农业有机废物与城市生活垃圾堆肥高温期微生物种群结构比较

通过PCR、克隆文库方法分析了农业有机废物和城市垃圾堆肥高温期间细菌和真菌种群的多样性.提取堆肥高温期的DNA,PCR扩增,构建各高温期的16S rDNA和18S rDNA克隆文库,结果表明:农业有机废物和城市生活垃圾16S rDNA克隆文库中分别共有18个、21个OTUs,分别属于细菌域的14个、15个不同属,其18S rDNA克隆文库中分别共有8个、9个OTUs,分别属于细菌域的8个、9个不同属,推断农业有机废物堆体的优势菌为Bacillus megaterium、Rhizobium sp.、Phanerochaete chrysosporium、Penicillium sp.同属或同种的菌株;城市生活垃圾堆体的优势菌为Bacillus megaterium、Azospirillum sp.、Phanerochaete chrysosporium同种或同属的菌株.     

高通量测序技术分析猪粪堆肥过程中微生物群落结构变化

为了解猪粪堆肥过程中微生物群落结构组成及多样性的变化,采集猪粪堆肥过程的三个代表性样品—新鲜猪粪、高温堆肥、腐熟堆肥,利用Illumina Miseq高通量测序技术对16S rRNA V4～V5可变区序列进行测序,分别获得37 009、42 470、36 713条有效序列及328、280、160个操作分类单元(OTU)。Alpha多样性分析表明,在堆肥过程中微生物群落丰富度呈现降低趋势,而多样性呈现先上升后下降趋势。随着堆肥的进行,在门水平上,厚壁菌门、拟杆菌门和软壁菌门相对丰度降低,而变形菌门和放线菌门相对丰度升高;在属水平上,Turicibacter、Terrisporobacter、Parabacteroides、Clostridium sensu stricto、Corynebacterium等来自动物肠道的微生物相对丰度明显下降,Thermopolyspora、Thermomonospora、Thermobifida、Halocella等耐热耐盐微生物成为最主要优势菌。堆肥过程不同菌群优势度的变化是微生物与堆肥中各理化因子相互作用的结果。     

外接堆肥微生物在餐厨废弃物好氧堆肥中的应用

微生物是堆肥过程的主要驱动力,其群落在堆肥过程中不断演替,进而影响好氧发酵进程和堆肥的品质。大量研究表明：接种外源微生物可促进堆肥进程,加快有机物分解和堆肥腐熟,消解抗生素等有害物质等作用。餐厨废弃物油脂、盐、水含量高和易酸化等问题会影响好氧发酵过程中微生物的活动。通过特定样品的富集驯化、选择性培养,并结合先进的分子生物学技术,筛选具有不同降解功能的菌株,并以此为基础构建的微生物菌剂能够一定程度上克服餐厨废弃物用于好氧堆肥的限制性问题。主要阐述了餐厨废弃物好氧发酵过程中微生物菌群的演替规律,构建微生物菌剂的菌种类型及功能和不同菌剂对好氧发酵的作用及潜在影响机制,以期能够为相关微生物强化技术的研发提供一些参考。     

鸡粪堆肥的微生物变化规律研究

目的：研究鸡粪堆肥中细菌、放线菌和真菌数量的变化规律,为有机堆肥提供技术参数。方法：采取稀释倒平板法和涂布法对堆肥样品进行计数。结果：在发酵过程中,菌数量变化在肥料表面上基本是呈先下降后上升最后达到稳定状态。其中细菌在30cm和60cm深处趋于平稳,真菌在30cm和60cm深处先上升再下降再上升,在第12d后有个急速下降的过程。放线菌在30cm和60cm深处数量比较少。而在后熟发酵过程中,3种菌数的变化规律比较平稳。结论：细菌和真菌的生长和繁殖都会抑制放线茵的生长,其中细菌作用大,真菌次之。     

