water irrigation.

Variations of dominant microbial populations in groundwater in response to the leachate from Laogang Landfill

Temporal changes of dominant microbial populations in groundwater in response to the leachate from Shanghai Laogang Landfill were investigated. Concentrations of dissolved redox relevant species in groundwater suggested that the dominating redox process had changed from denitrification to methane production/sulfate reduction due to landfilling. Dominant microbial populations were determined using restriction fragment length polymorphism(RFLP) analyses of 16S rRNA gene libraries, which were further studied by sequencing and phylogenetic analyses. The results indicated that obvious shifts of dominant microbial populations had occurred in groundwater in response to the pollution of leachate. The closest relatives of some dominant clones are accordant with the dominating redox processes determined by hydrochemical analyses, based on the GenBank's indications on the ability to perform redox reactions.

Dynamics of the Eukaryotic Microbial Community at the Breeding Sites of the Large Yellow Croaker Pseudosciaena crocea in the Southern East China Sea

Clarifying eukaryotic microbial spatial distribution patterns and their determinants is an important idea in ecological research.However,information on the distribution patterns of eukaryotic microbial community structures(EMCSs)within oceans remains unclear.In this study,surface water samples from the southern East China Sea(SECS)were collected to investigate the spatiotemporal variation in EMCSs by using 18S rRNA high-throughput sequencing technology and the impact of this variation on Pseudosciaena crocea during the breeding season.The results indicated that the distribution patterns of the eukaryotic microbial community structure were different among the Sansha Bay,Mindong and Wentai reserves and the offshore East China Sea.In addition,there were notable potential effects of EMCSs on fishery activities.The variation partitioning analysis showed the environmental and spatial factors caused 53.4%of the variation in the EMCSs,indicating that spatially structured environmental factors were the key determinants of the EMCSs spatial heterogeneity in the SECS and may have contributed to the general distribution of P.crocea.In addition,all the environmental factors were the main factors driving the distribution of eukaryotic microbes except for total phosphorus.Furthermore,it was noted some phytoplankton such as Poterioochromonas and Rhizophydium of fungi in Sansha Bay can effectively prevent Cyanobacteria blooms.Chrysophyceae are natural high-quality baits for juvenile fish distributed in Sansha Bay,Mindong and Wentai reserves.This study provides a part of the insight into potential eukaryotic community distributions in large water bodies and how they are affected by environmental factors.

温度对南极衣藻ICE-L(Chlamydomonas sp.ICE-L)谷胱甘肽含量及其相关酶活性的影响

采用分光光度法研究了在不同温度下(包括最适温度、低于或高于最适温度)南极衣藻ICE-L(Chlamydomonassp.ICE-L)谷胱甘肽(GSH)含量、蛋白含量、谷胱甘肽过氧化物酶(GPx)、谷胱甘肽还原酶(GR)和谷胱甘肽硫转移酶(GST)活性,同时分析了已适应高温(16℃)的衣藻重新适应低温(8℃)时这些指标的变化,以期阐明谷胱甘肽系统与南极冰藻低温适应性的关系。结果表明,当温度低于对照组(最适温度8℃)时,蛋白含量降低,而GSH含量、GPx、GST和GR活性上升,已适应高温的衣藻重新适应低温时也出现类似的结果。但当温度高于最适温度时,GSH含量、GST和GPx活性下降,而蛋白含量和GR活力有上升的趋势,GR活力增长幅度比低于最适温度时的变化小。由此可见谷胱甘肽系统在南极衣藻低温适应过程中,GSH、GPx、GR、GST与低温适应呈正相关,同时除GR外其他因子与南极衣藻高温适应呈负相关,GSH及其相关酶在南极冰藻低温适应中具有重要作用。

