• Journal of Microbiology and Biotechnology
• /
• v.16 no.10
• /
• pp.1597-1604
• /
• 2006

To screen for an anti-yeast substance (AYS), many bacteria were isolated from soil and a strain AY2000 was selected. The strain AY2000 was identified as Rahnella aquatilis by morphology, biochemical properties, and 16S r-RNA nucleotide sequence analyses. The strain AY2000 showed anti-yeast activity against Candida albicans and Saccharomyces cerevisiae, whereas R. aquatilis ATCC33071 as a type strain did not show the activity against the yeasts under the same condition. The growth of yeast cell was significantly inhibited by AYS produced by the strain AY2000, as shown by optical density and MTT assay. The minimum inhibitory concentration (MIC) of the AYS against S. cerevisiae and C. albicans at $28^{\circ}C\;was\;20{\mu}g/ml\;and\;60{\mu}g/ml$, respectively. The MIC of AYS against hyphae of C. albicans at $37^{\circ}C\;was\;600{\mu}g/ml$. Scanning electron microscopic analysis revealed that yeast cells treated with AYS had an irregular form with a wrinkled and rough surface.

• Korean Journal of Microbiology
• /
• v.47 no.2
• /
• pp.163-166
• /
• 2011

For reduction of side effects by anti-fungal agents, a less toxic anti-fungal substance or a synergistic substance with a new mechanism is needed. The anti-yeast substance (AYS) originated from Rahnella aquatilis strain AY2000 is like to be a heterogeneous protein. The AYS inhibited the growth of Candida albicans in culture broth, and AYS-treated cells were arrested in each phase during cell cycle. Among AYS-treated cells, the population of the cells belonging to sub-G1 phase was not increased during cell cycle. Therefore, AYS has rather yeaststatic than yeastcidal effect to C. albicans. Moreover, with combination of itraconazole or fluconazole, AYS had a synergistic anti-yeast activity against Saccharomyces cerevisiae based on the analysis of fractional inhibitory concentration index.

• Microbiology and Biotechnology Letters
• /
• v.37 no.4
• /
• pp.361-364
• /
• 2009

Rahnella aquatilis strain AY2000 produces an anti-yeast substance (AYS), however activity of the AYS tends to be decreased by heat. To investigate whether trehalose can protect AYS activity against heat, comparative studies on the AYS with and without trehalose were performed. After heat treatment at high temperatures ($50^{\circ}C-70^{\circ}C$), the AYS with trehalose had higher activity than the AYS without trehalose had. In case of AYS with trehalose (0.3-0.9M), activity of the AYS could be determined at ranging from $7.8\;{\mu}g/mL$ to $31.3\;{\mu}g/mL$ on S. cerevisiae by MTT method. Consequently, activity of the AYS after heating was well maintained by trehalose.

• Microbiology and Biotechnology Letters
• /
• v.36 no.4
• /
• pp.285-290
• /
• 2008

Rahnella aquatilis strain AY2000 produces an anti-yeast substance (AYS), however activity of the AYS has a declining tendency during storage. To investigate what has been decreased activity of the AYS, the AYS was treated with various physicochemical agents in this paper. The activity of AYS was decreased by heat treatment. Thiol reagent such as $\beta$-mercaptoethanol or dithiothreitol was also another factor decreasing the activity of AYS. However, pH, EDTA, and NaCl were not factors decreasing the activity of AYS. Use of methanol to precipitate the AYS was also decreased the activity of AYS. The activity of AYS was not lost after Sepharose S-400 gel filtration. However, the AYS activity was completely lost, when a polysaccharide and a unknown substance (230 nm absorption) among components of the AYS was separated by DEAE-cellulose chromatography. MIC of the AYS against S. cerevisiae was usually determined at $7.8-15.6{\mu}g/ml$.

• Microbiology and Biotechnology Letters
• /
• v.33 no.2
• /
• pp.90-95
• /
• 2005

An Actinomycetes producing an anti-VRSA (vancomycin-resistant Staphylococcus aureus) substance was isolated from soil. The cultural, morphological, physiological and phylogenetic analyses of an isolated strain were investigated for identification. Cultural characteristics based on ISP (International Streptomyces Project) were as follows: white aerial mycelium, yellow reverse side, and good growth on various medium. Also, the isolate did not produce the soluble pigment. Morphological characteristics were showed cylindrical spore chain and smooth spore surface by SEM (Scanning Electron Microscope). Physiological characteristics were showed LL-type by DAP isomer analysis and detected glycine, glutamic acid and alanine. A phylogenetic analysis of the 16S rDNA provided a clue that the isolated strain was actually a member of the genus Streptomyces, because the determined sequence exhibited a higher homology with Streptomyces echinatus. The isolate was identified to be a genus of Streptomyces sp.. The optimal culture conditions for the maximum production of anti-VRSA substance by Streptomyces sp. were attained in a culture medium composed of $2.0\%$ (w/v) glucose, and $0.4\%$ (w/v) yeast extract. The anti-VRSA substance was highly produced after 5 days of culture. Optimal pH and temperature conditions for the production of anti-VRSA substance were pH 7.0 and $28^{\circ}C$, respectively.

