Bacteria were streaked out from the culture stock and grew on 2, 3, 5-triphenyltetrazolium chloride (TZC) agar medium (dextrose 5 gL⁻¹, peptone 10 gL⁻¹, 0.001% sterilized TZC, and agar 18 gL⁻¹) at 28°C for 2 days. Bacterial genomic DNA was isolated from pure culture using QIAGEN Genomic-tip 100/G, following the manufacturer’s instruction (QIAGEN, Valencia, CA, USA). The Seqwell plexWell LP384 Library Preparation Kit and Native Barcoding Kit 24 V14 (SQK-NBD112.24) were used for barcode-indexed whole genome sequencing with Illumina NovaSeq system (Illumina San Diego, CA, USA) and Oxford Nanopore MinIoN Mk1C device (Oxford Nanopore Technologies, ONT, Oxford, UK), respectively. ONT long reads were base called and demultiplexed using basecaller and barcoder of GUPPY v6.3.2 on MANA, a high-performance computing cluster at the University of Hawaii at Manoa.

The hybrid assembler, Unicycler v0.4.8 plugged in the web-server of BV-BRC 3.26.4,² was employed by uploading paired-end (2 × 150 bp) Illumina short-read, high-accuracy basecalled ONT long reads for de novo genome assemblies (Wattam et al., 2017; Wick et al., 2017; Klair et al., 2022; Olson et al., 2023). In brief, Unicycler carried out SPAdes (v3.13.0) to assemble the Illumina short reads, and then, miniasm, minimap2 (v2.17), and Racon (v1.4.13) were run for long-read plus contig assembly, long-read bridging, and contig polishing, respectively. Alternatively, the genome of the strain (A2111) with a lower coverage of short reads was assembled by performing Flye v2.9.1 and genome assembly pipeline in the web server of BV-BRC 3.26.4 (see text footnote 2). Moreover, the genomic completeness and contamination were assessed by implementing the CheckM algorithm (Parks et al., 2015). The genome annotations were performed using Prokaryotic Genome Annotation Pipeline (PGAP v4.10) on NCBI (Tatusova et al., 2016) and Rapid Annotation using Subsystem Technology (RAST v2.0) web server (Aziz et al., 2008) as well.

The partial 16S rRNA gene sequences of new species strains were amplified using primer set P16S-F1 (5’-AGACTCCTACGGGAGGCAGCA-3′) and P16S-R1 (5’-TTGACGTCATCCCC ACCTTCC-3′) by end-point PCR (Larrea-Sarmiento et al., 2019). Each 25 μL of PCR reaction mix contained 5 μL of 5X Q5 buffer, 5 μL of GC enhance, 2.5 μL of 5 μM primer F and R, 0.5 μL of 2.5 mM dNTPs, 0.5 μL of Q5 polymerase, 1 μL of gDNA, and 6.5 μL of nuclease-free water. The PCR reaction was run as follows: 10 s at 98°C; 35 cycles of 10 s denaturing at 98°C, 30 s of annealing at 58°C, and 30 s extending at 72°C; and 2 min at 72°C for final extension in a T100 Thermal Cycler (BIO-RAD Lab. Inc., Hercules, CA, USA). The sizes of PCR products were checked by running agarose gel electrophoresis, purified using Exo (exonuclease I)-SAP (shrimp alkaline phosphatase) method (GE Healthcare, Little Chalfont, UK) following the manufacturer’s instruction, and sent for Sanger sequencing service at the GENEWIZ company (South Plainfield, NJ, USA). The sequences were double checked with the assembled genomes.

For the phylogenetic analysis of 16S rRNA gene, the full-length sequences of 65 Stenotrophomonas and Xanthomonas species type strains were retrieved from their whole genome sequences and downloaded from GenBank on NCBI (Supplementary Table 1). The multiple alignment was performed using Geneious Prime 2021.2.2.³ The module of finding the best DNA/Protein model for the multiple alignment data was conducted, and the maximum likelihood (ML) phylogenetic tree was built using MEGA X (Kumar et al., 2018). The consistency of the phylogenetic tree was assessed by computing 1,000 bootstrapping analyses.

