Semi-scale production of PHAs from waste frying oil by Pseudomonas fluorescens S48

Abstract

The present study aimed at developing a strategy to improve the volumetric production of PHAs by Pseudomonas fluorescens S48 using waste frying oil (WFO) as the sole carbon source. For this purpose, several cultivations were set up to steadily improve nutrients supply to attain high cell density and high biopolymer productivity. The production of PHAs was examined in a 14 L bioreactor as one-stage batch, two-stage batch, and high-cell-density fed-batch cultures. The highest value of polymer content in one-stage bioreactor was obtained after 60 h (33.7%). Whereas, the two-stage batch culture increased the polymer content to 50.1% after 54 h. High-cell-density (0.64 g/L) at continuous feeding rate 0.55 mL/l/h of WFO recorded the highest polymer content after 54 h (55.34%). Semi-scale application (10 L working volume) increased the polymer content in one-stage batch, two-stage batch and high cell density fed-batch cultures by about 12.3%, 5.8% and 11.3%, respectively, as compared with that obtained in 2 L fermentation culture. Six different methods for biopolymer extraction were done to investigate their efficiency for optimum polymer recovery. The maximum efficiency of solvent recovery of PHA was attained by chloroform–hypochlorite dispersion extraction. Gas chromatography (GC) analysis of biopolymer produced by Pseudomonas fluorescens S48 indicated that it solely composed of 3-hydrobutyric acid (98.7%). A bioplastic film was prepared from the obtained PHB. The isolate studied shares the same identical sequence, which is nearly the complete 16S rRNA gene. The identity of this sequence to the closest pseudomonads strains is about 98–99%. It was probably closely related to support another meaningful parsiomony analysis and construction of a phylogenetic tree. The isolate is so close to Egyptian strain named EG 639838.

Production of biodegradable plastic by polyhydroxybutyrate (PHB) accumulating bacteria using low cost agricultural waste material

“…Sample bioplastic film was prepared by dissolving 50 mg PHB extract in 10 ml chloroform according to Rawia et al [15]. …”

Polyhydroxyalkanoates: Properties and chemical modification approaches for their functionalization

“…In a study, palladium (Pd) NPs were introduced into different polymer matrix and thermal degradation of these polymers were investigated. This study concluded that thermal degradation of polystyrene (PS), PP, and methyl methacrylate were decreased by Pd NPs, while thermal degradation of polyamide (PA) and poly(ethylene‐terephthalate) (PET) were enhanced. In another study the effect of silver sulfide on thermal degradation of PHB was studied and this study concluded that PHB is degraded at lower temperature in the presence of silver sulfide .…”

“…Polyhydroxyalkanoates are one of the biodegradable and biocompatible thermoplastics . These are larger molecules that are produced by Gram‐negative and Gram‐positive bacteria .…”

Production of polyhydroxyalkanoates (PHA) from a non‐lignocellulosic component of sugarcane bagasse: fueling a biobased economy

“…After incubation, the cells were harvested by centrifugation at 6000 rpm for 10 minutes and treated with sodium hypochlorite for 60 minutes. The cells were then successively treated with 5 ml acetone, methanol, and boiling chloroform with intermittent centrifugation . The treated cells were filtered and the filtrate was collected in a Makarthy tube.…”