Alcaligenes eutrophus forms PHB as a way of fixing carbon and as a form of intercellular storage [4]. When the bacterium runs out of extracellular carbon, PHB is broken down effectively and quickly into organic compounds to be reused. In fact, A. eutrophus is not the only bacterium that degrades PHB.
Lemoigne (1923-1927) discovered that B. megaterium releases [R]-3-hydroxybutyric in an aqueous environment. Wilkinson et al. (1958) also studied B. megaterium and figured out that this bacterium degrades PHB and releases both acetoacetic acid and acetic acid as byproducts. In 1962, Merrick et al., worked on B. rubrum and found that the bacterium self-catabolizes its “native” granules through hydrolysis with the aid of the enzyme depolymerase (sometimes referred as hydrolase). This was followed by Williamson et al., in 1967, who discovered a specific dehydrogenase that convertes [R]-3-hydroxybutyric acid to acetoacetic acid. Another enzyme that carries the synthesis of acetic acid from acetoacetic acid was classified by Dawes and his team in 1973.
Base on those discoveries above, the biodegradation of PHB into simple organic compounds can be done through any of these possible ways:
• PHB can be broken down through hydrolisis with the aid of depolymerase—an enzyme secreted by many bacteria and fungi. In 1965, Delafield, Doudoroff and co-workers identified some pseudomonas that treat PHB as their energy and carbon source.
• Many microorganisms have the ability to both catabolize PHB and metabolize [R]-3-hydroxybutyric acid.
• Depolymerases are associated with long alkyl chained PHA classes.
• Polyester depolymerases are found in many different organisms and their characteristics and structure have been well studied.
Alcaligenes eutrophus forms PHB as a way of fixing carbon and as a form of intercellular storage [4]. When the bacterium runs out of extracellular carbon, PHB is broken down effectively and quickly into organic compounds to be reused. In fact, A. eutrophus is not the only bacterium that degrades PHB. Lemoigne (1923-1927) discovered that B. megaterium releases [R]-3-hydroxybutyric in an aqueous environment. Wilkinson et al. (1958) also studied B. megaterium and figured out that this bacterium degrades PHB and releases both acetoacetic acid and acetic acid as byproducts. In 1962, Merrick et al., worked on B. rubrum and found that the bacterium self-catabolizes its “native” granules through hydrolysis with the aid of the enzyme depolymerase (sometimes referred as hydrolase). This was followed by Williamson et al., in 1967, who discovered a specific dehydrogenase that convertes [R]-3-hydroxybutyric acid to acetoacetic acid. Another enzyme that carries the synthesis of acetic acid from acetoacetic acid was classified by Dawes and his team in 1973.Base on those discoveries above, the biodegradation of PHB into simple organic compounds can be done through any of these possible ways:• PHB can be broken down through hydrolisis with the aid of depolymerase—an enzyme secreted by many bacteria and fungi. In 1965, Delafield, Doudoroff and co-workers identified some pseudomonas that treat PHB as their energy and carbon source.
• Many microorganisms have the ability to both catabolize PHB and metabolize [R]-3-hydroxybutyric acid.
• Depolymerases are associated with long alkyl chained PHA classes.
• Polyester depolymerases are found in many different organisms and their characteristics and structure have been well studied.
การแปล กรุณารอสักครู่..