Development of a bioprocess for CO2 conversion into microbial biomass and polyhydroxyalkanoates

Nowadays plastic is used in all the fields of life, starting from the daily routine to the medical field. A total of 8.3 billion tonnes of plastic products were manufactured from 1950 to 2015, while 6.3 billion tonnes of plastic waste were generated. Plastic debris are found in every corner of the globe, polluting the water and the earth. The importance to individuate some valid alternative to the petrolbased polymer it is evident, to move through a better and green world. The Polyhydroxyalkanoates (PHAs) are challenging bio-polymers that can be utilized in very different way. PHAs have good properties (depending on their composition) comparable to the PET and other petrol-based polymer, moreover they are biocompatible, so it can be used for human surgery. Since they are “bio” and since the world is going in a direction of all bio-based product, it is very important to find some valid alternative to produce the polymer mentioned. Nowadays, the challenge in the production of PHAs are: to reach a high quantity production and reduce the production costs. The aim of the study is to individuate a bioprocess that allow us to produce PHAs with Mixed Microbial Cultures (MMCs) and utilizing CO2 as substrate. The process is based on the feast and famine of an Iron-Oxidize MMCs trying to let them accumulate PHAs, experimenting different feeding strategies and evaluating the growth of the cell. The investigation on the bioprocess individuated and conducted is done with the use of different analysis, as for example: Fourier transform infrared radiation (FTIR), Gas Chromatography, and other.