Isolation and Characterization of Soil Bacteria That Are Able to Degrade Organohalide

• Main Author: Nurani, Atika
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/32278
• Institution: Institut Teknologi Bandung

Organohalide compounds are often used in many industries such as in pharmacy, paint, and adhesive industries. These compounds are toxic and persistent in nature so they can accumulate in the environment and in the body of many organisms. There are some species of bacteria identified to be able to degrade these compounds and convert them into less-toxic compounds. Organohalide-degrading bacteria have dehalogenase, an enzyme catalyzes the break off of carbon-halogen bond. In this research, isolated bacteria from a soil near a pharmacy waste pipeline was grown with 1,2-dichloroethane (1,2-DCE) as the sole carbon source. From 24 single colonies picked from the medium, there were 3 colonies, colony 6, 7. And 15, that are able to grow well in minimal medium without NaCl with concentration of 1,2-DCE up to 30 mM, 40 mM, and 35 mM respectively. The growth patterns of these three isolates showed that the bacteria were in the lag phase after 36 hours. The degradation activities were measured by calculating the concentration of Cl- ions released into the medium using Bergmann dan Sanik methode. It was found that the concentration of Cl- released has a tendency to increase with the increase of the bacteria growth. In further test by varying organohalide concentrations, the three isolates were grown in the medium containing 0.01% (w/v) glucose. The result was shown that colony 6 and 7 were able to grow well in a media with 1,2-DCE concentration up to 200 mM and 150 mM while colony 15 was able to grow up to 250 mM. To obtain the optimum growth condition, he tree isolates were grown in three different minimum medium compositions. It was found that colony 6 and 15 were able to grow in minimum medium containing 0.01% (w/v) glucose and 10 mM 1,2-DCE, meanwhile colony 7 is able to grow best in the media containing only 0.01% (w/v) glucose. DNA chromosomes isolation of the three isolates was performed and identification of the bacteria using 16s rDNA typing shows that colony 6 has the similarity closest to Enterobacter sp., colony 7 has the closest similarity to Xanthomonadaceae bacterium clone t301E6, and there is no match up for colony 15 with the NCBI database.