胞外聚合物在蓝细菌钙化过程中的作用及其地质意义     

钟怡江  文华国  陈洪德  刘磊  陈安清  王兴龙  王志伟  白璇 《沉积学报》2022,40(1):88-105

化石记录长达35亿年的蓝细菌在地球历史的生态演化方面发挥了极其重要的作用.与蓝细菌有关的"前寒武纪之谜"等系统性科学问题一直困扰着研究学者.胞外聚合物在蓝细菌钙化起到了至关重要的作用.在分析国内外大量文献基础上,通过系统介绍蓝细菌及胞外聚合物的主要特征,回顾和总结前人在蓝细菌光合作用有关和降解过程中的钙化过程的研究成果...  相似文献   

Bacterial production,glucosidase activity and particle-associated carbohydrates in Dona Paula bay,west coast of India   总被引：1，自引：0，他引：1  

P.V. Bhaskar  N.B. Bhosle 《Estuarine, Coastal and Shelf Science》2008

Size-fractionated bacterial production, abundance and α- and β- glucosidase enzyme activities were studied with respect to changes in hydrography, total suspended matter (TSM), chlorophyll a, particulate organic carbon and nitrogen ratio (POC:PON), 1.5 M NaCl-soluble and 10 mM EDTA-soluble carbohydrates (Sal-PCHO and CPCHO) and transparent exopolymeric particles (TEP) in the surface waters from July 1999–2000 at a shallow coastal station in Dona Paula Bay, west coast of India. The bulk of the total bacterial production and glucosidase activity were associated with particles (75% and >80%, respectively). Total bacterial production was linearly correlated to chlorophyll a (r = 0.513; p < 0.05) whereas enzyme activity was significantly correlated to TSM (α-glucosidase: r = 0.721 (p < 0.001); β-glucosidase: r = 0.596 (p < 0.01)). Both α-glucosidase (r = 0.514; p < 0.05) and β-glucosidase enzymes (r = 0.598; p < 0.01) appeared to be involved in the degradation of CPCHO and Sal-PCHO, respectively. Changes in α-glucosidase/β-glucosidase ratios highlighted the varying composition of particulate organic matter. The bacterial uptake of ¹⁴C-labeled bacterial extracellular carbohydrate measured over 11 days showed a strong linear correlation between ¹⁴C-uptake and bacterial production using tritiated thymidine. The turnover rate of ¹⁴C-labeled carbohydrate-C was 0.52 d⁻¹, higher than the estimated annual mean potential carbohydrate carbon turnover rate of 0.33 ± 0.2 d⁻¹. Our study suggests that carbohydrates derived from sediments may serve as an important alternative carbon source sustaining the bacterial carbon demand in the surface waters of Dona Paula Bay.  相似文献   

Properties of proteolytic toxin of Vibrio anguilolarum from diseased flounder     

Mo Zhao-lan  Chen Shi-yong  Zhang Pei-jun 《中国海洋湖沼学报》2002,20(4):316-322

Extracellular products (ECP) produced byVibrio anguillarum strain M3 originally isolated from diseased flounder (Paralichthys olivaceus) were prepared. ECP of M3 showed gelatinase, casinase, amylase and haemolytic activity on agarose plates. High protease activity against azocasin was detected. Bacterium M2 showed highest growth and protease activity at 25°C. The protease present in ECP showed maximal activity at pH 8 and 55°C; was completely inactivated by application of 80°C heat for 30 min; was completely inhibited by EDTA and HgCl₂, and was partially inhibited by PMSF, SDS, MnCl₂ and iodoacetic acid; but not inhibited by CaCl₂ and MgCl₂. The ECP was toxic to flounder fish at LD₅₀ values of 3.1 μg protein/g body weight. The addition of HgCl₂ and application of heat at 50°C decreased the lethal toxicity of ECP. When heated at 100°C, ECP lethality to flounder was completely inhibited. After intramuscular injection of ECP into flounder, it showed evident histopathological changes including necrosis of muscle, extensive deposition of haemosiderin in the spleen, dilated blood vessels congested with numerious lymphocytes in the liver. These results showed that ECP protease was a lethal factor produced by the bacteriumV. anguillarum M3. Contribution No. 4213 from the Institute of Oceanology, Chinese Academy of Sciences. Funded by projects under the Major State Basic Research Development Program, Grant G1999012003.  相似文献   

盐度波动和蛋白质/碳水化合物比值对凡纳滨对虾存活和生长的影响     

王兴强  曹梅  阎斌伦 《海洋通报(英文版)》2010,12(2):61-73

本实验探讨了盐度波动（S0和S10）和蛋白质/碳水化合物比值（P/C：4.1、1.9、1.0和0.6）对凡纳滨对虾存活和生长的影响。实验周期35天。结果表明：I）随着饲料中P/C比值的降低,对虾特定生长率和吸收效率呈下降趋势,而饲料系数呈上升趋势。在盐度波动S0处理中,4.1P/C比值饲料组对虾的摄食量和特定生长率显著高于1.0和0.6P/C比值饲料组;而在盐度波动S10处理中,各P/C比值饲料处理组差异不显著。II）4.1和1.9P/C比值饲料处理组中,S0盐度波动处理组对虾的摄食量和特定生长率高于S10盐度波动处理组;而1.0和0.6P/C比值饲料处理组中,S0盐度波动处理组对虾的摄食量和特定生长率低于S10盐度波动处理组的对虾。对于4个P/C比值处理组,S0盐度波动处理组的对虾饲料系数最低。  相似文献   

