Bioconversion of residual soybean oil into polyhydroxyalkanoates

Comparative analysis of various extraction processes based on economy, eco-friendly, purity and recovery of polyhydroxyalkanoate: A review

Bioplastics have been an interesting area of research and development in the last few decades. Normal plastics are made out of petroleum products, which is a non-renewable resource. Apart from that, its non-biodegradable nature makes it a serious threat to the environment, and hence a better alternative is needed. Bioplastics are synthesized by microorganisms and are biodegradable; this property makes them a promising alternative to normal plastic. However, the major drawback related to bioplastic is the high cost of its production. Polyhydroxyalkanoate (PHA) is a very popular biopolymer produced by different types of microbes. The review focuses on the different methods of extraction of PHA based on the percentage of purity, recovery, eco-friendly, and cost-effectiveness. There is a wide array of extraction methods reported to date, wherein there is the involvement of different types of solvents (like halogenated, non-halogenated, and green solvents) or mechanical or enzymatic methods. Each extraction process has its advantages and disadvantages. In this study, we have attempted to present a structured comparison of these different methods and highlight the factors that can be addressed for better extraction of PHA thereby making it a feasible alternative to commercial synthetic plastic.

Simultaneous production of polyhydroxyalkanoate and xanthan gum: From axenic to mixed cultivation

In the present study, mixed and axenic submerged cultures of Cupriavidus necator and Xanthomonas campestris were performed for simultaneous and individual PHA and XG productions using palm oil (Elaeis guineensis) as substrate. Rotational Central Compound Design (RCCD) was successfully used in the optimization of individual productions of PHA (3.39 g L^-1, Mw = 692.6 kDa) and XG (1.77 g L^-1, Mw = 36.6 × 10⁵ kDa). Novel simultaneous production of PHA (6.43 g L^-1, Mw = 629.2 kDa) and XG (1.98 g L^-1, Mw = 25.0 × 10⁵ kDa), executed in bacterial co-cultivation, revealed to be a successful strategy to increment polymer synthesis, especially PHA. XG bioconversions followed a general trend of lower production in co-culture. Culture configurations also altered polymers properties and characteristics.