Cultivation technology development of Rhodothermus marinus DSM 16675

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.Electronic supplementary materialThe online version of this article (10.1007/s00792-019-01129-0) contains supplementary material, which is available to authorized users.

Engineering the carotenoid biosynthetic pathway in Rhodothermus marinus for lycopene production

“…Further optimization of the carotenoid production through genetic engineering and culture conditions is likely to improve yields significantly. For instance, in previous work on cultivation of R. marinus, a 28-fold increase of 450 ​nm absorption was observed in native carotenoid extracts from sequential batch cultivation with cell recycling, as compared to that of shake flask cultivations ( Ron et al., 2019 ). Taking the higher cell densities into consideration, carotenoid absorption per cell density was still 11-fold higher than shake flask cultivations.…”

Global Transcriptomic Responses of Roseithermus sacchariphilus Strain RA in Media Supplemented with Beechwood Xylan

“…Based on the list of CAZymes genes and the activities of the marker enzymes, strain RA is not a good degrader of plant biomass compared to that of other microorganisms in the hot spring. Furthermore, the performance of strain RA may be relatively low compared to the close relatives Rhodothermus marinus (DSM 4252) and Rhodothermus marinus SG0.5JP17-172 [24][25][26][27][28][29]. Nevertheless, strain RA had enhanced enzymatic activities, showed better growth, and higher transcriptomic responses toward xylan as the carbon source.…”

“…Members of Rhodothermaceae are halothermophile. Rhodothermus is well understood from the aspects of phenotypic, chemotypic, genomic and extrachromosomal elements, pathway and gene manipulations, environmental adaptation, as well as the discovery of industrial enzymes [23][24][25][26][27]. Bacteria strains such as Rhodothermus marinus (DSM 4252) and R. marinus SG0.5JP17-172 are excellent plant biomass degraders [28,29].…”

A genome-scale metabolic reconstruction provides insight into the metabolism of the thermophilic bacteriumRhodothermus marinus

“…In a previous study we engineered the carotenoid biosynthetic pathway in R. marinus to produce the industrially relevant carotenoid lycopene, instead of native carotenoids [18]. In another, sequential batch cultivation resulted in higher carotenoid production than shake flask cultivation [8]. Drawing upon the metabolic reconstruction of the current study, we further investigated the effects of culture conditions on carotenoid production and growth of R.…”

“…Several enzymes from R. marinus have been characterized, and many have biotechnological potential, including a number of polysaccharide degrading enzymes, such as cellulase [3], laminarinase [4] and xylanase [5], [6] (see [7] for a review). R. marinus grows on a wide range of sugars from second and third generation biomass and can be cultivated to relatively high yields [8]. It has anabolic pathways and precursor pools for production of various biotechnologically interesting primary and secondary compounds, such as polyamines [9], exopolysaccharides [10], carotenoids [11], compatible solutes [12] and lipids [13], [14].…”