Enzymatic Synthesis of Glucosyl Rebaudioside A and its Characterization as a Sweetener.

Rebaudioside A was modified via glucosylation by recombinant dextransucrase of Leuconostoc lactis EG001 in Escherichia coli BL21 (DE3), forming single O-α-D-glucosyl-(1″→6') rebaudioside A with yield of 86%. O-α-D-glucosyl-(1″→6') rebaudioside A was purified using HPLC and Diaion HP-20 and its properties were characterized for possible use as a food ingredient. Almost 98% of O-α-D-glucosyl-(1″→6') rebaudioside A was dissolved after 15 days of storage at room temperature, compared to only 11% for rebaudioside A.

Bacteroides koreensis sp. nov. and Bacteroides kribbi sp. nov., two new members of the genus Bacteroides.

Three bacterial isolates from human faeces, YS-aM39, R2F3-3-3 and R2F3-5-1, were characterized as Gram-negative, strictly anaerobic, non-spore-forming, non-motile, and rod-shaped. Isolate YS-aM39 formed a distinct line of descent, showing greatest 16S rRNA gene sequence relatedness with R2F3-3-3 (97.5 %), R2F3-5-1 (97.

Description of Absiella argi gen. nov., sp. nov., and transfer of Eubacterium dolichum and Eubacterium tortuosum to the genus Absiella as Absiella dolichum comb. nov. and Absiella tortuosum comb. nov.

Gram-positive, straight or slightly curved rod-shaped bacteria, designated as strains N6H1-5 and N6H1-3, were isolated from fecal samples of old dog. The analysis of 16S rRNA gene sequences indicated that the isolates belonged to the Clostridium cluster XVI and were closely related to Eubacterium dolichum KCTC 5832, Eubacterium tortuosum DSM 3987, Clostridium innocuum KCTC 5183, Allobaculum stecoricanis DSM 13633, Eubacterium limosum KCTC 3266, and Clostridium butyricum KCTC 1871, with 94.0%, 93.

Structural insight for substrate tolerance to 2-deoxyribose-5-phosphate aldolase from the pathogen Streptococcus suis.

2-deoxyribose-5-phosphate aldolase (DERA) is a class I aldolase that catalyzes aldol condensation of two aldehydes in the active site, which is particularly germane in drug manufacture. Structural and biochemical studies have shown that the active site of DERA is typically loosely packed and displays broader substrate specificity despite sharing conserved folding architecture with other aldolases. The most distinctive structural feature of DERA compared to other aldolases is short and flexible C-terminal region.

Silver wire amplifies the signaling mechanism for IL-1beta production more than silver submicroparticles in human monocytic THP-1 cells.

Silver materials have been widely used in diverse fields. However, their toxicity and their mechanism, especially in different forms, have not been studied sufficiently. Thus, cytotoxicity, apoptosis, and interleukin-1beta (IL-1β) production were investigated using macrophage-like THP-1 cells in the presence of Ag microparticles (AgMPs, 2.

Peptoniphilus rhinitidis sp. nov., isolated from specimens of chronic rhinosinusitis.

Chronic rhinosinusitis (CRS) is an inflammatory disorder of the nasal cavity and paranasal sinus related to bacterial infection. A previous study suggested that a specific bacterial group may have an important role in the course of CRS. In this study, bacteria isolated from CRS patients were characterized.

First thermostable endo-β-1,4-glucanase from newly isolated Xanthomonas sp. EC102.

A novel gene encoding thermostable endoglucanase was identified in Xanthomonas sp. EC102 from soil. The gene had 1,458 base pairs of open reading frame, which encode a 52-kDa protein of 486 amino acid residues.

Enzymatic synthesis of puerarin glucosides using Leuconostoc dextransucrase.

Puerarin (P), an isoflavone derived from kudzu roots, has strong biological activities, but its bioavailability is often limited by its low water solubility. To increase its solubility, P was glucosylated by three dextransucrases from Leuconostoc or Streptococcus species. Leuconostoc lactis EG001 dextransucrase exhibited the highest productivity of puerarin glucosides (P-Gs) among the three tested enzymes, and it primarily produced two P-Gs with a 53% yield.

Mass production of rubusoside using a novel stevioside-specific β-glucosidase from Aspergillus aculeatus.

Rubusoside (R) is a natural sweetener and a solubilizing agent with antiangiogenic and antiallergic properties. However, currently, its production is quite expensive, and therefore, we have investigated nine commercially available glycosidases to optimize an economically viable R-production method. A stevioside (ST)-specific β-glucosidase (SSGase) was selected and purified 7-fold from Aspergillus aculeatus Viscozyme L by a two-step column chromatography procedure.

Bacillus manliponensis sp. nov., a new member of the Bacillus cereus group isolated from foreshore tidal flat sediment.

A Gram-positive, endospore-forming, new Bacillus species, strain BL4-6(T), was isolated from tidal flat sediment of the Yellow Sea. Strain BL4-6(T) is a straight rod, with motility by peritrichate flagella. The cell wall contains meso-diaminopimelic acid, and the major respiratory quinone is menaquinone-7.

Description of Lysinibacillus sinduriensis sp. nov., and transfer of Bacillus massiliensis and Bacillus odysseyi to the genus Lysinibacillus as Lysinibacillus massiliensis comb. nov. and Lysinibacillus odysseyi comb. nov. with emended description of the genus Lysinibacillus.

A Gram-positive, rod-shaped, endospore-forming bacterium, designated strain BLB-1(T), was isolated from samples of tidal flat sediment from the Yellow Sea. 16S rRNA gene sequence analysis demonstrated that the isolate belonged to the Bacillus rRNA group 2 and was closely related to Bacillus massiliensis CIP 108446(T) (97.4%), Bacillus odysseyi ATCC PTA-4993(T) (96.

NF-kappaB/STAT3/PI3K signaling crosstalk in iMyc E mu B lymphoma.

Background: Myc is a well known driver of lymphomagenesis, and Myc-activating chromosomal translocation is the recognized hallmark of Burkitt lymphoma, an aggressive form of non-Hodgkin's lymphoma. We developed a model that mimics this translocation event by inserting a mouse Myc cDNA gene into the immunoglobulin heavy chain locus, just upstream of the intronic Emu enhancer. These mice, designated iMyc E mu, readily develop B-cell lymphoma.

Application of rpoB and zinc protease gene for use in molecular discrimination of Fusobacterium nucleatum subspecies.

Fusobacterium nucleatum is classified into five subspecies that inhabit the human oral cavity (F. nucleatum subsp. nucleatum, F.

Bacillus acidiproducens sp. nov., vineyard soil isolates that produce lactic acid.

Two novel spore-forming lactic acid bacteria, strains SL213T and SL1213, were isolated from vineyard soils in Korea. Cells of both isolates were rod-shaped bacilli and contained subterminal, ellipsoidal spores. Strains were facultatively anaerobic, catalase-positive, oxidase-negative and motile with single flagella.

Mechanistic study of the intramolecular conversion of maltose to trehalose by Thermus caldophilus GK24 trehalose synthase.

This paper questions what types of molecular transformation are involved in the conversion of maltose to trehalose by trehalose synthase from Thermus caldophilus GK24. The reverse reaction pathway has been examined with the aid of alpha,alpha-(2,4,6,6',2',4',6",6"'-(2)H(8))trehalose (1). The mass data of the isolated reaction products clearly indicate that deuterated glucose is confined only to substrate molecules, and thus the reversible enzymatic conversion of trehalose into maltose proceeds through an intramolecular pathway.