Additionally, the precise MLSA was performed to reveal the phylogenetic relations between the novel species and other Stenotrophomonas and Xanthomonas species. Nine housekeeping genes (atpD, dnaA, dnaK, gltA, gyrB, nuoD, ppsA, rpoH, and uvrB) used from the previous studies (Ramos et al., 2011b; Vasileuskaya-Schulz et al., 2011; Chuang, 2023) were retrieved from downloaded genomes. The sequences of the nine housekeeping genes were aligned with free end gaps algorithm separately. After trimming the both sequence ends of each gene, nine gene sequences were concatenated in alphabetic order using Geneious Prime for further analyzing. The ML phylogenetic tree was formed using MEGA X following the process as detailed above. The phylogenetic trees with bootstrapping analyses were created using web-based tool Interactive Tree Of Life (iTOL v6)⁴ (Letunic and Bork, 2021).

To define new species, the pairwise comparisons of overall genomic relatedness indices (OGRIs) among the genomes of new species strains and other type strains of Stenotrophomonas and Xanthomonas species retrieved from NCBI database were calculated. The pairwise ANI and AP (alignment percentage) values were calculated using CLC Genomics Workbench 22.0.2 (CLC Bio-QIAGEN, Arahus, Denmark). Due to the inclusion of some incomplete genomes, OrthoANI (Average Nucleotide Identity by Orthology), which only considered the orthologous fragment pairs, was additionally calculated by performing Orthologous Average Nucleotide Identity tool (OAT) (Lee et al., 2016). Moreover, the pairwise dDDH values and the differences in G + C content (mol%) were inferred by estimating precise distance from whole genome sequences using the Genome-Genome Distance Calculator (GGDC) v3.0 on Type Strain Genome Server (TYGS) web server⁵ (Meier-Kolthoff et al., 2013, 2022).

Whole genome sequences of the new species and closely phylogenetically related species in each genus were used for pan-genome and core-genome analyses. Prokka v1.14.6 (Seemann, 2014) was used to re-annotate representative genomes, and the output gff files were used as input files for the Roary v3.13.0 pipeline (Page et al., 2015). For Roary, core and accessory genes were assessed with 80% minimum BLASTp identity, and multi-FASTA alignment of the core genome was generated using highly accurate PRANK, which is a probabilistic multiple alignment program (Löytynoja, 2014; Page et al., 2015). The number of core and unique genes among species of each genus was assessed from the Roary output and was used for the flower plots by computing R script in RStudio (R Core Team, 2022). A core gene phylogenetic tree was established using an ML tree inference tool Randomized Axelerated Maximum Likelihood – Next Generation (RAxML -NG) v0.8.0 (Kozlov et al., 2019), which combine the strengths of RAxML (Stamatakis, 2014) and Exascale Maximum Likelihood (ExaML) (Kozlov et al., 2015). The DNA substitution model, General Time Reversible (GTR) + GAMMA (G), was performed and ran separately with core genomes of type species of Xanthomonas spp. and Stenotrophomonas spp., with 1,000 bootstrap replicates. The core genome phylogenetic tree was displayed using a web-based tool Interactive Tree Of Life (iTOL v6, see text footnote 4) (Letunic and Bork, 2021). The Roary matrix with the presence and absence of core and accessory genes was combined with the core genome ML tree, and the results were visualized by conducting roary_plots.py (Page et al., 2015).

Antibiotic sensitivity assays were performed using disc diffusion methods described by Klair et al. (2022). Single colonies were picked from the pure culture plates of four new species strings and incubated in 10 mL of Luria-Bertani (LB) broth at 28°C with shaking at 200 rpm for 16 h. Light absorbance at 600 nm (OD600) of bacterial inoculum was adjusted to the value ~1.0, and 100 μL of inoculum was spread evenly on nutrient agar (NA, CRITERION^™, Hardy Diagnostics). Seven antibiotics with different concentrations of bacitracin (50 mg/mL), chloramphenicol (50 mg/mL), gentamicin (50 mg/mL), kanamycin (50 mg/mL), penicillin (50 mg/mL), tetracycline (40 mg/mL), and polymyxin B sulfate (50 mg/mL) were tested. One Petri dish was divided into four zones, and three discs impregnated with each antibiotic solution and one disc soaked with sterile distilled water as control were placed in the center of each zone. Inhibition zones were observed and measured after incubating the plates at 28°C for 24 h.

