Valorization of Wastewater from the Beverage Industry for Polyhydroxyalkanoate Production with Its Improved Applicability to Agricultural Use

The massive water consumption of the beverage industry results in significant wastewater discharges that contain unused sugar and is highly alkaline. This wastewater results in the rise in the BOD of water and is responsible for soil alkalinity. Consumption of this unused sugar for bacterial growth leads to the remediation of the wastewater by lowering the BOD. The primary objectives of the study are the value-added production of green plastic, i.e., polyhydroxyalkanoate (PHA) from beverage industrial wastewater and controlling water pollution by consuming residual sugar and reducing the pH. PHA is the biopolymer accumulated through various bacterial species in a carbon-rich medium. The novel organism HLI13B (Priestia filamentosa) isolated from mess sludge is capable to accumulate the PHA and has the strong ability to grow in highly alkaline conditions. Aseptically collected beverage industrial wastewater was examined and found 4.65 g/L sugar and pH 11. Wastewater containing residual sugar as a carbon source supplemented with mineral salt media (MSM) was used to culture HLI13B for biomass production in optimized conditions (37 ? and 2% glucose). The biomass production using wastewater significantly reduced the medium pH to 7.5 from 11 within 24 h and finally to pH 6.5, and polymer yield was up to 1.38 g/L at optimized conditions. The accumulated polymer was extracted using solvent extraction and was found identical to the polymer produced using standard glucose. The agricultural applicability of treated water and wastewater was validated by irrigating the chickpea plant. The results indicate that alkaline wastewater has a reduced growth effect.

Automated summary

The massive water consumption by the beverage industry leads to significant wastewater discharge, which contains unused sugar and is highly alkaline. The objective of this study is to produce a green plastic, polyhydroxyalkanoate (PHA), from beverage industrial wastewater and control water pollution by consuming residual sugar and reducing the pH. An isolated organism HLI13B (Priestia filamentosa) has the ability to accumulate PHA and grow in highly alkaline conditions. Beverage industrial wastewater with 4.65 g/L sugar and pH 11 was used to culture HLI13B for biomass production, resulting in a reduction in pH and a polymer yield of 1.38 g/L. The extracted polymer showed identical properties to the one produced using standard glucose. The treated water and wastewater were validated for agricultural use, showing a reduced growth effect on chickpea plants.