• Korean journal of food and cookery science
• /
• v.4 no.1
• /
• pp.41-46
• /
• 1988

Omija tea with a pH range of 2.8~3.0 was stored at $25^{\circ}C$ to study its spoilage due to microbial growth. Titratable acidity was increasing during the storage period in the tea stored with the Omija fruits but not in removed of the fruits after extraction. Microbial cells began to show up earlier in the tea without the fruits than that with the fruits. Four strains of yeasts and a strain of mold were isolated from spoiled Omija tea. Morphological, cultural and physiological characteristics of yeasts were investigated and the yeasts were identified as Rhodotorula rubra, Saccharomyces kluyveri, Cryptococcus hungaricus and Candida humicola. Morphological characteristics of the isolated mold was observed and the mold was identified as Mucor circinelloides f. janssenii.

• The Korean Journal of Food And Nutrition
• /
• v.22 no.1
• /
• pp.97-102
• /
• 2009

In order to obtain a non-toxic and more active and stable microorganism-produced tyrosinase inhibitor, we isolated actinomycetes F-97, a producer of tyrosinase inhibitor, from soil. The aerial hyphae of this strain were gray in color with tree types. Under the microscopic examination, the isolate formed a spiral aerial spore mass with a smooth surface. The analysis of cell wall acid hydrolysate of the isolate revealed the presence of LL-diaminopimelic acid(LL-DAP). No specific sugar was detected. From these results and the cultural and physiological characteristics described in the Bergey's Manual, actinomycetes F-97 was identificated as, or best-matched to, Streptomyces aburaviensis.

• Archives of Pharmacal Research
• /
• v.15 no.1
• /
• pp.30-34
• /
• 1992

In order to obtain acetaminophen, a popular analgesic-antipyretic, through microbial p-hydroxylation and N-acetylation of aniline, various fungi and bacteria were secreened. Among them, Streptomyces species were chosen for strain improvement by the use of interspecific protoplast fusion technique. Two interspecific fused strains were developed between S. rimosus (N-cetylation function) and S. aureofaciens (p-hydroxylation function) and also between S. lividans and S. globisporus. For efficient protoplast fusion and cell wall regeneration, various conditions were examined. In a typical experiment of mixed S rimosus ($pro^- \;his^-$) and S. aureofaciens ($ilv^-$) protoplasts with 40% (w/v) polythylene glycol 3350 (PEG) for 3 min gave $8.3\times10^{-7}$ of fusion frequency. Treatment of mixed S. lividans (pant-) and S. globisporus (leu-) protoplasts with 50% (w/v) PEG for 3 min at $30^\circ{C}$ gave $1.2\times10^{-6}$ of frequency. Among the fused strains, up to 40-50% increase in p-hydroxylation power was observed. To investigate the possibility of plasmid involvement in p-hydroxylation power was observed. To investigate the possibility of plasmid involvement in p-hydroxylation of acetanilide, plasmid curing was attempted. We found that cells treated with acriflavine (at the frequency of 100%) and cells regenerated from protoplsts of S. auroefaciens (2% frequency) lost their p-hydroxylation function.

• Journal of Food Hygiene and Safety
• /
• v.9 no.4
• /
• pp.191-198
• /
• 1994

The major purpose of the present study is to syrvey vegetables, meats, seafoods, processed foods and imported foods for the presence of Listeria spp. and to prevent listeriosis caused by the contamination of Listeria monocytogenes. Listeria spp. was not found in vegetables and processed foods. The optimum growth condition of isolates indentified as Listeria monocytogenes was pH 7.0 and 37$^{\circ}C$. the antimicrobial effect of grapefruit seed extract(GFSE) was observed in the level of more than 100ppm by disk method. When 1ml(2.5$\times$106 CFU/ml) of Listeria monocytogenes was inoculated and incubated for 3 days at 3$0^{\circ}C$, the total cell number of the organism was 4.5$\times$109 in the control, 7.2$\times$103 in 100 $\mu\textrm{g}$/ml of GFSE medium, and 3.5 $\mu\textrm{g}$/ml of GFSE medium. Direct visualization of microbial cells by using both transmission electron microscope and scanning electron microscope showed microbial cell membrane the function of which was destroyed by treating with the dilute solutions of GFSE. It could be confirmed that GFSE completely inhibited the growth of the test strain of Listeria monocytogenes.