鸡粪堆肥的微生物变化规律研究

目的:研究鸡粪堆肥中细菌、放线菌和真菌数量的变化规律,为有机堆肥提供技术参数。方法:采取稀释倒平板法和涂布法对堆肥样品进行计数。结果:在发酵过程中,菌数量变化在肥料表面上基本是呈先下降后上升最后达到稳定状态。其中细菌在30cm和60cm深处趋于平稳,真菌在30cm和60cm深处先上升再下降再上升,在第12d后有个急速下降的过程。放线菌在30cm和60cm深处数量比较少。而在后熟发酵过程中,3种菌数的变化规律比较平稳结论:细菌和真菌的生长和繁殖都会抑制放线菌的生长,其中细菌作用大,真菌次之。     

变性梯度凝胶电泳在堆肥微生物研究中的应用

对当前堆肥中微生物种群分布及其对有机物分解作用的研究进行分析,论述了分子生物技术中的变性梯度凝胶电泳(DGGE)的特点。将DGCE与PCR扩增技术相结合,可用于研究自然菌种堆肥和人工培养驯化菌种堆肥过程中微生物的演替规律,为研究和筛选堆肥中的微生物提供更加有效、快速的信息,促进堆肥技术的发展。     

微生物燃料电池在固体废物堆肥中的应用进展

微生物燃料电池(Microbial fuel cell,MFC)是一种近几年快速发展的废物处理与能源化技术,可以与污水处理、污染物降解、脱盐等环境技术结合。微生物燃料电池与堆肥技术结合可以在处理日益增长的固体废弃物的同时回收能量,具有很好的发展前景。文中分析了堆肥微生物燃料电池系统的微生物特征,探讨了堆肥过程中影响微生物燃料电池产电性能的因素,包括电极,隔膜,供氧和构型。最后归纳说明了堆肥微生物电池作为一种新的废弃物处理技术的特点:较高的微生物量并可产生较高的电流密度;对不同环境的适应性强;可以自身调节温度,能源利用效率高;质子从阳极向阴极的移动会受到不同堆肥原料的影响。     

土霉素对堆肥过程中酶活性和微生物群落代谢的影响

摘 要;以猪粪和秸秆为试验材料,研究了土霉素对堆肥温度、种子发芽指数、C/N、纤维素酶、脲酶、过氧化氢酶以及微生物群落代谢的影响。结果表明, 0 mg/kg (对照处理)的堆肥在第 2 天上升到 50 ℃以上, 维持了 5 d,达到了无害化处理的要求。35 mg/kg 土霉素处理(A1 处理）第 4 天升到 51.0 ℃,其高温期维持了 1 d。70 mg/kg 土霉素处理(A2 处理)第 3 天升到 50 ℃以上,高温期维持了 2 d。105 mg/kg 土霉素处理(A3 处理)和 140 mg/kg 土霉素处理(A4 处理)的温度在整个堆肥期间均未达到 50 ℃。在堆肥结束时各个处理的种子发芽指数均达到 80 % 以上。CK（Control check, 对照处理）、A1、A2、A3 和 A4 处理的 C/N 由 34.50 分别降为 16.64、16.07、19.48、18.45 和 19.83。堆肥的第 1 天,A1、A2、A3 和 A4 处理对纤维素酶活性的抑制率分别为 60.30%、21.30%、48.81% 和 76.05%,第 3 天,土霉素对纤维素酶活性起促进作用,在 4—30 d,A3、A4 处理对纤维素酶活性有抑制作用。在堆肥的前期（1—3 d）,土霉素刺激脲酶活性,随着堆肥时间的延长,土霉素对脲酶活性由刺激变为抑制作用,在第 18—30 天 A3、A4 处理与 CK 相比有着显著的抑制作用。在堆肥第 1 天到第 18 天,土霉素基本上促进过氧化氢酶的活性,堆肥 18 d 之后土霉素对过氧化氢酶起着是抑制作用。用 Biolog (ECO Microplate)方法研究了土霉素对堆肥过程中微生物群落代谢的影响,结果表明,在升温期 CK 处理的 AWCD (Average Well Color Development, 平均颜色变化率)在培养 60 h 之后大于其他处理,高温期 A2 处理的 AWCD 值最高,在降温期 CK 的 AWCD 值一直是最高的。对 Shannon 指数进行分析显示,堆肥的初始阶段土霉素降低微生物群落的功能多样性,随着时间的延长,土霉素增加微生物群落的功能多样性。对微生物利用六大类碳源分析表明, 140 mg/kg 的土霉素浓度能够改变微生物利用碳源的种类。     

