Dual roles of CD11b+CD33+HLA-DR-/lowCD14- myeloid-derived suppressor cells with a granulocytic morphology following allogeneic hematopoietic stem cell transplantation: from inflammation promoters to immune suppressors within 90 days.

Introduction: Granulocytic myeloid-derived suppressor cells (G-MDSCs) show fast recovery following allogeneic hematopoietic stem cell transplantation (allo-HSCT) constituting the major part of peripheral blood in the early phase. Although G-MDSCs mediate immune suppression through multiple mechanisms, they may also promote inflammation under specific conditions. Methods: G-MDSCs were isolated from 82 patients following allo-HSCT within 90 days after allo-HSCT, and their interactions with autologous CD3+ T-cells were examined. T-cell proliferation was assessed by flow cytometry following CFSE staining, while differentiation and interferon-γ secretion were characterized using chemokine receptor profiling and ELISpot assays, respectively. NK cell cytotoxicity was evaluated through co-culture with K562 cells. An aGVHD xenogeneic model in humanized mice was employed to study the in vivo effects of human leukocytes. Furthermore, transcriptional alterations in G-MDSCs were analyzed via RNA sequencing to investigate functional transitions. Results: G-MDSCs promoted inflammation in the early-stage, by facilitating cytokine secretion and proliferation of T cells, as well as their differentiation into pro-inflammatory T helper subsets. At day 28, patients with a higher number of G-MDSCs exhibited an increased risk of developing grades II-IV aGvHD. Besides, adoptive transfer of G-MDSCs from patients at day 28 into humanized mice exacerbated aGvHD. However, at day 90, G-MDSCs led to immunosuppression, characterized by upregulated expression of indoleamine 2,3-dioxygenase gene and interleukin-10 secretion, coupled with the inhibition of T cell proliferation. Furthermore, transcriptional analysis of G-MDSCs at day 28 and day 90 revealed that 1445 genes were differentially expressed. These genes were associated with various pathways, revealing the molecular signatures of early post-transplant differentiation in G-MDSCs. In addition, genes linked to the endoplasmic reticulum stress were upregulated in patients without aGvHD. The acquisition of immunosuppressive function by G-MDSCs may depend on the activation of CXCL2 and DERL1 genes. Conclusion: Our findings revealed the alteration in the immune characteristics of G-MDSCs within the first 90 days post-allo-HSCT. Moreover, the quantity of G-MDSCs at day 28 may serve as a predictive indicator for the development of aGvHD.

Solibacillus ferritrahens sp. nov., a novel siderophore-producing bacterium isolated from Wumeng Mountain National Nature Reserve in Yunnan Province.

A gram-stain-positive, aerobic, rod-shaped bacterial strain capable of producing siderophores, named YIM B08730T, was isolated from a soil sample collected from Wumeng Mountain National Nature Reserve, Zhaotong City, Yunnan Province. Growth occurred at 10-45 °C (optimum, 35-40 â„ƒ), pH 7.0-9.0 (optimum, 7.0) and in the presence of 0-5 % (w/v) NaCl (optimum, 0-1 %, w/v). A comparative analysis of the 16S rRNA gene sequence (1558 bp) of strain YIM B08730T showed the highest similarity to Solibacillus isronensis JCM 13838T (96.2 %), followed by Solibacillus silvestris DSM 12223T (96.0 %) and Solibacillus kalamii ISSFR-015T (95.4 %). The main polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylserine and one unidentified lipid. The main respiratory quinone of strain YIM B08730T was menaquinone 7 (MK-7). The major fatty acids were iso-C15:0 and C16:1ω7c alcohol. The digital DNA-DNA hybridization and average nucleotide identity values between strain YIM B08730T and the reference strain S. isronensis JCM 13838T were 24.8 % and 81.2 %, respectively. The G + C content of the genomic DNA was 37.1 mol%. The genome of the novel strain contained genes associated with the production of siderophores, and it also revealed other functional gene clusters involved in plant growth promotion and soil bioremediation. Based on these phenotypic, chemotaxonomic and phylogenetic analyses, strain YIM B08730T is considered to be a novel species of the genus Solibacillus, for which the name Solibacillus ferritrahens sp. nov. is proposed. The type strain is YIM B08730T (= NBRC 116268T = CGMCC 1.60169T).

