硝化抑制剂对酸性红壤硝化作用及氨氧化微生物丰度和群落结构的影响

以一种典型酸性红壤为研究对象,在微宇宙培养条件下,研究硝化抑制剂双氰胺(DCD)和乙炔对酸性土壤硝化过程以及氨氧化微生物丰度和群落结构的影响。结果表明:硫酸铵(铵态氮肥)施加刺激了土壤硝化过程,硝化抑制剂处理显著抑制了硝化作用并且C_2H_2对硝化过程的抑制作用比DCD更强。研究还发现氨氧化细菌(Ammonia-Oxidizing Bacteria,AOB)的丰度与的浓度呈显著正相关关系,而氨氧化古菌(Ammonia-oxidizing Archaea,AOA)的丰度与的浓度呈显著负相关关系。末端限制性片段多态性(T-RFLP)分析和主坐标分析(PCo A)表明单施硫酸铵处理改变了AOB和AOA的群落结构。硝化抑制剂处理对AOA和AOB的群落结构没有显著影响。这些结果表明在高铵氮条件下AOB是土壤硝化过程的主要执行者,硝化抑制剂通过抑制AOB的丰度从而抑制硝化过程。     

微生物共培养厌氧同步消化反硝化处理污水的研究

以塑料网为载体附着生长厌氧消化菌、反硝化菌和厌氧氨氧化菌。厌氧消化菌将有机污染物转化为小分子有机酸、醇类、醛类、二氧化碳和甲烷等,有机物厌氧消化产生的丙酸和丁酸等作为反硝化菌和厌氧氨氧化菌脱氮时的碳源被消耗,从而实现模拟污水中有机污染物和含氮污染物的协同、高效去除。     

化学竹浆废水活性污泥细菌菌群结构分析

本研究利用超高通量基因组454测序技术分析实际化学竹浆废水活性污泥中的细菌菌群结构和多样性,分析表明,不同竹浆废水处理厂废水香农指数为4.48～5.19,ACE指数为767.80～1066.15,进一步得到不同化学竹浆废水活性污泥细菌菌群不仅具备多样性,同时具有较为显著的差异性。结果表明,化学竹浆废水活性污泥中比较常见的菌门包括Proteobacteria (变形菌门)、Chloroflexi (绿弯菌门)、Bacteroidetes (拟杆菌门)和Actinobacteria (放线菌门),其中Proteobacteria(变形菌门)占主导地位,最高丰度为59.47%;主要属为Hyphomicrobium (生丝微菌属)、Candidatus_Competibacter、JdFR-76和SWB02,其中生丝微菌属占主导地位,丰度为3.69%～18.29%。这些菌属不仅与硝化和反硝化过程相关,还与多环芳香族类化合物、醇类及烷烃类物质的降解直接有关。     

淮安地区小龙虾及其外环境中致病菌分布规律和耐药性分析

目的了解淮安地区生鲜小龙虾及其外环境中致病菌的分布规律以及相关菌株的耐药性,为食源性疾病的防控提供依据。方法根据食品微生物检测国家标准,检测70份小龙虾样品(养殖环节30份、销售环节40份)和40份外环境水体样本(养殖环节15份、销售环节25份)中的沙门氏菌、金黄色葡萄球菌、单核细胞增生李斯特氏菌、大肠埃希菌O157和副溶血性弧菌,并对沙门氏菌进行血清型鉴定,然后用纸片扩散法测定沙门氏菌和金黄色葡萄球菌的耐药性。结果小龙虾中致病菌的总检出率为41.43%,致病菌类型包括沙门氏菌、金黄色葡萄球菌、副溶血性弧菌和单核细胞增生李斯特菌。外坏境水体中致病菌的总检出率为22.50%,致病菌类型包括沙门氏菌、金黄色葡萄球菌和副溶血性弧菌。沙门氏菌分离株主要对萘啶酸和氨苄西林具有较强的耐药性;金黄色葡萄球菌分离株则对红霉素、甲氧苄氨嘧啶/磺胺甲(?)唑和克林霉素具有较强的耐药性。结论淮安地区小龙虾及其外环境水体中存在致病菌污染,并且沙门氏菌和金黄色葡萄球菌分离菌株的耐药情况严重。     

