Microencapsulated biofertilizer formulation: product development and effect on growth of green pepper seedlings

Aim of the study: This study aimed to formulate a novel, commercially applicable biofertilizer, to optimize the microencapsulation procedure of Bacillus subtilis NCIM 2063 and examine the stability and phytostimulatory effects of obtained formulation. Area of the study: Southestern Serbia. Material and methods: Microbial powder formulations were prepared using spray drying with maltodextrin as a carrier. The spray drying conditions were set according to Box-Benkhen experimental desing. The effect of the formulation was tested on green pepper (Capsicum annuum) seeds in controled conditions. Main results: Response surface models were developed. All of the models were statistically significant, adequately fitted and reproducible. The maximum achieved values of viability and yield in a formulation were 1.99.10 9 CFU/g and 96.8%, respectively, whilst the driest formulation had 1.44% moisture. The following optimum conditions were proposed for the spray drying procedure: an inlet air temperature of 133 degrees C, maltodextrin concentration of 50 g/L and a feed flow rate of 6.5 mL/min. The obtained microbial formulation had a high survival rate after being stored at room temperature over a 1--year period. Its application on green pepper seeds had beneficial effect on plant height, leaf dry weight and chlorophyll content of the seedlings. Research highlights: B. subtilis was successfully microencapsulated on maltodextrin as a carrier. Interaction effects between the process variables were fully explained and statistically significant models were developed. In addition to biocontrol properties formulation had a phytostimulatory effect, excellent stability and satisfactory physical properties.

Automated summary

The aim of this study was to develop a commercially applicable biofertilizer by microencapsulation of Bacillus subtilis NCIM 2063 and investigate its stability and phytostimulatory effects. The research demonstrated that the microencapsulated formulation had high viability and yield, and remained stable after a one-year storage period. Application of the formulation on green pepper seeds led to beneficial effects on plant height, leaf dry weight, and chlorophyll content of the seedlings.