PHA biosynthesis by using palm oil-based carbon sources | Biodegradation of PHA | Cyanobacteria | Molecular level study

Research

PHA biosynthesis by using palm oil-based carbon sources

Among the key features of tomorrow’s plastics are eco-friendly characteristics and sustainability. Microbial polyhydroxyalkanoates (PHAs) have attracted research and commercial interest because they can be used as biodegradable thermoplastics that can be produced from renewable resources. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) [P(3HB-co-3HHx)] is currently the most promising bioplastic because of its properties that resemble polypropylene (PP) and low-density polyethylene (LDPE). Further studies have been done to lower the cost of production of P(3HB-co-3HHx) by using renewable resources that are cheap and readily available. Results from shake flasks culture show that various palm oil products can be used to produce P(3HB-co-3HHx) at high yield and constant quality.


Ralstonia eutropha H16 with P(3HB-co-3HV) at 36 h
Poly(3-hydroxybutyrate-co-3-hydroxyvalerate [P(3HB-co-3HV)] is another interesting polymer due to its hardness and excellent processability. Currently, we are able to produce high amount of this copolymer (up to 90 wt%) by using Wautersia eutropha H16 with the combination of various palm oil products and suitable 3HV-generating carbon sources. By using palm oil as the main carbon source, the cost of production is significantly reduced.

In addition, P(3HB-co-4HB) is another commercially important copolymer possessing superior properties that are useful for applications in the medical and pharmaceutical fields as absorbable materials and as controlled drug delivery agents, respectively. Similarly, this copolymer could be produced from renewable resources such as palm oil and 4HB-generating carbon sources.


Nile Blue A-stained Burkholderia sp.
At the same time, glycerol and glycerol pitch are also feasible for the efficient synthesis of P(3HB) homopolymer by a locally isolated bacterium, identified Burkholderia sp. Glycerol pitch is one the wastes generated by the Malaysian oleochemicals industry whereas glycerol is the major by-products from the bioprocessing of biodiesel fuel.

Based on our results and facilities available in our laboratory, we are currently producing these biomaterials in a larger-scale by using a 13 L fermenter.

Next...