Metabolic patterning of biosilicification     

Derek R. Amores  Lesley A. Warren   《Chemical Geology》2009,268(1-2):81-88

Here we show a discernibly unique biosilicification pattern for live, metabolically active Synechococcus cyanobacterial cell surfaces compared to dead Synechococcus cells under identical experimental conditions. The live cell treatments showed signs of cell division and the growth of fimbriae indicating metabolic activity during the 5-day silicification experiment. Live treatment cells were also recultivable after the experiments confirming their continued viability. The metabolically active live cyanobacteria treatment bound twice the amount of colloidal SiO₂ and held it more tightly compared to the dead cell treatment. Further, biosilicification of the live, actively metabolizing bacteria was unipolar, leaving the core surface largely unencrusted. In contrast, biosilicification of the dead cells was heterogeneous, occurring across the entire cell surface with no observable localized pattern. The directed biosilicification localization of live cell surfaces is likely a bacterial strategy to protect the cell functionality against the potentially inhibitory effects of mineral encrustation. Localization of silica biominerals to the polar end of the cell is also consistent with reported bacteria regulated cell polarity, which, under the experimental pH of 3, would enable localized differential attraction between the charged colloidal silica (+) particles and the bacterial cell polar surface (−). Our results show a novel metabolically-linked distinct colloidal SiO₂ biomineralization fingerprint, suggesting a putative biomineralization signature.  相似文献   

几种氨基酸对碳酸钙矿化的影响   总被引：1，自引：0，他引：1  

陈昕  任冬妮  冯庆玲  李胜荣 《矿物学报》2011,31(4):692-697

采用扩散法在CaCl2水溶液中加入不同氨基酸进行碳酸钙的体外矿化实验,利用扫描电子显微镜及拉曼光谱等方法对矿化结果进行观察和分析。结果表明,极性和碱性的氨基酸在pH值与其等电点不同的溶液中会发生解离,从而使自身荷电,并对碳酸钙的矿化产生影响;非极性的氨基酸对矿化基本没有影响。利用模板效应理论可以解释甘氨酸和丝氨酸对球文石沉淀结晶的诱导机理。  相似文献   

乳腺病变伴发生物矿化的类型及机制研究     

梅放  柳剑英  张燕  王长秋  鲁安怀  赵文雯  熊翠娥  张波 《矿物学报》2011,31(4):704-712

乳腺病变伴发生物矿化的类型多样、机制复杂。本试验对手术切除或粗针穿刺获得的乳腺脂肪坏死标本5例、乳腺增生症8例、乳腺纤维腺瘤7例及乳腺浸润性癌或原位癌6例分别进行常规HE（苏木素-伊红）染色、普鲁士蓝、茜素红S、Masson三色特殊染色及Ⅲ型胶原、Ⅳ型胶原免疫组织化学染色,以观察各种病变伴发矿化的常规病理学改变及无机、有机成分的差异。染色结果显示各种矿化物的主要无机成分均为钙盐。脂肪坏死和纤维腺瘤伴发的矿化均与Ⅲ型胶原有关,乳腺增生症伴发的矿化与Ⅳ型胶原有关,而乳腺导管原位癌矿化与上述两种胶原的关系不大。根据形态可将乳腺病变伴发的生物矿化分为坏死相关性矿化及非坏死相关性矿化。前者又可分为肿瘤性坏死相关性矿化和非肿瘤性坏死相关性矿化。非坏死相关性矿化可分为上皮相关性矿化及间质相关性矿化。乳腺病变类型不同,其伴发矿化的机制也不尽相同。  相似文献   

酸性环境下生物成因施氏矿物稳定性研究          下载免费PDF全文

谢越  周立祥 《地学前缘》2011,18(5):310-318

施氏矿物是酸性矿山废水中广泛存在的次生矿物,其形成和转化受环境pH值、温度和共存离子等条件影响。文中研究了酸性环境中生物成因施氏矿物和吸附了三价砷的生物成因施氏矿物,在不同温度和钾离子浓度条件下的稳定性。结果表明,老化温度的增加促进施氏矿物相的转变:4℃条件下,在15周的老化时间里,无砷及含砷施氏矿物均未发生相转变;而在40℃条件下,经过15周的老化,则无砷和含砷施氏矿物均发生了部分相转变。此外,钾离子浓度变化可以导致施氏矿物老化产物不同:生物成因施氏矿物在0.01mM钾离子条件下老化15周后的转化产物主要为针铁矿,在100mM钾离子条件下老化产物为黄钾铁矾和针铁矿。含As(Ⅲ)施氏矿物在0.01mM钾离子条件下老化15周后没有发生相转变,在100mM钾离子条件下发生了部分相转变,产物为黄钾铁矾。生物成因施氏矿物中的As(Ⅲ)使得矿物在环境中更加稳定。  相似文献   

In vivo and in vitro biomineralization in the presence of the inner-shell film of pearl oyster     

YAN Zhenguang  MENG Wei  LIU Zhengtao  YANG Suwen  LIU Xiaojun  SUN Juan  XIE Liping  ZHANG Rongqing 《海洋学报(英文版)》2011,30(1):87-93

The inner shell surface is the biomineralization site in shell formation and an inner-shell film covers it.This surface is composed of two regions:an outer calcitic region and an inner aragonitic region.In this study,some amalgamated calcite crystals were found in the calcitic region and some aragonitic "imprints" were found in the central part of the aragonitic region.The "imprints" are probably the trace of mantle cells that adhered to the inner shell surface when the shell was produced.Furthermore,to build a novel in vitro biomineralization system,the inner-shell film was detached from the shell and introduced to the calcitic crystallization solution.Crystallization experiments showed that nacre proteins could induce aragonite crystals in the novel system but inhibited calcite growth in the absence of the inner-shell film.These data suggested that the inner-shell film may induce aragonite growth in vivo by combining nacre proteins.  相似文献   

