Enhanced whole-cell biotransformation of 3-chloropropiophenone into 1-phenyl-1-propanone by hydrogel entrapped Chlorella emersonii (211.8b)

AbstractObjectives This study focuses on dehalogenation ofhalogenated organic substrate (3-Chloropropiophenone) using both free and hydrogel entrapped microalgae Chlorella emersonii (211.8b) as biocatalyst. Weaimed at successful immobilization of C. emersonii(211.8b) cells and to assess their biotransformationefficiency.Results Aquasorb (entrapping material in this study)was found to be highly biocompatible with the cellulargrowth and viability of C. emersonii. A promisingnumber of entrapped cells was achieved in terms ofcolony-forming units (CFUs = 2.1 9 104) per hydrogel bead with a comparable growth pattern to that offree cells. It was determined that there is no activity ofhydrogenase that could transform 1-phenyl-2-propenone into 1-phenyl-1-propanone because after 12 hthe ratio between two products (0.36 ± 0.02)remained constant throughout. Furthermore, it wasfound that the entrapped cells have higher biotransformation of 3-chloropropiophenone to 1-phenyl-1-propanone as compared to free cells at every intervalof time. 1-phenyl-2-propenone was excluded from thewhole-cell biotransformation as it was also found inthe control group (due to spontaneous generation).Conclusion Hence, enhanced synthesis of 1-phenyl1-propanone by entrapped Chlorella (211.8b) can beascribed to either an enzymatic activity (dehalogenase) or thanks to the antioxidants from 211-8b,especially when they are in immobilized form. Theaquasorb based immobilization of microalgae ishighly recommended as an effective tool for exploiting microalgal potentials of biocatalysis specificallywhen free cells activities are seized due to stress.