Biosynthesis and Characterization of Bioplastic Polyhydroxybutyrate from Halophilic Bacterium Halomonas elongata BK-AB8

• Main Author: Falahuddin, Wendi
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/32235
• Institution: Institut Teknologi Bandung

Bioplastics are biodegradable biopolymer synthesized by bacteria. Bioplastics are typically produced by bacteria when they grow in the medium containing minimum amount of key nutrients, such nitrogen, magnesium, and phosforus but rich of carbon source. It has been known that some bacteria from the genus Halomonas can produce bioplastics compound called as polyhydroxybutirate (PHB). In the present study, we evaluated the potential of Halomonas elongata BK-AB8 in producing PHB. The bacteria was grown on the medium containing nile red and the grown bacterial colony exhibited orange luminescence when exposed under UV light indicating that the bacteria was able to produce bioplastics. Production of bioplastic have been done by growing the bacteria in the modified High Medium (HM) at 37 °C for 22 hours with aeration rate of 150 rpm. The produced bioplastics was extracted by using the mixture of chloroform-NaOCl (1: 1), and then the soluble bioplastics was precipitated with methanol solution. The highest efficiency of bioplastics production by Halomonas elongata BK-AB8 was about 24.7% using glucose as the main carbon resource. FTIR characterization to bioplastic sample showed high similarity to the profile of polyhydroxybutyrate (PHB). Further characterization by Thermogravimetry Analysis (TGA) showed that our PHB sample was degraded at temperatures above 210 oC. Differential Scanning Calorimetry (DSC) analysis identified two agregated PHB structure with melting temperature at 119.3 oC, and 161.8 oC.