MBR中厌氧氨氧化运行特性及微生态结构

研究了膜生物反应器(MBR)中厌氧氨氧化(Anammox)的运行特性与微生态结构变化.采用含氮模拟废水进行试验,最终获得粒径集中在0.2~1 mm的红褐色厌氧氨氧化颗粒污泥.运行结果显示,厌氧氨氧化菌能够承受的容积负荷达0.245 kgTN/(m3·d);总氮、NH4+-N和NO-2-N去除率分别达到80 %、81 %、91 %.水力负荷冲击试验表明,当HRT从14 h下降到7.9 h时,NH4+-N、NO-2-N去除率相对稳定,分别保持在75 %和85 %左右,厌氧氨氧化仍然能够稳定进行.通过末端限制性酶切片断长度多态性(T-RFLP)试验发现,反应器运行完成后微生物呈多态性分布,优势菌突出,其中起Anammox作用的菌属主要为planctomyce、pirellula、gemmata、pseudomonas,这为厌氧氨氧化运行过程中微生物群落结构变化提供理论依据.     

应用Illumina MiSeq高通量测序技术分析巴东地区豆瓣酱中微生物多样性

为了解湖北省恩施市巴东地区豆瓣酱中微生物的多样性,采用Illumina MiSeq高通量测序技术,分析豆瓣酱中细菌16S r RNA及真菌18S rRNAV4区基因序列,进而比较豆瓣酱微生物的群落结构组成及多样性差异。结果 3个样品共获得117644条有效序列,867个OTUs数目。多样性分析表明,豆瓣酱中具有高度的微生物群落多样性。微生物群落组成分析表明,样品中子囊菌门(Ascomycota,95.84%)、变形菌门(Proteobacteria,47.13%)、厚壁菌门(Firmicutes,32.37%)、放线菌(Actinobacteria,12.87%)为优势菌门,所占比例都超过了10.0%。在豆瓣酱样品中分别鉴定出311个细菌属和16个真菌属,优势细菌和真菌属平均相对含量分别为8.09%和24.74%,细菌及真菌多样性在属的水平上差异显著(p0.05)。研究结果加深了对豆瓣酱微生物群落组成和多样性的认识,以期为巴东地区豆瓣酱中微生物菌种资源的发掘与保护提供理论依据。     

凡纳滨对虾优势腐败菌鉴定及其致腐能力的初步研究

分析鉴定了凡纳滨对虾0℃与20℃贮藏条件下的菌相组成与优势腐败菌,并对优势腐败菌16SrDNA、生长动力学、致腐能力与菌落数的变化进行了测定。结果表明,0℃与20℃贮藏条件下,对虾优势腐败菌分别是希瓦氏菌(30%)、不动杆菌(16.7%)与希瓦氏菌(46.5%)、发光杆菌(17.7%)。7℃条件下,将一定浓度的希瓦氏菌与不动杆菌菌悬液接种到无菌对虾上,结果显示接种希瓦氏菌的样品其腐败代谢产物产量因子YTVB-N/CFU、YTMA/CFU分别为12.44×10-9、6.193×10-10,而接种不动杆菌的样品其YTVB-N/CFU、YTMA/CFU分别为8.937×10-9、5.548×10-10。结果表明,7℃条件下,希瓦氏菌的致腐能力强于不动杆菌,希瓦氏菌在对虾腐败过程中占主导作用,其分析结果与对虾菌相组成的鉴定结果相一致。     

分离自养殖水体的异养硝化-好氧反硝化菌及其脱氮作用研究

本研究从8份养殖水体样品中富集、分离、纯化、鉴定能脱除亚硝态氮、硝态氮和氨氮的菌株资源,获得8株亚硝态氮脱除菌、8株硝态氮脱除菌和11株氨氮脱除菌,分布在Pseudomonas、Paracoccus、Zobellella、Achromobacter、Bosea、Paenarthrobacter、Corynebacterium、Bacillus、Delftia和Gordonia等属。对这27株菌进行脱氮特性分析,筛得2株异养硝化-好氧反硝化菌,分别鉴定为Pseudomonas stutzeri j-1和Zobellella denitrificans2G-5。这2株菌脱氮性能优越,在3种氮素培养基中培养18 h后,对亚硝态氮、硝态氮和氨氮的脱除率在99.53%～99.89%之间。将之用于未灭菌的养殖水脱氮,菌株j-1表现出一定的定殖和增殖能力,发挥出良好的脱氮效果;但菌株2G-5增殖能力较弱,脱氮效果不明显。本研究发掘了一批脱氮菌株资源,获得了2株具有重要应用潜力的异养硝化-好氧反硝化菌,为细菌氮循环代谢机制研究和脱氮技术研发积累了物质基础。     