• Proceedings of the Microbiological Society of Korea Conference
• /
• 2002.10a
• /
• pp.90-93
• /
• 2002

The revolution in molecular biology has given us greatly increased ability to obtain and to modify biological resources and to use them for the benefit of all humankind. The sequencing and the associated analysis of gene functions for a growing number of genomes will have an unprecedented effect on the uses of biological resources and the need for access to them. To investigate the diversity of microbial community in swamp, molecular systematic methods were applied. By amplified rDNA restriction analysis (ARDRA) and rDNA partial sequence analysis, $75\%$ of the isolates were known species. In case of uncultured analysis, almost all the selected clones were new species candidate. Especially archea and uncultured bacterial analyses, all clones were new taxon candidates. As for the eukaryotic diversity, several yeast form cultures were isolated from various samples of swamp. Among them, about $60\%$ of the isolates were easily identified. In case of a new species candidate, most strain were included in hymenomycetal yeasts.

• Microbiology and Biotechnology Letters
• /
• v.27 no.2
• /
• pp.172-178
• /
• 1999

In this study, we tested possibility of replacing nitrite salts, which were always added during the meat product processing, with the metabolites produced by antimicrobial and red pigment producing Monascus strains. We have already shown that Monascus No. 116 strain has the highest antimicrobial activity among the strains isolated from Ang-Khak. Monascus isolate No. 229 was chosen due to its outstanding red pigment producing ability. The red pigment production by No. 229 was highest in the medium containing 8% sucrose, 2% yeast extract, 0.1% K2HPO4, 0.5% MgSO4. Optimum pH and temperature for the red pigment production were pH 6.2 and 3$0^{\circ}C$, was found in spot or Rf value 0.54 on TLC plate using ethyl acetate-acetone-water (4:4:1, v/v/v) as development solvent system. Isolate No. 116 and No. 229 were cultured in a optimal condition for the antimicrobial activity and red pigmentation. The culture concentrates were applied in situ to the production of instantly processed ham. Mixed application of 89 ppm Na-nitrite and 300 ppm of culture broth concentrate of Monascus isolate No. 116 and 500 ppm of red color produced by Monascus isolate No. 229 showed similar results with the single application of 94 ppm Na-nitrite. These results confirmed that the antimicrobial activity and red pigment of Monascus strains might be valuable to replace Na-nitrite salt in meat processing.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.34 no.3
• /
• pp.174-178
• /
• 2014

The present study was planned to analyze the nutritional quality, microbial counts and fermentative acids in Italian ryegrass (IRG) 80% and alfalfa 20% (IRG-HV) mediated silage inoculated with lactic acid bacteria (LAB) as a probiotic strain for 3 months. Crude protein (CP), acid detergent fiber (ADF), and neutral detergent fiber (NDF), total digestible nutrient (TDN) and In-vitro dry matter digestibility (IVDMD), lactic acid bacteria (LAB), yeast and fungi counts and fermentation metabolites such as lactic acid, acetic acid and butyric acids were analyzed. The result shows that the nutritional quality and metabolite profiles of silage were significantly improved with LAB. For microbial counts, LAB showed dominant followed by yeast as compared with control silage. The pH of the silage also reduced significantly when silage inoculated with LAB. The result confirmed that silage preparation using different crops with L. plantarum inoculation is most beneficial for the farmers.