Whole genome sequencing provides evidence for Bacillus velezensis SH-1471 as a beneficial rhizosphere bacterium in plants.

Bacillus is widely used in agriculture due to its diverse biological activities. We isolated a Bacillus velezensis SH-1471 from the rhizosphere soil of healthy tobacco, which has broad-spectrum antagonistic activity against a variety of plant pathogenic fungi such as Fusarium oxysporum, and can be colonized in the rhizosphere of a variety of plants. This study will further explore its mechanism by combining biological and molecular biology methods. SH-1471 contains a ring chromosome of 4,181,346 bp with a mean G + C content of 46.18%. We identified 14 homologous genes related to biosynthesis of resistant secondary metabolite, and three clusters encoded potential new antibacterial substances. It also contains a large number of genes from colonizing bacteria and genes related to plant bacterial interactions. It also contains genes related to environmental stress, as well as genes related to drug resistance. We also found that there are many metabolites in the strain that can inhibit the growth of pathogens. In addition, our indoor pot test found that SH-1471 has a good control effect on tomato wilt, and could significantly improve plant height, stem circumference, root length, root weight, and fresh weight and dry weight of the aboveground part of tomato seedlings. Therefore, SH-1471 is a potential biological control strain with important application value. The results of this study will help to further study the mechanism of SH-1471 in biological control of plant diseases and promote its application.

Research Progress of Nervonic Acid Biosynthesis.

Nervonic acid (NA) is a very-long-chain monounsaturated fatty acid with great application values. It plays a vital role in the development of brain nervous system and the treatment of neurological diseases, so it has attracted much attention from all walks of life. Although NA has a wide range of sources, its current acquisition methods are still mainly relied on chemical synthesis and plant extraction, which are challenging to meet the market and green industry demands, limiting its development and application. In recent years, with the rapid development of synthetic biology technology, NA biosynthesis has become an alternative production strategy. In this study, we summarize the physicochemical properties, pharmacological activities, resources, biosynthetic pathways and heterologous biosynthesis of NA, and discuss the challenges and prospects of NA biosynthesis. The application prospects of cell-free systems and retrobiosynthesis in NA synthesis were also reviewed.

Differential Responses of Bacterial and Fungal Communities to Siderophore Supplementation in Soil Affected by Tobacco Bacterial Wilt (Ralstonia solanacearum).

Siderophores secreted by microorganisms can promote ecological efficiency and could be used to regulate the unbalanced microbial community structure. The influence of the siderophore activity of Trichoderma yunnanense strain 2-14F2 and Beauveria pseudobassiana strain (2-8F2) on the physiological/biochemical functions and community structure of soil microbes affected by tobacco bacterial wilt (TBW) was studied. DNS Colorimetry and Biolog-eco plates were used to quantify the impacts of strain siderophores on soil enzyme activities and microbial metabolism. Based on Illumina MiSeq high-throughput sequencing, the soil 16S rDNA and ITS sequences were amplified to dissect the response characteristics of alpha/beta diversity and the structure/composition of a soil microbial community toward siderophores. The KEGG database was used to perform the PICRUSt functional prediction of the microbial community. We found that siderophores of 2-14F2 and 2-8F2, at certain concentrations, significantly increased the activities of sucrase (S-SC) and urease (S-UE) in the TBW soil and enhanced the average well color development (AWCD, carbon source utilization capacity) of the microbial community. The metabolic capacity of the diseased soil to amino acids, carbohydrates, polymers, aromatics, and carboxylic acids also increased significantly. The response of the bacterial community to siderophore active metabolites was more significant in alpha diversity, while the beta diversity of the fungal community responded more positively to siderophores. The relative abundance of Actinobacteria, Chloroflexi, and Acidobacteria increased and was accompanied by reductions in Proteobacteria and Firmicutes. LEfSe analysis showed that Pseudonocardiaceae, Gemmatimonas, Castellaniella, Chloridiumand and Acrophialophora altered the most under different concentrations of siderophore active metabolites. The PICRUSt functional prediction results showed that siderophore increased the abundance of the redox-related enzymes of the microbial community in TBW soil. The BugBase phenotypic prediction results showed that the siderophore activity could decrease the abundance of pathogenic bacteria. The study concludes that siderophore activity could decrease the abundance of pathogenic bacteria and regulate the composition of the microbial community in TBW soil. The activities of sucrase (S-SC) and urease (S-UE) in TBW soil were significantly increased. Overall, the siderophore regulation of community structures is a sustainable management strategy for soil ecosystems.

