In-silico evaluation of the genes and proteins involved in bacterial bio-plastic production pathways

Plastic pollution is a worldwide concern endangering both fossil fuel resources and the environment through rise in their production and usage. Bioplastics emerged as a suitable replacement and proved more environment friendly than traditional plastics. Among bioplastics, polyhydroxyalkanoates (PHA) proved to be in demand due to their promising properties such as high rate of biodegradability. Three key genes (phaA, phaB, and phaC) are involved in the biosynthesis of PHA. An analysis based on bioinformatics approaches was performed in this study to analyze these key genes and their translated proteins in potential PHA producing microorganisms found on the Gen-solution database. The sequences (DNA and Protein) obtained from PHA producing microorganisms were analyzed in MEGA X to check their evolutionary history. The arrangement of genes was highly diverse. The PHA biosynthetic genes belonging to Proteobacteria showed promising phylogenetic relationship and the occurrence and their distribution in these organisms suggested that a single gene cluster related to PHA might have been segmented in the form of small groups of genes and got transferred among various organisms. The results indicated that the gene and protein sequences were not fully conserved suggesting that the genes had undergone addition, deletion or replacement of nucleotides resulting in gene rearrangement. However, the function of the proteins remained fully conserved suggesting that the protein function had the highest level of conservation and the gene sequences had the least level of conservation according to this study. Overall, the results were a strong indicative that horizontal gene transfer had a strong influence on the distribution and molecular evolution of these PHA biosynthetic genes.