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111.
A series of batch-type experiments with acetate acid as the primary substrate were performed using enrichment cultures developed from the anaerobic sludge to investigate the effect of acetate acid on tetrachloroethylene (PCE) biodegradation. Experimental results indicated that acetate acid was an efficient electron donor in affecting the biotransformability of PCE. Trichloroethylene (TCE) was the primary dehalogenation product, and small amounts of dichloroethylenes (DCEs) were also detected. No significant further DCEs degradation was detected. PCE degradation rate in the experiment was 36.6 times faster than background rate in natural groundwater.  相似文献   
112.
对4种假单胞菌产脓菌素培养基进行筛选,确定琥珀酸钠培养基为基础培养基,并考察了添加不同物质对假单胞菌脓菌素产量的影响,结果表明,向琥珀酸钠培养基中添加甘油、海盐、硝酸铵时对铁载体产量有明显的促进作用.采用正交实验法获得了高产脓菌素的最佳发酵培养基配方:4g/dm~3琥珀酸钠,6 g/dm~3K2HPO4,3 g/dm~3KH2PO4,1 g/dm~3(NH4)2SO4,1 g/dm~3NH4NO3,5 g/dm~3海盐,1.5%甘油.其脓菌素产量最高可达到265 mg/dm~3,约是基础培养基产量的7倍以上,此培养基成分简单不含复杂的有机氮源,脓菌素产量高,有利于脓菌素的进一步分离纯化与制备.同时本实验对其发酵条件进行优化研究,结果确定最佳发酵条件:培养基起始p H值为6.9,接种量1.0%,培养温度为25℃,转速为220 r/min,发酵时间为28 h.  相似文献   
113.
表生环境中广泛存在以硝酸盐或Fe(Ⅲ)为电子受体、有机物或还原性无机盐为电子供体进行生长的微生物。硝酸盐还原菌具有降低水体硝态氮浓度的功能(Gesche等,2010),而铁还原菌具有固碳、磷(代谢产物Fe(Ⅱ)与CO32-、PO43-等反  相似文献   
114.
115.
南海区拖网方目网囊选择性试验   总被引:2,自引:0,他引:2  
为了科学地确定南海区拖网网囊的结构和适宜网目尺寸,于2000年11月24日-12月20日在南海北部珠江口以外海域水深36-70m拖网渔场,对4种不同网目尺寸的方目网囊进行了网囊套网式捕鱼选择性试验,获得了蓝圆Cuan(Decapterus maruadsi),多齿蛇鲻(Saurida tumbil),条尾绯鲤(Upeneus bensasi)等3种主要鱼种的选择性曲线,试验结果表明,4种方目网囊的数量平均逃逸率均高于重量平均逃逸率,网囊渔获的优势体长总是大于套网渔获的优势体长,蓝Cuan,多齿蛇鲻,条尾绯鲤之类的圆体鱼类比扁体鱼类更易于逃出方目网囊。  相似文献   
116.
借助相分析中的偏提取方法对取自东太平洋莱恩群岛水下海山上的水成型铁锰结壳进行了选择性提取实验.结果显示,稀土元素在结壳中的富集归因于其中的矿物或氧化物而受环境影响较小,主要富集于无定形铁的氧化物/氢氧化物相中而只有少量存在于δ-MnO2中,显示出无定形铁的氧化物,氢氧化物比δ-MnO2对稀土元素具有更强的络合能力.虽然...  相似文献   
117.
Eighteen agar media were tested for the culture of gut-associated bacteria from farmed adult turbot(Scophthalmus maximus),including 16 agar media with or without 1% gastrointestinal(GI)supernatant,or with 2% or 4% GI supernatant.A total of 1 711 colonies were analyzed and 24 operational taxonomic units(OTUs)were identifi ed.The greatest bacterial diversity was isolated on Zobell 2216E/Zobell 2216E+ agar media,whereas MRS/MRS+ agar media produced a low diversity of colonies.Agar media with GI supernatant(1%,2%,or 4%)showed increased diversity and yielded different profi les of OTUs from the corresponding original media,suggesting that GI supernatant provides substances that enhance the culture effi ciency of bacteria from the turbot GI tract.The large majority of the colonies(82%)were γ-Proteobacteria,whereas 15.6% and 2.4% of colonies were Firmicutes and Actinobacteria,respectively.At the genus level,49.4% of all colonies were assigned to Vibrio.Other potential pathogens,including Pseudomonas,Photobacterium,and Enterobacter,and potential probiotics,including Bacillus,Paenibacillus,and Pseudomonas,were also isolated on agar media.Most cultured bacteria belonged to species that were fi rst described in the turbot GI tract.The impact of these species on turbot physiology and health should be investigated further.  相似文献   
118.
Calcium carbonate (CaCO3) crystals in their preferred orientation were obtained in BG11 culture media inoculated with Synechocystis sp. PCC6803 (inoculated BG11). In this study, the features of calcium carbonate deposition were investigated. Inoculated BGll in different calcium ion concentrations was used for the experimental group, while the BGll culture medium was used for the control group. The surface morphologies of the calcium carbonate deposits in the experimental and control groups were determined by scanning and transmission electron microscopy. The deposits were analyzed by electronic probe micro-analysis, Fourier transform infrared spectrum, X-ray diffraction, thermal gravimetric analysis and differential scanning calorimetry. The results show that the surfaces of the crystals in the experimental group were hexahedral in a scaly pattern. The particle sizes were micrometer-sized and larger than those in the control group. The deposits of the control group contained calcium (Ca), carbon (C), oxygen (O), phosphorus (P), iron (Fe), copper (Cu), zinc (Zn), and other elements. The deposits in the experimental group contained Ca, C, and O only. The deposits of both groups contained calcite. The thermal decomposition temperature of the deposits in the control group was lower than those in the experimental group. It showed that the CaCO3 deposits of the experimental group had higher thermal stability than those of the control group. This may be due to the secondary metabolites produced by the algae cells, which affect the carbonate crystal structure and result in a close-packed structure. The algae cells that remained after thermal weight loss were heavier in higher calcium concentrations in BGll culture media. There may be more calcium- containing crystals inside and outside of these cells. These results shall be beneficial for understanding the formation mechanism of carbonate minerals.  相似文献   
119.
传统的地物类别尺度上的遥感影像分类不确定性评价仅能实现分类精度的数学度量,无法反映分类不确定性的空间分布,难以完整、准确地描述和理解遥感影像分类信息的不确定性.文章首先在像元尺度上对遥感影像分类的不确定性进行评价,并在此基础上利用计算机技术从彩色可视化、用户交互式可视化和用户选择性可视化模式3个方面在空间域上对分类不确定性进行描述,从视觉感知角度表达遥感影像分类的不确定性信息,从而使用户更加形象直观地理解不确定性信息数据的大小及其空间分布.  相似文献   
120.
《地理教学》2010,(5):F0002-F0002
上海市普教系统双名工程第二期地理名师培养基地具有高水平的专家组。专家组由7人组成:中国教育学会地理教学研究会理事长、华东师大博士生导师陈澄教授,中国教育学会地理教学研究会常务理事、  相似文献   
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