复合微生物菌剂在剩余污泥堆肥中的作用研究

随着我国社会经济的快速发展,社会经济活动中产生的污水和污泥处理问题也越来越严重,广泛存在于污水处理机构中的污泥成为一个日渐严重的问题,复合微生物菌剂在污水处理活动中剩余污泥的处理活动中,因为其对污泥无害化处理的积极作用而备受欢迎,本文将从复合微生物菌剂的角度出发,结合剩余污泥堆肥处理中的实际,对复合微生物菌剂在剩余污泥堆肥处理中的作用进行简要的分析。     

The cyanobacterial community of polygon soils at an inland Antarctic nunatak

Inland Antarctic terrestrial ecosystems and biodiversity are poorly understood in comparison with Antarctic coastal regions. Microorganisms, as primary colonists, are integral to Antarctic soil ecosystem development, essential for pedogenesis and structuring the soil, and providing the nutrients necessary for the subsequent establishment of macroorganisms. This study analysed the microbial communities present in polygon soils of Coal Nunatak (Alexander Island, at the southern limit of the maritime Antarctic). Soils were analysed across three polygons (centre and margins) and at three depths (0–1, 1–2, 2–5 cm). Cyanobacterial communities were characterised using two complementary molecular biological approaches, temperature gradient gel electrophoresis and clone library analysis. The three polygons exhibited conspicuous differences in community composition, both between different polygons and spatially (horizontally and vertically) within a single polygon. Comparison of our data with that from previous studies using classical culture and morphological identification techniques clearly shows the need for more intensive research on patterns of microbial diversity in terrestrial habitats throughout the Antarctic. The majority of the 17 cyanobacterial genera identified at Coal Nunatak are thought to have ubiquitous distributions, while none are known only from the Antarctic. Three of the genera present are also known to be capable of being lichen photobionts.     

Investigation of the microbial community structure and activity as indicators of compost stability and composting process evolution

In a bid to identify suitable microbial indicators of compost stability, the process evolution during windrow composting of poultry manure (PM), green waste (GW) and biowaste was studied. Treatments were monitored with regard to abiotic factors, respiration activity (determined using the SOUR test) and functional microflora. The composting process went through typical changes in temperature, moisture content and microbial properties, despite the inherent feedstock differences. Nitrobacter and pathogen indicators varied as a monotonous function of processing time. Some microbial groups have shown a potential to serve as fingerprints of the different process stages, but still they should be examined in context with respirometric tests and abiotic parameters. Respiration activity reflected well the process stage, verifying the value of respirometric tests to access compost stability. SOUR values below 1 mg O₂/g VS/h were achieved for the PM and the GW compost.     

Characterization of bacterial communities in four freshwater lakes differing in nutrient load and food web structure

The phylogenetic composition of bacterioplankton communities in the water column of four shallow eutrophic lakes was analyzed by partially sequencing cloned 16S rRNA genes and by PCR-DGGE analysis. The four lakes differed in nutrient load and food web structure: two were in a clearwater state and had dense stands of submerged macrophytes, while two others were in a turbid state characterized by the occurrence of phytoplankton blooms. One turbid and one clearwater lake had very high nutrient levels (total phosphorus > 100 microg/l), while the other lakes were less nutrient rich (total phosphorus < 100 microg/l). Cluster analysis, multidimensional scaling and ANOSIM (analysis of similarity) were used to investigate differences among the bacterial community composition in the four lakes. Our results show that each lake has its own distinct bacterioplankton community. The samples of lake Blankaart differed substantially from those of the other lakes; this pattern was consistent throughout the year of study. The bacterioplankton community composition in lake Blankaart seems to be less diverse and less stable than in the other three lakes. Clone library results reveal that Actinobacteria strongly dominated the bacterial community in lake Blankaart. The relative abundance of Betaproteobacteria was low, whereas this group was dominant in the other three lakes. Turbid lakes had a higher representation of Cyanobacteria, while clearwater lakes were characterized by more representatives of the Bacteroidetes. Correlating our DGGE data with environmental parameters, using the BIOENV procedure, suggests that differences are partly related to the equilibrium state of the lake.     

