| 1. |
- Ron, Emanuel Y C, et al.
(författare)
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Cultivation technology development of Rhodothermus marinus DSM 16675
- 2019
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Ingår i: Extremophiles : life under extreme conditions. - : Springer Science and Business Media LLC. - 1433-4909. ; 23:6, s. 735-745
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Tidskriftsartikel (refereegranskat)abstract
- This work presents an evaluation of batch, fed-batch, and sequential batch cultivation techniques for production of R. marinus DSM 16675 and its exopolysaccharides (EPSs) and carotenoids in a bioreactor, using lysogeny broth (LB) and marine broth (MB), respectively, in both cases supplemented with 10 g/L maltose. Batch cultivation using LB supplemented with maltose (LBmalt) resulted in higher cell density (OD620 = 6.6) than use of MBmalt (OD620 = 1.7). Sequential batch cultivation increased the cell density threefold (OD620 = 20) in LBmalt and eightfold (OD620 = 14) in MBmalt. In both single and sequential batches, the production of carotenoids and EPSs using LBmalt was detected in the exponential phase and stationary phase, respectively, while in MBmalt formation of both products was detectable in both the exponential and stationary phases of the culture. Heteropolymeric EPSs were produced with an overall volumetric productivity (QE) of 0.67 (mg/L h) in MBmalt and the polymer contained xylose. In LB, QE was lower (0.1 mg/L h) and xylose could not be detected in the composition of the produced EPSs. In conclusion, this study showed the importance of a process design and medium source for production of R. marinus DSM 16675 and its metabolites.
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| 2. |
- Sardari, Roya R R, et al.
(författare)
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Evaluation of the production of exopolysaccharides by two strains of the thermophilic bacterium Rhodothermus marinus
- 2017
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617. ; 156, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- The thermophile Rhodothermus marinus produces extracellular polysaccharides (EPSs) that forms a distinct cellular capsule. Here, the first data on EPS production in strains DSM4252(T) and MAT493 are reported and compared. Cultures of both strains, supplemented with either glucose, sucrose, lactose or maltose showed that the EPS were produced both in the exponential and stationary growth phase and that production in the exponential phase was boosted by maltose supplementation, while stationary phase production was boosted by lactose. The latter was higher, resulting in 8.8 (DSM4252(T)) and 13.7mg EPS/g cell dry weight (MAT493) in cultures in marine broth supplemented with 10g/L lactose. The EPSs were heteropolymeric with an average molecular weight of 8×10(4)Da and different monosaccharides, including arabinose and xylose. FT-IR spectroscopy revealed presence of hydroxyl, carboxyl, N-acetyl, amine, and sulfate ester groups, showing that R. marinus produces unusual sulfated EPS with high arabinose and xylose content.
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