• Microbiology and Biotechnology Letters
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• v.42 no.3
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• pp.293-296
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• 2014

This study was conducted to investigate the effect of culture temperature on the growth rate and protease activity of Antarctic microorganisms. The Antarctic microorganisms PAMC 25641, 25614, 25719 and 25617 were obtained from the Polar and Alpine Microbial Collection (PAMC) at the Korea Polar Research Institute. These microorganisms were confirmed for the excretion of protease on a plate with skim milk. The identification of microorganisms was carried out using the 16S rDNA sequencing method. PAMC 25641 showed the highest protease activity among the subjects tested, and PAMC 25617 exhibited the highest growth rate. The growth rates of the microorganisms were not affected by temperature, except for PAMC 25617. However, protease activities were increased for all strains in a temperature dependent fashion. These results suggest the possible application of Antarctic microorganisms for the efficient production of low temperature proteases.

• The Korean Journal of Ecology
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• v.12 no.2
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• pp.67-73
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• 1989

The action and growth of soil microorganisms were studied in accordance with the leachates from leaf litter over the time lapse, and soil properties and species compositions in studied area were investigated. The investigations of soil microorganisms were made through dividing into two groupsbacterial and fungal groups. The abundance of soil microorganisms showed high correlation with organic matter(0.98) and total nitrogen(0.97) of soil. The amount of soil microorganisms was found the highest in litter layer and the next were humus and A layer in order. The bacterial growth rate in leachates from leaf letter was increased continuously by two weeks. The fungal growth rate was increased only for one week and after then it was decreased abruptly.

• Journal of Life Science
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• v.11 no.1
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• pp.76-82
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• 2001

Fifteen species of microorganisms were isolate form the intestines of fishes, fish feed, and ferment. Eleven microorganisms except HY4, HY8, HY12, and HY13 were Gram-positive, and HY1, HY2, HY3, HY5, HY6, and HY7 produced lactic acid. The species of HY1, HY2, HY3, HY4, HY5, HY6, HY13, and HY14 showed some growth in the medium containing 1% of NaCl. Except HY6, HY7, HY8, HY12 and HY5, 10 isolates had proteolytic activity, whereas only HY13 and HY14 had lipase activity. From all the results four isolates (HY3, HY4, HY13 and HY14) were chosen for the degradation of fish wastes. There was no mutual inhibition among the microorganisms, and the optimum temperature and pH for the growth of the mixed culture were found to be 3 2$\^{C}$ and 7, respectively. Under the optimum growth conditions the maximum optical density and the maximum specific growth rate were estimated to be 2.35 and {TEX}$0.46h^{-1}${/TEX}, respectively. Major microorganisms in the mixed culture at the log-phase were HY3 and HY4, which occupied 70%. The degrading efficiency of fish waste by the mixed microorganisms was 2.3 times higher, compared to control. The total amount of free amino acids in the degraded products from fish wastes was 39g/100g protein and little odor was produced by the mixed microorganisms after 48 hours.

• Journal of Korean Society on Water Environment
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• v.21 no.4
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• pp.347-352
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• 2005

The isolated microorganisms, Pseudomonas stutzeri, Raoultella planticola (Klebsiella), Serratia fonticola from petroleum contaminated soil were enriched on benzene, toluene, ethylbenzene, o-xylene as carbon and energy sources, respectively. And the degradation characteristics of BTEX was observed in the mixed BTEX substrates. We found that the BTEX in mixed substrates were degraded more than 50% by three isolated microorganisms. Among three isolated microorganisms, the highest degradation rate was observed in Pseudomonas stutzeri, but the degradation rate was different according to microorganisms. In order to increase the degradation efficiency, we applied the co-culture of isolated three microorganisms. The mixture rate of pseudomonas stutzeri : Raoultella planticola (Klebsiella) : Serratia fonticola was follows ; 1:2:1, 1:1:2, and 2:1:1, respectively. In two co-culture of 1:2:1 and 1:1:2, degradation rate was lower than isolated microorganisms. However, degradation rate became higher than isolated microorganisms and the degradation rate of benzene, toluene, and ethylene was more than 95% in co-culture of 2:1:1. The degradation rate increased through the co-culture of isolated microorganisms, however, the growth rate decreased. This was resulted from the substrate competition between microorganisms. The co-culture of microorganisms is a effective method to increase the degradation efficiency of BTEX and the co-culture mixing rate is a important factor for determination of degradation efficiency.

• Applied Biological Chemistry
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• v.41 no.1
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• pp.1-5
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• 1998

In order to investigate antimicrobial substances from natural spices, the effects of garlic juice and ginger juice on the growth of microorganisms were investigated. It was showned that garlic juice inhibited the growth of bacteria, yeasts and fungi but ginger juice did not inhibit the growth of bacteria and yeasts. As result of concentration effect of garlic juice on the growth of microorganisms, the higher concentration of garlic juice was employed, the more growth inhibition was obtained. Comparing the specific growth rate at various concentration of garlic juice, the inhibition effect on yeast appeared much higher than that on bacteria.

