Title

The Effects of Acidification of Swine Waste on Bacterial Growth

School Name

South Carolina Governor's School for Science & Mathematics

Grade Level

12th Grade

Presentation Topic

Microbiology

Presentation Type

Mentored

Abstract

A fundamental issue of keeping pigs on farms is the disposal and maintenance of their waste. Typically funneled into a lagoon by spraying the waste through slates in the pigs’ quarters with water, this waste contains potentially harmful bacteria, including potentially antibiotic resistant strains. In addition to the risks of exposure, this waste is also used as fertilizer for food given to livestock. This waste is subjected to antibiotics, creating a dangerous selection for these antibiotic resistant traits. Based on research in European countries such as Denmark and Sweden, it was hypothesized that acidifying the waste could efficiently eliminate the bacteria. We attempted to determine the most effective pH and time of exposure for bacterial death. By adding sulfuric acid to liquified pig waste, we lowered the pH of the waste to pH 6, 4.5, 3, and 2. We collected samples zero, one, three, and twenty-four hours after acidification. For each experimental pH, we then incubated diluted samples on plates for approximately 24 hours. A pH of 2 resulted in the most bacteria death within three hours of acidification. The next step is to evaluate the cost of acidification for farmers based on the volume of their waste pond. This would enable the farmers to dispose of the waste in a safer and more profitable way. It also benefits the consumer, since antibiotic resistance could potentially be avoided.

Location

Founders Hall 213 B

Start Date

3-30-2019 11:00 AM

Presentation Format

Oral Only

Group Project

No

COinS
 
Mar 30th, 11:00 AM

The Effects of Acidification of Swine Waste on Bacterial Growth

Founders Hall 213 B

A fundamental issue of keeping pigs on farms is the disposal and maintenance of their waste. Typically funneled into a lagoon by spraying the waste through slates in the pigs’ quarters with water, this waste contains potentially harmful bacteria, including potentially antibiotic resistant strains. In addition to the risks of exposure, this waste is also used as fertilizer for food given to livestock. This waste is subjected to antibiotics, creating a dangerous selection for these antibiotic resistant traits. Based on research in European countries such as Denmark and Sweden, it was hypothesized that acidifying the waste could efficiently eliminate the bacteria. We attempted to determine the most effective pH and time of exposure for bacterial death. By adding sulfuric acid to liquified pig waste, we lowered the pH of the waste to pH 6, 4.5, 3, and 2. We collected samples zero, one, three, and twenty-four hours after acidification. For each experimental pH, we then incubated diluted samples on plates for approximately 24 hours. A pH of 2 resulted in the most bacteria death within three hours of acidification. The next step is to evaluate the cost of acidification for farmers based on the volume of their waste pond. This would enable the farmers to dispose of the waste in a safer and more profitable way. It also benefits the consumer, since antibiotic resistance could potentially be avoided.