16SrRNA序列分析法在大气微生物检测中的应用

随着微生物核糖体数据库的日益完善 ,16SrRNA序列分析技术已应用于海洋、湖泊和土壤等环境微生物多样性的分析 ,但尚未见其在大气微生物菌群分析中的应用报道。本研究选择 5株大气中采集分离的菌株 ,通过细菌 16SrRNA通用引物PCR扩增其对应序列 ,直接对PCR产物进行测序 ,分析鉴定其对应细菌的种属 ,并将该结果同细菌表型鉴定、全自动微生物分析仪以及气相色谱分析结果加以比较。结果表明 16SrRNA序列分析获得的鉴定结果与表型分析和气相色谱分析结果较为一致 ,该方法具有快速、准确和不依赖于细菌生长状态等优点 ,说明 16SrRNA序列分析法可以作为大气微生物分析的一个有效技术。

16SrRNA在海洋微生物系统分子分类鉴定及分子检测中的应用

16 S r RNA序列分析作为微生物系统分类的主要依据已得到广泛认同 ,随着微生物核糖体RNA数据库的日臻完善 ,该技术成为细菌分类和鉴定的一个有力工具。本文总结了 16 S r RNA作为海洋微生物系统分子分类鉴定的理论基础和具体方法 ,分析了用 16 S r RNA研究海洋微生物的进化关系 ,并且对 16 S r

热锻炼能提高菜豆细胞可溶性蛋白、SOD、膜ATP酶和质子泵在体外的热稳定性

以菜豆为实验材料，研究了蛋白质分子和生物膜在体外热稳定性的变化和原因。实验结果表明：热锻炼可增加细胞的耐热性，并赋予ＳＯＤ、膜ＡＴＰ酶和生物膜质子泵在体外的热稳定性；通过对可溶性蛋白热变性后的浊度分析和用ＡＮＳ荧光探针探测蛋白质的结构变化，发现蛋白热变性的原因是疏水区的暴露和分子相互团聚，^（３５）Ｓ－Ｍｅｔ标记分析和二维电泳谱揭示，热锻炼诱导合成的热激蛋白具有阻止蛋白质热变性和生物膜热破坏的功能。

微生物铁硫还原耦合水体中As(V)吸附行为研究

采用循环伏安法(CV)、铁的L边和硫的K边X射线近边吸收光谱(XANES)和电感耦合离子光谱发生仪等,研究了碱性厌氧环境中S.oneidensis介导下的铁硫还原过程与水体中As(V)的吸附行为。结果表明,核黄素能够促进S.oneidensis介导的铁硫还原,电子传递过程为乙酸盐→核黄素→底物;S.oneidensis作用24 h后,沉积物中铁硫形态逐渐被还原,Fe(Ⅱ)/Fe(Ⅲ)的比例不断增加,出现硫化矿物特征峰,表明有新的铁的硫化矿物(FeS)生成;FeS对As(V)的吸附量随着时间而增加,6 h后逐渐达到平衡,120 h时吸附量为8.35 mg,吸附效率为89%。微生物铁硫还原生成的Fe S对水体中As(V)有显著的吸附效果,有良好的应用前景。

温度和CO_2驯养对南极鱼P.brachycephalum肝指数(HSI)和Fulton′s K肥满度的影响

研究温度驯养和CO2驯养对南极鱼P.brachycephalum的肝指数(HSI)和Fulton′s K肥满度的影响,结果表明:5℃的高温驯养显著提高P.brachycephalum的肝指数(HSI),1 900μatm CO2驯养没有影响该鱼类的肝指数(HSI),而温度和CO2驯养均没有影响该鱼类的肥满度。说明P.brachycephalum对温度和CO2的变化有较强的适应能力,而5℃的驯养环境有可能更有利于它们的生理状况。

Characterization of Soil Bacterial Diversity in Relation to Irrigation Water: A Case Study in China

Use of wastewater for irrigation has become indispensable worldwide due to accelerating water scarcity, and it also carries a social dimension of poverty reduction in developing countries. However, the impacts of wastewater irrigation on soil properties are still insufficiently understood, especially with regard to change in soil microbial community characteristics. The present study presents an assessment of soil bacterial communities subjecting to different irrigation waters. We conducted soil sampling in farmlands irrigated with wastewater, river water and groundwater respectively in an arid region of China and performed a metagenomic survey of microbial populations using the prokaryotic 16S ribosomal RAN gene. It sheds new light on possible alteration of soil bacterial diversity due to irrigation water. It also reveals that the relative abundance of nitrifying bacteria is greater in soil irrigated with river water than soil irrigated with wastewater. The opposite is true for denitrifying bacteria. The findings serve as a call for further in-depth study to explore the long-term responses of soil microbial communities to irrigation waters for the sake of environmentally sound watershed management.