桂西金矿的生物成矿作用     

黄宏伟  乃中专 《南方国土资源》2002,15(1):19-24

生物成矿研究由来已久 ,但生物及其有机质演化在成矿中的作用长期得不到应有的重视。文章试图借鉴石油的成油理论 ,从生物及其有机质演化的角度对桂西右江盆地内部金矿的成矿作用作初步探讨。认为右江地区金矿的形成是生物 (特别是菌藻类生物 )的吸附和生物所产生的有机质热解、分异从而导致金的络合物形成 ,金元素活化、运移 ,在碳酸盐台地顶部超覆面 (不整合面 )上的细碎屑岩中因物理化学条件的变化而沉淀的结果。碳酸盐台地边缘是金矿成矿的有利场所。  相似文献   

醇羟基对碳酸钙矿物成核物相及界面能影响研究     

杨阳  朱辰  王洪涛  花浩  江锐捷  毛玮  赵良 《高校地质学报》2020,26(6):617-627

文章通过对醇类物质参与下的碳酸钙成核过程进行研究，探讨生物流体中常见的羟基对矿物物相以及界面能的影响。研究结果表明多羟基醇有利于亚稳定球文石的形成，醇的加入会增加方解石和球文石的界面能，醇的羟基定向吸附造成的吸附位密度降低是提升矿物界面能最可能的机制，而溶剂氢键数量决定了碳酸根的自由度，有利于对称度低且CO₃^{2 -} 不平行的球文石形成。水和乙醇—水体系氢键作用弱，界面能低的方解石物相成为热力学优势物相。研究结果凸显了生物成矿流体受羟基影响强烈，通过控制流体中羟基物质含量，生物体可以完全掌控碳酸钙物相的形成部位，加深了对生物成因碳酸钙形成过程的理解。  相似文献   

皱纹盘鲍外套膜cDNA表达文库的构建   总被引：1，自引：0，他引：1  

李静  张文兵  麦康森  张璐  艾庆辉  徐伟  谭北平  马洪明  刘付治国 《中国海洋大学学报(自然科学版)》2008,38(5)

  相似文献   

Biomineralization of organic matter in cobalt-rich crusts from the Marcus–Wake Seamounts of the western Pacific Ocean     

赵军  张海生  武光海  卢冰  PULYAEVAIrinaA  张海峰  庞雪辉 《海洋学报(英文版)》2014,33(12):67-74

Organic matter in cobalt-rich crust(CRC) from the Marcus–Wake Seamounts of the western Pacific Ocean, Sample CM1D03, has been analyzed to understand the source, geochemistry and mineralization of organic matter, and the mineralization environment. Biomarkers, including n-alkanes, isoprenoids, terpanes and sterols, have been detected in various layers of the CRC sample, using gas chromatography(GC) and gas chromatography–mass spectrometry(GC–MS). The content of organic carbon(OC) and its stable isotope(δ13C), and the combined features of the biomarkers show that the mineralized organic matter in CM1D03 CRC was mainly derived from microorganisms and lower plankton(e.g., bacteria and algae, respectively) from marine surface water, with some terrestrial higher plant components. The ratio of chloroform bitumen "A": OC was high in the CRC, between 10.51 and 20.66, showing significant migration characteristics of n-alkanes. Four mineralization categories of organic matter were recognized based on GC chromatograms of n-alkane molecules:(1) primitive type(bacteria and algae), which is characterized by moderately mature of n-alkanes preserving the original characteristics of the organic matter from microorganisms and lower plankton;(2) microbial degradation type, which is characterized by low contents of n-alkanes and rising baseline in the chromatogram, with the "bulge" being the products of organic matter by biodegradation;(3) organic matter migration type, which is characterized by low carbon number of n-alkanes with n C18 as the main peak carbon, without odd even predominance, and low concentrations of isoprenoids and hydrocarbons with high carbon number; and(4) organic matter hydrothermal type, which is characterized by relatively low concentration of small molecular weight n-alkanes, pristane, and phytane, accompanied by higher concentration of n-alkanes with carbon number greater than n C18. This study shows that biomarkers can record controlling factors of mineralization and their variation.  相似文献   

地塞米松和过氧化氢对合浦珠母贝珍珠层结构及基质蛋白表达的影响     

陈鹏  苏境坦  孔玮  王洪钟  张贵友  谢莉萍  张荣庆 《海洋科学》2014,38(11):7-15

分别用地塞米松(Dexamethasone,DEX)和过氧化氢(H2O2)处理合浦珠母贝(Pinctada fucata),研究其对贝珍珠层和基质蛋白表达的影响。扫描电镜观察显示,DEX可促进珍珠层生长,H2O2则抑制珍珠层生长。体外碳酸钙结晶实验表明,DEX处理组间液蛋白调控文石生成的趋势加强,并加速碳酸钙结晶速率;H2O2处理组相反。实时定量PCR实验显示,DEX处理组TGFβ和NF-кB信号通路关键因子pf-smad3、pf-rel等和基质蛋白Nacrein等基因表达水平明显降低,H2O2作用组则显著上升。由上述结果推测,DEX和H2O2可通过抑制或激活合浦珠母贝的TGFβ和NF-кB信号通路,从而调控与珍珠层形成相关的基质蛋白的表达,并影响珍珠层的结构;同时暗示贝的免疫体系和矿化系统可能存在协同作用,该作用机制具有生物进化学意义,并对养殖珍珠的培育具有借鉴作用。  相似文献