Minimal NOx emission by Lysinibacillus sphaericus in nutrient poor soil

The aim of this study was to determine whether nitrogen dioxide emissions by Lysinibacillus sphaericus exist in nutrient poor soil. First, we evaluated the presence of two genes involved in denitrification (nosF and nosD) by PCR screening of five strains of L. sphaericus (III (3)7, OT4b.49, OT4b.25, OT4b.31 and CBAM5). We then applied a bacterial consortium made up by L. sphaericus III (3)7 and OT4b.49 into closed microcosms of soil and with minimum salts medium (MSM) supplemented with ammonia to measure the concentration of produced nitrogen dioxide over time. The assays with closed microcosms showed a minimum level of nitrogen dioxide over time. The nosF and nosD primers amplified the expected fragment for the five strains and the sequenced nosF and nosD PCR product showed an ATPase domain and a copper-binding domain respectively, which was consistent with the function of these genes. The basal emission of nitrogen dioxide by L. sphaericus in soil is coupled to its ability to enhance the nitrogen bioavailability for soils deficient in nutrients. Therefore, our results indicate that this microorganism can be considered as a good c and idate to validate the low emission of NOx in field and in the future as an alternative for biofertilization..