A multi-omics study to boost continuous bolaform sophorolipid production

Comprehensive metabolomics reveals correlation between sophorolipid biosynthesis and autophagy

“…All processes started with a batch phase (24 h), followed by a fed-batch phase where glucose and oleic acid were fed discontinuously to maintain concentrations higher than 50 g L − 1 and 5 g L − 1 , respectively. In HS and NS, the fed-batch phases lasted 165 h, at which point the processes were ended, whereas in RET, a subsequent cell recycle phase was commenced as describedin [12]. The broth was continuously pumped over a 0.2 µm ceramic tangential flow micro-filtration unit (Tami industries, Nyons, France) at a rate of 50 L h − 1 .…”

“…Polar to medium-polar metabolite extractions were performed as described in [12,20]. Representative samples were collected from HS (n = 6), NS (n = 6) and RET (n = 15) (Supplementary Table A.1).…”

“…SIMCA® 15 (Sartorius, Göttingen, Germany) was used to perform multivariate analysis, as described in [12]. First, peak intensities were log transformed and pareto scaled (1/√σ) to induce normality and standardise peak intensities, respectively.…”

“…One of the main advances of the last 5 years is the development of (semi-) continuous in-situ product recovery systems (ISPR) to produce WT SLs. Therein, lactonic SLs were predominantly separated from the bioreactor broth by gravimetrical separation [11], whereas others focussed on the production of bola SLs with a continuous in-situ product separation (ISPS) process [12]. In the latter, an external micro-filtration unit was coupled to a bioreactor to create a retentostat set-up that reached mean volumetric productivities of up to 0.56 g L − 1 h − 1 , in contrast to 0.22 g L − 1 h − 1 for a 'classic' fed batch set up [9].…”

“…An integrated omics study revealed that no genomic variants were detected after 1306 h of incubation, implying that the fall in productivity was thus not caused by mutations and that the metabolite 8-hydroxyguanosine (8-OHG) was correlated with high bola SL productivity [12]. However, the authors could not fully explain the productivity decline observed in the retentostat set-up, as only one significantly discriminating metabolite responsible for this productivity drop could be identified [12]. To effectively interpret the metabolic interactions leading to this bola SL productivity decline, more information, i.e.…”