Polyhydroxyalkanoates(PHA)have been produced by some bacteria as bioplastics for many years.Yet their commercialization is still on the way.A few issues are related to the difficulty of PHA commercialization:namely,hi...Polyhydroxyalkanoates(PHA)have been produced by some bacteria as bioplastics for many years.Yet their commercialization is still on the way.A few issues are related to the difficulty of PHA commercialization:namely,high cost and instabilities on molecular weights(Mw)and structures,thus instability on thermo-mechanical properties.The high cost is the result of complicated bioprocessing associated with sterilization,low conversion of carbon substrates to PHA products,and slow growth of microorganisms as well as difficulty of downstream separation.Future engineering on PHA producing microorganisms should be focused on contamination resistant bacteria especially extremophiles,developments of engineering approaches for the extremophiles,increase on carbon substrates to PHA conversion and controlling Mw of PHA.The concept proof studies could still be conducted on E.coli or Pseudomonas spp.that are easily used for molecular manipulations.In this review,we will use E.coli and halophiles as examples to show how to engineer bacteria for enhanced PHA biosynthesis and for increasing PHA competitiveness.展开更多
基金This research was financially supported by a grant from Ministry of Sciences and Technology(Grant No.2016YFB0302504)grants from National Natural Science Foundation of China(Grant No.31430003)Tsinghua President Fund also supported this project(Grant No.2015THZ10).
文摘Polyhydroxyalkanoates(PHA)have been produced by some bacteria as bioplastics for many years.Yet their commercialization is still on the way.A few issues are related to the difficulty of PHA commercialization:namely,high cost and instabilities on molecular weights(Mw)and structures,thus instability on thermo-mechanical properties.The high cost is the result of complicated bioprocessing associated with sterilization,low conversion of carbon substrates to PHA products,and slow growth of microorganisms as well as difficulty of downstream separation.Future engineering on PHA producing microorganisms should be focused on contamination resistant bacteria especially extremophiles,developments of engineering approaches for the extremophiles,increase on carbon substrates to PHA conversion and controlling Mw of PHA.The concept proof studies could still be conducted on E.coli or Pseudomonas spp.that are easily used for molecular manipulations.In this review,we will use E.coli and halophiles as examples to show how to engineer bacteria for enhanced PHA biosynthesis and for increasing PHA competitiveness.
