Na Yang

Paenibacillus algorifonticola sp. nov., isolated from a cold spring.

A Gram-stain-positive, endospore-forming, rod-shaped bacterium, designated XJ259(T), was isolated from a cold spring sample from Xinjiang Uyghur Autonomous Region, China. The isolate grew optimally at 20-30 °C and pH 7.3-7.8. Comparative analysis of the 16S rRNA gene sequence showed that isolate XJ259(T) belonged phylogenetically to the genus Paenibacillus, and was most closely related to Paenibacillus xinjiangensis B538(T) (with 96.6 % sequence similarity), Paenibacillus glycanilyticus DS-1(T) (96.3 %) and Paenibacillus castaneae Ch-32(T) (96.1 %), sharing less than 96.0 % sequence similarity with all other members of the genus Paenibacillus. Chemotaxonomic analysis revealing menaquinone-7 (MK-7) as the major isoprenoid quinone, diphosphatidylglycerol, phosphatidylethanolamine and two unknown phosphoglycolipids as the major cellular polar lipids, a DNA G+C content of 47.0 mol%, and anteiso-C₁₅:₀ and C₁₆:₀ as the major fatty acids supported affiliation of the new isolate to the genus Paenibacillus. Based on these data, isolate XJ259(T) is considered to represent a novel species of the genus Paenibacillus, for which the name Paenibacillus algorifonticola sp. nov. is proposed. The type strain is XJ259(T) ( = CGMCC 1.10223(T)  = JCM 16598(T)).

Yuhushiella deserti gen. nov., sp. nov., a new member of the suborder Pseudonocardineae

A thermotolerant, Gram-stain-positive, aerobic, sporangium-forming actinomycete, strain RA45(T), was isolated from a desert region in Xinjiang Uigur Autonomous Region, north-western China. Comparative analysis of the 16S rRNA gene sequence and phenotypic characterization revealed that strain RA45(T) belonged phylogenetically to the family Pseudonocardiaceae of the suborder Pseudonocardineae. Strain RA45(T) showed more than 5  % 16S rRNA gene sequence divergence from recognized species of genera in the family Pseudonocardiaceae, forming a distinct lineage within the evolutionary radiation occupied by the genera Amycolatopsis, Prauserella, Thermocrispum, Saccharomonospora, Saccharopolyspora and Sciscionella, but distinct from each of them. The affiliation to the family was supported by the presence of suborder- and family-specific 16S rRNA signature nucleotides, a DNA G+C content of 69.9 mol%, the presence of meso-diaminopimelic acid, ribose, arabinose, glucose and galactose, which are characteristic components of cell-wall chemotype IV of actinomycetes, the presence of menaquinone MK-9(H₄) as the major respiratory lipoquinone, a lack of mycolic acids and the presence of an N-acetylated type of muramic acid. However, strain RA45(T) differed from known genera of the family in its polar lipid composition: the major phospholipids were phosphatidylethanolamine, phosphatidylinositol mannosides, phosphatidylmethylethanolamine, diphosphatidylglycerol, phospholipids of unknown structure and phospholipids of unknown structure containing glucosamine (phospholipid type IV). Based on its morphological, chemotaxonomic and phylogenetic characteristics, strain RA45(T) is considered to represent a novel species of a new genus in the family Pseudonocardiaceae, for which the name Yuhushiella deserti gen. nov., sp. nov. is proposed. The type strain of Yuhushiella deserti is RA45(T) (=CGMCC 4.5579(T) =JCM 16584(T)).

Quinazolin-4-one Coupled with Pyrrolidin-2-iminium Alkaloids from Marine-Derived Fungus Penicillium aurantiogriseum

Three new alkaloids, including auranomides A and B (1 and 2), a new scaffold containing quinazolin-4-one substituted with a pyrrolidin-2-iminium moiety, and auranomide C (3), as well as two known metabolites auranthine (4) and aurantiomides C (5) were isolated from the marine-derived fungus Penicillium aurantiogriseum. The chemical structures of compounds 1–3 were elucidated by extensive spectroscopic methods, including IR, HRESIMS and 2D NMR spectroscopic analysis. The absolute configurations of compounds 1–3 were suggested from the perspective of a plausible biosynthesis pathway. Compounds 1–3 were subjected to antitumor and antimicrobial screening models. Auranomides A–C exhibited moderate cytotoxic activity against human tumor cells. Auranomides B was the most potent among them with an IC50 value of 0.097 μmol/mL against HEPG2 cells.