• Journal of Microbiology
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• v.39 no.3
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• pp.195-201
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• 2001

The effect of moisture content an the reductive dechlorination of polychlorinated biphenyls and population dynamics of dechlorinating microorganisms was investigated in sediments spiked with Aroclor 1248. In sediment slurry with an overlying water layer, dechlorination ensued after a 4-week lag period and reduced the average number of chlorines per biphenyl from 3.91 to 3.15 after 48 weeks. In the sediments of reduced moisture content, however, dechlorination occurred after a lag period of 12 weeks and decreased the average number of chlorines per biphenyl to only 3.62, and the dechlorination rate was also slower. When the population size of dechlorinators, methanogens, and sulfate-reducing bacteria was determined by the most probable number techniques, however, no difference was found between the slurry and the low-moisture sediments, except for methanogens. The growth of dechlorinating populations coincided with the end of the lag period and they then increased by 3 orders of magnitude in two conditions. Specific growth rate of dechlorinators showed little difference between the slurry and the low-moisture sediments; however, growth yield was high in the sediments of reduced moisture content. The reduction of sediment moisture decreased the dechlorination rate and extent of PCBs but did not inhibit the growth of PCB dechlorinators.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.3
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• pp.433-440
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• 1998

In order to select probiotics with a high survival rate in gut and the growth inhibition of virulent pathogens to human beings or animals, we have examined a variety of microorganisms to assess the acid, bile, and pancreatic tolerance and the growth inhibition of E. colt O8 and Salmonella choleraesuis ATCC 8391. Lactobacillus acidophilus KCTC 3155 was shown to inhibit the growth of E. coli and Salmonella dramatically within 24 h of incubation, although it was vulnerable to the exposure of bile acids. Bacillus polyfermenticus showed a good growth inhibition against E. coli, with a moderate acid and bile tolerance, while Clostridium butyricum KCTC 1786 inhibited the growth of E. coli and Salmonella slightly with a good bile tolerance. However, Saccharomyces cerevisiae KCTC 7928 and Aspergillus oryzae KCTC 6075 did not inhibit the growth of E. coli and Salmonella, suggesting that these microorganisms can be used as the sources of nutritional suppliment rather than as probiotics itself.

• 보존과학연구
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• s.30
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• pp.31-46
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• 2009

In the study, we confirmed morphological traits and calculated the Risk Class of 25 mould species, including Tyromyces palustris, through decomposition rate of substrate for characteristic confirmation of injured microorganisms. We received the injured microorganisms in wood and it was pure cultivated. We observed growth traits and decomposition rate of substrate. Also, it allows the calculation of Risk Class to be worried in the case of growth in wooden cultural properties. As a result, Tyromyces palustris, representative of brown-rot, has the characteristics about decomposition rate of substrate - Cellulose ; more active(+++), Lignin ; more active(+++), Xylan ; more active(+++), Starch ; active(++). We classified Tyromcyes palustris as a first Risk Class and as a second Risk Class about Schizophyllum commune et al(9 species, See table 1. We look forward to offering standard data base for evaluating Risk Class as a matter of applying preventive conservation in wooden cultural properties through our study.

• Journal of the Korean Society of Industry Convergence
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• v.2 no.1
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• pp.85-90
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• 1999

The possibility of employment of ceramics, known to be emitting far infrared waves, to keep the growth and the viability of the antagonistic microorganisms was examined. Among four kinds of commercial ceramics, the ceramic powders composed of soft ferrite as a main component has exhibited to grow Pseudomonas cepacia and Saccharomyces cerevisiae better. The ceramic powder in the growth medium has increased the number of cells of P. cepada about ten times and that of S. cerevisiae two to five times more than that in the control at $27^{\circ}C$. The viability of the microorganism at low temperature which was measured from the regrowth behavior at $27^{\circ}C$ after five days store at $4^{\circ}C$ has shown that the lag time of the two microorganisms reduced about three hours without any defect in the rate of logarithmic growth. These results demonstrated that the ceramic powders was available to the growth and viability at low temperature of antagonistic microorganisms.

• Journal of environmental and Sanitary engineering
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• v.13 no.3
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• pp.133-140
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• 1998

The food wastes from a refectory and an eating house were heated in domestic microwave oven(700W) equipped with a fan and the drying rates and destruction of microorganisms were investigated. The drying rate was decreased with the size of food waste and the food wastes in polypropylene basket were dried faster than that on glass dish. The rate was increased with lower initial moisture content. Death rate of microorganisms was also decreased with the size of food waste. Ninety eight percent of reduction in viable cell numbers for the 400g of food waste could be achieved in 240sec of microwave irradiation. The growth of microorganisms in food wastes after microwave irradiated was observed at $32^{\circ}C$ and 95% relative humidity after 7days and the cell numbers in microwave irradiated food wastes were found to be 1/2 ~ 1/20 of the numbers in untreated wastes in accordance with the mass and the length of exposed time to microwave. To minimize the moisture and microorganisms in food wastes, the use of microwave oven are recommended.