微生物转化生产S-腺苷甲硫氨酸

S-腺苷甲硫氨酸(S-adenosyl-L-methionine,SAM)是具有广阔市场前景的活性氨基酸,微生物转化法是近年来报道较多的SAM生产方法。综合近年来SAM生产菌株的基因改造和发酵优化方面的进展,从提高SAM合成酶表达和酶活、优化甲醇和甘油的流加方式、改善ATP的生成和L-甲硫氨酸的补料、阻断下游代谢路径等方面,综述了促进SAM合成及其积累的多重策略及机制。最后结合笔者多年研究实践,讨论了微生物转化生产SAM的未来研究方向。

Influence of temperature on glutathione level and glutathione-related enzyme activities of Antarctic ice microalgae Chlamydomonas sp.ICE-L

GSH system plays a role in the control of the redox balance state, anti-oxidation and protecting life from injury of ROS （ reactive oxygen species）. In present paper, the possible GSH system of Chlamydomonas sp. ICE-L has been investigated by evaluating GSH and GSH-related enzymatic responses at different temperatures using spectrophotometer methods. The results showed that the GSH system is correlated positively to low temperature, and other factors but GR are correlated negatively to high temperature. So GSH and GSH-related enzymes play an important role in the adaptation of Antarctic ice microalgae to low temperature.

Consistent Alterations of Human Fecal Microbes After Transplantation into Germ-free Mice

Fecal microbiota transplantation(FMT)of human fecal samples into germ-free(GF)mice is useful for establishing causal relationships between the gut microbiota and human phenotypes.However,due to the intrinsic differences between human and mouse intestines and the different diets of the two organisms,it may not be possible to replicate human phenotypes in mice through FMT;similarly,treatments that are effective in mouse models may not be effective in humans.In this study,we aimed to identify human gut microbes that undergo significant and consistent changes(i.e.,in relative abundances)after transplantation into GF mice in multiple experimental settings.We collected 16S rDNA-seq data from four published studies and analyzed the gut microbiota profiles from 1713 human–mouse pairs.Strikingly,on average,we found that only 47%of the human gut microbes could be re-established in mice at the species level,among which more than 1/3 underwent significant changes(referred to as“variable taxa”).Most of the human gut microbes that underwent significant changes were consistent across multiple human–mouse pairs and experimental settings.Consequently,about 1/3 of human samples changed their enterotypes,i.e.,significant changes in their leading species after FMT.Mice fed with a controlled diet showed a lower enterotype change rate(23.5%)than those fed with a noncontrolled diet(49.0%),suggesting a possible solution for rescue.Most of the variable taxa have been reported to be implicated in human diseases,with some recognized as the causative species.Our results highlight the challenges of using a mouse model to replicate human gut microbiota-associated phenotypes,provide useful information for researchers using mice in gut microbiota studies,and call for additional validations after FMT.An online database named FMT-DB is publicly available at http://fmt2mice.humangut.info/#/.

