Optimization of submerged fermentation process for improved production of β-carotene by Exiguobacterium acetylicum S01

Abstract

Carotenoids are natural pigments with substantial applications in nutraceutical, pharmaceutical, and food industries. In this study, optimization of the fermentation process for enhancement of β-carotene and biomass production by Exiguobacterium acetylicum S01 was achieved by employing statistical designs including the Placket-Burman design (PBD) and response surface methodology (RSM). Among the seven variables investigated by two levels in PBD, glucose, peptone, pH and temperature were indicated as crucial variables ( p < 0.0001) for β-carotene and biomass productivity. Response surface methodology was further applied to evaluate the optimal concentrations of these four variables for maximum β-carotene and biomass productivity. The optimized medium contained glucose 1.4 g/L, peptone 26.5 g/L, pH 8.5, and temperature 30 °C, respectively. A significant increase in β-carotene (40.32 ± 2.55 mg/L) and biomass (2.19 ± 0.10 g/L) productivities in E. acetylicum S01 were achieved by using RSM, which was 3.47-fold and 2.36-fold higher in the optimized medium compared to the un-optimized medium. Further, the optimum fermentation condition in the 5-L bioreactor was achieved a maximal β-carotene yield of 107.22 ± 5.78 mg/L within 96 h. Moreover, the expression levels of carotenoid biosynthetic genes (phytoene desaturase (CrtI) and phytoene synthase (CrtB)) were up-regulated (2.89-fold and 3.71-fold) in E. acetylicum under the optimized medium conditions. Overall, these results suggest that E. acetylicum S01 can be used as a promising microorganism for the commercial production of β-carotene.

Dynamic consolidated bioprocessing for innovative lab-scale production of bacterial alkaline phosphatase from Bacillus paralicheniformis strain APSO

“…Scale-up production of bacterial ALP. Bioreactors, often regarded as the heart of the fermentation process, have helped researchers overcome issues facilitating the scale-up of submerged fermentation from a shake flask to production scale 39 . As this work aims to establish a large-scale fermentation system to evaluate the kinetics of microbial growth in a submerged cultivation system, both shake-flask and stirred-bioreactor batch cultivation methodologies were employed and compared.…”

“…1. Mathematical experimental designs including the Plackett-Burman design (PBD) and response surface methodology (RSM) are employed to optimize the media constituents during the fermentation process to address the shortcomings of the traditional one-factor-at-a-time approach (OFAT) and to enhance metabolite productivity 13 .…”

Redirecting Metabolic Flux towards the Mevalonate Pathway for Enhanced β-Carotene Production in M. circinelloides CBS 277.49

“…Glucose was also documented as the best carbon source in optimizing the production of β- carotene by B. trispora [ 31 ]. Investigation of Jinendiran et al also discovered that glucose gave a maximum production of β -carotene as compared to other carbon sources by Exiguobacterium acetylicum S01 [ 32 ].…”

“…In the recent few years, the production of β -carotene has increased worldwide due to vast applications in various industries. Currently, remarkable achievements have been made in the optimization of medium components, and the optimal composition of media proved to be a key factor for the commercialization of the fermentation operation [ 32 ]. Even though it is the first time that the optimization of carotenoids using a metabolic flux redirecting strategy has been conducted in M. circinelloides , several previous studies demonstrated the metabolic flux redistribution in other microorganisms [ 20 , 42 ].…”

HERBICIDAL EFFECTS ON BIOCHEMICAL COMPONENTS AND YIELD IN RICE PLANTS (Oryza sativa L.)

“…Chlorophyll is the main instrument responsible for photosynthesis. Carotenoids are natural pigments with substantial applications in nutraceutical and pharmaceutical, food industries ( Jinendiran et al, 2019), it is provide several biological functions in micro-organisms and plants such as in photoprotection (Britton et al, 2004). Herbicides exhibited some phytotoxic effects on crop plants (Sundaru, 1983, Nandihalli and Bhowmik, 1992, Singh et al, 1996, Kushwaha and Bhowmik, 1999, Thapa, 2012, Singh et al, 2016, Tagour and Mosaad, 2017, Saha et al, 2018.…”