2023 12 B1

BIOL446: Thermophilic Enzyme Activity in Hydrogenobacter hydrogenophilus

By: Ivy Lin

Department: Biology

Faculty Advisor: Dr. José R. De La Torre

Hydrogenobacter hydrogenophilus, a thermophilic bacteria that belong to the Aquaficota family, must survive in a hot-spring environment in which the temperatures tend to vary from 72-76°C. An important part of the survival of thermophilic bacteria is heightened metabolism and the enzymes and proteins that protect their biological bonds from breaking in higher temperatures. The enzymes enable the physical and chemical bonds to be kept stable. Thermophiles also show increased DNA recombination and gene transfer in order to reduce the chances of DNA damage when in higher temperatures. In prior studies, it has been found that thermophiles are able to survive in higher temperatures due to the stability of their membrane lipids. Gram-negative bacteria like H. hydrogenophilus have a thin peptidoglycan layer that is beneath a Lipopolysaccharide layer. It is crucial that these two layers have strong bonds in order for bacteria to survive as heat tends to break the bonds that hold the two membrane layers together for non-thermophilic bacteria. In this project, I have found many enzymes that protect other thermophilic bacteria from heat such as alpha-Amylases found in Thermococcus profundus which contributes to food production and digestion. Looking into more metabolic and bond-strengthening enzymes, comparing the known enzymes found in other thermophilic bacteria will help determine which enzymes in H. hydrogenophilus contribute to its survival in a 72-76°C environment.