Research I am a microbiologist with interests in understanding the biosynthesis and physiological function of “molecular fossils” or biomarkers in extant bacteria. Biomarker signatures in ancient rocks have been used to reconstruct important events in the Earth’s past, such as the first appearance of major groups of organisms, the catastrophic loss of biodiversity and the evolution of cyanobacteria and oxygenic photosynthesis. Despite the significant implications biomarker studies have on our interpretation of microbial evolution and of the Earth’s ancient environment, our understanding of the phylogenetic distribution and physiological function of most of these molecules in modern bacteria is quite limited. My research utilizes a combination of bioinformatics, microbial genetics, physiology, and biochemistry to address three general questions that can be applied to any biomarker: 1) what is its phylogenetic distribution in modern bacteria? 2) what are its physiological roles in modern bacteria? 3) what is the evolutionary history of its biosynthetic pathway?
Teaching My teaching will focus on two of my main interests: 1) microbial physiology and metabolism and 2) how molecular biosignatures are used to study microbial systems in both modern and ancient environments.
A distinct pathway for tetrahymanol synthesis in bacteria.Proceedings of the National Academy of Sciences of the United States of AmericaBanta, A. B., Wei, J. H., Welander, P. V.2015; 112 (44): 13478-13483
Elucidation of the Burkholderia cenocepacia hopanoid biosynthesis pathway uncovers functions for conserved proteins in hopanoid-producing bacteriaENVIRONMENTAL MICROBIOLOGYSchmerk, C. L., Welander, P. V., Hamad, M. A., Bain, K. L., Bernards, M. A., Summons, R. E., Valvano, M. A.2015; 17 (3): 735-750
Methane Oxidation and Molecular Characterization of Methanotrophs from a Former Mercury Mine Impoundment. MicroorganismsMicroorganisms Baesman, S. M., Miller, L. G., Wei, J. H., Cho, Y., Matys, E. D., Summons, R. E., Welander, P. V., Oremland, R. E.2015; 3 (2): 290-309
Diverse capacity for 2-methylhopanoid production correlates with a specific ecological nicheISME JOURNALRicci, J. N., Coleman, M. L., Welander, P. V., Sessions, A. L., Summons, R. E., Spear, J. R., Newman, D. K.2014; 8 (3): 675-684
Molecular indicators of microbial diversity in oolitic sands of Highborn Cay, BahamasGeobiologyEdgecomb, V. P., Bernhard, J. M., Beaudoin, D., Pruss, S., Welander, P. V., Shubotz, F., Mehay, S., Gillespie, A. L., Summons, R. E.2013; 11: 234-251
Identification and quantification of polyfunctionalized hopanoids by high temperature gas chromatography-mass spectrometryOrganic GeochemistrySessions, A. L., Zhang, L., Welander, P. V., Doughty, D. M., Summons, R. E., Newman, D. K.2013; 56: 120-130
Identification and characterization of Rhodopseudomonas palustris hopanoid biosynthesis mutantsGeobiologyWelander, P. V., Doughty, D. M., Wu, C. H., Mehay, S., Summons, R. E., Newman, D. K.2012; 10: 163-177
Discovery, taxonomic distribution, and phenotypic characterization of a gene required for 3-methylhopanoid productionProceedings of the National Academy of SciencesWelander, P. V., Summons, R. E.2012; 109: 12905-12910
Identification of the bacteriochlorophylls, carotenoids, quinones, lipids, and hopanoids of Candidatus Chloracidobacterium thermophilumJournal of BacteriologyGarcia Costas, A. M., Tsukatani, Y., Rijpstra, W. I., Schouten, S., Welander, P. V., Summons, R. E., Bryant, D. A.2012; 194: 1158-68
Using Taguchi-based statistics to produce robust PCR resultsBioprocessingWelander, P., Cantin, E., Lundberg, P.2011; 10: 22-26
Identification of a methylase required for 2-methylhopanoid production and implications for the interpretation of sedimentary hopanesProceedings of the National Academy of SciencesWelander , P. V., Coleman, M. C., Sessions, A. L., Summons, R. E., Newman, D. K.2010; 107: 8537-8542
Hopanoids play a role in membrane integrity and pH homeostasis in Rhodopseudomonas palustris TIE-1Journal of BacteriologyWelander, P. V., Hunter, R. C., Zhang, L., Sessions, A. L., Summons, R. E., Newman, D. K.2009; 191: 6145-6156
The continuing puzzle of the great oxidation eventCurrent BiologySessions, A. L., Doughty, D. M., Welander, P. V., Summons, R. E., Newman, D. K.2009; 19: R567-R574
Mutagenesis of the C1 oxidation pathway in Methanosarcina barkeri: new insights into the Mtr/Mer bypass pathwayJournal of BacteriologyWelander, P. V., Metcalf, W. W.2008; 190: 1928-1936
Tumor necrosis factor (TNF) protects resistant C57BL/6 mice against herpes simplex virus-induced encephalitis independently of signaling via TNF receptor 1 or 2Journal of VirologyLundberg, P., Welander, P. V., Edwards, 3rd, C. K., van Rooijen, N., Cantin, E.2007; 81: 1451-1460
Loss of the mtr operon in Methanosarcina blocks growth on methanol, but not methanogenesis, and reveals an unknown methanogenic pathwayProceedings of the National Academy of SciencesWelander, P. V., Metcalf, W. W.2005; 102: 10664-10669
Herpes simplex virus type 1 DNA is immunostimulatory in vitro and in vivoJournal of VirologyLundberg, P., Welander, P., Han, X., Cantin, E.2003; 77: 11158-11169
A locus on mouse chromosome 6 that determines resistance to herpes simplex virus also influences reactivation, while an unlinked locus augments resistance of female miceJournal of VirologyLundberg, P., Welander, P., Openshaw, H., Nalbandian, C., Edwards, C., Moldawer, L., Cantin, E.2003; 77: 11661-11673