Novel Method of Culturing Bacteria Using Soil Extract and Nutrient-Rich Broths

Presented by:
Duy Nguyen & Sarah Huang (Grinnell College)

The misuse of antibiotics and the lack of development for novel antimicrobial compounds have culminated in an antibiotic resistance crisis that threatens the life of humans. Various strategies have been proposed to overcome this crisis, one of which is to find compounds in unknown bacteria through different techniques of bacterial culturing. With the same goals in mind, we investigated our method of combining soil extract with nutrient-rich broths to create compound agars. We designed a multifactorial experiment, blocked by temperatures of incubation and pathogens in the soft agar overlay, to assess the efficiency of these agars in growing more diverse bacterial colonies and colonies with antimicrobial characteristics. Our results indicated that compound agars provided a suitable environment for a wide range of bacteria but original soil extract agar produced more colonies with antimicrobial characteristics. In the future, more advanced techniques such as gene sequencing should be included for better assessment of diversity and future studies should narrow on the pathogens to potentially explore other antimicrobial mechanisms.