Desulfovibrio vulgaris Hildenborough, or DvH, is an anaerobic sulfate-reducing bacterium (SRB) that is often used as a model organism in the lab because its genome is widely known, and therefore hypotheses can be postulated an tested with increased accuracy. As a strict anaerobe, DvH requires a completely oxygen-free environment to live and thrive, meaning that in nature it is found only in particular environments such as deep saltwater, sewage, soil, and the digestive tracts of other living organisms. Studying anaerobes has only recently been made possible due to the development of technology needed to produce an anaerobic environment, and much still remains to be discovered about their energy metabolisms. In the case of DvH, research often focuses on the bacteria’s reduction and bioremediation abilities for certain kinds of metallic pollutants, including uranium and chromium. While the DvH bacterium does have an economic impact on oil-drilling fields because of its tendency to eat away at expensive iron tubing and equipment, its reduction of metals and sulfur has largely positive implications including improved soil and water health. DvH, along with other SRBs and microorganisms, plays a vital role in the sulfur cycle. When sulfates produced by volcanic activity and fossil fuel combustion enter the soil, they are not ready for reuse by organisms. It is not until the sulfates have been reduced to elemental sulfur that plants can utilize the nutrient, making SRBs a key part of the system. Understanding the reduction pathways and further exploring the genetic processes used by DvH to reduce harmful materials may allow scientists to propose and test experiments on the effective utilization of these bacteria and other SRBs to help cleanse various environments of toxic pollutants.
Daaniya and Anne performed multiple growth-curve experiments using several mutants that they identified in the beginning of their internship. The goal of their research was to further examine the metabolic processes of DvH, where the manipulated variable in question was the type of media in which DvH was growing. They inoculated the growth tubes, recorded the optical density (or absorbance) of the bacterial growth at specified time points, and later analyzed the data in graphs. They found that not only did the control, or wild type, react differently in changing media, but that the different mutant strains responded in unexpected ways. These findings set the stage for future research to be done to explain the divergence of certain mutants from the control data, which may lead to interesting discoveries about the metabolic pathways of SRBs and DvH.