Optimization of Bioreactor Cultivation Parameters by Taguchi Orthogonal Array Design for Enhanced Prodigiosin Production

Abstract

One of the major steps toward the industrialization of microbial product(s) is to optimize the cultivation conditions at the large scale bioreactor and successfully control the microbial behavior within large scale production environment. Statistical Design of Experiment was proven to optimize a vast number of microbial processes to achieve robustness and explore possible interactions among the variables. In this research, Taguchi Orthogonal Array was applied to optimize the cultivation condition of a newly isolated Prodigiosin-producing marine bacterial strain, Serratia AM8887, at bioreactor level. Two steps fermentation process was applied; as the productivity was scaled up from shake flask level to a bench top bioreactor (5L) and subsequently to an in-situ sterilization bioreactor system (20L) leading to a yield of 7g/L compared to 100mg/L prior to optimization confirming that; applying Taguchi experimental design is a reliable and good positive option for the optimization of biotechnological processes..

Prodigiosin: a promising biomolecule with many potential biomedical applications

“…Besides, to the best of our knowledge, only one report recently described the production of prodigiosin in two-stage fermenters determined by Taguchi’s experimental statistical design. The results indicate that the prodigiosin production was increased up to 70 times [ 32 ]. Table 1 compiles the published works of PG production by mainly S. marcescens , but also from other members of the Serratia genus, such as S. nematodiphila [ 33 , 34 ] and the marine isolated S. rubidaea [ 35 ], but also other microbial sources, such as a member of the Streptomyces genus [ 36–38 ], Achromobacter denitrificans [ 39 ], and the marine isolates Hahella chuejuensis and Zooshikella rubidus [ 40 ].…”

“… Strain Methodology (volume) Medium Productivity (mg L −1 h − [ 1 ] ) (Production/time) Temperature (°C) – pH References Serratia spp. AM8887 Bioreactor (20 L) 6 g L −1 Sucrose, 6 g L −1 , and glycerol, 15 g L −1 NaCl, and 12 g L −1 fertilizer waste 368.4 7,000 mg L −1 /19 h 25°C – 6.5 [ 32 ] S. marcescens WT Bioreactor (7 L) Saline medium 10.9 600 mg L −1 /55 h 30°C – 6.0 [ 156 ] S. marcescens UTM1 Bioreactor (5 L) Brown sugar and lactose in nutrient broth ≈333.3 ≈8000 mg L −1 /24 h 25°C – 7.0 [ 50 ] S. marcescens NPLR1 Bioreactor (2 L) Saline suppl. with tannery fleshing 1,200 48,000 mg L −1 /40 h 30°C – 8.0 [ 157 ] S. marcescens CF-53 Bioreactor (2 L) Peanut oil cake extract 0.95 40 mg L −1 /42 h 30°C – 7.0 [ 158 ] Serratia sp.…”