The world’s rising energy needs, and the depletion of fossil resources demand a shift from fossil-based feedstocks to organic waste to develop a competitive, resource-efficient, and low-carbon sustainable economy in the long run. It is well known that the production of fuels and chemicals via chemical routes is advantageous because it is a well-established technology with low production costs. However, the use of toxic/environmentally harmful and expensive catalysts generates toxic intermediates, making the process unsustainable. Alternatively, utilization of renewable resources for bioprocessing with a multi-product approach that aligns novel integration improves resource utilization and contributes to the “green economy”. The present review discusses organic waste bioprocessing through the anaerobic fermentation (AF) process to produce biohydrogen (H₂), biomethane (CH₄), volatile fatty acids (VFAs) and medium chain fatty acids (MCFA). Furthermore, the roles of photosynthetic bacteria and microalgae for biofuel production are discussed. In addition, a roadmap to create a fermentative biorefinery approach in the framework of an AF-integrated bioprocessing format is deliberated, along with limitations and future scope. This novel bioprocessing approach significantly contributes to promoting the circular bioeconomy by launching complete carbon turnover practices in accordance with sustainable development goals.

With the growing interest in bioplastics, there is an urgent need to develop rapid analysis methods linked to production technology development. This study focused on the production of a commercially non-available homopolymer, poly(3-hydroxyvalerate) (P(3HV)), and a commercially available copolymer, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (P(3HB-co-3HV)), through fermentation using two different bacterial strains. The bacteria Chromobacterium violaceum and Bacillus sp. CYR1 were used to produce P(3HV) and P(3HB-co-3HV), respectively. The bacterium Bacillus sp. CYR1 produced 415 mg/L of P(3HB-co-3HV) when incubated with acetic acid and valeric acid as the carbon sources, whereas the bacterium C. violaceum produced 0.198 g of P(3HV)/g dry biomass when incubated with sodium valerate as the carbon source. Additionally, we developed a fast, simple, and inexpensive method to quantify P(3HV) and P(3HB-co-3HV) using high-performance liquid chromatography (HPLC). As the alkaline decomposition of P(3HB-co-3HV) releases 2-butenoic acid (2BE) and 2-pentenoic acid (2PE), we were able to determine the concentration using HPLC. Moreover, calibration curves were prepared using standard 2BE and 2PE, along with sample 2BE and 2PE produced by the alkaline decomposition of poly(3-hydroxybutyrate) and P(3HV), respectively. Finally, the HPLC results obtained by our new method were compared using gas chromatography (GC) analysis.