• Microbiology and Biotechnology Letters
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• v.6 no.3
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• pp.121-127
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• 1978

This paper deals with investigation on the various effects of phosphodiesterase production of Streptomyces sp. and several properties of the enzyme. The results were as follows. 1) As a carbon source, sucrose was most effective PDase production when it was added. to the basal medium at 3％ concentration. 2) These enzymes were remarkably activated by $Ca^{2+}$, Co$^{2+}$ and Mn$^{2+}$ but inhibited by Cu$^{2+}$. It was observed that concentration of metal ions, 0.1％ of $Ca^{2+}$, 0.01％ of Co$^{2+}$ and 0.04％ of Mn$^{2+}$ were effective on the production of phosphodiesterase and phosphomonoesterase. 3) In case of the effect of aeration volume, 25 ml was very effective, that is, the more sufficient aeration, the better enzyme activity. Enzyme activity was to be found effective at 3％ of inoculation volume, and comparatively more effective at 2％, 4％ of inoculation volume. 4) Initial pH was 8. The enzyme activity reached to the maximum at 48 hours of cultivation time. 5) The optimum pH of phosphodiesterase was about 8 and that of phosphomonoesterase was about 9. The optimum temperature of phosphodiesterase and phosphomonoesterase was 6$0^{\circ}C$ and 5$0^{\circ}C$ respectively. respectively.

• Korean Journal Plant Pathology
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• v.1 no.3
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• pp.169-172
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• 1985

Natural sclerotia of Rhizoctonia solani causing rice sheath blight were inoculated at 10 day intervals from June 15 to July 15 in paddy field, Icheon, Korea. Percentage of infected stems, top lesion height and percentage of. lesion height vs. plant height were higher in the early inoculated plots than in the late inoculated ones. However, rio significant differences among inoculation dates of sclerotia were found on the basis of degree of damage at maturing stage and rice yield. These results suggest that the time of initial symptom appearance under the same inoculum potential may not affect the damage of rice plants by the fungus.

• The Plant Pathology Journal
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• v.23 no.4
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• pp.239-244
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• 2007

MicroTom is a miniature tomato plants with various properties that make it as a model system for experiments in plant molecular biology. To extend its utility as a model plant to study a plant - bacterial wilt system, we investigated the potential of the MicroTom as a host plant of bacterial wilt caused by Ralstonia solanacearum. We compared the disease progress on standard tomato and MicroTom by two inoculation methods, root dipping and soil drenching, using a race 1 strain GMI1000. Both methods caused the severe wilting on MicroTom comparable to commercial tomato plant, although initial disease development was faster in root dipping. From the diseased MicroTom plants, the same bacteria were successfully reisolated using semiselective media to fulfill Koch's postulates. Race specific and isolate specific virulence were investigated by root dipping with 10 isolates of R. solanacearum isolated from tomato and potato plants. All of the tested isolates caused the typical wilt symptom on MicroTom. Disease severities by isolates of race 3 was below 50 % until 15 days after inoculation, while those by isolates of race 1 reached over 50% to death until 15 days. This result suggested that MicroTom can be a model host plant to study R. solanacearum - plant interaction.

• Journal of Dairy Science and Biotechnology
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• v.41 no.3
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• pp.103-112
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• 2023

This study aimed to assess the effectiveness of 10 different pre-enrichment methods using Real-Time polymerase chain reaction (PCR) in support of the FDA method. When the initial Cronobacter spp. (Enterobacter sakazakii) inoculation was 7.2 CFU/g, the Ct values were observed in the following order: 21.37 (Enterobacteriaceae enrichment [EE] broth), 21.95 (brain heart infusion [BHI]), 22.72 (tryptic soy broth [TSB]), 23.02 (violet red bile lactose [VRBL]), 22.31 (TSB-0.1% sodium pyruvate [SP]), 23.43 (distilled water [DW]), 24.34 (phosphate buffered saline [PBS]), 24.95 (nutrient broth [NB]), 25.82 (TSB-0.6% yeast extract [YE]), and 28.27 (violet red bile glucose [VRBG]). For an inoculation of 1.82% CFU/g of Cronobacter spp. (E. sakazakii), the Ct values were recorded in this sequence: 20.34 (EE broth), 22.16 (TSB-0.6% YE), 22.37 (BHI), 22.71 (VRBL), 22.88 (TSB), 23.01 (DW), 23.19 (NB), 23.79 (TSB-0.1% SP), 24.66 (VRBG), and 24.70 (PBS). Finally, when the inoculum of Cronobacter spp. (E. sakazakii) was 0.182 CFU/g, the Ct values followed this order: 21.93 (VRBL), 23.07 (TSB-0.6% YE), 23.31 (DW), 23.47 (PBS), 23.70 (BHI), 24.14 (TSB-0.1% SP), 25.14 (TSB), 29.00 (VRBG), 31.55 (EE broth), and were undetected in the case of NB. Consequently, these results indicate that there were no significant differences among the 10 different pre-enrichment broths. Future studies should focus on exploring pre-enrichment broths that can improve the limit of detection at very low Cronobacter spp. (E. sakazakii) concentrations and enhance the selective recovery of Cronobacter spp. (E. sakazakii) under acid, antibiotic, cold, and heat damage conditions.

