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381.
Mao-Cheng Deng Jing Li Fu-Rui Liang Meisheng Yi Xiao-Ming Xu Jian-Ping Yuan Juan Peng Chou-Fei Wu Jiang-Hai Wang 《Marine pollution bulletin》2014
Microorganisms play an important role in the biodegradation of petroleum contaminants, which have attracted great concern due to their persistent toxicity and difficult biodegradation. In this paper, a novel hydrocarbon-degrading bacterium HZ01 was isolated from the crude oil-contaminated seawater at the Daya Bay, South China Sea, and identified as Achromobacter sp. Under the conditions of pH 7.0, NaCl 3% (w/v), temperature 28 °C and rotary speed 150 rpm, its degradability of the total n-alkanes reached up to 96.6% after 10 days of incubation for the evaporated diesel oil. Furthermore, Achromobacter sp. HZ01 could effectively utilize polycyclic aromatic hydrocarbons (PAHs) as its sole carbon source, and could remove anthracene, phenanthrene and pyrence about 29.8%, 50.6% and 38.4% respectively after 30 days of incubation. Therefore, Achromobacter sp. HZ01 may employed as an excellent degrader to develop one cost-effective and eco-friendly method for the bioremediation of marine environments polluted by crude oil. 相似文献
382.
Wenjun Han Jingyan Gu Qiujie Yan Jungang Li Zhihong Wu Qianqun Gu Yuezhong Li 《中国海洋大学学报(英文版)》2012,11(3):375-382
Bacteria of the genus Flammeovirga can digest complex polysaccharides (CPs), but no details have been reported regarding the CP depolymerases of these bacteria. MY04, an agarolytic marine bacterium isolated from coastal sediments, has been identified as a new member of the genus Flammeovirga. The MY04 strain is able to utilize multiple CPs as a sole carbon source and grows well on agarose, mannan, or xylan. This strain produces high concentrations of extracellular proteins (490 mg L-1 ± 18.2 mg L-1 liquid culture) that exhibit efficient and extensive degradation activities on various polysaccharides, especially agarose. These proteins have an activity of 310 U mg-1 ± 9.6 U mg-1 proteins. The extracellular agarase system (EAS) in the crude extracellular enzymes contains at least four agarose depolymerases, which are with molecular masses of approximately 30-70 kDa. The EAS is stable at a wide range of pH values (6.0-11.0), temperatures (0-50℃), and sodium chloride (NaCl) concentrations (0- 0.9 mol L-1). Two major degradation products generated from agarose by the EAS are identified to be neoagarotetraose and neoagarohexaose, suggesting that β-agarases are the major constituents of the MY04 EAS. These results suggest that the Flammeovirga strain MY04 and its polysac-charide-degradation system hold great promise in industrial applications. 相似文献
383.
384.
双眉藻(Amphora sp.)是糙刺参(Stichopus horrens)喜食的优良饵料。本文采用光密度法分别测定了该藻在光照强度28~149 μmol/(m2·s)、温度20~35℃、盐度25~45 和氮质量浓度0~7 500 mg/L、磷质量浓度0~440 mg/L、硅质量浓度0~1 500 mg/L 以及氮磷硅多因子组合情况下的比生长速率, 探讨了光照、温度、盐度和不同质量浓度的氮、磷、硅单因子及多因子组合对该藻生长的影响, 以及该藻的最适生长条件。单因子试验结果表明, 该藻在光照范围为35~149 μmol/(m2·s)时都能良好生长, 最适光照为56~99 μmol/(m2·s), 低温时该藻生长缓慢, 最适生长温度为25~30℃。Amphora sp.为广盐性, 在盐度25~45 都能较好生长, 最适盐度为30~35。氮、磷、硅的最适质量浓度分别是750~7 500 mg/L、44 mg/L和150mg/L, 磷对该藻生长的影响比氮更显著。正交实验结果表明, 氮、磷、硅的最佳质量浓度分别为75 mg/L、44 mg/L 和150 mg/L, 最佳配比为2.4:1:3.4, 与其他底栖硅藻的相应指标存在一定的差异, 可能是物种和地域环境差异引起的, 反映出该藻适应高温、强光特殊栖息环境的特征。 相似文献
385.
