Zinc solubilizing Bacillus spp. potential candidates for biofortification in maize

Area of Science:

• Agricultural Microbiology
• Plant Nutrition
• Soil Science

Background:

• Zinc deficiency in soils leads to crop yield loss and human malnutrition.
• Bioaugmentation with zinc solubilizing rhizobacteria offers a sustainable solution to improve zinc bioavailability.
• Rhizobacteria possess diverse plant growth-promoting traits.

Purpose of the Study:

• To isolate and screen rhizobacteria for zinc solubilization and other beneficial traits.
• To evaluate the efficacy of selected rhizobacterial isolates in promoting maize growth.
• To identify potent strains for use as bio-inoculants in maize biofortification.

Main Methods:

• Isolation and screening of rhizobacteria from maize rhizosphere.
• Assessment of zinc and phosphate solubilization, IAA, protease, catalase, and starch hydrolysis.
• Evaluation of plant growth promotion in maize under axenic conditions.
• Identification of promising strains using 16S rRNA sequencing.

Main Results:

• Multiple rhizobacterial isolates demonstrated zinc oxide solubilization and other plant growth-promoting activities.
• Isolates ZM20, ZM31, ZM63, and S10 significantly enhanced maize shoot length, root length, and biomass.
• Strains were identified as Bacillus sp., Bacillus aryabhattai, and Bacillus subtilis.

Conclusions:

• Selected zinc solubilizing rhizobacteria effectively promote maize growth.
• These Bacillus strains show potential as bio-inoculants for enhancing maize yield and nutritional value.
• Bioaugmentation with these rhizobacteria is a viable strategy for combating zinc malnutrition.