Production and Characterization of Polyhydroxyalkanoate (PHA) Using Mango Seed Kernel as an Alternative to Glucose

Abstract

Aim: To explore the possibility of using Mango (Mangifera indica) seed kernel as an alternative to glucose in the production of biodegradable plastic (polyhydroxyalkanoate) using soil isolated Bacillus megaterium. Study Design: Experimental design. Place and Duration of Study: This research was carried out at Biotechnology and Genetic Engineering Advanced Laboratory, Sheda Science and Technology Complex and Biochemistry Department, Federal University of Technology Minna, Nigeria, between the periods of June 2014 to October 2015. Methodology: Using fed-batch fermentation technology, polyhydroxyalkanoate (PHA) pellets were produced, extracted and purified via solvent extraction. Polyhydroxyalkanoate produced was quantified using the crotonic acid assay at 235 nm by UV-VIS spectrophotometry. Fourier transform infrared spectrometry (FTIR) was used to characterize the PHA. Results: Mango seed kernel produced a significantly greater (p<0.05) dry cell weight (DCW) and polyhydroxyalkanoate (PHA) (10.60±0.90 g/L; 64.22±0.55%) compared to glucose (10.19±0.01 g/L; 54.40±5.60%). Optimum conditions for maximum production of polyhydroxyalkanoate (PHA) were pH 7.5; temperature 35°C; substrate concentration of 2 g/100 ml; Bacilli inoculums volume of 2 ml and an incubation period of 72 hours. Fourier transform infrared spectrometry (FTIR) of extracted PHA revealed C-O, C=O, C-H, O-H functional groups at respective wave bands of 1125.5, 1644.37, 2938.65 and 3399.65 cm-1 for extracted mango seed kernel PHA; and 1086.92, 1646, 2937 and 3403.51 cm-1 for extracted glucose PHA. Conclusion: Mango (Mangifera indica) seed kernel produced higher dry cell weight and polyhydroxyalkanoate than glucose hence, could be a substitute to glucose in PHA production.