Study Links U.S.Fish Microbe to New Brain Syndrome

这是一则读后让人大吃一惊的消息。美国东海岸一种名叫Pfiesterispiscicida的有毒微生物杀死了数以百万计的鱼。而且,有人也染上了一种可怕的神经综合症: …some sufferers would set out by car on an errand only to forget where theywere going and what they had planned to do once they got there. 因此,令人垂涎的所谓生猛海鲜也让人避退三舍: …the seafood industry saw sales plunge by more than $40 million as consumerspanicked over a supposed threat to local fisheries. 再看看我们这里的情形,也让人不寒而栗。据报道,我国渤海已成为一个死海,已无多少鱼虾可捕。 更让人难以置信的是,北极圈一带,由于核潜艇常出没,排放的有害物质污染了海面,侵入幼熊体内,造成它们有雄雌两套生殖器。 Pfiesteria piscicida是新词,我们向上海译文出版社词典编辑室询问此词,也得不到相应的汉译。读者中如有解此“密”者,请写信与我们联系。谢谢！

土壤有机质分解的温度敏感性:培养与测定模式

土壤有机质分解的温度敏感性(Q_(10))不仅是生态学和土壤学研究的核心科学问题之一,也是全球变化生态学研究的热点领域。国内外学者对Q_(10)的影响因素或机制开展了大量卓有成效的研究工作,并有不少相关的综述或展望;然而,迄今为止有关培养与测定模式的探讨却非常少。鉴于培养和测定模式对研究结果的重要性,在简要描述Q_(10)定义、基本理论和计算方法的基础上,重点比较了当前Q_(10)研究的不同培养和测定模式及其优缺点。结合最新研究进展,重点介绍了新发展的连续变温培养+连续自动测试模式,并简要阐述了新模式的应用前景。通过探讨,希望能为国内从事Q_(10)研究的学者提供一定的经验与借鉴;同时,希望能引起青年科研人员重视研究方法、技术和仪器的研发,更好更快地推动原创性研究。

不同驯化方式对微生物降解乐果的影响

为了获得有效降解有机磷农药乐果的微生物,采用北京大兴黄村施用过乐果的土壤为菌源,以乐果作为唯一碳源和能源采用一次性大剂量冲击驯化和逐渐加量的驯化方式分离得到7株对乐果有一定降解能力的微生物。微生物降解乐果实验结果显示:不同的驯化方式对微生物的降解能力有明显的影响,大剂量冲击驯化获得的微生物对乐果的降解能力优于逐渐加量驯化获得的微生物。

纤维素分解菌剂对水稻秸秆田间降解效果的研究

在水稻 西瓜轮作模式中研究纤维素分解菌剂对水稻秸秆田间降解效果的影响。结果表明水稻秸秆还田中应用纤维素分解菌剂可以显著降低水稻秸秆的强度 ,增加土壤转化酶、脲酶、多酚氧化酶和纤维素酶的活性。应用纤维素分解菌剂在不同时期可以增加秸秆的降解率 5 .5 %～ 10 .7% ,增加下季作物西瓜产量6 .0 %～ 10 .0 %和糖度 9.1%～ 11.9%。秸秆应用纤维素分解菌剂还田是合理利用秸秆资源 ,用地养地 ,促进农业可持续发展的重要途径 ,是解决秸秆问题的根本出路。

高产絮凝剂复合菌的基因分型及絮凝效果研究

利用从土壤中经分离、纯化得到的絮凝剂产生菌筛选出产高效絮凝剂的复合菌,并借助电子显微技术、随机扩增多态性DNA技术等对其进行了系统鉴别。研究表明:三种菌中有两种是放线菌,一种为酵母菌,它们的生理、生化特性有相似之处。基因分型结果表明,三种菌的DNA存在一定的同源性,但特异性显著。处理污染水体的试验结果表明,该复合菌所产絮凝剂能够很好地絮凝如赖氨酸废水、铬黑T废水、高岭土悬浊液等,与传统絮凝剂相比其絮凝效果更显著。

驯化活性污泥处理高含盐量有机废水的研究

在有菌种存在的好氧系统中,采用驯化活性污泥的方法处理高含盐量有机废水。结果表明,驯化活性污泥可以有效地处理高含盐量有机废水,在Na2SO4含量小于20000mg/L范围内,驯化污泥可以正常降解废水中的有机物,指示剂苯酚的去除率稳定在90%以上,通过驯化可以大大增强微生物抵御盐抑制的能力;在好氧系统中甜菜碱的抗钠毒性作用不明显。