The high-quality genomes of the strains A6251^T, A5588^T, and A5586^T were assembled using Unicycler v0.4.8, whereas strain A2111 had a better de novo assembly using another hybrid genome assembler, Flye v2.9.1 (Table 1). The genome sizes of new species strains from anthurium, A5588^T and A5586^T, are 4.33 Mbp and 4.68 Mbp with 66.44 mol% and 65.3 mol% of GC content, respectively. In comparison, the GC content was higher in the other two strains, i.e., A6251^T (4.88 Mbp) from spathiphyllum and A2111 (4.87 Mbp) from colocasia, with 68.93 mol% and 68.88 mol% GC content, respectively (Table 1). Based on the annotation of NCBI-PGAPservice, the average CDS number of the four strains was 4,016. The strain A5588^T has the lowest CDS number, whereas the strain A5586^T has the highest number (Table 1). The CheckM completeness estimates were 99.9% in A6251^T and A2111 and 100% in A5588^T and A5586^T (Table 1). Although the CDS numbers estimated by RAST web server were slightly different from PGAP annotation, the strain A5588^T had the lowest CDS number which correlated with its genome size (data not shown). By contrast, the coverage of subsystem features presented in A5588^T was the highest and in A5586^T was the lowest (Figure 1A). Four strains comprised 23 out of the total 27 subsystem feature categories including virulence, stress response, membrane transport, DNA, and protein metabolism (Figure 1B). Notably, only strains A6251^T and A2111 contained proteins in the iron acquisition and metabolism subsystem but not strains A5588^T and A5586^T (Figure 1B). Stenotrophomonas maltophilia was reported to use two putative iron acquisition systems for the mediation of siderophores and heme as iron starvation (Kalidasan et al., 2018), implying that strains A5588^T and A5586^T from anthurium were different from the opportunistic human pathogen.

The partial sequences of 16S rRNA gene were amplified using primer set P16S-F1 and P16S-R1 and deposited in the NCBI GenBank database under accession numbers OP962219 (A6251^T), OP962220 (A2111), OP964727 (A5586^T), and OP964728 (A5588^T). The 16S rRNA gene sequences were retrieved from the whole genomes of new species strains, and 38 type strains of Xanthomonas species and 23 type strains of Stenotrophomonas species published in the NCBI database (Supplementary Table 1). The sequences of the nearly entire 16S rRNA gene ranging from 1,415 bp (S. bentonitica LMG 29893^T) to 1,421 bp (S. chelatiphaga DSM 21508^T) were analyzed for phylogenetic relationships. The 16S rRNA gene sequences of A6251^T and A2111 were identical with X. sacchari CFBP 4641^T and only one base was different from “X. sontii” PPL1^T. A5588^T and A5586^T were closely related to each other and S. bentonitica LMG 29893^T and showed higher similarity values of 16S rRNA ranging from 99.6 to 99.8%. In the maximum likelihood (ML) phylogenetic tree, 16S rRNA gene sequences depicted better resolution within Stenotrophomonas species than Xanthomonas species because of very poor species discrimination, which was higher than the 98.7% cutoff of 16S similarity (Figure 2).

For more detailed phylogenetic analysis, nine housekeeping genes (atpD, dnaA, dnaK, gltA, gyrB, nuoD, ppsA, rpoH, and uvrB) were selected and retrieved from whole genomes of formerly mentioned type strains of Xanthomonas and Stenotrophomonas species. Total length of concatenated sequence with nine genes in alphabetic order was approximately 14.3 Kb, which contained the maximum ~2,443 bp of gyrB gene and the minimum ~879 bp of uvrB gene sequences. The similarity of the concatenated gene sequences of two strains A6251^T and A2111 was 99.3%; strain A5588^T and strain A5586^T showed 89.8% similarity. Based on nine housekeeping genes, the ML tree indicated that two major phylogenetic clades, Clade I and Clade II, were present within the Xanthomonas clade with high bootstrapping value support (Figure 3). Similar Clade I and II phylogenetic groupings were reported in the previous studies (Koebnik et al., 2021; Mafakheri et al., 2022; Rana et al., 2022). The strains A6251^T and A2111 formed a monoclade clustering with X. sacchari, X. indica, X. sontii, and X. albilineans in Clade I, which also include X. surreyensis, X. bonasiae, X. traslucens, X. hyacinthi, X. theicola, and X. youngii (Figure 3). Stenotrophomonas bentonitica consistently clustered with strains A5588^T and A5586^T with strong bootstrapping value. Stenotrophomonas rhizophila and S. nematodicola formed a clade closely related to the A5588^T-A5586^T-S. bentonitica clade (Figure 3); however, no grouping was formed in the 16S rRNA phylogenetic tree (Figure 2).