• Journal of Ginseng Research
• /
• v.34 no.4
• /
• pp.321-326
• /
• 2010

Enzymatic treatment conditions for red ginseng residue (RGR) were investigated to apply RGR as a microbial medium. Polysaccharide hydrolyase and protease were screened to obtain high solid and carbohydrate yields, and a good degree of carbohydrate hydrolysis. The optimal dosage and reaction time for Viscozyme, the chosen polysaccharide hydrolyase, were found to be 1.0% (w/w) and 3 h, respectively. Of the tested proteases, Flavourzyme, whose optimal dosage was 0.5% (w/w), was selected. Co-treatment with the optimal dosages of Flavourzyme and Viscozyme increased solid yield, carbohydrate yield, and degree of carbohydrate hydrolysis by 76%, 65%, and 1,865%, respectively, over levels in non-treated RGR. The culture characteristics of Leuconostoc mesenteroides strain KACC 91459P grown in enzymatically hydrolyzed red ginseng residue (ERGR) and RGR suspensions were compared. After cultivation for 6 h, the viable cell counts of both cell suspensions rapidly increased to $1.3{\times}10^9$ colony-forming units (CFU)/g. Moreover, while the viable cell population drastically decreased to $2.4{\times}10^6\;CFU/g$ for cells grown in RGR medium, it was maintained in cells fermented in ERGR medium for 24 h.

• Microbiology and Biotechnology Letters
• /
• v.42 no.2
• /
• pp.152-161
• /
• 2014

The in vitro antimicrobial potential of the unexplored Moringa oleifera seed coat (SC) was evaluated against some Gram-positive and Gram-negative bacteria and yeast pathogens. Antimicrobial studies with various solvent extracts indicated ethyl acetate to be the best extractant, which was used for the rest of the antimicrobial studies as it tested neither toxic nor mutagenic. Gram-positive bacteria including a methicillin resistant Staphylococcus aureus (MRSA) strain were more susceptible with a minimum inhibitory concentration (MIC) range of 0.03-0.04 mg/ml. The antimicrobial pharmacodynamics of the extract exhibited both concentration-dependent and time-dependent killing. Most of the test organisms exhibited a short post antibiotic effect (PAE) except Enterococcus faecalis, Staphylococcus aureus, and Klebsiella pneumoniae 1, which exhibited longer PAEs. Amongst the major phytoconstituents established, flavonoids, diterpenes, triterpenes and cardiac glycosides exhibited inhibitory properties against most of the test organisms. The identified active phytochemicals of the M. oleifera seed coat exhibited antimicrobial potential against a wide range of medically important pathogens including the multidrug-resistant bugs. Hence, the M. oleifera seed coat, which is usually regarded as an agri-residue, could be a source of potential candidates for the development of drugs or drug leads of broad spectrum that includes multidrug-resistant bugs, which are one of the greatest concerns of the $21^{st}$ century.

• Journal of Microbiology
• /
• v.41 no.4
• /
• pp.277-283
• /
• 2003

Haloaliphatic hydrocarbons have been widely used as solvents and ingredients of pesticides and herbicides. However, when these compounds contaminate the environment, they can be very hazardous to animals and humans because of their potential toxicity and carcinogenicity. Therefore, lots of studies have been made for microbial degradation of those pollutant chemicals. In this study, 11 bacterial strains capable of degrading 1,2-dichloroethane (1,2-DCA), 2-chloropropionic acid (2-CPA), 2,3-dichloropropionic acid (2,3-DCPA), and 2-monochloroacetic acid (2-MCA) by hydrolytic dechlorination under aerobic conditions were isolated from wastewaters and rice paddy soil samples. Their morphological and biochemical characteristics and their degradation capabilities of haloaliphatic hydrocarbons were examined. On the basis of the 16S rDNA sequences, 8 different kinds of microbial species, including Pseudomonas plecoglossicida, Xanthobacter flavus, Ralstonia eutropha, were identified. All of the isolated strains can degrade MCA. In particular, strains UE-2 and UE-15 degraded 1,2-DCA, and strain CA-11 degraded 2,3-DCPA, which are hardly degraded by other strains.