Medium development and production of carotenoids and exopolysaccharides by the extremophile Rhodothermus marinus DSM16675 in glucose-based defined media
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Published:2022-10-23
Issue:1
Volume:21
Page:
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ISSN:1475-2859
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Container-title:Microbial Cell Factories
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language:en
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Short-container-title:Microb Cell Fact
Author:
Mukti Israt Jahan,Sardari Roya R. R.,Kristjansdottir Thordis,Hreggvidsson Gudmundur O.,Karlsson Eva Nordberg
Abstract
Abstract
Background
The marine thermophilic bacterium Rhodothermus marinus can degrade many polysaccharides which makes it interesting as a future cell factory. Progress using this bacterium has, however, been hampered by limited knowledge on media and conditions for biomass production, often resulting in low cell yields and low productivity, highlighting the need to develop conditions that allow studies of the microbe on molecular level. This study presents development of defined conditions that support growth, combined with evaluation of production of carotenoids and exopolysaccharides (EPSs) by R. marinus strain DSM 16675.
Results
Two defined media were initially prepared: one including a low addition of yeast extract (modified Wolfe’s medium) and one based on specific components (defined medium base, DMB) to which two amino acids (N and Q), were added. Cultivation trials of R. marinus DSM 16675 in shake flasks, resulted in maximum cell densities (OD620 nm) of 2.36 ± 0.057, cell dry weight (CDW) 1.2 ± 0.14 mg/L, total carotenoids 0.59 × 10–3 mg/L, and EPSs 1.72 ± 0.03 mg/L using 2 g/L glucose in DMB. In Wolfe’s medium (supplemented by 0.05 g/L yeast extract and 2.5 g/L glucose), maximum OD620 nm was 2.07 ± 0.05, CDW 1.05 ± 0.07 mg/L, total carotenoids 0.39 × 10–3 mg/L, and EPSs 1.74 ± 0.2 mg/L. Growth trials at 5 g/L glucose in these media either failed or resulted in incomplete substrate utilization. To improve reproducibility and increase substrate utilization, a screening of macroelements (e.g. phosphate) in DMB, was combined with use of trace elements and vitamins of the modified Wolfe’s medium. The resulting defined minimal R. marinus medium, (DRM), allowed reproducible cultivations to a final OD620nm of 6.6 ± 0.05, CDW 2.85 ± 0.07 mg/L, a maximum specific growth rate (µmax) of 0.26 h−1, total carotenoids 0.77 × 10–3 mg/L and EPSs 3.4 ± 0.17 mg/L in cultivations supplemented with up to 5 g/L glucose.
Conclusion
A minimal defined medium (DRM) was designed that resulted in reproducible growth and an almost doubled formation of both total carotenoids and EPSs. Such defined conditions, are necessary for systematic studies of metabolic pathways, to determine the specific requirements for growth and fully characterize metabolite production.
Funder
Novo Nordisk Foundation Horizon 2020 project SECRETed Lund University
Publisher
Springer Science and Business Media LLC
Subject
Applied Microbiology and Biotechnology,Bioengineering,Biotechnology
Reference44 articles.
1. Zhu D, Adebisi WA, Ahmad F, Sethupathy S, Danso B, Sun J. Recent development of extremophilic bacteria and their application in biorefinery. Front Bioeng Biotechnol. 2020;8:483–483. 2. Sardari RRR, Kulcinskaja E, Ron EYC, Björnsdóttir S, Friðjónsson ÓH, Hreggviðsson GÓ, Karlsson EN. Evaluation of the production of exopolysaccharides by two strains of the thermophilic bacterium Rhodothermus marinus. Carbohydr Polym. 2017;156:1–8. 3. Ron EYC, Plaza M, Kristjansdottir T, Sardari RRR, Bjornsdottir SH, Gudmundsson S, Hreggvidsson GO, Turner C, van Niel EWJ, Nordberg-Karlsson E. Characterization of carotenoids in Rhodothermus marinus. Microbiologyopen. 2018;7:1. 4. Nolan M, Tindall BJ, Pomrenke H, Lapidus A, Copeland A, Glavina Del Rio T, Lucas S, Chen F, Tice H, Cheng JF, Saunders E, Han C, Bruce D, Goodwin L, Chain P, Pitluck S, Ovchinikova G, Pati A, Ivanova N, Mavromatis K, Chen A, Palaniappan K, Land M, Hauser L, Chang YJ, Jeffries CD, Brettin T, Göker M, Bristow J, Eisen JA, Markowitz V, Hugenholtz P, Kyrpides NC, Klenk HP, Detter JC. Complete genome sequence of Rhodothermus marinus type strain (R-10). Stand Genom Sci. 2009;1:283–90. 5. Alfredsson G, Kristjansson J, Hjörleifsdottir S, Stetter K. Rhodothermus marinus, gen. nov., sp. nov., a thermophilic, halophilic bacterium from submarine hot springs in Iceland. J Gen Microbiol. 1988;134:299–306.
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