“…Specific in vitro assays are commonly used to quickly screen promising microorganisms for their plant growth-promoting characteristics. For examples, phosphate solubilization abilities can be assessed by growing bacteria on Pikovskaya's (PVK) agar, nitrogen fixation by using N-free medium, siderophore production with chrome azurol S (CAS) agar, IAA and other phytohormones production with Salkowski reagent and colorimetric methods, ACC deaminase activity with Dworkin and Foster's (DF) salts medium (Afzal et al, 2015;Ngalimat et al, 2021), biofilm formation with crystal violet staining (Selin et al, 2009), and metabolic capabilities with Biolog microarrays (Gómez-Lama Cabanás et al, 2018;Zboralski et al, 2020). For screening of biocontrol determinants, in vitro confrontational assays are commonly used to assess the growth inhibition of culturable pathogens (Afzal et al, 2015;Kusari et al, 2017;Balthazar et al, 2021), Mueller Hinton (MH) media are used for antibiotic diffusion assays, Cyantesmo paper for HCN production, UV-visible spectroscopy for phenazines and pyoverdine detection, and gas and/or liquid chromatography methods for quantification of volatile compounds (VOCs) and soluble antibiotics (Selin et al, 2009;Gómez-Lama Cabanás et al, 2018;Ngalimat et al, 2021).…”