A Gram-positive bacterium designated as strain ORF15-23 was isolated from a soil sample collected from rainfed organic paddy fields in Roi Et province, Thailand. This strain is previously reported to produce indole-3-acetic acid and 2-acetyl-1-pyrroline (2AP) compound, solubilize potassium feldspar and promote growth of rice seedlings. The genome sequencing was carried out using Illumina MiSeq platform. The draft genome of strain ORF15-23 was 2,562,005 bp in length with 1677 protein coding sequences and an average G + C content of 72.97 mol.%. Phylogenomic tree supports the assignment of strain ORF15-23 as member of the genus Micrococcus. A comparison of average nucleotide identity (ANIb) values revealed that strain ORF15-23 shared 96.95 % identity with the genome of M. yunnanensis DSM 21948T. The draft genome sequence of M. yunnanesis ORF15-23 has been deposited in the DDBJ/EMBL/GenBank databases under the accession number JAZDRZ000000000. This genome sequence data provides insightful information for the taxonomic characterization and further biotechnological exploitation of M. yunnanesis ORF15-23.
Sulfur (S) fertilizer is routinely applied together with other macronutrients by farmers across all regions to improve grain yield and quality, but its distinct effects on grain yield and aroma intensity in fragrant rice remain inadequately studied, especially when applied under varying existing soil S levels. This study aimed to determine the effects of S fertilizer application on grain yield and aroma intensity (2-Acetyl-1-Pyrroline, 2AP) in fragrant rice grown under varying soil S levels (very low, low, and medium). The premium Thai fragrant rice cultivar KDML105 was grown under field conditions during two cropping seasons in 2021 and 2022 in Surin province, northeastern Thailand. Sulfur fertilizer in the form of (NH4)2SO4 was applied at 0, 30, 60, 90, and 120 kg S ha−1 at one time with the basal fertilizers phosphorus (P) and potassium (K) under varying soil S levels, using the same protocol in both cropping seasons. Plant growth parameters were evaluated at the tillering stage, and grain samples were harvested at maturity to evaluate grain yield and aroma intensity. The results showed that applying S at rates between 60 and 90 kg ha−1 to soils with very low and low S increased grain yield from 4 to 20% compared to no S application, while no effect of S application was observed for the medium soil S level. The results were primarily attributed to the number of tillers and panicles per hill and the 1000-grain weight in both cropping seasons. Dissimilar effects of S application rates and soil S level were found for grain 2AP content. There was a higher grain 2AP content in the low and medium soil S levels compared to very low S, but the pattern varied according to the S application rate. Applying the appropriate rate of S fertilizer can significantly improve rice productivity, especially when cultivated under S-deficient soil, and higher soil S levels can promote the grain 2AP content of fragrant rice.