**2. Materials and methods**

Tryptone Type-1(Casitose Type-I) from Hi-Media laboratories, India; Yeast extract powder from Hi-Media laboratories, India; Sodium chloride from Merck, India; Dimethyl sulfoxide (DMSO) from Daejung, South Korea; skim milk powder (DANO) from Bangladesh; Agar powder from Merck, India; Dextrose from Hi-Media laboratories, India. And all other culture media were procured from Hi-Media laboratories, India and the reagents and chemicals from Merck, USA.

## **2.1 Isolation of** *Pseudomonas fluorescens*

Soil sample was collected from rhizosphere of maize plant roots and brought to the lab. Then cetrimide agar media was prepared (pH 7.0 ± 0.2), autoclaved, poured, and 1.0 g soil was diluted in 0.9% saline solution. Diluted soil samples were spread on cetrimide agar plate and incubated for 72 hours. Vigorous growth colonies were picked up and subculture on LB plate. Light yellowish colonies were selected for the further process [11]. The strains were confirmed further by biochemical and 16 s rRNA genomic analysis.

## **2.2 Media preparation**

Luria-Bertani (LB) a common media for microbial growth in the laboratory was used. The composition of media (g/l) is Tryptone 10 g, Yeast extract powder 5 g, and NaCl 10 g. pH was adjusted to 7.0 ± 0.2. LB Media was sterilized at 121°C, 15p si for 15 min. *P. fluorescens* strain was grown at 30°C in LB broth media [12–14] and was also maintained in paraffin at -86°C for further process.

### **2.3 Mother inoculum preparation**

*P. fluorescens* (FLU-L) strain was routinely maintained in Luria-Bertani (LB) media. The broth media is used to prepare the mother inoculum for lab-scale production [14]. The 2% of previous cells were used as inoculum for lab-scale production. QC checked and recorded the CFUs.
