Determining the Impact of Genetic Engineering on Replacing Petroleum Based Non-Biodegradable Plastic

Abstract

Petroleum based plastics and their derivatives that are non-biodegradable cannot be ignored at all because they have been using in every aspect of our daily life such as applications in packaging, textile, agriculture, electronics, medical, building construction, injection and moulding. Consumption of these materials are growing day-by-day that are ultimately increasing environmental pollution, global warming, and waste management cost as well as threatening the biodiversity and life on earth. Since our earth is the only planet that contains life among the countless planets in outer space, this world needs to be protected by reducing the pollution and implementing other regulatory measures. Therefore, biodegradable plastics should be used as alternative to non-biodegradable plastics. Poly-3-hydroxybutyrate (PHB) has been extensively studied and is the best-characterized biodegradable plastic within the poly-hydroxyalkanoates family. It is used to make a wide range of household and packaging products, as well as medical products. Although biodegradable PHB is environmentally friendly and does not require fossil resources, it has traditionally been exceedingly expensive to produce utilising bacterial fermentation processes involving recombinant E. coli. For efficient PHB synthesis, recombinant diatoms and transgenic plants have also been investigated. But, increasing PHB yield at the theoretical maximum level has been proved extremely difficult that prohibits its industrial scale production. To address these problems, the objective of this chapter is to focus the importance on the metabolic pathway manipulations in recombinant E. coli. The main advantage of using genetically engineered E. coli is that PHB granules are not degraded once synthesized since they lack PHB degradation pathways unlike native producers. Other benefits of employing recombinant E. coli include their capacity to (i) use a wide range of inexpensive carbon sources, (ii) accumulate huge amounts of polymers with better productivity, (iii) maintain high-cell density fermentation, and (iv) recover the PHB very easily.Since no single strategy has been proved to be sufficient enough to produce PHB industrially until today, this chapter has also shed light on developing the advanced and integrated approaches for efficient PHB production in order to compete with non-biodegradable petrochemical plastics.