Chitinolyticbacter albus sp. Nov., A Novel Chitin-Degrading Bacterium Isolated from Ancient Wood Rhizosphere Soil.

In this study, a novel aerobic mesophilic bacterial strain with capable of degrading chitin, designated YIM B06366T, was isolated and classified. The rod-shaped, Gram-stain-negative, on-spore-forming bacterium originated from rhizosphere soil sample collected in Kunming City, Yunnan Province, southwest PR China. Strain YIM B06366T exhibited growth at temperatures between 20 and 35 °C (optimum, 30 °C) and at pH 6.0-8.0 (optimum, pH 6.0). The analysis of 16S rRNA gene sequence similarity revealed that strain YIM B06366T was most closely related to type strain Chitinolyticbacter meiyuanensis SYBC-H1T (98.9%). Phylogenetic analysis based on genome data indicated that strain YIM B06366T should be assigned to the genus Chitinolyticbacter. The Average Nucleotide Identity (ANI) and digital DNA-DNA Hybridization (dDDH) values between strain YIM B06366T and the reference strain Chitinolyticbacter meiyuanensis SYBC-H1T were 84.4% and 27.7%, respectively. The major fatty acids included Summed Feature 3 (C16:1 ω6c/C16:1 ω7c), Summed Feature 8 (C18:1 ω6c/C18:1 ω7c), and C16:0. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, aminophospholipids, and two unidentified phospholipids. The predominant menaquinone was Q-8, and the genomic DNA G + C content was 64.1%. Considering the polyphasic taxonomic evidence, strain YIM B06366T is proposed as a novel species within the genus Chitinolyticbacter, named Chitinolyticbacter albus sp. nov. (type strain YIM B06366T = KCTC 92434T = CCTCC AB 2022163T).

Pseudomonas subflava sp. nov., a new Gram-negative bacterium isolated from Guishan in Yunnan province, south-west China.

A new Gram-negative, rod-shaped, flagellated bacterium was isolated from soil in the Guishan, Xinping County, Yuxi City, Yunnan Province, China, and named YIM B01952T. Growth occurred at 10-40 °C (optimum, 30 °C), pH 6.0-9.0 (optimum, pH 7.5) and with up to ≤ 5.0% (w/v) NaCl on Tryptic Soy Broth Agar (TSA) plates. Phylogenetic analysis based on the 16S rRNA gene and draft-genome sequence showed that strain YIM B01952T belonged to the genus Pseudomonas, and was closely related to the type strain of Pseudomonas alcaligenes (sequence similarity was 98.8%). The digital DNA-DNA hybridization (dDDH) value between strain YIM B01952T and the parallel strain P. alcaligenes ATCC 14909T was 49.0% based on the draft genome sequence. The predominant menaquinone was Q-9. The major fatty acids were summed feature 8 (C18:1 ω6c and/or C18:1 ω7c), summed feature 3 (C16:1 ω6c and/or C16:1 ω7c) and C16:0. The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, and phosphatidylglycerol. The genome size of strain YIM B01952T was 4.341 Mb, comprising 4156 predicted genes with a DNA G + C content of 66.4 mol%. In addition, we detected that strain YIM B01952T had some traditional functional genes (plant growth promotion and multidrug resistance), unique genes through genome comparison and analysis with similar strains. Based on genetic analyses and biochemical characterization, the strain YIM B01952T was identified as a novel species in the genus Pseudomonas, for which the name Pseudomonas subflava sp. nov. is proposed. The type strain is YIM B01952T (=CCTCC AB 2021498T = KCTC 92073T).

Intracellular angiopoietin-1 promotes TKI-resistance via activation of JAK/STAT5 pathway in chronic myeloid leukemia.