To examine the accurate taxonomic classification, the overall genomic relatedness indices (OGRIs) including the values of ANI and dDDH of A6251^T from spathiphyllum and A2111 from colocasia were analyzed with other type strains of Xanthomonas species. Meanwhile, A5588^T and A5586^T strains were compared with other type strains in Stenotrophomonas. The general cutoff values of ANI and dDDH for species delineation are lower than 95–96 and 70%, respectively (Goris et al., 2007; Richter and Rosselló-Móra, 2009; Meier-Kolthoff et al., 2013). Strains A6251^T and A2111 shared 98.4% ANI and 85.2% dDDH with each other, which indicated that two strains belong to the same species. Based on the pairwise comparisons of the other Xanthomonas spp. reference genomes with either A6251^T or A2111, the ANI and dDDH values were 83.4–94.9% and 22.3–59.3%, respectively, which strongly signified that A6251^T and A2111 are distinguished from the others and should be considered a novel lineage (Table 2). Despite that X. sacchari CFBP 4641^T shared slightly higher OrthoANI values (95.04, 95.1) with A6251^T and A2111, other OGRIs supported the assignment as a new species (Table 2). The estimations of ANI and dDDH of anthurium strains, A5588^T and A5586^T, were 86.4 and 28.2%, respectively. Both strains shared ANI and dDDH values lower than 90% (83.4–86.8%) and 30% (20.7–29.9%) with other type strains of Stenotrophomonas spp., respectively, except for that A5588^T and S. bentonitica LMG 29893^T shared 94.7% of ANI and 56.4% of dDDH sequence identities (Table 3). In addition to ANI and dDDH values, other OGRIs including AP, OrthoANI, and G + C differences supported that A5588^T and A5586^T are two novel species (Table 3). To combine the phylogenetic analyses and evidence of OGRIs, three novel species were proposed, i.e., X. hawaiiensis sp. nov. strains A6251^T and A2111; S. aracearum sp. nov. strain A5588^T; and, S. oahuensis sp. nov. strain A5586^T.

Among 40 reference genomes of Xanthomonas spp. including X. hawaiiensis sp. nov. strains A6251^T and A2111, 425 core orthologous genes (99% ≤ strains ≤100%) and 28,285 cloud genes (0% ≤ strains <15%) were found (Figure 4A). The lowest two numbers of unique genes present in A6251^T and A2111 were 87 and 103, respectively, and follow X. sacchari CFBP 4641^T which had 171 unique genes, as shown in the Figure 4B. The number of exclusive hypothetical protein encoded genes was comparatively lower in strains A6251^T and A2111, whereas 50 common hypothetical proteins existed in all type strains of Xanthomonas spp. (Figure 4C). Based on the phylogenetic tree constituted with 425 core genes, the closest relative of X. hawaiiensis sp. nov. was X. sacchari CFBP 4641^T, which successively clustered with “X. sontii” PPL1^T and “X. indica” CFBP 9039^T in Xanthomonas clade I species (Figure 5). The groupings were concordant with the previously described MLSA tree (Figure 3). The 34,713 gene clusters estimated in the Roary matrix revealed that the genomes of xanthomonads were highly diversified (Figure 5).

On the other hand, the pan genome size of 20 Stenotrophomonas spp. type strains, including S. aracearum sp. nov. (A5588^T) and S. oahuensis sp. nov. (A5586^T), was 31,069 with 576 core genes (Figures 6A, 7). The genome of the strain A5588^T contained 396 unique genes, 317 of which were hypothetical protein encoding genes; whereas, a high number of hypothetical protein encoding genes (1,242 genes) were harbored in the genome of the strain A5586^T, possessing total 1,526 unique genes (Figures 6B–C). As presented in the 9-gene ML tree (Figure 3), A5588^T and S. bentonitica DSM 103927^T were closely clustered together and grouped with A5586^T, which was a sister group of the clade formed with S. rhizophila DSM 14405^T and “S. nematodicola” CPCC 101271^T (Figure 7). The average number of unique genes with unknown functions was higher in 25 Stenotrophomonas spp. than 40 Xanthomonas spp. (806 > 538), implying higher genetic diversity within stenotrophomonads, which warrants further investigations on Stenotrophomonas species.

The inhibition zones with seven tested antibiotics, namely, bacitracin (50 mg/mL), chloramphenicol (50 mg/mL), gentamicin (50 mg/mL), kanamycin (50 mg/mL), penicillin (50 mg/mL), tetracycline (40 mg/mL), and polymyxin B sulfate (50 mg/mL), indicated various degrees of sensitivity of four new species strains. Strains A6251^T, A2111, and A5586^T were sensitive to all tested antibiotics, whereas strain A5588^T was sensitive to all tested antibiotics except penicillin (Supplementary Table 2). Strains A6251^T and A2111, belonging to the same new species, displayed similar results, except for the tolerance to polymyxin B sulfate. Notably, A5586^T displayed a very small inhibition zone (0.1 cm in radius) surrounding the discs of bacitracin on the NA plate after incubating at 28°C for 24 h (Supplementary Table 2).

