An efficient bioreactor platform for scaling up the proliferation of Nordmann fir’s (Abies nordmanniana) somatic embryos

Abstract

Increased market demand for high-quality Nordmann fir (Abies nordmanniana) Christmas trees, achieving reduced production costs and improved pest resistance, necessitates the establishment of efficient mass micropropagation platforms for the species. Somatic embryogenesis is a powerful tool for clonal propagation of woody plants. Utilizing the advantages of liquid culture media over solid media, the scalability of Nordmann fir somatic embryo proliferation was investigated through developing a batch culture using the disposable WAVE bioreactor (DWB) system, without feedback controls for pH and dissolved oxygen. This study revealed that the inoculation of a 10-L cellbag with 1 g L−1 FW (fresh weight) of A. nordmanniana embryogenic callus can produce ~ 70,000–111,000 vigorous and synchronized somatic embryos. Such outcomes were achieved with the rock speeds of 25 and 35 rpm and rock angle of 6° for 25 days at 24 ± 1 °C, respectively. The gas mix was a combination of O2 (21%) and a stepwise reduction of CO2 ended by 2% (v/v), at a flow rate of 0.2 L min−1. The application of 500 mg L−1 of 2-(N-morpholino)ethanesulfonic acid (MES) effectively stabilized the pH between 5.3 and 5.4. Furthermore, DWB was found an efficient system for accelerating and scaling up the proliferation of A. nordmanniana somatic embryos, as it is a high-yielding, user-friendly, functional, and rapid alternative to conventional methods with solid media.