Drug resistance from BCR-ABL tyrosine kinase inhibitors (TKIs) and other chemotherapeutics results in treatment failure and disease progression in chronic myeloid leukemia (CML). However, the mechanism is still uncertain. In this study, we investigated the role of angiopoietin-1 (ANG-1) as a potential prognostic factor for drug resistance in CML. Both intracellular and secretory ANG-1 (iANG-1 and sANG-1) were overexpressed in multidrug-resistant CML samples. The IC50 value was higher in primary CD34+ CD38- cells with more ANG-1. Silencing ANG-1significantly sensitized three TKI-resistant CML cell lines to imatinib (IM) while recombinant human ANG-1 failed to retain cell survival in vitro. This indicated the important role of iANG-1 as opposed to sANG-1 in CML drug resistance. Moreover, a similar effect was observed in xenograft mice models bearing ANG-1-silenced CML cells. Subsequently, pathway analysis and protein validation experiments showed activation of the JAK/STAT pathway and augmentation of STAT5a phosphorylation in ANG-1 restored CML cells. Upstream Src phosphorylation, which plays a crucial role in CML drug resistance, was also upregulated as a key event in iANG-1-related JAK/STAT pathway activation. In conclusion, our study elucidated a new BCR-ABL independent molecular mechanism induced by intracytoplasmic ANG-1 overexpression as a potential strategy for overcoming CML resistance.

Brevibacillus daliensis sp. nov., Isolated From Soil in Machangqing Nature Reserve.

A new aerobic bacterial strain, designated strain YIM B02290T, was isolated from the soil of Machangqing, Dali city, Yunnan Province, China. Cells were Gram-stain-positive, sporogenous, rod-shaped, and motile with peritrichous flagella. Strain YIM B02290T showed the highest 16S rRNA gene sequence similarity with Brevibacillus laterosporus (97.6%) and Brevibacillus halotolerans (97.6%). The ANI and dDDH values between strain YIM B02290T and the two reference strains Brevibacillus laterosporus LAM00312T and Brevibacillus halotolerans DSM 25T are 72.6% and 72.2%, 20.2% and 19.5% based on the draft genome sequence, respectively. The major cellular fatty acids contain anteiso-C15: 0 and iso-C15: 0. The diagnostic diamino acid of the cell-wall peptidoglycan was meso-diaminopimelic acid. The predominant menaquinone was identified as menaquinone-7. The main polar lipids of strain YIM B02290T were diphosphatidylglycerol, phosphatidylglycerol, phospholipid, phosphatidyl monomethylethanolamine. The genomic DNA G + C content was 40.6 mol%. All results showed that strain YIM B02290T represents a novel species of the genus Brevibacillus, for which the name Brevibacillus daliensis sp. nov. is proposed. The type strain is YIM B02290T (= CCTCC AB 2021094T = CGMCC 1.18802T = KCTC 43376T).

TKIs combined with chemotherapy followed by allo-HSCT in Philadelphia chromosome-positive myelodysplastic syndrome: A case report and literature review.

INTRODUCTION: Philadelphia chromosome (Ph) positive myelodysplastic syndrome (MDS) is a very rare disease. At present, the specific role of Ph in MDS is not clear, but such patients seem to have a poor prognosis, so the disease deserves attention. Here, we describe the history of a woman with Ph-positive MDS and perform a systematic review of related literature. PATIENT CONCERNS AND DIAGNOSIS: We report a 38-year-old woman with Ph-positive MDS. INTERVENTIONS AND OUTCOMES: She received chemotherapy with decitabine, cytarabine, aclarubicin, and granulocyte colony-stimulating factor (DCAG) combined with imatinib mesylate and achieved a bone marrow remission. She then underwent an allogeneic hematopoietic stem cell transplant. The condition is good and no recurrence of the disease has been observed. CONCLUSION: Ph-positive MDS is a very rare disease. Ph may aid in the malignant progression of MDS leaving such patients with a very poor prognosis. Tyrosine kinase inhibitors (TKIs) plus chemotherapy followed by allogeneic hematopoietic stem cell transplantation has provided these patients with satisfactory outcomes.

Cohnella mopanensis sp. nov., a new Gram-negative bacterium isolated from soil in Xinping Mountain National Forest Park.