Colonies of the type strain A6251^T are yellow (Honey, Hex code #FFC30B), circular shape, mucoid consistency, smooth surface, convex relief with entire margins, and 0.3–0.6 (avg. 0.45) mm in diameter on yeast dextrose calcium carbonate (YDC) medium plate after incubating at 28°C for 2 days. Cells are gram-negative and able to utilize dextrin, D-maltose, D-trehalose, D-cellobiose, gentiobiose, sucrose, D-turanose, α-D-lactose, D-melibiose, Β-methyl-D-glucoside, D-salicin, N-acetyl-D-glucosamine, α-D-glucose, D-mannose, D-fructose, D-galactose, L-fucose, 1% NaCl, 1% sodium lactate, glycerol, gelatin, L-glutamic acid, lincomycin, pectin, quinic acid, vancomycin, tetrazolium violet, tetrazolium blue, citric acid, bromo-succinic acid, lithium chloride, Tween 40, and acetic Acid. In contrast, cells are unable to oxidize stachyose, D-raffinose, N-acetyl-β-D-mannosamine, N-acetyl-D-galactosamine, N-acetyl-neuraminic acid, 8% NaCl, inosine, fusidic acid, D-sorbitol, D-mannitol, D-arabitol, myo-inositol, D-aspartic acid, minocycline, L-arginine, L-histidine, L-pyroglutamic acid, guanidine HCl, D-gluconic acid, mucic acid, D-saccharic acid, p-hydroxy-phenylacetic acid, D-lactic acid methyl ester, α-keto-glutaric acid, D-malic acid, γ-aminobutryric acid, α-hydroxybutyric acid, α-ketobutyric acid, formic acid, sodium butyrate, and sodium bromate. Some utilization of carbon resources and chemical components showed borderline results or inconsistency between two strains after growing cell suspension in GEN III Microplate (Biolog Inc., Hayward, CA, USA) at 28°C for 24 h.

X. hawaiiensis sp. nov. is sensitive to seven tested antibiotics, including bacitracin (50 mg/mL), chloramphenicol (50 mg/mL), gentamicin (50 mg/mL), kanamycin (50 mg/mL), penicillin (50 mg/mL), tetracycline (40 mg/mL), and polymyxin B sulfate (50 mg/mL). The genome size of type strain A6251^T is 4.88 Mbp with 68.93 mol% of DNA G + C content.

The type strain A6251^T = D-93^T = ICMP 25022^T = LMG 33200^T was isolated from Spathiphyllum (Araceae family) in 1985 in Hawaii, USA. Another strain A2111 = D-194 = ICMP 25023 = LMG 33199 was isolated from Colocasia (Araceae family) in 1986 in Hawaii, USA.

Colonies of S. aracearum strain A5588^T are dark yellow (Mustard, Hex code #E8B828), irregular shape, butyrous consistency, smooth surface, raised relief with entire margins, and 0.4–0.5 mm (average 0.45) in diameter on YDC medium plates after incubation at 28°C for 2 days. Cells are gram-negative and able to utilize D-maltose, D-cellobiose, gentiobiose, N-acetyl-D-glucosamine, N-acetyl-D-galactosamine, α-D-glucose, D-mannose, 1% sodium lactate, D-serine, troleandomycin, rifamycin SV, gelatin, lincomycin, guanidine HCl, vancomycin, tetrazolium violet, tetrazolium Blue, α-ketoglutaric acid, L-malic acid, bromo-succinic acid, acetic acid, and aztreonam. Cells grow under pH 6 and 1% NaCl but neither at pH 5 nor 8% NaCl. In the contrary, cells are unable to oxidize sucrose, D-turanose, stachyose, D-raffinose, α-D-lactose, D-melibiose, Β-methyl-D-glucoside, N-acetyl-β-D-mannosamine, N-acetyl-neuraminic acid, D-galactose, 3-methyl-glucose, inosine, fusidic acid, D-sorbitol, D-mannitol, D-arabitol, myo-inositol, glycerol, D-glucose-6-PO4, D-aspartic acid, D-serine, minocycline, L-arginine, L-aspartic acid, L- glutamic acid, L-histidine, L-pyroglutamic acid, L-serine, pectin, D-galacturonic acid, D-gluconic acid, mucic acid, quinic acid, D-saccharic acid, p-hydroxy-phenylacetic acid, D-lactic acid methyl ester, L-lactic acid, citric acid, D-malic acid, nalidixic acid, potassium tellurite, γ-aminobutryric acid, α-hydroxybutyric acid, α-ketobutyric acid, β-hydroxy-D, L-butyric acid, acetoacetic acid, formic acid, sodium butyrate, and sodium bromate. Some utilization of carbon sources and chemical components, such as dextrin and glucuronamide showed faded positive results after growing A5588^T cell suspension in GEN III Microplate (Biolog Inc., Hayward, CA, USA) at 28°C for 24 h.

