We present the 1.06 Gb sequenced genome of Gastrodia elata, an obligate mycoheterotrophic plant, which contains 18,969 protein-coding genes. Many genes conserved in other plant species have been deleted from the G. elata genome, including most of those for photosynthesis. Additional evidence of the influence of genome plasticity in the adaptation of this mycoheterotrophic lifestyle is evident in the large number of gene families that are expanded in G. elata, including glycoside hydrolases and urease that likely facilitate the digestion of hyphae are expanded, as are genes associated with strigolactone signaling, and ATPases that may contribute to the atypical energy metabolism. We also find that the plastid genome of G. elata is markedly smaller than that of green plant species while its mitochondrial genome is one of the largest observed to date. Our report establishes a foundation for studying adaptation to a mycoheterotrophic lifestyle.

Proteomics was used to identify a protein encoded by ORF 3a in a SARS-associated coronavirus (SARS-CoV). Immuno-blotting revealed that interchain disulfide bonds might be formed between this protein and the spike protein. ELISA indicated that sera from SARS patients have significant positive reactions with synthesized peptides derived from the 3a protein. These results are concordant with that of a spike protein-derived peptide. A tendency exists for co-mutation between the 3a protein and the spike protein of SARS-CoV isolates, suggesting that the function of the 3a protein correlates with the spike protein. Taken together, the 3a protein might be tightly correlated to the spike protein in the SARS-CoV functions. The 3a protein may serve as a new clinical marker or drug target for SARS treatment.

A systematic comparison of the ginsenosides and physicochemical properties of white ginseng (WG), red ginseng (RG) and black ginseng (BG) was performed. The purpose of the present study was to identify the effects of the physicochemical properties by steaming process. During the steaming process, ginsenosides transform into specific ginsenosides by hydrolysis, dehydration and isomerization at C-3, C-6 or C-20. Steaming ginseng led to a significant increase in reducing sugar, acidic polysaccharide and phenolic compounds content. Antioxidative properties were investigated using the DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, compared with BHA (Butylated hydroxyanisole). RG and BG exhibited higher antioxidant activity than WG. The maximum residue level for Benzo(a)pyrene was established to 5 μg/kg in food products. The levels of benzo(a)pyrene in WG and RG were not detected. Benzo(a)pyrene was detected in the BG, the content was 0.17 μg/kg. The scientific achievements of the present study could help consumers to choose different type of ginseng products available on the market.

The synthesis of silver nanoparticles (AgNPs) by microorganisms is an area attracting growing interest in nanobiotechnology, due to the applications of these nanoparticles in various products including cosmetics and biosensors, and in the biomedical, clinical, and bioimaging fields as well. Various microorganisms have been found to be able to synthesize AgNPs when silver salts are supplied in the reaction system. The main objectives of this study were to evaluate the efficiency of synthesis of AgNPs by the strain Bacillus methylotrophicus DC3, isolated from the soil of Korean ginseng, a traditionally known oriental medicinal plant in Korea. The AgNPs showed maximum absorbance at 416 nm, when assayed by ultraviolet-visible spectroscopy (UV-vis). The field emission transmission electron micrograph (FE-TEM) results showed that the particles were spherical and 10-30 nm in size. In addition, the product was also characterized by energy dispersive X-ray spectroscopy (EDX), which displayed a 3 keV peak corresponding to the silver nanocrystal. Elemental mapping results also confirmed the presence of silver elements in the electron micrograph region. Furthermore, the AgNPs demonstrated antimicrobial activity against various pathogenic microorganisms such as Candida albicans, Salmonella enterica, Escherichia coli, and Vibrio parahaemolyticus, with enhanced antimicrobial activity being exhibited against C. albicans. Therefore, the current study describes the simple, efficient, and green method of synthesis of AgNPs by B. methylotrophicus DC3.