386.
Accumulation and biodegradation of phenanthrene and fluoranthene by the algae enriched from a mangrove aquatic ecosystem 总被引:3,自引:0,他引:3
This study focused on the accumulation and biodegradation of two typical polycyclic aromatic hydrocarbons (PAHs), phenanthrene (PHE) and fluoranthene (FLA), by the diatoms enriched from a mangrove aquatic ecosystem in the Jiulong River estuary, China. After separation, purification and culture, Skeletonema costatum (Greville) Cleve and Nitzschia sp. were exposed to different concentrations of PHE, FLA, and a mixture of the two. The results showed that the tolerance of S.costatum to PHE and FLA was greater than that of Nitzschia sp., and that the toxic effect of FLA on S. costatum and Nitzschia sp. was higher than that of PHE. The microalgal species S. costatum and Nitzschia sp. were capable of accumulating and degrading the two typical PAHs simultaneously. The accumulation and degradation abilities of Nitzschia sp. were higher than those of S. costatum. Degradation of FLA by the two algal species was slower, indicating that FLA was a more recalcitrant PAH compound. The microalgal species also showed comparable or higher efficiency in the removal of the PHE-FLA mixture than PHE or FLA singly, suggesting that the presence of one PAH stimulated the degradation of the other. 相似文献
387.
研究分离自对虾养殖池的一株促藻生长细菌的最佳培养条件,通过单因子实验得到该菌株的最佳碳源为葡萄糖,最佳氮源为酵母膏,初始pH值为7.5,最佳氯化钠质量浓度5 g/L;在其他培养条件不变的情况下,通过对酵母膏、葡萄糖、初始pH值做三因子三水平的正交实验,得到培养基最佳组合为:酵母膏10 g/L,葡萄糖1 g/L,初始pH值7.5。 相似文献
388.
Palaeomanicapsocus margoae gen. et sp. nov. and Palaeomanicapsocus fouadi gen. et sp. nov. are characterized, described, illustrated, from the Cretaceous Burmese amber. Their phylogenetic position is discussed. These fossil taxa are the first manicapsocid barklice to be described from the Burmese amber. 相似文献
389.
The third Cretaceous Aeshnoptera in amber is described from Myanmar. It represents a new family Burmaeshnidae fam. nov., genus and species Burmaeshna azari gen. et sp. nov. Its exact affinities remain uncertain but it is probably the sister group of the Late Cretaceous family Enigmaeshnidae. This discovery supports the hypothesis of an intense period of appearance of many aeshnopteran subclades during the late Early Cretaceous and the Late Cretaceous. 相似文献
390.
Previous studies conducted in the semiarid thornscrub of the Biosphere Reserve of Tehuacán-Cuicatlán have reported a high consumption of cactus and legume fruits by domestic goats. To test the hypothesis that goats may effectively disperse seed, we collected domestic goat feces from different microhabitats (bare ground, under shrub or under tree). The area occupied by each microhabitat was measured in the field. We then quantified the presence of viable seeds in goat feces and their deposition in microhabitats suitable for seedling establishment. We collected 209 seeds and using a seed reference collection, we identified these as belonging to three endemic cactus species, two legumes and several unidentified species. A high proportion of the cactus seeds germinated. Although most of the feces were found in open areas, more than 30% were recorded beneath the canopies of perennial plants, a suitable microhabitat for seedling establishment and survival. Contrary to the general assumption that goats cause only degradation of vegetation, these findings show that goats can effectively disperse viable seeds of diverse species. Studies that evaluate the ecological role of goats as important elements of biotic interactions are needed in order to generate an adequate management program for livestock. 相似文献