Improving biological production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) co-polymer: a critical review

Abstract Although poly(3-hydroxybutyrate- co -3-hydroxyvalerate) (PHBV) is the most promising biopolymer for petroleum-based plastics replacement, low processes productivity as well high sale price represent a major barrier its widespread usage. The present work examines comparatively existing methods to enhance yield of PHBV co-polymer biologically produced and/or reduce their costs. study addressed researchers working on development new biological production improvement those currently used. At this aim, authors have considered analysis some crucial aspects related substrates and microorganism’s choice. strategies been individuated, presented discussed, either based single aspect (type substrate or microorganism) combined microorganism). Process operating conditions discussed well. indicates that addition 3HV precursors capable dramatically hydroxyvalerate fraction in biopolymers. On other hand, due costs precursors, utilization wild bacterial species produce from unrelated carbon sources (i.e. no precursors) also can be valuable strategy reduction. Moreover, metabolic engineering techniques successfully used promote precursors-independent biosynthesis pathways process productivity. use mixed cultures extremophile bacteria avoids need sterile conditions, therefore favours scale-up. organic waste plays key role sharp reduction Finally, selection suitable substrate-microorganism combination cannot separated by adoption an appropriate choice reactor configuration abiotic factors. Graphic abstract