Microbacterium salsuginis sp. nov., a halotolerant actinobacterium with antimicrobial activity.

A novel Gram-staining-positive actinobacterium with antimicrobial activity, designated CFH 90308T, was isolated from the sediment of a salt lake in Yuncheng, Shanxi, south-western China. The isolate exhibited the highest 16S rRNA gene sequence similarities to Microbacterium yannicii G72T, Microbacterium hominis NBRC 15708T and Microbacterium xylanilyticum S3-ET (98.5, 98.4 and 98.2 %, respectively), and formed a separate clade with M. xylanilyticum S3-ET in phylogenetic trees. The strain grew at 15-40 ºC, pH 6.0-8.0 and could tolerate NaCl up to a concentration of 15 % (w/v). The whole genome of strain CFH 90308T consisted of 4.33 Mbp and the DNA G+C content was 69.6 mol%. The acyl type of the peptidoglycan was glycolyl and the whole-cell sugars were galactose and mannose. The cell-wall peptidoglycan mainly contained alanine, glycine and lysine. The menaquinones of strain CFH 90308T were MK-12, MK-13 and MK-11. Strain CFH 90308T contained anteiso-C15:0, anteiso-C17:0, iso-C16:0 and iso-C15:0 as the predominant fatty acids. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between CFH 90308T and the other species of the genus Microbacterium were found to be low (ANIb <81.3 %, dDDH <25.6 %). The secondary metabolite produced by strain CFH 90308T showed antibacterial activities against Bacillus subtilis, Pseudomonas syringae, Aeromonas hydrophila and methicillin-resistant Staphylococcus aureus. Based on genotypic, phenotypic and chemotaxonomic results, the isolate is considered to represent a novel species of the genus Microbacterium, for which the name Microbacterium salsuginis sp. nov. is proposed. The type strain is CFH 90308T (=DSM 105964T=KCTC 49052T).

Thermalbibacter longus gen. nov., sp. nov., isolated from a hot spring.

An isolate, designated CFH 74404T, was recovered from a hot spring in Tengchong, Yunnan province, PR China. Phylogenetic analysis indicated that the isolate belongs to the family Thermomicrobiaceae and showed the highest 16S rRNA gene sequence similarity to Thermorudis peleae KI4T (93.6 %), Thermorudis pharmacophila WKT50.2T (93.1 %), Thermomicrobium roseum DSM 5159T (92.0 %) and Thermomicrobium carboxidum KI3T (91.7 %). The average amino acid identity and average nucleotide identity values between strain CFH 74404T and the closest relatives were 42.0-75.9 % and 67.0-77.3 %, respectively. Cells of strain CFH 74404T stained Gram-positive and were aerobic, non-motile and short rod-shaped. Growth occurred at 20-65 °C (optimum, 55 °C), pH 6.0-8.0 (optimum, pH 7.0) and with up to 2.0 % (w/v) NaCl (optimum 0-1.0 %, w/v). The predominant respiratory quinone was MK-8. The major fatty acids (>10 %) were C18 : 0 (50.8 %) and C20 : 0 (16.8 %). The polar lipid profile of strain CFH 74404T included diphosphatidylglycerol, four unidentified phosphoglycolipids, phosphatidylinositol and three unidentified glycolipids. The G+C content of the genomic DNA was determined to be 67.1 mol% based on the draft genome sequence. On the basis of phenotypic, phylogenetic and genotypic analyses, it is concluded that strain CFH 74404T represents a new species of a novel genus Thermalbibacter of the family Thermomicrobiaceae, for which the name Thermalbibacter longus gen. nov., sp. nov. is proposed. The type strain is CFH 74404T (=KCTC 62930T=CGMCC 1.61585T).

One-pot biosynthesis of gastrodin using UDP-glycosyltransferase itUGT2 with an in situ UDP-glucose recycling system.

