AimsProducing dry, zeolite-based granular and powder inoculants of the Gram-negative, plant growth-promoting bacterium Paraburkholderia phytofirmans PsJN. Key aspects were maintenance of cell viability during desiccation and throughout storage at ambient conditions. Methods and ResultsTwenty additives and exopolysaccharide (EPS) produced by PsJN were screened for conserving cell viability of PsJN in air-drying and lyophilization. Suitable combinations (e.g. skimmed milk+air-drying) increased survival of PsJN up to 100000-fold and maintained it for >7months. EPS performed as good as skimmed milk during air-drying, but was second-rank regarding shelf life. Combinations of zeolite, skimmed milk and gelatin as a film-forming agent were extruded and processed into granules and powders, both displaying relatively stable viability for over 4weeks at ambient conditions. Gelatin promoted brittleness of zeolite-based inoculants. ConclusionsViability of highly sensitive PsJN was successfully conserved in dry formulations, taking into account the interplay between carrier, protectants, drying method and coating agent. Significance and Impact of the StudyThis is the first study to provide ways of maintaining viability of PsJN during desiccation stress and to investigate the applicability of its EPS as a protectant, thus ultimately facilitating successful plant inoculation especially under field conditions.