ABC transporters coupled with the elevated ergosterol contents contribute to the azole resistance and amphotericin B susceptibility.

Most screening approaches produce compounds that target survival genes and are likely to generate resistance over time. Simply having more drugs does not address the potential emergence of resistance caused by target mutation, drug efflux pumps over-expression, and so on. There is a great need to explore new strategies to treat fungal infections caused by drug-resistant pathogens. In this study, we found that azole-resistant Candida albicans with CaCDR1 and CaCDR2 over-expression is hypersensitive against amphotericin B (AmB) by our high throughput synergy screening (HTSS). In contrast, Δcdr1 and Δcdr2 knockout strains were resistant to AmB. Moreover, clinical isolates with increased expression of CaCDR1 and CaCDR2 demonstrated susceptibility to AmB, which can also synergize with the efflux pumps inducer fluphenazine (FPZ). Finally, the increased drug susceptibility to AmB in azole-resistant C. albicans with drug efflux pumps over-expression was consistent with the elevated expression of CaERG11 and its associated ergosterols in clinical isolates. Our data implies that the level of ergosterol contents determines the susceptibility to azoles and AmB in C. albicans. Deep understanding of the above mechanisms would offer new hope to treat drug-resistant C. albicans.

Amphibacillus marinus sp. nov., a member of the genus Amphibacillus isolated from marine mud

A gram-positive, spore-forming, rod-shaped bacterium, designated J1(T) was isolated from deep-sea mud collected from the South China Sea and subjected to polyphasic taxonomic investigation. Phylogenetic analysis based on 16S rRNA gene sequences revealed that J1(T) clustered with the type strains of Amphibacillus cookii, Amphibacillus sediminis and Amphibacillus jilinensis and exhibited a range of similarity of 93.9-97.0 % to members of the genus Amphibacillus. The DNA G+C content was 36.7 mol%. Chemotaxonomic analysis showed no quinones, and the cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid for strain J1(T). The major cellular fatty acids were iso-C15 : 0 and anteiso-C15 : 0. Strain J1(T) was positive for catalase activity and negative for oxidase activity. On the basis of phylogenetic position and phenotypic properties, strain J1(T) represents a novel species of the genus Amphibacillus and the name Amphibacillus marinus sp. nov. is proposed. The type strain is J1(T) ( = CGMCC 1.10434(T) = JCM 17099(T)).

The Inhibition and Resistance Mechanisms of Actinonin, Isolated from Marine Streptomyces sp. NHF165, against Vibrio anguillarum

Vibrio sp. is the most serious pathogen in marine aquaculture, and the development of anti-Vibrio agents is urgently needed. However, it is extreme lack of high-throughput screening (HTS) model for searching anti-Vibrio compounds. Here, we established a protein-based HTS screening model to identify agents targeting peptide deformylase (PDF) of Vibrio anguillarum. To find potential anti-Vibrio compounds, crude extracts derived from marine actinomycetes were applied for screening with this model. Notably, crude extract of strain Streptomyces sp. NHF165 inhibited dramatically both on V. anguillarum PDF (VaPDF) activity and V. anguillarum cell growth. And actinonin was further identified as the functional component. Anti-VaPDF and anti-V. anguillarum activities of actinonin were dose-dependent, and the IC50 values were 6.94 and 2.85 μM, respectively. To understand the resistance of V. anguillarum against actinonin, spontaneous V. anguillarum mutants with resistance against actinonin were isolated. Surprisingly, for the resistant strains, the region between 774 and 852 base pairs was found to be absent in the gene folD which produces 10-formyl-tetrahydrofolate, a donor of N-formyl to Met-tRNAfmet. When compared to the wild type strain, ΔfolD mutant showed eight times of minimum inhibition concentration on actinonin, however, the folD complementary strain could not grow on the medium supplemented with actinonin, which suggested that folD gene mutation was mainly responsible for the actinonin resistance. To our knowledge, this is the first report showing that marine derived Streptomyces sp. could produce actinonin with anti-VaPDF activity and the resistance against actinonin by V. anguillarum is mediated by mutation in folD gene.

Arthrobacter liuii sp. nov., resuscitated from Xinjiang desert soil.