Gastrodin, the major effective ingredient in Tianma (Gastrodia elata), is a p-hydroxybenzoic acid derivative with various activities. Gastrodin has been widely investigated for food and medical applications. The last biosynthetic step for gastrodin is UDP-glycosyltransferase (UGT)-mediated glycosylation with UDP-glucose (UDPG) as glycosyl donor. In this study, we performed a one-pot reaction both in vitro and in vivo to synthesize gastrodin from p-hydroxybenzyl alcohol (pHBA) by coupling UDP-glucosyltransferase from Indigofera tinctoria (itUGT2) to sucrose synthase from Glycine max (GmSuSy) for regeneration of UDPG. The in vitro results showed that itUGT2 transferred a glucosyl group to pHBA to generate gastrodin. After 37 UDPG regeneration cycles with 2.5% (molar ratio) UDP, the pHBA conversion reached 93% at 8 h. Furthermore, a recombinant strain with itUGT2 and GmSuSy genes was constructed. Through optimizing the incubation conditions, a 95% pHBA conversion rate (220 mg/L gastrodin titer) was achieved in vivo without addition of UDPG, which was 2.6-fold higher than that without GmSuSy. This in situ system for gastrodin biosynthesis provides a highly efficient strategy for both in vitro gastrodin synthesis and in vivo biosynthesis of gastrodin in E. coli with UDPG regeneration.

Qipengyuania thermophila sp. nov., isolated from a Chinese hot spring.

A novel Gram-stain-negative, non-motile, short rod-shaped and aerobic bacterial strain, designated as CFH 74456 T, was isolated from sediment of a hot spring, Tengchong, Yunnan Province, south-western China. Growth occurred at 20-53 ºC (optimum 45 ºC), pH 7.0-9.0 (optimum pH 8.0) and up to 2.0% (w/v) NaCl (optimum 0-1.0%, w/v). The predominant respiratory quinone was ubiquinone 10 (Q-10). The major fatty acids (> 10%) were C17:1 ω6c (17.9%) and summed feature 8 (38.6%). The polar lipid profile of strain CFH 74456 T was identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid, three unidentified glycolipids and three unidentified polar lipids. Phylogenetic analysis based on 16S rRNA gene sequence indicated that strain CFH 74456 T belongs to the genus Qipengyuania, and was most closely related to Qipengyuania sediminis CGMCC 1.12928 T (95.7%). The draft genome size of the isolate was 2.29 Mb with G + C content of 68.5%. The amino acid identity, average nucleotide identity and the digital DNA-DNA hybridization values between strain CFH 74456 T and the closest relatives ranged from 67.0 to 67.9%, 73.0 to 74.2% and 18.2-19.3%, respectively. On the basis of phenotypic, phylogenetic and genotypic analyses, it is concluded that strain CFH 74456 T represents a new species of the genus Qipengyuania, for which the name Qipengyuania thermophila sp. nov. is proposed. The type strain is CFH 74456 T (= KCTC 62921 T = CCTCC AB 2018237 T).

Agromyces agglutinans sp. nov., isolated from saline lake sediment.

A novel actinobacterium, designated strain CFH 90414T, was isolated from sediment sampled at a saline lake in Yuncheng, Shanxi, PR China. The taxonomic position of the strain was investigated by using a polyphasic approach. Cells of strain CFH 90414T were Gram-reaction-positive, aerobic and non-motile. Growth occured at 4-40 °C, pH 5.0-9.0 and in the presence of up to 0-3.0 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CFH 90414T was a member of the genus Agromyces. The 16S rRNA gene sequence similarity analysis indicated that strain CFH 90414T was most closely related to Agromyces italicus JCM 14320T (98.07 %) and Agromyces lapidis JCM 14321T (97.18 %). The whole genome of CFH 90414T was 3.64 Mb, and showed a G+C content of 71.5 mol%. The average nucleotide identity (ANI) values and digital DNA-DNA hybridization (dDDH) values between CFH 90414T and the other species of the genus Agromyces were found to be low (ANI <78.99 % and dDDH <22.9 %). The whole-cell sugars were rhamnose, mannose, ribose, glucose and galactose. The isolate contained l-2,4-diaminobutyric acid, d-alanine, d-glutamic acid and glycine in the cell-wall peptidoglycan. The predominant menaquinone was MK-12. The major cellular fatty acids were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C16 : 0. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol and an unidentified glycolipid. On the basis of phenotypic, genotypic and phylogenetic data, strain CFH 90414T is considered to represent a novel species of the genus Agromyces, for which the name Agromyces agglutinans sp. nov. is proposed. The type strain is CFH 90414T (=DSM 105966T=KCTC 49062T).