NSF Minority Postdoctoral Research Fellowship for FY2008

这一行动为NSF 2008财年少数民族博士后奖学金提供了资金。该奖学金支持在东道主实验室为该研究员制定的研究和培训计划，该研究员还提出了扩大生物学参与度的计划。保拉·V·韦兰德的这项研究和培训计划的标题是《阐明光营养细菌中类胡萝卜素的生物合成和生理功能》，由麻省理工学院的黛安·K·纽曼教授赞助。古代地球的大气主要由二氧化碳、一些氮和基本上不含氧的物质组成。人们认为，通过氧气光合作用，蓝藻(也被称为蓝藻)负责地球大气的氧气。现代蓝藻是2-甲基类胡萝卜素的重要生产者，这是一种结构类似于胆固醇等甾醇的脂类。由于蓝藻是唯一能够进行氧合光合作用的微生物，所以在古代岩石和沉积物中发现的2-甲基合欢化石被用作蓝藻和氧合光合作用本身的生物标志物。然而，最近在另一种细菌-沼泽红假单胞菌中发现了显著的2-甲基类霍帕尼类物质的产生，该细菌也利用光合作用进行生长，但在这个过程中不产生氧气。该研究计划的主要目标是了解细菌为什么会产生2-甲基并吡喃类化合物，并确定这些分子是否是氧气光合作用的合适标记物。这项研究是为了鉴定沼泽红假单胞菌中产生2-甲基霍普诺所需的基因，然后创造不再能够产生2-甲基霍普诺的基因缺失突变体。这些突变体正被用来证明缺乏2-甲基杂环鸟苷如何影响这种有机体的生长、生理和结构。这项研究为分子地球生物学的跨学科培训提供了一个极好的机会，在细菌代谢方面进行了广泛的培训。更广泛的影响包括增加博士后水平上代表不足的群体的参与。这位研究员是一个榜样，并通过生物推广计划指导学生。

This action funds an NSF Minority Postdoctoral Fellowship for FY 2008. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Paula V. Welander is "Elucidating the biosynthesis and physiological function of hopanoid lipids in phototrophic bacteria" and is under the sponsorship of Professor Dianne K. Newman at the Massachusetts Institute of Technology. The atmosphere of the ancient Earth was composed primarily of carbon dioxide, some nitrogen, and essentially no oxygen. It is thought that, through oxygenic photosynthesis, cyanobacteria (also known as blue-green algae)were responsible for the oxygenation of the Earth's atmosphere. Modern cyanobacteria are significant producers of 2-methylhopanoids, which are lipids similar in structure to sterols such as cholesterol. Because cyanobacteria are the only microbes capable of oxygenic photosynthesis, 2-methylhopanoid fossils discovered in ancient rocks and sediments have been used as "biomarkers" for both cyanobacteria and oxygenic photosynthesis itself. However, significant 2-methylhopanoid production has been recently discovered in another bacterium, Rhodopseudomonas palustris, which also uses photosynthesis for growth, but does not produce oxygen in the process. The main objective of the research plan is to understand why bacteria produce 2-methylhopanoids and determine if these molecules are appropriate markers for oxygenic photosynthesis. This research is is identifying the genes required to produce 2-methylhopanoids in R. palustris and then create gene deletion mutants that are no longer able to produce 2-methylhopanoids. These mutants are being used to demonstrate how the lack of 2-methylhopanoids affects the growth, physiology and structure of this organism. This research provides an excellent opportunity for interdisciplinary training in molecular geobiology with extensive training in bacterial metabolism. The broader impacts include increasing the participation of an underrepresented group at the postdoctoral level. The Fellow is serving as a role model and mentoring students through outreach programs in biology.