鲜鸡蛋蛋壳表面细菌多样性分析

目的了解鲜鸡蛋蛋壳表面菌落构成及其随时间的变化情况。方法收集榆林、汉中和西安三个地市不同养殖场的鲜鸡蛋,于不同的时间点进行试验,采用聚合酶链式反应-变性梯度凝胶电泳(polymerase chain reaction-denaturing gradient gel electrophoresis,PCR-DGGE)和胶回收测序的方法对细菌构成多样性和样品间相似性进行分析。结果与榆林组和西安组比较,汉中组的Shannon多样性指数和Dice相似性系数差异有统计学意义(P0.05),菌落构成主要为厚壁菌门(Firmicutes)和放线菌门(Actinobacteria),葡萄球菌属(Staphylococcus)、链霉菌属(Streptomyces)和乳酸杆菌属(Lactobacillus)为优势菌属。结论不同地区蛋壳表面的细菌存在多样性和复杂性,而存放初期和末期菌落的相似度较高。     

南美白对虾感染真菌毒素后的微生物菌相变化

为探明在养殖过程中受T-2毒素、黄曲霉毒素B1、赭曲霉毒素A和呕吐毒素污染的南美白对虾,经贮藏后微生物菌相结构变化的特征,采用食品安全国家标准(GB 47892-2010)对菌落总数测定的方法,计算染毒对虾中的菌落总数,同时从染毒的南美白对虾中分离筛选和鉴定出不同属的微生物,并与未染毒对虾中的微生物数量、种类及其变化趋势进行比较。实验结果表明:染毒对虾肌肉微生物种类在贮存第1~8 d和第16~20 d间,菌落种类保持在2~4种和4~7种,菌群总数呈先下降后上升再下降的趋势。从未染毒对虾和染毒对虾样品中共分离出7株菌,经16S rDNA进行测序,分别鉴定为考克氏菌属、金黄杆菌属、希瓦氏菌属、弯曲芽孢杆菌属、假单胞菌属、细杆菌属和微小杆菌属,每株样品菌种匹配率均在97%以上,其中对水产品的腐败能力较强的金黄杆菌属、希瓦氏菌属和假单胞菌属在染毒对虾中检出,空白组只检出希瓦氏菌属。真菌毒素使对虾肌肉产生变化,导致对虾肌肉品质下降,从而形成适合腐败能力强细菌的生长环境,产生新的菌种。     

Perfluorinated compounds in coastal waters of Hong Kong, South China, and Korea

Perfluorinated compounds (PFCs), such as perfluorooctanesulfonate (PFOS) and related compounds, have recently been identified in the environment. PFOS, the terminal degradation product of many of the PFCs, has been found globally in many wildlife species, as well as open ocean waters, even in remote regions far from sources. In this study, a solid-phase extraction procedure coupled with high-performance liquid chromatography interfaced to high-resolution mass spectrometry was used to isolate, identify, and quantify small concentrations of PFCs in seawater. These techniques were applied to investigate the local sources of PFCs in several industrialized areas of Asia and provide information on how the PFCs are circulated by coastal currents. Ranges of concentrations of PFOS in coastal seawaters of Hong Kong, the Pearl River Delta, including the South China Sea, and Korea were 0.09-3.1, 0.02-12, and 0.04-730 pg/mL, respectively, while those of perfluorooctanoic acid (PFOA) were 0.73-5.5, 0.24-16, and 0.24-320 pg/mL, respectively. Potential sources of PFCs include major industrialized areas along the Pearl River Delta of southern China and major cities of Korea, which are several of the fastest growing industrial and economic regions in the world. Detectable concentrations of PFOS and PFOA in waters of southern China were similar to those in the coastal marine environment of Japan and certain regions in Korea. Concentrations of PFCs in several locations in Korean waters were 10-100-fold greater than those in the other locations on which we report here. The spatial and seasonal variations in PFC concentrations in surface seawaters in the Pearl River Delta and South China Sea indicate the strong influence of the Pearl River discharge on the magnitude and extent of PFC contamination in southern China. All of the concentrations of PFOS were less than those that would be expected to cause adverse effects to aquatic organisms or their predators except for one location in Korea adjacent to an industrialized area. Hazard quotients were from <0.001 to 0.002 for aquatic animals and ranged from <0.001 to 17 for predatory birds.     

