Bacteria isolated from cultivated soil after liming promote seed germination and seedling growth of crop plants

Abstract

Soil acidification is a major concern in crop production in the Barind region of Bangladesh. Liming raises the soil pH and alters the bacterial community. The major goal of this study was to isolate bacterial strains from two Barind soil samples before and after liming, and to determine the effects of those strains in enhancing seed germination and seedling growth. The isolated strains were identified as Staphylococcus lentus, Klebsiella pneumoniae, Acinetobacter junii, and Serratia marcescens through morphological tests, biochemical tests, and 16S-rRNA gene sequencing. Although Acinetobacter junii and Serratia marcescens bacteria preferred an alkaline environment, Staphylococcus lentus and Klebsiella pneumoniae favored an acidic environment. Antibiotic sensitivity studies revealed that the microorganisms were multidrug-resistant. Acinetobacter junii, compared with Staphylococcus lentus, enhanced the seed germination rate by 50%, 53.33%, and 43.75% for wheat, chickpea, and rice, respectively. Acinetobacter junii also enhanced the root length, shoot length, and leaf length by 8.9 cm, 7.8 cm, and 3.9 cm, respectively, for wheat; 2 cm, 8.9 cm, and 1.3 cm, respectively, for chickpea; and 8.4 cm, 2.5 cm, and 3 cm, respectively, for rice. Serratia marcescens increased the seed germination rate for wheat, chickpea, and rice by 43.75%, 53.33%, and 43.75%, respectively, and the root, shoot, and leaf lengths increased by 8.4 cm, 7.8 cm, and 3.9 cm, respectively, for wheat; 2.1 cm, 8.1 cm, and 1.4 cm, respectively, for chickpea; and 8.2 cm, 2.8 cm, and 2.8 cm, respectively, for rice. Thus, the present study provides new insights into the use of beneficial bacteria to improve soil quality in the Barind region of Bangladesh to improve the crop production in an ecologically friendly manner.

Keywords

• Soil microorganisms
• Characterization
• Germination
• Seedling growth
• Crop plants