不同微生物菌剂处理对猪粪堆肥中氨挥发的影响

研究不同微生物复合菌剂及添加比例对猪粪与木屑混合(鲜重比为鲜猪粪∶木屑9∶1)堆肥过程中NH₃挥发的影响.结果表明,在堆肥过程中,NH₃挥发主要产生在堆肥前期15 d的升温和高温期,添加3‰的微生物复合菌剂1、2和3对猪粪堆肥中NH₃挥发都有一定的抑制作用,减轻氮素损失与堆肥恶臭,添加5‰复合菌剂1有显著抑制作用（P＜0.05）.     

What drives bacteria to produce a biofilm?

Nearly 40 years ago, Dr. R.J. Gibbons made the first reports of the clinical relevance of what we now know as bacterial biofilms when he published his observations of the role of polysaccharide glycocalyx formation on teeth by Streptococcus mutans [Sci. Am. 238 (1978) 86]. As the clinical relevance of bacterial biofilm formation became increasingly apparent, interest in the phenomenon exploded. Studies are rapidly shedding light on the biomolecular pathways leading to this sessile mode of growth but many fundamental questions remain. The intent of this review is to consider the reasons why bacteria switch from a free-floating to a biofilm mode of growth. The currently available wealth of data pertaining to the molecular genetics of biofilm formation in commonly studied, clinically relevant, single-species biofilms will be discussed in an effort to decipher the motivation behind the transition from planktonic to sessile growth in the human body. Four potential incentives behind the formation of biofilms by bacteria during infection are considered: (1) protection from harmful conditions in the host (defense), (2) sequestration to a nutrient-rich area (colonization), (3) utilization of cooperative benefits (community), (4) biofilms normally grow as biofilms and planktonic cultures are an in vitro artifact (biofilms as the default mode of growth).     

宏蛋白质组学——研究微生物群落基因表达的新技术

宏蛋白质组学是应用蛋白质组学技术对微生物群落进行研究的一项新技术,其定义为在特定的时间对微生物群落的所有蛋白质组成进行大规模鉴定。通过对宏蛋白质组学的研究策略、进展情况的综述、介绍,展望了宏蛋白组学在研究微生物群落基因表达中的应用前景。     

低龄婴幼儿龋微生物群落的研究进展

低龄婴幼儿龋（early childhood caries,ECC）是影响全世界儿童最常见的疾病之一,然而龋病并不是由单一致龋细菌引起,而是由微生物、宿主、饮食和时间,即“龋病病因四因素”之间复杂的相互作用所引起,其中微生物因素起着主要作用。口腔微生物之间存在着一种稳定关系,与宿主保持着和谐的生态平衡,一旦受到某种特殊环境改变的影响,这种平衡则可能被打破。到目前为止,国内外关于ECC的微生物群落研究方法很多,结果不尽相同,因此了解ECC的组成及动态变化对于儿童龋病的预防和防治极其重要。本文就ECC微生物群落的研究进展作一详细综述。     

铅胁迫对木榄幼苗抗氧化酶的影响

用含不同浓度Pb(NO₃)₂(0～40 mmol·L^-1)的Hoagland营养液处理沙培中的木榄（Bruguiera gymnorrhiza）幼苗,2个月后测定幼苗过氧化物酶(POD)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性并对其同工酶进行电泳分析。结果表明,1～10 mmol·L^-1 Pb促进幼苗根和叶中抗氧化酶活性,但在20～40 mmol·L^-1 Pb高浓度下,酶活性下降。电泳结果显示,Pb主要影响阴离子型POD同工酶活性。20～40 mmol·L^-1Pb强烈抑制根中所有CAT同工酶的活性;30～40 mmol·L^-1 Pb诱导出1条新的Cu/Zn-SOD同工酶LS-3和3条新的CAT同工酶RC-3、LC-2和LC-3。