• Journal of Microbiology
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• v.42 no.4
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• pp.285-291
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• 2004

The soil bacterial community and some inoculated bacteria were monitored to assess the microbial responses to prescribed fire in their microcosm. An acridine orange direct count of the bacteria in the unburned control soil were maintained at a relatively stable level $(2.0\~2.7\times10^9\;cells/g^{-1}{\cdot}soil)$ during the 180 day study period. The number of bacteria in the surface soil was decreased by fire, but was restored after 3 months. Inoculation of some bacteria increased the number of inoculated bacteria sev­eral times and these elevated levels lasted several months. The ratios of eubacteria detected by a flu­orescent in situ hybridization (FISH) method to direct bacterial count were in the range of $60\~80\%$ during the study period, with the exception of some lower values at the beginning, but there were no definite differences between the burned and unburned soils or the inoculated and uninoculated soils. In the unburned control soil, the ratios of $\alpha-,\beta-\;and\;\gamma-subgroups$ of the proteobacteria, Cytophaga-Fla­vobacterium and other eubacteria groups to that of the entire eubacteria were 13.7, 31.7, 17.1, 16.8 and $20.8\%,$ respectively, at time 0. The overall change on the patterns of the ratios of the 5 subgroups of eubacteria in the uninoculated burned and inoculated soils were similar to those of the unburned con­trol soil, with the exception of some minor variations during the initial period. The proportions of each group of eubacteria became similar in the different microcosms after 6 months, which may indicate the recovery of the original soil microbial community structure after fire or the inoculation of some bac­teria. The populations of Azotobacter vinelandii, Bacillus megaterium and Pseudomonas fluorescens, which had been inoculated to enhance the microbial activities, and monitored by FISH method, showed similar changes in the microcosms, and maintained high levels for several months.

• Korean Journal of Agricultural Science
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• v.44 no.4
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• pp.558-565
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• 2017

This study was conducted to determine the effect of inoculation of microorganism isolated from pig feces on nutrient contents of fermented hulless barley. The microbial flora in feces of a total of four crossbred piglets ($Landrace{\times}Yorkshire{\times}Duroc$) was analyzed by 16s rRNA sequencing. The most abundant strain was then selected for fermentation of hulless barley. Lactobacillus plantarum (L. plantarum) was dominant (64.56%) in intestinal microbial flora in the pig feces. The selected candidate strain showed significantly higher survival rate at pH 7 than at pH 2.5 and 3.0 (p < 0.05). Incubated culture containing the candidate strain showed an increased growth rate with lower pH levels after 7.5 h incubation compared to initial incubation period (p < 0.05). When compared with commercial multiple probiotics which were used as control, the selected strain showed faster growth rate at 5 h post-incubation (p < 0.05). During the fermentation period, neither inoculated nor non-inoculated control hulless barley showed any change in pH value. Crude fat, fiber and ash contents were lower (p < 0.05) in hulless barley inoculated by the selected strain compared to control. However, moisture, energy, NDF and ADF were not affected by the inoculation of strain or fermentation period. Lactic acid was increased and acetic acid was decreased in the hulless barley inoculated with the selected strain during the fermentation period (p < 0.05). Taken together, our results suggest that L. plantarum derived from the pigs could be utilized as a new microorganism for manufacturing fermented feed stuffs.

