Ulleungdo and Dokdo are volcanic islands that experience a characteristic marine climate, influenced by warm currents. The richness and diversity of the plant species, particularly vascular plants, are higher on Ulleungdo than on Dokdo. In contrast to the native plant life, little is known about the diversity of soil fungi living in the rhizosphere of these two islands. In this study, we utilized the barcoded pyrosequencing method to analyze rhizosphere soil fungi on Ulleungdo and Dokdo. In total, 768 operational taxonomic units (OTUs) were analyzed from the Ulleungdo samples, while 640 OTUs and 382 OTUs were analyzed from the Dongdo and Seodo (islets of Dokdo) samples, respectively. Species richness was considerably higher in the Ulleungdo samples than in the Dongdo and Seodo samples, while there was little difference in species diversity between the samples. The taxonomic composition analyses demonstrated that members of the phylum Basidiomycota dominated the Ulleungdo samples, whereas members of the phylum Ascomycota were predominant in the Dokdo samples. Ectomycorrhizal fungi belonging to the phylum Basidiomycota, in particular, were more abundant in the Ulleungdo samples. This finding suggests that the difference in the abundance of the ectomycorrhizal fungi in the rhizospheres of Ulleungdo and Dokdo may have been affected by species richness and diversity of the vascular plants. Our study is the first detailed report of the composition of soil fungal communities on the Ulleungdo and Dokdo islands. In addition, our findings provide a basis for understanding the ecological interactions between plants and fungi.
The aim of this study was to develop a minimal medium for the cultivation of Escherichia coli B, which could be especially suitable for the industrial propagation of bacteriophage T4. The new defined, minimal SM-1 culture medium, contains free amino acids as the only nitrogen source and enables the bacteria generation time to be prolonged and satisfactory phage titers to be achieved. The presence of organic ingredients, such as meat extracts, yeast hydrolysates, enzymatic protein hydrolysates, in a culture medium may cause problems in the case of bacteria or phage cultures for therapeutic purposes. In the present study, we introduce a new medium, together with some procedures and applications for its usage. We also present new kinetics of E. coli B growth. Some traits such as the lack of high molecular proteins, a bacterial growth comparable to that in a rich medium, and the cost effectiveness of the medium, makes it highly competitive with currently used microbiological media. The surprisingly high titers of bacteriophage T4 obtained in our experiments suggest that SM-1 medium has the potential to find a broad application in medicine, especially in infectious disease therapy, pharmacy and biotechnology.
In the course of searching for insecticides from soil microorganisms, we found that a fermentation broth of the fungus, Trichoderma brevicompactum FKI-6324, produced Trichopolyn VI, a new peptaibol, which possessed significant insecticidal potential. Spectroscopic analysis showed the compound to be a new trichopolyn I derivative. This paper describes the isolation, structure elucidation and biological activity of trichopolyn VI.
DNA extracted from the bacterial culture used in this paper was analyzed by the massively parallel DNA sequencing. The sequence similarity search showed that most of the obtained DNA sequences were similar to those of Enterobacter genomic DNA. PCR analyses using primers to detect Enterobacter DNA showed that the original Roseobacter culture was contaminated with this bacterium. The authors recognized that the cultures used in this paper were considered as a mixture of Enterobacter and Roseobacter litoralis, and the deduced results were not well rationalized. Thus, the JGAM editorial board agreed to retract the paper.