Isolation and evaluation of endophytic Bacillus tequilensis GYLH001 with potential application for biological control of Magnaporthe oryzae.

Biological control is a promising measure in the control of plant disease. In the present study, we isolated 13 endophytic strains from Angelica dahurica. Among them, an endophytic strain which was named GYLH001 exhibited remarkable activity against Magnaporthe oryzae. 16S rRNA sequence analysis, biochemical and physiological proved that it is Bacillus tequilensis. The sterilized culture filtrate of GYLH001 can inhibit the growth of M.oryzae, which suggests the presence of secondary metabolites. Proved by experiment, GYLH001 can produce cellulase, protease, gelatinase, indole-3-acetic acid and 1-amino-cyclopropane-1-carboxylate deaminase. In addition, the temperature experiment showed that secondary metabolites produced by GYLH001 had good thermal stability. They can remain activity even heated at 100°C for 30 min. They also had good acid-resistance in heavily acidic condition. But under alkaline condition, the antifungal effect decreased significantly. By simulative field tests, the spraying of GYLH001 spore solution could prevent and treat rice blast. Through continuous separation and purification of sterilized culture filtrate and identification by mass spectrometry, the molecular weight of an active substance is 364.26. In the control of rice blast, B. tequilensis GYLH001 has potential as a biological control agent in agriculture.

Decursin and Z-Ligustilide in Angelica tenuissima Root Extract Fermented by Aspergillus oryzae Display Anti-Pigment Activity in Melanoma Cells.

The anti-melanogenic effects of the extract of Angelica tenuissima (AT) root and the extract of AT root fermented by Aspergillus oryzae (FAT) were investigated. These effects were determined by measuring the inhibitory activity of AT and FAT on melanin production in B16F10 melanocytes and with in vitro tyrosinase activity assays. The AT extract inhibited melanin production at concentrations above 250 µg/ml, and this inhibitory effect was significantly enhanced by the fermentation process with A. oryzae. HPLC analysis resulted in the isolation of two active compounds from both the AT and FAT extracts. Their chemical structures were identified as decursin and Z-ligustilide through comparison with previously reported NMR data. The decursin and Z-ligustilide contents were increased in the FAT extract and could be responsible for its enhanced inhibitory effects on melanin production and tyrosinase activity compared with that of the AT extract.

Two novel Talaromyces species isolated from medicinal crops in Korea.

Two novel biverticillate Talaromyces species, T. angelicus and T. cnidii, were collected from the medicinal crops Angelica gigas and Cnidium officinale, respectively, in Korea. Phylogenetic analyses with the nuclear ribosomal internal transcribed spacer (ITS) region and the ß-tubulin gene as well as morphological analyses revealed that the two species differ from any known Talaromyces species. Talaromyces angelicus is related to T. flavovirens in the phylogeny of the ITS region, but the new species is grouped together with Penicillium liani and T. pinophilus in terms of its ß-tubulin phylogeny, and its growth rate on Czapek yeast autolysate differs from that of T. flavovirens. Talaromyces cnidii is phylogenetically similar to T. siamensis, but exhibits differences in the morphologies of the colony margin, metulae, and conidia.

Mucilaginibacter angelicae sp. nov., isolated from the rhizosphere of Angelica polymorpha Maxim.

A Gram-negative-staining, non-motile rod, designated GG-w14(T), was isolated from the rhizosphere of Angelica polymorpha Maxim. Phylogenetic analysis of 16S rRNA gene sequences revealed that the isolate belonged to the genus Mucilaginibacter and exhibited 93.9-97.4% 16S rRNA gene sequence similarity with recognized members of the genus Mucilaginibacter (closest relative Mucilaginibacter gossypii Gh-67(T)). DNA-DNA relatedness between strain GG-w14(T) and M. gossypii KCTC 22380(T) was <41%. Strain GG-w14(T) grew at 4-35 °C, at pH 5.0-8.0 and with 0-1% (w/v) NaCl. The isolate hydrolysed casein, CM-cellulose and starch and contained menaquinone 7 as the major menaquinone. The major cellular fatty acids were summed feature 3 (C(16:1)ω7c and/or iso-C(15:0) 2-OH; 39.9%), iso-C(15:0) (24.2%) and iso-C(17:0) 3-OH (12.4%). The DNA G+C content was 42.5 mol%. These data suggest that strain GG-w14(T) should be considered as a representative of a novel species of the genus Mucilaginibacter, for which the name Mucilaginibacter angelicae sp. nov. is proposed. The type strain is GG-w14(T) (=KCTC 23250(T)=NCAIM B 02415(T)).