A Gram-stain-negative, aerobic, rod-shaped bacteria strain, named YIM B01951T, was isolated from a forest soil sample collected from Mopan Mountain National Forest Park, Xinping City, Yunnan Province, southwest PR China (101°58'06" N, 23°03'02" E). Growth occurred at 15-40 °C (optimum, 30 °C), pH 5.0-8.0 (optimum, pH 6.5) and with up to ≤ 3.0% (w/v) NaCl on Nutrient Agar plates. The results of 16S rRNA gene sequence similarity analysis showed that strain YIM B01951T was closely related to the type strain of Cohnella arctica M9-62T (96.5%) and Cohnella lupini RLAHU4BT (96.3%). YIM B01951T contains anteiso-C15:0 and iso-C16:0 as the major cellular fatty acids; the main polar lipids are diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), lysylphosphatidylglycerol (PGL) and five aminophospholipids (APL). The MK-7 is the major respiratory quinone and the DNA G + C content is 49.2 mol%. Based on these phenotypic, chemotaxonomic and phylogenetic analyses, strain YIM B01951T is considered to be a novel species of the genus Cohnella, and named Cohnella mopanensis sp. nov. The type strain is YIM B01951T (= NBRC 115331T = KCTC 43370T).

Stability Mechanism of Low Temperature C2H4-SCR with Activated-Carbon-Supported MnO x -Based Catalyst.

Manganese-based catalysts have shown great potential for use as a hydrocarbon reductant for NO x reduction (HC-SCR) at low temperatures if their catalytic stability could be further maintained. The effect of CeO2 as a promoter and catalyst stability agent for activated carbon supported MnO x was investigated during low temperature deNO x based on a C2H4 reductant. The modern characterization technology could provide a clear understanding of the activity observed during the deNO x tests. When reaction temperatures were greater than 180 °C and with ceria concentrations more than 5%, the overall NO conversion became stable near 70% during long duration testing. In situ DRIFTS shows that C2H4 is adsorbed on the Mn3Ce3/NAC catalysts to generate hydrocarbon activated intermediates, R-COOH, and the reaction mechanism followed the E-R mechanism. The stability and the analytical data pointed to the formation of stable oxygen vacancies within Ce3+/Ce4+ redox couplets that prevented the reduction of MnO2 to crystalline Mn2O3 and promoted the chemisorption of oxygen on the surface of MnO x -CeO x structures. Based on the data, a synergetic mechanism model of the deNO x activity is proposed for the MnO x -CeO x catalysts.

Propioniciclava soli sp. nov., isolated from forest soil, Yunnan, China, and reclassification of the genus Brevilactibacter into the genus Propioniciclava, and Brevilactibacter sinopodophylli, Brevilactibacter flavus, and Brevilactibacter coleopterorum as Propioniciclava sinopodophylli comb. nov., Propioniciclava flava comb. nov., and Propioniciclava coleopterorum comb. nov., respectively.

A Gram-stain-positive, coccus-shaped, facultatively anaerobic, non-motile bacterial strain, designated YIM S02567T, was isolated from a forest soil sample collected from Gejiu City, Yunnan Province, southwest PR China. Growth was observed at 10-45 °C, at pH 6.0-9.5, in the presence of up to 4.0% (w/v) NaCl on R2A medium. The results of 16S rRNA gene sequence similarity analysis showed that strain YIM S02567T was most closely related to the type strain of Brevilactibacter sinopodophylli (95.4%) and Propioniciclava tarda (94.7%), and phylogenetic analysis based on genome data showed that strain YIM S02567T should be assigned to the genus Propioniciclava. The cell-wall diamino acid was meso-diaminopimelic acid. The major cellular fatty acids were identified as anteiso-C15:0 and C16:0, and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and two unidentified glycolipids. The predominant menaquinone was MK-9(H4). The genomic DNA G + C content was 71.2 mol%. Based on the polyphasic taxonomic evidence, strain YIM S02567T is assigned to a novel member of the genus Propioniciclava, for which the name Propioniciclava soli sp. nov., (type strain YIM S02567T = CCTCC AB 2020128T = CGMCC 1.18504T = KCTC 49478T) is proposed. Furthermore, we propose the reclassification of Brevilactibacter as Propioniciclava gen. nov.

Viridibacillus soli sp. nov., isolated from forest soil in Ailaoshan National Nature Reserve.