We cloned and characterized a β-glucosidase (bgp3) gene from Microbacterium esteraromaticum isolated from ginseng field. The bgp3 gene consists of 2,271 bp encoding 756 amino acids which have homology to the glycosyl hydrolase family 3 protein domain. The molecular mass of purified Bgp3 was 80 kDa, as determined by SDS-PAGE. The enzyme (Bgp3) catalyzed the conversion of ginsenoside Rb1 to the more pharmacologically active minor ginsenoside Rd and compound K. The Bgp3 hydrolyzed the outer glucose moiety attached to the C-20 position of ginsenoside Rb1, followed by hydrolysis of the inner glucose moiety attached to the C-3 position. Using 0.1 mg mL(-1) enzyme in 20 mM sodium phosphate buffer at 40 °C and pH 7.0, 1.0 mg mL(-1) ginsenoside Rb1 was transformed into 0.46 mg mL(-1) compound K within 60 min with a corresponding molar conversion yield of 77%. Bgp3 hydrolyzed the ginsenoside Rb1 along the following pathway: Rb1 → Rd → compound K.

A cultivation-based approach was employed to compare the culturable actinobacterial diversity associated with five marine sponge species (Craniella australiensis, Halichondria rugosa, Reniochalina sp., Sponge sp., and Stelletta tenuis). The phylogenetic affiliation of the actinobacterial isolates was assessed by 16S rDNA-RFLP analysis. A total of 181 actinobacterial strains were isolated using five different culture media (denoted as M1-M5). The type of medium exhibited significant effects on the number of actinobacteria recovered, with the highest number of isolates on M3 (63 isolates) and the lowest on M1 (12 isolates). The genera isolated were also different, with the recovery of three genera on M2 and M3, and only a single genus on M1. The number of actinobacteria isolated from the five sponge species was significantly different, with a count of 83, 36, 30, 17, and 15 isolates from S. tenuis, H. rugosa, Sponge sp., Reniochalina sp., and C. australiensis, respectively. M3 was the best isolation medium for recovery of actinobacteria from S. tenuis, H. rugosa, and Sponge sp., while no specific medium preference was observed for the recovery of actinobacteria from Reniochalina sp., and C. australiensis. The RFLP fingerprinting of 16S rDNA genes digested with HhaI revealed six different patterns, in which 16 representative 16S rDNAs were fully sequenced. Phylogenetic analysis indicated that 12 strains belong to the group Streptomyces, three strains belong to Pseudonocardia, and one strain belongs to Nocardia. Two strains C14 (from C. australiensis) and N13 (from Sponge sp.) have only 96.26% and 96.27% similarity to earlier published sequences, and are therefore potential candidates for new species. The highest diversity of three actinobacteria genera was obtained from Sponge sp., though the number of isolates was low. Two genera of actinobacteria, Streptomyces, and Pseudonocardia, were isolated from both S. tenuis and C. australiensis. Only the genus of Streptomyces was isolated from H. rugosa and Reniochalina sp. Sponge species have been demonstrated here to vary as sources of culturable actinobacterial diversity, and the methods for sampling such diversity presented may be useful for improved sampling of such diversity.

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BackgroundGinsenoside F1 has been described to possess skin-whitening effects on humans. We aimed to synthesize a new ginsenoside derivative from F1 and investigate its cytotoxicity and melanogenesis inhibitory activity in B16BL6 cells using recombinant glycosyltransferase enzyme. Glycosylation has the advantage of synthesizing rare chemical compounds from common compounds with great ease.MethodsUDP-glycosyltransferase (BSGT1) gene from Bacillus subtilis was selected for cloning. The recombinant glycosyltransferase enzyme was purified, characterized, and utilized to enzymatically transform F1 into its derivative. The new product was characterized by NMR techniques and evaluated by MTT, melanin count, and tyrosinase inhibition assay.ResultsThe new derivative was identified as (20S)-3β,6α,12β,20-tetrahydroxydammar-24-ene-20-O-β-D-glucopyranosyl-3-O-β-D-glucopyranoside (ginsenoside Ia), which possesses an additional glucose linked into the C-3 position of substrate F1. Ia had been previously reported; however, no in vitro biological activity was further examined. This study focused on the mass production of arduous ginsenoside Ia from accessible F1 and its inhibitory effect of melanogenesis in B16BL6 cells. Ia showed greater inhibition of melanin and tyrosinase at 100 μmol/L than F1 and arbutin. These results suggested that Ia decreased cellular melanin synthesis in B16BL6 cells through downregulation of tyrosinase activity.ConclusionTo our knowledge, this is the first study to report on the mass production of rare ginsenoside Ia from F1 using recombinant UDP-glycosyltransferase isolated from B. subtillis and its superior melanogenesis inhibitory activity in B16BL6 cells as compared to its precursor. In brief, ginsenoside Ia can be applied for further study in cosmetics.