The use of biological inputs is an interesting approach to optimize crop production and reduce the use of chemical inputs. Understanding the chemical communication between bacteria and plants is critical to optimizing this approach. Recently, we have shown that Sphingomonas (S.) sediminicola can improve both nitrogen supply and yield in pea. Here, we used biochemical methods and untargeted metabolomics to investigate the chemical dialog between S. sediminicola and pea. We also evaluated the metabolic capacities of S. sediminicola by metabolic profiling. Our results showed that peas release a wide range of hexoses, organic acids, and amino acids during their development, which can generally recruit and select fast-growing organisms. In the presence of S. sediminicola, a more specific pattern of these molecules took place, gradually adapting to the metabolic capabilities of the bacterium, especially for pentoses and flavonoids. In turn, S. sediminicola is able to produce several compounds involved in cell differentiation, biofilm formation, and quorum sensing to shape its environment, as well as several molecules that stimulate pea growth and plant defense mechanisms.

Background: The callus cultures from the fronds of the lycophyte Phlegmariurus taxifolius produce the huperzine A (HupA) alkaloid, which is used in Alzheimer’s disease treatment. This study aimed to establish the growth kinetics and HupA production by the newly HupS21 cell line grown in 250 mL flasks and in a 2 L airlift bioreactor. Methods: Batch-type kinetics were carried out for 60 days in 250 mL flasks and for 20 days in a 2 L airlift bioreactor. Measurements of dry weight (DW), specific growth rate (μ), doubling time (dt), pH, carbohydrate consumption, and HupA quantification were performed. The acetylcholinesterase (AChE) inhibitory assay of the HupS21 alkaloidal extract was determined. Results: The 250 mL flasks kinetic reached a maximum cell growth of 8.17 g/L DW, with a μ of 0.045 day⁻¹ and a dt of 15.40 days. The maximum HupA production was of 2.03 μg/g DW at day 45. In the 2 L airlift reactor, a maximum growth of 16.70 g/L DW, a μ of 0.062 day⁻¹, a dt of 11.20 days, and HupA production of 2.48 μg/g DW at day 15 were obtained. The alkaloidal extract from the HupS21 cell line at 100 μg/mL showed an AChE inhibitory activity of 85.6 ± 1.27%. Conclusions: The airlift reactor outperformed the flask cultures in maximum cell growth, specific growth rate, doubling time, and HupA production. To our knowledge, this research is the first report on the establishment of suspension cell cultures of P. taxifolius in shaken flasks and in an airlift bioreactor, providing a foundation for scaling up HupA production for pharmaceutical use.