CAREER: Investigating the relationship between giant sulfur bacteria and microfossil-bearing phosphorites.

职业：研究巨型硫细菌与含有微化石的磷矿之间的关系。

• 批准号: 1057119
• 负责人: Jake Bailey
• 金额: $ 46万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-15 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1057119&HistoricalAwards=false
• 关键词: CAREER; Investigating; relationship; between; giant

Phosphatic mineral deposits are well known for their exquisite preservation of soft tissue ? including fossilized cells. Large septate filaments interpreted as the oldest eukaryotes are preserved in 1.6 billion-year-old phosphorites from the Vindhyan Basin in Central India, and the oldest putative metazoans are preserved as phosphatized symmetrical cell clusters in the 600-milion-year-old Doushantuo Formation in southern China. Interestingly, large vacuolate sulfur-oxidizing bacteria are thought to mediate modern phosphogenesis, and commonly possess morphologies that closely resemble both the Vindhyan filaments and the Doushantuo globular microfossils. Could the Vindhyan or Doushantuo microfossils represent vacuolated sulfur bacteria, rather than eukaryotes? Could these microfossils provide evidence of the ancient mediation of phosphorites by sulfur bacteria? In the case of the Doushantuo microbiota, some microfossils are clearly eukaryotic, and likely metazoan in origin, while others cannot be easily interpreted as animals ? but are the bacterial and animal interpretations mutually exclusive? Other ancient and recent phosphorite deposits also possess structures that might well represent fossilized sulfur bacteria, but criteria for their recognition are not yet established. The PI?s research group will: 1) investigate newly-discovered modern sulfur bacteria that are partially entombed in phosphatic minerals; 2) perform phosphatization experiments with modern sulfur bacteria to investigate the taphonomy of phosphatized bacteria; 3) compare modern phosphatized sulfur bacteria with ancient microfossils from Proterozoic and Phanerozoic phosphorites; and 4) use observations of modern sulfur bacteria to develop new criteria for differentiating fossils of giant sulfur bacteria from those of microbial eukaryotes - including embryonic metazoans.The research component of this proposal is tied closely to an education and outreach plan that develops new undergraduate and graduate courses as the foundation of a geobiology curriculum at the University of Minnesota. A graduate student who will work on the projects describer herein will also be supported and mentored throughout the grant period. The education and outreach plan also increases research opportunities for military veterans through the establishment of a summer research experience for student veterans, as well as providing outreach to high school students and underrepresented minorities through participation in the NSF-funded North Star STEM Alliance, the UMN Exploring Careers in Engineering and Physical Science Program, and the annual meeting of the Society for the Advancement of Chicanos and Native Americans in Sciences.

磷酸盐矿床因其对软组织的精美保存而闻名？包括化石细胞。印度中部 Vindhyan 盆地 16 亿年前的磷岩中保存着被认为是最古老的真核生物的大型隔膜丝，而中国南部 6 亿年前的陡山沱组中则以磷化对称细胞簇的形式保存了最古老的假定后生动物。有趣的是，大型液泡硫氧化细菌被认为介导现代磷发生作用，并且通常具有与温迪亚丝和陡山沱球状微化石非常相似的形态。温迪亚或陡山沱微化石是否代表空泡硫细菌，而不是真核生物？这些微化石能否提供古代硫细菌介导磷矿的证据？就陡山沱微生物群而言，一些微化石显然是真核生物，并且可能起源于后生动物，而其他微化石则不能轻易解释为动物？但细菌和动物的解释是相互排斥的吗？其他古代和现代的磷矿矿床也具有很可能代表化石硫细菌的结构，但其识别标准尚未建立。 PI 的研究小组将： 1) 研究新发现的现代硫细菌，这些细菌部分埋藏在磷酸盐矿物中； 2）用现代硫细菌进行磷酸化实验，研究磷酸化细菌的埋藏学； 3）将现代磷化硫细菌与元古代和显生宙磷矿的古代微化石进行比较； 4）利用对现代硫细菌的观察来制定新标准，以区分巨型硫细菌化石与微生物真核生物（包括胚胎后生动物）的化石。该提案的研究部分与一项教育和推广计划密切相关，该计划开发新的本科生和研究生课程，作为明尼苏达大学地球生物学课程的基础。将从事本文描述的项目的研究生也将在整个资助期内得到支持和指导。该教育和外展计划还通过为退伍军人学生建立暑期研究经验，增加退伍军人的研究机会，并通过参加 NSF 资助的北极星 STEM 联盟、UMN 探索工程和物理科学职业计划以及奇卡诺人和美洲原住民科学促进会年会，为高中生和代表性不足的少数族裔提供外展活动。