A Gram-stain positive, aerobic, non-motile actinobacterium, designated DSXY973(T), was isolated from soil samples collected from Xinjiang desert using medium supplemented with resuscitation-promoting factor, and subjected to a polyphasic taxonomic investigation. Phylogenetic analysis based on 16S rRNA gene sequences revealed that DSXY973(T) belonged to the genus Arthrobacter and was most closely related to Arthrobacter oryzae JCM 15922(T) with 97.1 % similarity. The DNA G+C content was 67.6 %. Cells of strain DSXY973(T) mainly contained MK-9(H2), and the cell wall contained l-lysine as the primary diamino acid. The major cellular fatty acids were anteiso-C15 : 0, anteiso-C17 : 0 and iso-C15 : 0. Strain DSXY973(T) was positive for catalase and negative for oxidase activity. On the basis of its phylogenetic position and phenotypic properties, strain DSXY973(T) represents a novel species of the genus Arthrobacter, for which the name Arthrobacter liuii sp. nov. is proposed. The type strain is DSXY973(T) ( = CGMCC1.12778(T) = JCM 19864(T)).

Prauserella shujinwangii sp. nov., from a desert environment.

A Gram-positive, spore-forming, rod-shaped actinomycete, designated XJ46(T), was isolated from Xinjiang Uyghur Autonomous Region, China and subjected to a polyphasic taxonomic analysis. Morphological and chemotaxonomic characteristics of XJ46(T) were identified as being similar to those of members of the genus Prauserella. The phylogenetic tree based on 16S rRNA gene sequences showed that XJ46(T) shared the highest similarity (95.9%) with Prauserella marina MS498(T). Based on its phenotypic characteristics, chemotaxonomic analysis and 16S rRNA gene sequence analysis, strain XJ46(T) is proposed to represent a novel species of the genus Prauserella, named Prauserella shujinwangii sp. nov. The type strain is XJ46(T) ( =CGMCC 4.7125(T) =JCM 19736(T)).

Salinibacillus xinjiangensis sp. nov., a halophilic bacterium from a hypersaline lake

A Gram-positive, endospore-forming, rod-shaped bacterium, designated isolate J4(T), was isolated from a neutral saline lake sample from Xinjiang Uyghur Autonomous Region, China, and subjected to a polyphasic taxonomic investigation. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain J4(T) is most closely related to Salinibacillus aidingensis 25-7(T) (with 96.7 % similarity), Salinibacillus kushneri 8-2(T) (96.5 %), Ornithinibacillus scapharcae TW25(T) (96.4 %), Salirhabdus euzebyi CVS-14(T) (96.4 %) and Ornithinibacillus californiensis MB-9(T) (96.2 %). Chemotaxonomic analysis showed menaquinone-7 (MK-7) to be the major isoprenoid quinone of strain J4(T); diphosphatidylglycerol and phosphatidylglycerol were the major cellular polar lipids and the cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid. The major cellular fatty acids were iso-C15 : 0 and anteiso-C15 : 0. The genomic DNA G+C content of strain J4(T) was determined to be 36.2 mol%. Strain J4(T) was positive for catalase activity and negative for oxidase activity. Strain J4(T) was observed to grow at 25-50 °C (optimal 35-42 °C), pH 6.5-8.0 (optimal 7.0-7.5) and in media containing 1-21 % (w/v) NaCl (optimal 9-12 %). Based on these data, strain J4(T) represents a novel species of the genus Salinibacillus and the name Salinibacillus xinjiangensis sp. nov. is proposed. The type strain is J4(T) ( = CGMCC 1.12331(T) = JCM 18732(T)).

Isolation of Viable but Non-culturable Bacteria from Printing and Dyeing Wastewater Bioreactor Based on Resuscitation Promoting Factor

Printing and dyeing wastewater with high content of organic matters, high colority, and poor biochemical performance is hard to be degraded. In this study, we isolated viable but non-culturable (VBNC) bacteria from printing and dyeing wastewater with the culture media contained resuscitation promoting factor (Rpf) protein secreted by Micrococcus luteus, counted the culturable cells number with the most probable number, sequenced 16S rRNA genes, and performed polymerase chain reaction-denaturing gradient gel electrophoresis. It is obviously that the addition of Rpf in the enrichment culture could promote growth and resuscitation of bacteria in VBNC state to obtain more fastidious bacteria significantly. The identified bacteria were assigned to nine genera in the treatment group, while the two strains of Ochrobactrum anthropi and Microbacterium sp. could not be isolated from the control group. The function of isolated strains was explored and these strains could degrade the dye of Congo red. This study provides a new sight into the further study including the present state, composition, formation mechanism, and recovery mechanism about VBNC bacteria in printing and dyeing wastewater, which would promote to understand bacterial community in printing and dyeing wastewater, and to obtain VBNC bacteria from ecological environment.