Event Title

Streptomyces Tolerance to Alkaline Conditions and Production of Calcite

Location

CSU Ballroom

Start Date

18-4-2016 10:00 AM

End Date

18-4-2016 11:30 AM

Student's Major

Biological Sciences

Student's College

Science, Engineering and Technology

Mentor's Name

Dorothy Wrigley

Mentor's Department

Biological Sciences

Mentor's College

Science, Engineering and Technology

Description

Concrete is prone to cracking and failure due to infiltrating water damage. Repair of cracks with calcium carbonate crystals (calcite) would prolong the life of concrete. Bacteria can promote calcite crystallization by acting as nucleation sites for calcite. This project focused on discovering the best environmental conditions in which three strains of bacteria could produce optimum amounts of calcite. The bacteria need to raise the pH or a least maintain the alkaline pH of the medium and cause the precipitation of the alkaline insoluble calcium carbonate. Two Streptomyces strains and one Bacillus strain, which enhance calcite production on agar plates, were tested for the ability to grow and alter the initial alkaline pH of media (pH8) with different carbon source. The initial and final pH of the cultures was monitored and monitoring growth by plate counts or changes in turbidity. Their ability to produce calcite with the same carbon sources in modified B4 medium was used for detecting calcite precipitation. Calcite production was measured by passing the bacteria and media with the calcite through a filter paper. The filter paper was dried and weighed. The amount of calcite was calculated from the change in weight of dry filter paper. Both the glucose based B4 and the peptone based B4 allowed the organism to grow but led to an acidic pH. Glucose in B4 was also more acidic. However, neither glucose nor peptone based B4 media resulted in significant precipitation of calcite.

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Apr 18th, 10:00 AM Apr 18th, 11:30 AM

Streptomyces Tolerance to Alkaline Conditions and Production of Calcite

CSU Ballroom

Concrete is prone to cracking and failure due to infiltrating water damage. Repair of cracks with calcium carbonate crystals (calcite) would prolong the life of concrete. Bacteria can promote calcite crystallization by acting as nucleation sites for calcite. This project focused on discovering the best environmental conditions in which three strains of bacteria could produce optimum amounts of calcite. The bacteria need to raise the pH or a least maintain the alkaline pH of the medium and cause the precipitation of the alkaline insoluble calcium carbonate. Two Streptomyces strains and one Bacillus strain, which enhance calcite production on agar plates, were tested for the ability to grow and alter the initial alkaline pH of media (pH8) with different carbon source. The initial and final pH of the cultures was monitored and monitoring growth by plate counts or changes in turbidity. Their ability to produce calcite with the same carbon sources in modified B4 medium was used for detecting calcite precipitation. Calcite production was measured by passing the bacteria and media with the calcite through a filter paper. The filter paper was dried and weighed. The amount of calcite was calculated from the change in weight of dry filter paper. Both the glucose based B4 and the peptone based B4 allowed the organism to grow but led to an acidic pH. Glucose in B4 was also more acidic. However, neither glucose nor peptone based B4 media resulted in significant precipitation of calcite.

Recommended Citation

Jallow, Kaddijatou and Ali Oku. "Streptomyces Tolerance to Alkaline Conditions and Production of Calcite." Undergraduate Research Symposium, Mankato, MN, April 18, 2016.
http://cornerstone.lib.mnsu.edu/urs/2016/poster-session-A/25