• Microbiology and Biotechnology Letters
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• v.38 no.3
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• pp.329-334
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• 2010

In this study, the rhizoremediation of petroleum and heavy metal-contaminated soil was characterized employing Zea mays and two plant-growth promoting rhizobacteria, Gordonia sp. S2RP-17 and Serratia sp. SY5 which have petroleum-degrading activity and heavy metal-resistance, respectively. After 51 days, the average dry weights of Zea mays' root without and with the inoculation of rhizobacteria were $1.9{\pm}0.2$ and $5.6{\pm}0.7\;g$, respectively. Compared with initial TPH concentration in soil ($21,576{\pm}3,426\;mg-TPH{\cdot}kg-dry\;soil^{-1}$), the residual TPH concentrations were $220{\pm}98\;mg-TPH{\cdot}kg-dry\;soil^{-1}$ in soil planted with Zea mays, and $20{\pm}41\;mg-TPH{\cdot}kg-dry\;soil^{-1}$ in soil planted with Zea mays and inoculated with rhizobacteria. These results indicated that the inoculation of S2RP-17 and SY5 could promote TPH removability in soil as well as the growth of Zea mays' root. There was little positive effect of the rhizobacteria inoculation on the removability of heavy metal such as Cu, Cd and Pb in soil planted with Zea mays.

• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.1
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• pp.89-96
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• 2018

The object of this study was to evaluate the change of antibody titers on virus strains after inoculation with commercial killed equine influenza (EI) vaccines in horses. Serum antibodies of 20 Thoroughbred yearlings were detected using hemagglutination inhibition test for 41 weeks. Second vaccination is inoculated 4 weeks after the initial vaccination. Most of antibody titers were not increased until 4 weeks after first vaccination. The highest titers were detected 6-10 weeks after vaccination. The titers were decreased slowly and maintained for 16 weeks after inoculation. We could barely detect the antibody 41 weeks after vaccination in most cases. Vaccine anergia were appeared in 3 horses (15%) but it depended on virus strains. A/Equine/La Plata/93(H3N8) strain that induce high and durable antibody responses was the most effective among three strains. This study presents the first comprehensive data on the endurance of antibody titers against EI. Our data also suggests that yearlings should be inoculated three times in order to maintaining optimal antibody titers against EI. We speculate the causes of anergia were vaccine break down or individual specificity. Further research is needed to investigate immunological unresponsiveness. This was the first study on strain of equine vaccine in Korea.

• Korean journal of food and cookery science
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• v.26 no.3
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• pp.335-345
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• 2010

The objective of this study was to model the kinetics of S. aureus survival on high risk foods in school foodservice operations. After inoculating S. aureus ATCC25923 onto the various high risk foods, the effects of competitive microorganism, storage temperatures($25^{\circ}C$, $35^{\circ}C$), and initial contamination levels ($1.0{\times}10^2\;CFU/g$, $1.0{\times}10^5\;CFU/g$) on the growth of S. aureus were investigated. Lag time decreased and specific growth rate increased with a storage temperature ($25^{\circ}C$<$35^{\circ}C$) and with a higher initial inoculation level ($1.0{\times}10^2\;CFU/g$<$1.0{\times}10^5\;CFU/g$). Previously it was shown that S. aureus is a weaker competitor than other organisms, but it proliferates aggressively in a noncompetitive environment. However, in our study, when S. aureus was used to inoculate japchae (glass noodles with sauteed vegetables) and meat ball, the growth of S. aureus was similar and more active with competitive organisms than that without competitive organisms. Regardless of other factors, the initial level of S. aureus was a more significant factor of the growth. High inoculation levels of S. aureus were reached at 6 log CFU/g within 3 hours. An incubation temperature of $35^{\circ}C$ and the animal protein component of menu items also were identified as significant factors influencing the growth of S. aureus. Therefore, the duration of time meals are stored before serving should be considered a critical control point. Food service providers must control time and temperature to insure the safety of cooked foods.

• Korean Journal of Plant Resources
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• v.22 no.4
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• pp.337-342
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• 2009

Present studies were conducted to evaluate the effects of medium strength(MS and Hyponex), carbon sources and their concentrations, agar concentrations, and inoculation amounts on prothallus propagation of Pterdium aquilinum var. latiusculum(Desv.) Underw. ex Hell in vitro. The optimum MS medium strength for prothallus propagation was 2MS concentration. Phosphate source was most effective for prothallus growth of P. aquilinum var. latisculum. The addition of 1% sucrose or glucose to MS medium promoted prothallus multiplication. Growth of prothallus was not affected by agar concentration. Propagation of homogenized prothallus was vigorous even in liquid medium. Chopped gametophytes(100 and 200 mg) were inoculated on 250 ml ${\Delta}$flask with 100 mL of 2MS concentration medium and suspension culture was done at 100 rpm for 22 days. After 20 days, prothallus multiplication slowed down, so 100 mg of chopped prothalli is recommended for initial inoculation, since initial amount of inoculum did not affect subsequent prothallus multiplication. Consequently after 20 days of suspension culture, prothallus should be subcultured or transplanted outside of growing vessels.