清代广东盐产地新探

明清时期,广东海盐产地的分布经历了由珠江三角洲地区向珠江三角洲东、西两翼的沿海地区转移的过程。清代前期,广东东部的惠州府、潮州府和广东西部的高州府等沿海地区形成盐产地的新中心,康熙朝的官帑收盐改革促使这一格局最终形成。     

乾嘉时期珠江三角洲的私盐问题——中国第一历史档案馆一则关于东莞盐务档案的解读

嘉庆十八年两广总督和广东巡抚联署的一则私盐案奏折,反映出乾隆、嘉庆年间珠江三角洲的私盐案件易受重视和数额较大两个特点。这些特点一方面是由于当时的地方官员将珠江三角洲地区的私盐问题与海洋安全联结在一起考虑的结果,另一方面则是人口不断增长而官方所定食盐销售额不增加的必然结果。同时,作为两广盐区私盐较为严重的珠江三角洲地区,其私盐经历了主要由家内淋煎自用到出现大额船运的过程。     

珠三角地区印刷包装产业绿色化发展对策研究

绿色印刷已成为全球印刷业未来发展趋势。实施绿色战略,促进我国印刷包装产业的绿色化发展,需要各方面共同努力。为了了解印刷包装产业绿色化的实施现状,对珠三角地区具有一定规模的10家印刷包装企业进行了实际走访,并在调研分析的基础上,针对珠三角地区印刷包装企业的绿色印刷状况及绿色化进程中存在的主要问题,从政府、行业协会及企业3个层面提出了进一步促进印刷包装产业绿色化发展的相关对策建议。     

东莞古代盐业与沿海城镇的兴起

在古代东莞即珠江口东西两岸的广大地区,盐业是重要的手工业之一。本文研究表明,东莞古代盐业的兴起和发展对珠三角沿海城镇的兴起产生了重要的影响。正是古代东莞即珠江口东西两岸的盐业生产为珠三角沿海城镇的兴起集聚了最初的人脉,为城镇的发展提供了人口、商贸流通、文化的基础。     

甘蔗施用增效粒铵肥效的研究

在珠江三角洲３种不同土壤类型和不同耕作制度进行田间小区试验和大田对比示范，并进行氮素利用率分析。结果表明：甘蔗增效粒铵比施普通粉铵能显著提高产量；同时，氮素利用率也明显高于粉铵。     

半凝固型姜奶饮料的研制

利用姜粉和奶粉制成类似广东珠三角传统名特小食“姜撞奶”,通过试验确定了产品的工艺及配方。     

Distribution of polybrominated diphenyl ethers in sediments of the Pearl River Delta and adjacent South China Sea

Spatial and temporal distributions of polybrominated diphenyl ethers (PBDEs) in sediments of the Pearl River Delta (PRD) and adjacent South China Sea (SCS) of southern China were examined. A total of 66 surface sediment samples were collected and analyzed to determine the concentrations of 10 PBDE congeners (BDE-28, -47, -66, -100, -99, -154, -153, -138, -183, and -209). The concentrations of BDE-209 and SigmaPBDEs (defined as the sum of all targeted PBDE congeners except for BDE-209) ranged from 0.4 to 7340 and from 0.04 to 94.7 ng/g, respectively. The SigmaPBDEs concentrations were mostly < 50 ng/g, within the range for riverine and coastal sediments around the world, whereas the BDE-209 concentrations at the most contaminated sites were at the high end of the worldwide figures. Congener compositions were dominated by BDE-209 (72.6 - 99.7%), with minor contributions from penta- and octa-BDEs. Slightly different PBDE compositions were observed among samples collected from different locations, attributable to possible decomposition of highly brominated congeners and/or redistribution between particles of various sizes during atmospheric or fluvial transportation. The PBDE patterns in the SCS and Pearl River Estuary sediments were similar to those in sediments of the Zhujiang and Dongjiang Rivers, reflecting the widespread influence from local inputs. Analyses of two short sediment cores collected from the Pearl River Estuary showed that concentrations of BDE-209 rapidly increased in the upper layers of both cores, coincident with the growth of the electronics manufacturing capacities in the PRD region. The major sources of PBDEs were probably waste discharges from the cities of Guangzhou, Dongguan, and Shenzhen, the three fastest growing urban centers in the PRD.     

