Isolation and Characterization of Soil Bacteria Having Antibacterial Activity


Isolation and Characterization of Soil Bacteria Having Antibacterial Activity



Brenna Marie Reilly


This poster reflects research conducted as part of a course project designed to give students experience in the research process. Course: BIO 411L



Antibiotic resistance in bacteria against a single or multiple drugs is a burning issue worldwide. According to the 2019 Antibiotic/Antimicrobial Resistance (AR) threats report of the Centers for Disease Control and Prevention (CDC), more than 2.8 million antibiotic-resistance infections occur in the U.S. each year, and more than 35,000 people die as a result. Therefore, the current study was carried out to isolate and characterize soil bacteria having a new compound with antibacterial activity. Soil samples were collected from GPS coordinates of 39.73594418442152, -81.17545763942566 at a depth of 7.62cm. The weather was 16 Fahrenheit, even though the soil was hard, the deeper I dug the soil became moist and soil was collected and placed in a sterile test tube. The appearance of the soil was a dark brown. Individual bacteria from soil were separated and isolated using serial dilution techniques. Bacterial media such as Reasoners 2A Agar and Todd Hewitt were used for bacterial isolation. Six different bacterial isolates based on colony morphology, were screened for antibacterial efficacy against close relative bacteria to ESKAPE pathogens, such as B. subtilis and E. coli. Out of six, one bacterial isolate showed antibacterial activity against B. subtilis. Bacteria which showed the antibacterial activity against B. subtilis was characterized as gram-negative bacillus. Biochemical testing showed that bacteria was motile (by Sulfide Indole Motility), gelatinase positive (by gelatin Agar), non-lactose, sucrose and glucose fermenter (by triple Sugar Iron Agar) and citrate positive (examined by Simmons Citrate Agar). 16S ribosomal gene sequencing result is awaited. Organic extract of this bacteria furthered the antibacterial activity against B. subtilis on Todd Hewitt agar, while awaiting a test for toxicity to chia seeds. In future, organic extract from this bacteria will be characterized for structure of this active compound.

Publication Date


Project Designation

Course Project

Primary Advisor

Mrigendra Rajput

Primary Advisor's Department



Stander Symposium project, College of Arts and Sciences

United Nations Sustainable Development Goals

Good Health and Well-Being

Isolation and Characterization of Soil Bacteria Having Antibacterial Activity