Albert Lab Research

Dan Albert's research is aimed broadly at understanding the cycling of carbon, nitrogen, and sulfur in sedimentary environments and microbial mats. He is interested in the rates and mechanisms of organic matter decomposition in anaerobic systems, particularly the coupling of fermentative and terminal metabolic processes (e.g., sulfate reduction and methanogenesis) and the specific roles of low-molecular weight fermentation products, such as formate, acetate, and propionate, in this coupling. He has studied these processes in coastal sediments for several years, and has also worked on the generation of these organic acids in high-temperature hydrothermal settings, where they are formed abiotically through thermal breakdown of organic materials in sediments (Guaymas Basin) and through presumed reaction of CO2 with hydrogen in non-sedimented hydrothermal settings (Juan de Fuca ridge sites). He is seeking funding to do further work in Guaymas on sulfur and organic acid cycling in collaboration with the Teske and Martens labs (see above) and independently to pursue work on the Juan de Fuca ridge.

• C, N, and S-cycling in hypersaline mats
This study (funded by NASA’s Astrobiology program), which involves several researchers from the NASA-Ames lab and other universities, seeks understanding of carbon and energy flow from phototrophs to heterotrophs in two mat types from hypersaline lagoons in Guererro Negro, Mexico. Cyanobacteria in the mats store glycogen during daylight hours and ferment this glycogen at night, producing hydrogen, lactate, acetate, formate and propionate. This fermentation is used, in part, to fuel nitrogen fixation by the cyanobacteria. The fermentation products serve as substrates for heterotrophs living in the mat, such as sulfate reducing bacteria, which are also capable of nitrogen fixation. We are investigating this sharing of resources as a syntrophic interaction between the members of this type of primitive community. Phototrophs fermenting glycogen benefit thermodynamically from the removal of their fermentation products, while the heterotrophs receive a steady diet of desireable (albeit low nitrogen) substrates that enables them to grow and fix their own nitrogen, if necessary. The result is greater nitrogen fixation by the community as a whole.