广东省疾控机构食品安全事故流行病学调查能力现况分析

目的了解广东省各级疾病预防控制中心(疾病预防控制中心以下简称CDC)开展食品安全事故流行病学调查能力的现况,为制定卫生应急管理策略及人才培养计划提供科学依据。方法 2013年9~10月通过问卷函调查各级CDC相关科室负责人,从人、物、力、财等方面设置了人员情况、教育培训、应急现状、经费保障4部分35个条目的问题,对广东省市县两级124个CDC进行食品安全事故流行病学调查能力的普查。结果人员配备基本合理,但普遍反映紧缺。珠三角地区CDC专业人员中受过现场流行病学培训项目(FETP)培训的人员明显多于粤东西北地区;大多数地市级和县区级CDC制定了应急预案,但均未组织学习,而专业技术规范或标准的学习比例较高。全省CDC均储备了个案调查表,但未统一。大部分CDC配备了现场采样工具且定期补充,珠三角地区配置比例略高于粤东西北地区。食品安全事故信息来源主要为医疗机构(74.2%),任务来源主要为卫生行政部门(79.8%)。模拟案例调查结果提示CDC尤其是县区一级在现场流行病学调查技术能力上,如混杂因素排查、分析性流行病学、统计分析处理、样品采集和检测项目确定等方面还有较大的提升空间;食品安全事故流行病学调查专项经费缺口较大,各地经费差异也较大。地市级CDC流行病学调查经费政府拨款占82.8%,县区占64.1%。结论广东省各级CDC普遍存在人员、经费紧缺问题,流行病学调查技术能力在地市间和县区间存在较大差异,整体能力也亟待提升,各级政府应加强CDC人员和经费的保障,各级CDC应加强食品安全事故流行病学调查技术能力的建设。     

Abundances, depositional fluxes, and homologue patterns of polychlorinated biphenyls in dated sediment cores from the Pearl River Delta, China

Despite the recent efforts to investigate the distribution and fate of persistent organic pollutants in the tropical and subtropical regions of Asia, very little was known about the temporal change of polychlorinated biphenyls (PCBs) in the environmental ecosystem of China. In this study, three dated sediment cores collected from the Pearl River Delta of southern China were analyzed for a large suite of PCB congeners, from which the temporal profiles of PCB abundances, fluxes, and homologue patterns were constructed. The sedimentary inventories of total PCBs at the sampling sites ranged from 480 to 1310 ng/cm2, at the low end of the worldwide figures. Although production and use of PCBs have been banned or highly restricted in China since the early 1980s, the fluxes of total PCBs continued to increase in the Pearl River Delta sediments. There was a concurrent increase of PCB fluxes and gross domestic product per capita in the region from 1980 to 1997, and a decline of agricultural land use was evident at the same time. Apparently, large-scale land transform since the early 1980s as well as emissions from the PCB-containing electrical equipments were responsible for the sharp rise of PCB fluxes in the recent sediments. The difference in the PCB homologue patterns from 1940 to the mid-1970s was probably indicative of the different timelines of PCB usage in Macao/Hong Kong and mainland China and the differenttypes of technical PCBs commercially used. PCBs were detectable in sediments deposited well before the time frame when production of PCBs began (before 1930) and were relatively enriched in the less chlorinated homologue groups (3Cl and 4Cl PCBs), suggesting the downward mobility of lightly chlorinated PCB congeners in the sediment column.