A Gram stain-positive, rod-shaped, and subterminal endospore-forming bacterium, designated strain YIM B01967T, was isolated from a forest soil sample collected in Ailaoshan National Nature Reserve, Yuxi City, Xinpin county, Yunnan province, China. Strain YIM B01967T showed the highest 16S rRNA gene sequence similarity with Viridibacillus arvi (99.1%) and Viridibacillus arenosi (98.9%). Based on the phylogenetic and 16S rRNA gene sequence results, strain YIM B01967T was affiliated to the genus Viridibacillus. The growth of YIM B01967T was observed at 15-35 °C (optimum, 28 °C), pH 7.0-9.0 (optimum, pH 7.5) and in the presence of 0-2% (w/v) NaCl (optimum in 2% NaCl). The cell wall sugars include ribose, glucose, arabinose, galactose, and mannose. The quinone system consisted of the major compound MK-8 and moderate amounts of MK-7. The major fatty acids (> 10%) included iso-C15:0, anteiso-C15:0, C16:1 ω10c. The major polar lipids profile included DPG, PME. The cell wall peptidoglycan was most likely of the type A4α with an L-Lys-D-Asp interpeptide bridge. The genomic DNA G + C content of strain YIM B01967T was 36.3 mol%. The ANI and digital DNA-DNA hybridization (dDDH) values between strain YIM B01967T and Viridibacillus arvi DSM 16317 T, Viridibacillus arenosi DSM 16319 T were 61.0% and 32.1%, 60.0% and 33.1% based on the draft genome sequence. The results support the conclusion that strain YIM B01967T represents a novel species of the genus Viridibacillus, for which the name Viridibacillus soli sp. nov., is proposed. The type strain is YIM B01967T (= KCTC 43249 T = CGMCC 1.18436 T).

Optimized biosynthesis of santalenes and santalols in Saccharomyces cerevisiae.

Santalenes and santalols from Santalum album are the main components of the valuable spice sandalwood essential oil, which also has excellent pharmacological activities such as antibacterial, anti-inflammatory, and antitumor. Firstly, we constructed biosynthesis pathways of santalenes by synthetic biology strategy. The assembled biosynthetic cassettes were integrated into the multiple copy loci of δ gene in S. cerevisiae BY4742 with assistance of pDi-CRISPR, and 94.6 mg/L santalenes was obtained by shake flask fermentation of engineered yeast. Secondly, a selected optimized P450-CPR redox system was integrated into the chromosome of the santalenes-producing strain with a single copy, and 24.6 mg/L santalols were obtained. Finally, the yields of santalenes and santalols were increased to 164.7 and 68.8 mg/L, respectively, by downregulating ERG9 gene. This is the first report on the de novo synthesis of santalols by P450-CPR chimera in S. cerevisiae. Meanwhile, the optimized chimeric CYP736A167opt-46tATR1opt exhibits higher activity to oxidize santalenes into santalols. It would provide a feasible solution for the optimal biosynthesis of santalols. KEY POINTS: • First-time de novo synthesis of santalols by P450-CPR chimera in S. cerevisiae. • Truncated 46tATR1 has higher activity than that of CPR2. • Yields of santalenes and santalols were increased by downregulating ERG9 gene.

Functional Characterization of a New Bifunctional Terpene Synthase LpNES1 from a Medicinal Plant Laggera pter odonta.

Laggera pterodonta, known in China as 'Choulingdan' for its stimulous odor, has long been used as traditional herbal medicine. The essential oil of L. pterodonta, which exhibits various pharmacological activities, is a rich resource of monoterpenes and sesquiterpenes. To date, however, the terpene synthases responsible for their production remain unknown. In present study, a new terpene synthase gene (LpNES1) was identified from L. pterodonta, transcript level of which was significantly upregulated in response to methyl jasmonate treatment. Recombinant LpNES1 could synthesize (E)-nerolidol and minor ß-farnesene from farnesyl diphosphate and linalool from geranyl diphosphate in vitro. Whereas, only sesquiterpenes including (E)-nerolidol and minor ß-farnesene were released when LpNES1 was reconstituted in yeast, even coexpressed with a geranyl diphosphate synthase (ERG20WW). Combined with subcellular localization experiment, the result indicated that the cytosol-targeted LpNES1 was responsible for (E)-nerolidol biosynthesis exclusively in L. pterodonta. Additionally, the expression level of LpNES1 gene was more prominent in floral buds than that in other tissues. LpNES1 characterized in present study not only lays the molecular foundation for sesquiterpene biosynthesis of L. pterodonta, but provides a key element for further biosynthesis of bioactive compound in microbes.

Aestuariimicrobium ganziense sp. nov., a new Gram-positive bacterium isolated from soil in the Ganzi Tibetan autonomous prefecture, China.