螺旋藻胞外和胞内核酸酶活性研究     

王高歌  杨官品  茅云翔  张宝红  张学成 《中国海洋大学学报(自然科学版)》2001,31(6):883-888

通过分析比较 2个螺旋藻物种 7个品系胞外和胞内核酸酶活性 ,确定了抑制胞外和胞内核酸酶活性的方法。用液体培养基清洗两次可消除胞外核酸酶活性 ,添加 EDTA(2 m mol L-1)可显著地抑制胞内核酸酶活性。高温 (6 5℃ )处理也能显著抑制胞内核酸酶活性  相似文献   

The Energetic and Nutritional Contribution of Glucose and Glycine Taken up from Natural Sea Water by Adult Marine Mussels   总被引：2，自引：0，他引：2  

William T.  Gorham 《Marine Ecology》1988,9(1):1-14

Abstract. The removal of glycine and glucose by freshly collected adult Mytilus edulis was determined using radiolabeled substances added to ambient concentrations of dissolved organic materials in freshly collected natural sea water. Uptake rates were calculated for substrate concentrations of 0.5 μM glycine and 1.0 μM glucose and were compared with the animals' energy and nitrogen demands as measured by oxygen consumption and ammonia excretion rates. Respiration and ammonia excretion rates as well as cither glycine or glucose removal were all determined for the same animals. The mean respiration rate was 670μl O₂ g^-1h^-1, the mean ammonia excretion rate 1.95 μg-at NH₄-g^-1 h^-1. The calculated uptake rates were 0.48 μmol -g^-1-h^-1 for free amino acids and 0.44 μmol-g^-1 h^-1 for free simple sugars. Such uptake rates could have contributed roughly 13% of the mussels' energy requirements or 10% of the mussels' nitrogen requirements assuming the following conditions: 0.5 μM concentration of free amino acids, 1.0μM concentration of simple sugars, uptake of total amino acids at a rate based on a weighted removal rate of glycine, alanine, serine, and glutamic acid, and uptake of simple sugars at a rate equal to that of glucose removal. It is apparent that simple organic substances dissolved in sea water may be of some benefit to mussels, especially when the substances occur in concentrations typical of coastal sea water.  相似文献   

Particulate matter and chemical-physical conditions of an inner sea: The Mar Piccolo in Taranto. A new statistical approach     

G. Alabiso  M. Cannalire  D. Ghionda  M. Milillo  G. Leone  O. Caciorgna 《Marine Chemistry》1997,58(3-4)

As part of the environmental recovery plan for the Mar Piccolo (Ionian Sea), a basin suffering especially from urban pollution, a study was planned on the modifications induced by the human activities to distinguish them from those due to the alternation of the seasons and the exchanges with the neighbouring basin of Mar Grande. The present paper deals with the chemical-physical characteristics of sea water and its particulate matter content is investigated as a part of this study. The physical, chemical and biological variables (stochastic variables for the model) are: chlorophyll a, proteins, carbohydrates, organic matter, dry weight, temperature, salinity, dissolved oxygen, pH, ultraviolet absorbance, phosphate, nitrite, nitrate, ammonia, silicate, photosynthetically available radiation (PAR) and energy. These variables have been sampled at 15 different stations during one year of monthly sampling. A preliminary analysis was carried out on the variables for detecting possible interactions among all the investigated parameters. To this purpose, and for all the variables, an original computer program for non-parametric statistical-evaluation and data-correlation was used to find correlation-guided hierarchy of variables. The relations among: Prot and Chl-a, Carb and Chl-a and OM and DW have been studied. The slopes of linear regression of (Prot, Chl-a) and (Carb, Chl-a) allowed us to detect different relations at different space-time areas. A nonlinear relation between OM and DW has been found as well. This treatment is a first approach to the construction of a mathematical model of the basin. Different areas, for sea water characteristics, were observed to occur in the basin, despite its small extension. This may be due to the reduced water exchanges and the different residential development along the coast. Innermost areas, less involved in the water mass circulation, were more affected by eutrophication.  相似文献   

坛紫菜孢子囊枝形成过程中生化组分的变化     

陈烨  裴鲁青  严小军  杨锐 《海洋学研究》2007,25(2):23-28

坛紫菜孢子囊枝在形成过程中,从培养开始至第4周,3种色素(叶绿素a、类胡萝卜素和藻胆蛋白)的含量和蛋白质的质量分数逐渐上升,在第4周时达到某一最高值后逐渐下降;碳水化合物的质量分数和藻胆蛋白与叶绿素a的比值均一直呈上升趋势,它们与孢子囊枝数量之间呈较明显的正相关;碳水化合物与蛋白质的比值在培养前期略有下降,随着丝状体进一步发育(4周后),该比值逐渐上升。  相似文献   

石油和油分散剂对藻类胞内外有机氮的影响     

孙林枫  王兴建 《海洋科学》1990,14(3):22-25

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小角刺藻生长过程中溶解游离氨基酸含量在海水中的变化   总被引：2，自引：1，他引：2  

陆田生  纪明侯 《海洋与湖沼》1997,28(3):256-261

于1986年12月-1987年2月在温度为25±1℃下培养小角刺藻，以HPLC法测定该藻在培养过程中海水的溶解游离氨基酸（DFAA）含量变化。结果表明，小角刺藻不仅是海水中DFAA的主要生产者，而且也是DFAA的消耗者。小角刺藻不仅在缺乏硝酸盐的时候要吸收DFAA，即使在硝酸盐充足的情况下也会吸收。在小角刺藻的生长初期，水体中DFAA的含量迅速降低，而在后期却又大大增高。在小角刺藻的不同生长阶段，水体中DFAA的组成也不同。这些都可以说明海洋中DFAA的含量、组成和地区分布是密切地同浮游植物群落的繁殖消亡过程相关联的。  相似文献