Transgenic plants as a source of polyhydroxyalkanoates

Abstract

Polyhydroxyalkanoates (PHAs) make a large class of biodegradable biopolymers that are naturally synthesized by numerous microorganisms. These biopolymers could be an alternative to commonly used plastics based on petroleum. Production of PHAs in bioreactors using microorganisms is not widely applied due to its unprofitability. Using transgenic plants for this purpose may be cheaper and more environmental friendly because the biosynthesis of PHAs in plants is based only on water, mineral salts, CO 2 and light. Additionally, plants are not capable of degrading PHAs as bacteria do, and extraction of PHAs from plant tissues is not always necessary. The main objective of this work is a review of possibilities of PHA biosynthesis in transgenic plants and presentation of general information on properties and potential application possibilities of these biopolymers. The possibility of syntheses and accumulation of PHA in several transgenic plants has been studied for some years. Many experiments were performed on model plant Arabidopsis thaliana, however, the research has also revealed a great potential of transgenic crop plants such as camelina (Camelina sativa), tobacco (Nicotiana tabacum) or sugarcane (Saccharum officinarum) as a good sources of PHAs. The highest level of PHAs accumulation in plants was achieved in transgenic A. thaliana (up to 40% of the dry weight of the leaf), and among crop plants in C. sativa (up to 20% of the dry weight of the seed). Increasing knowledge on PHAs permits expansion of the possibilities of these biopolymers use even at a low level of their accumulation in plant tissues.

Recycling of Bioplastics: Routes and Benefits

“…DNA fragments containing the phbCAB operon can be used as a cartridge in other bacteria that express A. eutrophus PHBbiosynthetic genes, thus giving them the ability to synthesize P3HB from aceyl-CoA [96]. P3HB has also be generated in transgenic plants, which provides even greater control over monomer composition and thus final polymer properties [97].…”

Plastid Transformation: How Does it Work? Can it Be Applied to Crops? What Can it Offer?

“…αCD22HCH23PE40, αCD22PE40 -Targets and kills B cell tumor 0.2-0.3% TSP [20] Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) -Leads to the apoptosis of cancer cells 0.43-0.67% TSP [131] GBSS-AMA1, GBSS-MSP1 -Anti-malarial 0.2-1.0 µg/mg Starch [132] Human glutamic acid decarboxylase (hGAD65) -For the treatment of Type I diabetes 0.25-0.3% TSP [133] Protein VP1 of Foot-and-mouth disease virus (FMDV-VP1) -Mucosal vaccine 3% TSP [134] Bovine mammary-associated serum amyloid (M-SAA) -Mucin induction 3-5% TSP [135] Protein E2 of classical swine fever virus (CSFV-E2) -Prevents classical swine fever 1.5-2% TSP [136] Protein VP2 of Infectious burial disease virus (IBDV-VP2) -Prevents IBDV infection 0.8-4% TCP [137] DW: dry weight; FW: fresh weight; NR: not recorded; TCP: total cellular protein; TSP: total soluble protein.…”

“…The chloroplast genome has been repeatedly engineered to produce industrial enzymes and biomaterials. Polyhydroxyalkanoates (PHAs) are a large class of biodegradable polyesters biopolymers naturally synthesized by many microorganisms that can be used as an alternative to petroleum-based plastics [137]. The first described and most well-studied PHA is polyhydroxybutyrate (PHB).…”

Strategies for the production of biochemicals in bioenergy crops

“…One of the challenges is the testing of engineered crops under field conditions to asses stress resilience and possible yield penalty. As exemplified by the case study of crops engineered for production polyhydroxyalkanoates, subcellular compartmentalization represents an effective strategy to alleviate toxicity associated with high titers of bioproducts [318]. Similarly, promising strategies have been developed for introducing organelles that allow bioproduct sequestration and accumulation in engineered plant tissues [319].…”