An actinomycete strain, designated strain LUSFXJ, was isolated from a soil sample obtained near the Xiangtan Manganese Mine, Central-South China and characterised using a polyphasic taxonomic approach. The 16S rRNA gene sequence-based phylogenetic analysis indicated that this strain belongs to the genus Streptomyces. The DNA-DNA relatedness between this strain and two closely related type strains, Streptomyces echinatus CGMCC 4.1642 and Streptomyces lanatus CGMCC 4.137, were 28.7 ± 0.4 and 19.9 ± 2.0%, respectively, values which are far lower than the 70% threshold for the delineation of a novel prokaryotic species. The DNA G+C content of strain LUSFXJ is 75.0 mol%. Chemotaxonomic analysis revealed that the menaquinones of strain LUSFXJ are MK-9(H), MK-9(H), MK-9(H) and MK-8(H). The polar lipid profile of strain LUSFXJ was found to contain diphosphatidylglycerol and an unidentified polar lipid. The major cellular fatty acids were identified as iso-C, anteiso-C, iso-C, C and Summed feature 3. Strain LUSFXJ was found to contain meso-diaminopimelic acid as the diagnostic cell wall diamino acid and the whole cell hydrolysates were found to be rich in ribose, mannose and glucose. Based on phenotypic, phylogenetic and chemotaxonomic characteristics, it is concluded that strain LUSFXJ represents a novel species of the genus Streptomyces, for which the name S. xiangtanensis sp. nov. is proposed. The type strain is LUSFXJ (=GDMCC 4.133 = KCTC 39829).

Modern sugarcane cultivars are highly polyploid with complex nuclear genomic genetic background, while their mitochondrion (mt) genomes are much simpler, smaller and more manageable and could provide useful phylogenetic information. In this study, the mt genome of a modern commercial cultivar A1 was sequenced via Illumina Hiseq XTen and PacBio Sequel platform. The assembled and annotated mitochondrial genomes of A1 were composed of two circular DNA molecules, one large and one small, which were named Chromosome 1 and Chromosome 2. The two distinct circular chromosomes of mitogenome construct is consisted with other sugarcane cultivars i.e., Saccharum officinarum Khon Kaen 3 and Saccharum spp. hybrids ROC22 and FN15. The Chromosome 1 of A1 mitogenome is 300,822 bp in length with the GC content of 43.94%, and 7.14% of Chromosome 1 sequences (21,468 nucleotides) are protein coding genes (PCGs) while 92.86% (279,354 nucleotides) are intergenic region. The length of Chromosome 2 is 144,744 bp with the GC content of 43.57%, and 8.20% of Chromosome 2 sequences (11,865 nucleotides) are PCGs while 91.80% (132,879 nucleotides) are intergenic region. A total of 43 genes are located on Chromosome 1, which contains 22 PCGs (six nad genes, four rps genes, four atp genes, three ccm genes, three cox genes, one mat gene and one mtt gene) and 21 non-coding genes including 15 tRNAs and 6 rRNAs. Chromosome 2 includes 18 genes in total, which contains 13 PCGs (four nad genes, three rps genes, two atp genes, one ccm gene, one cob gene, one cox gene and one rpl gene) and five non-coding genes (tRNA genes). Analysis of codon usage of 35 PCGs showed that codon ending in A/U was preferred. Investigation of gene composition indicated that the types and copy numbers of CDS genes, tRNAs and rRNAs of A1 and FN15 were identical. The cox1 gene has two copies and the trnP gene has one copy in A1, FN15 and ROC22 three lines, while there is only one copy of cox1 and two copies of trnP in S. officinarum Khon Kaen 3. In addition, S. officinarum Khon Kaen 3 have no nad1 gene and rps7 gene. 100 sequence repeats, 38 SSRs and 444 RNA editing sites in A1 mt genome were detected. Moreover, the maximum likelihood phylogenetic analysis found that A1 were more closely related to S. spp. hybrid (ROC22 and FN15) and S. officinarum (Khon Kaen 3). Herein, the complete mt genome of A1 will provide essential DNA molecular information for further phylogenetic and evolutionary analysis for Saccharum and Poaceae.

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A novel actinomycete isolate, designated strain MK44, was isolated from a Manganese-polluted soil sample collected near Xiangtan Manganese Mine, South Central China and subjected to a polyphasic taxonomic characterization. Comparison of 16S rRNA gene sequences showed that strain MK44 was a member of the genus Streptomyces and most closely related to Streptomyces specialis JCM 16611 (97.9 %) and Streptomyces mayteni JCM 16957 (97.4 %). The DNA-DNA relatedness between strain MK44 and the above two related type species were 30.9±0.3 and 29.9±3.5 %, respectively, values which are far lower than the 70 % threshold for the delineation of a novel prokaryotic species. Furthermore, the results of physiological, biochemical and chemotaxonomic tests allowed further phenotypic differentiation. Therefore, it is concluded that strain MK44 represents a novel species of the genus Streptomyces, for which the name Streptomyces manganisoli sp. nov. is proposed. The type strain is MK44 (=GDMCC 4.137=KCTC 39920).

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