• Fisheries and Aquatic Sciences
• /
• v.3 no.1
• /
• pp.52-63
• /
• 2000

Non-specific reaction has been a problem in doing, especially, research and diagnosis for infectious agents. Avidin-biotin-peroxidase complex (ABC) techniques has widely been used to amplify a reaction. Photobacterium damse1a subsp. piscicdia (formerly Pasteurella piscicida) exhibited a capacity to bind with streptavidin non-specifically. The band, estimated 26 K Da in Western blotted paper, was blocked with biotin but incompletely. In an attempt to explore an involvement of the non-specific substance in attaching piscine cells, cell attachment test performed using anti- Ph. d. subsp piscicida sera raised mouse and rabbit exhibited slightly blocking effects for Mediterranean (1736) and significantly for Japanese (Sp 92144) isolate. Biotin decreased the attachment ability significantly for Sp92144 but it was not effective to 1736. Both isolates showed greatly enhanced attachment ability with poly-L-lysin. The non-specific binding substance was contained in bacterial extracellular products (ECPs). The substance was able to purified with 2-imminobiotin affinity column, the purified substance appeared to have 4 bands in silver staining, and had a carbohydrate branch. This purified substance showed cytotoxic effects selectively between 5 piscine cell lines. Moreover, it stimulated rainbow trout macrophage in terms of reduction of cytochrome cas well as yeast phagocytosis, significantly.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.24 no.2
• /
• pp.258-265
• /
• 2010

Atopic dermatitis (AD) is a chronically relapsing pruritic inflammatory skin disease. To find new anti-inflammatory products for skin inflammatory disease such as AD and contact dermatitis, we produced the effective microorganism fermentation substance (EM-S) by fermentation of medicinal plants with effective microorganisms including photosynthetic bacteria, lactic acid bacteria and yeast, screened the effects of EM-S on NC/Nga model mice. Murine AD-like skin lesions were made by painting Dermatophagoides farinae (Df) extract. Topically applied EM-S significantly reduced clinical severity score, ear thickness and histological grade in AD-like NC/Nga mouse model by Df antigen sensitization. In addition, the serum IgE and Th2 chemokine levels (TARC/CCL17, MDC/CCL22 and CTACK/CCL27) were significantly reduced by EM-S. Futhermore, skin tissue expressions of Th2 chemokines were significantly reduced by EM-S. These results demonstrate that topical application of EM-S may be improve the AD-like skin lesion by suppressing IgE and Th2 chemokines.

• Microbiology and Biotechnology Letters
• /
• v.36 no.3
• /
• pp.215-220
• /
• 2008

Rahnella aquatilis AY2000 has an unique characteristic which produces an anti-yeast substance (AYS). The AYS of the strain AY2000 was always secreted on agar plate, however, its activity in liquid culture was labile upon storage of the medium. In this paper, cultural conditions of the strain AY2000 for the AYS production were investigated in liquid culture, and minimal inhibitory concentration (MIC) against Saccharomyces cerevisiae was determined for the AYS activity. MIC of the AYS cultured in PYG broth at $^25{\circ}C$ for 24 hr was $23.5{\mu}g/mL$, however, that in MYCS (pH 5.5) broth at the same condition was $15.5{\mu}g/mL$. The activity of the AYS had increased rather in MYCS broth excluded $NH_4$-citrate than in the same broth contained $NH_4$-citrate, and MIC of the AYS produced in MYCS broth without $NH_4$-citrate was $15.5{\mu}g/mL$. When the strain AY2000 was maintained in MYCS broth without $NH_4$-citrate but added $100{\mu}M$ $FeCl_3$, the activity of the AYS had increased and its MIC was $7.8{\mu}g/mL$. MIC of the AYS was $7.8{\mu}g/mL$ after the strain AY2000 was cultured in MYCS broth containing $100{\mu}M$ $FeCl_3$ without $NH_4$-citrate, however, its MIC was $31.3{\mu}g/mL$ after 48-60 hr culture in the same broth.

• Microbiology and Biotechnology Letters
• /
• v.42 no.3
• /
• pp.312-315
• /
• 2014

So as to evaluate its use an immune stimulator in humans, the toxicity and action against immune cells by an anti-yeast substance (AYS), a bacterial proteoglycan, were investigated. The AYS did not possess hemolytic activity with human red blood cells (hRBC). Nor did it exhibit cytotoxicity against human peripheral blood mononuclear cells (hPBMC). In addition, the AYS did not induce hPBMC proliferation, but it did agglutinate hPBMCs in vitro. Moreover, hPBMC induced inflammatory cytokines such as IL-6, IL-5, IFN-${\gamma}$ and TNF-${\alpha}$ with the AYS during culture. Compared with alum, the AYS as an adjuvant has an increased antibody production rate against bovine serum albumin (BSA) in mice.

• Microbiology and Biotechnology Letters
• /
• v.41 no.3
• /
• pp.379-382
• /
• 2013

In order to investigate the anticancer activity of an anti-yeast substance (AYS), a proteoglycan produced by Rhanella aquatilis AY2000, the cytotoxicity of the AYS against cancer cells was determined in vitro. The AYS was not cytotoxic to the human Jurkat T cell or the mouse sarcoma 180 cell, but was cytotoxic to the human colon cancer TH20 cell. The AYS was increasingly cytotoxic against human colon cancer cells in a dose-dependent manner at range from 62.5 to 500 ${\mu}g/ml$. Anticancer activity by combination of the AYS and an anticancer agent was also determined. The anticancer agent combined with the AYS was shown to possess greater synergistic anticancer activity against human colon cancer cells, as compared with the anticancer agent alone.