A novel Gram-stain positive, oval-shaped, and non-flagellated bacterium, designated YIM S02566T, was isolated from alpine soil in Shadui Towns, Ganzi County, Ganzi Tibetan Autonomous Prefecture, Sichuan Province, PR China. Growth occurred at 23-35 °C (optimum, 30 °C) in the presence of 0.5-4% (w/v) NaCl (optimum, 1%) and at pH 7.0-8.0 (optimum, pH 7.0). The phylogenetic analysis based on 16S rRNA gene sequence revealed that strain YIM S02566T was most closely related to the genus Aestuariimicrobium, with Aestuariimicrobium kwangyangense R27T and Aestuariimicrobium soli D6T as its closest relative (sequence similarities were 96.3% and 95.4%, respectively). YIM S02566T contained LL-diaminopimelic acid in the cell wall. MK-9(H4) was the predominant menaquinone. The major fatty acid patterns were anteiso-C15:0 (60.0%). The major polar lipid was DPG. The genome size of strain YIM S02566T was 3.1 Mb, comprising 3078 predicted genes with a DNA G + C content of 69.0 mol%. Based on these genotypic, chemotaxonomic and phenotypic evidences, strain YIM S02566T was identified as a novel species in the genus Aestuariimicrobium, for which the name Aestuariimicrobium ganziense sp. nov. is proposed. The type strain is YIM S02566T (= CGMCC 1.18751 T = KCTC 49,477 T).

[Recent advances in biosynthesis of forskolin].

Forskolin is a complex labdane plant diterpenoid, which has been used in the treatment of a variety of diseases based on its activity as an activator of adenosine monophosphate(cAMP) cyclase. Natural forskolin exists only in the cork layer of the root of Coleus forskohlii. Due to the complexity of the extraction and chemical synthesis processes, the yield and purity of forskolin cannot meet commercial requirements. In recent years, with the rapid development of synthetic biology and the analysis and interpretation of many diterpene biosynthetic pathways, a new approach has been provided for the green production of forskolin. In this paper, the structure, activity, biosynthetic pathway and the heterologous biosynthesis of forskolin were reviewed. The problems and solutions in the heterologous biosynthesis of forskolin were also discussed and summarized, which will provide references for the construction of high-yielding forskolin engineering strains.

Cloning and Characterization of a Ginsenoside-Hydrolyzing α-L-Arabinofuranosidase, CaAraf51, From Cellulosimicrobium aquatile Lyp51.

Moutai Jiuqu is a famous aromatic raw material of Maotai flavor liquor in China. It is brewed at high temperature and contains many kinds of bacteria, molds, and yeasts. There are many useful glycoside hydrolases in these microfloras, from which efficient glycoside hydrolases can be screened for biotransformation of natural saponins. In this study, an α-L-arabinofuranosidase gene (CaAraf51, 1524 bp, 507 amino acid, 55.07 kDa, and pI = 4.8) was cloned from Cellulosimicrobium aquatile Lyp51, which was isolated from the Maotai Jiuqu. The CaAraf51 was heterogeneously expressed in E. coli BL21 (DE3) and purified by N-terminal His-tag with the Ni2+-affinity column chromatography. The results show that purified CaAraf51 has a 6.8-fold purification factor and specific activity of 15 U/mg. Under optimal conditions (pH 5.0, temperature 40 °C), kinetic parameters Km of CaAraf51 for pNPαAraf and Rc were 1.1 and 0.57 mM, the Vmax were 25 and 6.25 µmol/min/mg, respectively. 90% of 0.87 mg Rc substrate can be transformed by 9.6 U purified CaAraf51 in 1 mL reaction system under suitable conditions (30 °C, pH 7.5 phosphate buffer, 1 h). In addition, we also tested the effects of metal ions and chemical agents on the activity of CaAraf51. According to systematically studied its function and enzymatic properties, CaAraf51 has excellent value and potential of biotransformation Rc into Rd.

Two new compounds from cultures of the basidiomycete Daedaleopsis tricolor.

Two new compounds, daedatrin K (1) and 2-hydroxy-1-(5-(hydroxymethyl)furan-2-yl)propan-1-one (2), were isolated from cultures of the basidiomycetes Daedaleopsis tricolor. The new structures were elucidated on the basis of extensive spectroscopic methods. At the same time, two compounds were tested for their cytotoxicities against five human cancer cell lines. [Formula: see text].