Biosynthesis of Polyhydroxyalkanoates from Defatted Chlorella Biomass as an Inexpensive Substrate

Microalgae biomass has been recently used as an inexpensive substrate for the industrial production of polyhydroxyalkanoates (PHAs). In this work, a dilute acid pretreatment using 0.3 N hydrochloric (HCl) was performed to extract reducing sugars from 10% (w/v) defatted Chlorella (DCB). The resulting HCl DCB hydrolysate renewable assess ability three bacterial strains, namely Bacillus megaterium ALA2, Cupriavidus necator KCTC 2649, and Haloferax mediterranei DSM 1411, produce PHA in shake flasks. results show that under 20 g/L derived sugar supplementation, cultivated strains successfully accumulated up 29.7–75.4% their dry cell weight (DCW). Among C. 2649 exhibited highest (7.51 ± 0.20 g/L, 75.4% DCW) followed by H. 1411 B. which content 3.79 0.03 (55.5% 0.84 0.06 (29.7% recorded, respectively. Along with PHA, maximum carotenoid 1.80 0.16 mg/L produced at 120 h cultivation increased 1.45- 1.37-fold, respectively, when biotransformation upscaled 1 L working volume fermenter. Based on FTIR 1H NMR analysis, polymers ALA2 were identified homopolymers poly(3-hydroxybutyrate). However, copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) 3-hydroxyvalerate fraction 10.5 mol% 1411.