...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Marine ecology progress series >Dynamics and compositional changes in extracellular carbohydrates in estuarine sediments during degradation
【24h】

Dynamics and compositional changes in extracellular carbohydrates in estuarine sediments during degradation

机译：降解过程中河口沉积物中细胞外碳水化合物的动态和组成变化

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Microphytobenthic biofilms in estuarine sediments, consisting of photosynthetic microal-gae, heterotrophic bacteria and their associated exopolymers, contain high concentrations of water-soluble colloidal carbohydrates that can be separated using ethanol precipitation into low molecular weight (LMW) carbohydrate and colloidal extracellular polymeric substances (cEPS). These carbohydrate-rich components are potentially a significant carbon source, but utilisation processes are not well described. Short-term (24 h) degradation studies using sediment slurries with enhanced colloidal carbohydrate and cEPS concentrations found rapid increases in LMW carbohydrate concentrations during the first 4 h, with subseguent utilisation of LMW carbohydrate and cEPS after 8 to 24 h. The cEPS contribution to the colloidal carbohydrate pool increased (16 to between 67 and 97 %) in control and colloidal carbohydrate-enriched slurries, with decreasing glucose and increasing mannose and xylose contents within the EPS fraction after 24 h, suggesting initial utilisation of glucose-rich components in preference to more complex EPS. When cEPS concentrations were increased (cEPS-enrichment), there was greater EPS utilisation, and a decline in the relative contribution of EPS (72 to 31 % of the colloidal carbohydrate fraction), without significant change in the monosaccharide composition in the cEPS fraction. Using selective media with cEPS as a sole carbon source, a P-proteobacterium Variovorax sp. Alr1 was isolated. Variovorax sp. Alrl grew rapidly on cEPS as a sole carbon source, with increasing β-glucosidase activity and the production of new EPS rich in rhamnose, galactose and fucose, but showed only limited growth on EPS extracted from sediment using a hot-bicarbonate extraction procedure, despite increases in β-glucosidase and aminopeptidase activity. Differences in the short-term lability of different fractions of sediment carbohydrate and the ability of a heterotroph to utilise these fractions suggests a range of different heterotrophic bacteria may be involved in the complete degradation of EPS in situ.
机译：由光合微藻，异养细菌及其相关的外聚合物组成的河口沉积物中的微底栖生物膜含有高浓度的水溶性胶体碳水化合物，可通过乙醇沉淀将其分离为低分子量（LMW）碳水化合物和胶体细胞外聚合物（ cEPS）。这些富含碳水化合物的成分可能是重要的碳源，但利用过程并未得到充分描述。使用胶体碳水化合物和cEPS浓度增加的沉积物浆料进行的短期（24 h）降解研究发现，在最初的4 h中，LMW碳水化合物的浓度迅速增加，而在8至24 h之后，LMW碳水化合物和cEPS的使用随之增加。对照和富含胶体碳水化合物的浆液中，cEPS对胶体碳水化合物池的贡献增加了（16％，介于67％至97％之间），随着葡萄糖的减少以及24小时后EPS馏分中甘露糖和木糖含量的增加，表明了葡萄糖-葡萄糖的最初利用丰富的组件优先于更复杂的EPS。当cEPS浓度增加（cEPS富集）时，EPS利用率更高，EPS的相对贡献下降（胶态碳水化合物分数的72％至31％），而cEPS分数中的单糖组成没有明显变化。使用带有cEPS的选择性培养基作为唯一碳源的P-变形杆菌Variovorax sp。 Alr1已分离。 Variovorax sp。 Alrl在cEPS作为唯一碳源的情况下迅速增长，具有增加的β-葡萄糖苷酶活性以及富含鼠李糖，半乳糖和岩藻糖的新型EPS的产生，但尽管采用热碳酸氢盐萃取程序，但从沉积物中提取的EPS却仅表现出有限的增长，尽管增加了β-葡萄糖苷酶和氨肽酶的活性。沉积物碳水化合物不同馏分的短期不稳定性和异养菌利用这些馏分的能力的差异表明，一系列不同的异养菌可能参与了EPS原位的完全降解。

著录项

  • 来源
    《Marine ecology progress series》 |2009年第2009期|45-58|共14页
  • 作者

    Tanja Hofmann; Astrid R. M. Hanlon; Joe D. Taylor; Andrew S. Ball; A. Mark Osborn; Graham J. C. Underwood;

  • 作者单位

    Department of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK;

    Department of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK;

    Department of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK;

    Department of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK School of Biological Sciences, Flinders University of South Australia, Adelaide, GPO Box 2100, Adelaide SA5100, Australia;

    Department of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK;

    Department of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, UK;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

    Biofilms; EPS; microphytobenthos; exopolymers; degradation; mudflats;

    机译：生物膜;每股收益;微型底栖动物外聚合物;降解;泥滩;

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号