S. aracearum sp. nov. was sensitive to six tested antibiotics, namely, bacitracin (50 mg/mL), chloramphenicol (50 mg/mL), gentamicin (50 mg/mL), kanamycin (50 mg/mL), tetracycline (40 mg/mL), and polymyxin B sulfate (50 mg/mL) but resistant to penicillin (50 mg/mL) on NA plates. The genome size of type strain A5588^T is 4.33 Mbp with 66.44 mol% of DNA G + C content.

The type strain A5588^T = D-61-1L^T = ICMP 25025^T = LMG 33202^T was isolated from Anthurium (Araceae family) in 1985 in Hawaii, USA.

Colonies of the S. oahuensis strain A5586^T are dark yellow (Butterscotch, Hex code #FABD02), circular shape, butyrous consistency, smooth surface, flat relief with undulate margins, and 0.4–0.7 mm (average 0.55) in diameter on YDC medium plates after incubation at 28°C for 2 days. Cells are gram-negative and able to utilize dextrin, D-maltose, D-trehalose, D-cellobiose, gentiobiose, Β-methyl-D-glucoside, D-salicin, N-acetyl-D-glucosamine, α-D-glucose, D-mannose, 1% sodium lactate, gelatin, glycyl-L-proline, lincomycin, guanidine HCl, vancomycin, tetrazolium violet, tetrazolium blue, citric acid, α-ketoglutaric acid, L-malic acid, bromo-succinic acid, lithium chloride, propionic acid, acetic acid, and aztreonam. Cells grow under the conditions of pH 6, 1% NaCl, or 4% NaCl but cells survive neither pH 5 nor 8% NaCl solution. In contrast, cells are unable to oxidize sucrose, stachyose, D-raffinose, N-acetyl-β-D-mannosamine, N-acetyl-neuraminic acid, D-galactose, 3-methyl-glucose, inosine, D-fucose, L-fucose, L-rhamnose, inosine, fusidic acid, D-sorbitol, D-mannitol, D-arabitol, myo-inositol, glycerol, D-glucose-6-PO4, D-aspartic acid, D-serine, rifamycin SV, minocycline, L-arginine, L-aspartic acid, L- glutamic acid, L-histidine, L-pyroglutamic acid, L-serine, pectin, D-galacturonic acid, D-gluconic acid, D-glucuronic acid, mucic acid, quinic acid, D-saccharic acid, p-hydroxy-phenylacetic acid, D-lactic acid methyl ester, L-lactic acid, D-malic acid, nalidixic acid, potassium tellurite, γ-amino-butryric acid, α-hydroxy-butyric acid, β-hydroxy-D, L-butyric acid, α-keto-butyric acid, acetoacetic acid, formic acid, and sodium bromate. Some utilization of carbon resources and chemical components, such as D-turanose and sodium butyrate, showed faded positive results after growing A5586^T cell suspension in GEN III Microplate (Biolog Inc., Hayward, CA, USA) at 28°C for 24 h.

S. oahuensis sp. nov. was sensitive to seven tested antibiotics, namely, bacitracin (50 mg/mL), chloramphenicol (50 mg/mL), gentamicin (50 mg/mL), kanamycin (50 mg/mL), penicillin (50 mg/mL), tetracycline (40 mg/mL), and polymyxin B sulfate (50 mg/mL). The genome size of type strain A5586^T is 4.68 Mbp, which includes a chromosome (4.62 Mbp) and a plasmid (60.78 Kbp). The DNA G + C content of the type strain is 65.3 mol%.

The type strain A5586^T = D-31^T = ICMP 25024^T = LMG 33201^T was isolated from Anthurium (Araceae family) in 1981 in Hawaii, USA.