Can B-vitamins control phyto-and-bacterioplankton successions in a coastal upwelling region?

B 族维生素能否控制沿海上升流区域浮游植物和细菌的演替？

• 批准号: 1435666
• 负责人: Sergio Sanudo-Wilhelmy
• 金额: $ 70万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1435666&HistoricalAwards=false
• 关键词: vitamins; control; phyto; bacterioplankton; successions

B-vitamins (thiamin (B1), biotin (B7), and cobalamin (B12)) are organic molecules used by all organisms for many biochemical reactions ranging from DNA and amino acid synthesis to carbon dioxide assimilation. Despite their metabolic importance, many marine organisms cannot make them and need to obtain them from the environment. Because the requirement for a specific vitamin is different for different organisms, changes in the species composition of algae could be explained by their different B-vitamin requirements. For example, changes in the biological properties of waters during an algal bloom (removal of needed vitamins and release of other vitamins) may favor algae that require the vitamin released by the previous bloom (setting up a floral succession). This selective preconditioning of the waters may be one factor in the seasonal succession of algal species. However, evaluating the role of vitamins in marine ecology has been difficult. No study to date has been comprehensive enough to estimate the importance of vitamins in primary productivity and species succession. This is especially true in coastal upwelling regions that although relatively small in area, are orders of magnitude more productive than their open-ocean counterparts. In fact, those regions contribute a significant portion of the world fisheries. Therefore, in order to try to predict future changes in the world ocean due to human activity, the variables that influence or control the algal communities that dominate the very productive food chains of upwelling regions need to be identified. Undergraduate and graduate education will be furthered through active participation in the joint laboratory experiments and fieldwork. This project will support the dissertation work of one graduate student.This study will investigate how the availability of B-vitamins affects the dynamics of algal- and bacterioplankton population growth in coastal waters of an upwelling region off Southern California. This comprehensive field investigation will determine in situ temporal concentrations of several dissolved and particulate B-vitamins, inorganic micro- and macronutrients, concurrently with seasonal changes in phytoplankton and bacterial abundances and species composition at a long-term time series station within the San Pedro Basin near Los Angeles. Those measurements will be complemented with field incubation experiments with natural plankton assemblages to study the effect of organic and inorganic nutrient amendments on phytoplankton and bacterial community structure. This study will establish for the first time that the availability of ambient B-vitamins influence algal and bacterial species succession in a highly productive coastal upwelling region and that multiple and differing B-vitamin requirements limit growth of some phytoplankton species in those areas. Furthermore, this study will try to show that coastal upwelling transports some B-vitamins to the phytoplankton community in the photic zone from bacterially-influenced source waters within the upper mesopelagic zone.

B-维毒素（硫胺素（B1），生物素（B7）和钴胺素（B12）是所有生物体使用的有机分子，用于许多生化反应，从DNA和氨基酸合成到二氧化碳同化。尽管它们具有代谢的重要性，但许多海洋生物仍无法使它们成为环境中的它们。由于对不同生物的特定维生素的需求是不同的，因此藻类物种组成的变化可以通过其不同的B-Vitamin要求来解释。例如，藻华期间水的生物学特性的变化（去除所需的维生素和其他维生素的释放）可能有利于藻类，藻类需要先前的花朵释放的维生素（建立花卉继承）。水域的选择性预处理可能是藻类物种季节性继承的一个因素。但是，很难评估维生素在海洋生态学中的作用。迄今为止，还没有足够全面的研究来估计维生素在主要生产力和物种继承中的重要性。在沿海上升流地区尤其如此，尽管区域相对较小，但其生产率比其开放式海洋对应物高。 实际上，这些地区贡献了世界渔业的很大一部分。因此，为了试图预测由于人类活动而导致的世界海洋的未来变化，需要确定影响或控制占主导地位的藻类社区的变量，需要确定上升地区的富有生产性食品链。本科和研究生教育将通过积极参与联合实验室实验和实地调查来进一步进一步。 该项目将支持一名研究生的论文工作。这项研究将研究B-Vitamins的可用性如何影响南加州南部地区沿海地区沿海水域的藻类和细菌群人口增长的动态。 这项全面的现场调查将确定几种溶解和颗粒物B-维生素，无机微量营养素的原位时间浓度，同时，浮游植物的季节性变化以及细菌丰度的季节性变化以及细菌的丰度以及物种组成以及长期时间序列级别的Sando Pedro Basin附近的长期时间序列。这些测量将与天然浮游生物组合的现场孵育实验相辅相成，以研究有机和无机养分修正案对浮游植物和细菌群落结构的影响。这项研究将首次确定环境B-Vitamin的可用性在高生产力的沿海上升流域中影响藻类和细菌物种的继任，并且该地区某些浮游植物物种的多种和不同的B-Vitamin需求限制了某些浮游植物的生长。此外，这项研究将试图表明，沿海上升流将一些B-Vitamin运送到光学区域的浮游植物群落，从上介质区域内受细菌影响的源水。