• Korean Journal of Environmental Biology
• /
• v.22
• /
• pp.86-92
• /
• 2004

The marine viral density in the Gwangyang Bay was abundant about 2.0${\times}$10$^{8}$ particles ml$^{-1}$ . For each season, viral abundances were recorded from 9.0${\times}$10$^{8}$ particles ml$^{-1}$ in summer to 0.7${\times}$10$^{6}$ particles ml$^{-1}$ in winter. The spatial distributions of the viral, bacterial and phytoplankton biomass in the Gwangyang Bay were mostly highey in closed estuarine system (Station 2, 5, 10, 12, 16, 20) than open ocean system (Station 28, 38, 42, 46, 51), And the othey closed estuarine system (Station 22, 26, 32, 34) indicated higher viral abundances, lower bacterial and plankton biomass than open oceanic system. In depths of some stations, the bacterial abundances exceeded a hundred fold than viral abundances. Seasonal abundances of marine viruses and their host systems were dynamically changed, and their seasonal variations were closely correlated. In summer, viral and bacterial abundances were increased, and phytoplankton chlorophyll $\alpha$ concentrations were maintained in average values. In winter, viral and bacterial abundances were dramatically decreased, and chlorophyll a concentrations were decreased, but, immediately increased. The viral abundances were peaked in August 2001, and bacteyial abundance, in August 2001 and June 2002, while chlorophyll a concentrations were peaked in April. 2002. In total host and viral abundances, it was seemed that their pools were maintained to steady-states by viral mortality, and viral abundance maintained steady-states. In our assessments, this report is a unique research about marine viral ecology of the Gwangyang Bay in Korea.

• the MEAT Journal
• /
• s.34 winter
• /
• pp.14-25
• /
• 2007

The objective of this study was to investigate the physicochemical, microbiological and sensory properties of food additive-free grilled pork products manufactured using loin (T1), tender loin (T2) and ham (T3). The samples were heated for 30 min at $60^\circC$, and then 50 min for $150^\circC$. After cooling, vacuum packaged grilled pork samples was stored at $4\pm$$1^\circC$ for 40 days. The pH values of grilled pork samples ranged from 5.92 (T1) to 6.10 (T3) at the initial storage time, and from 6.28 (T1) to 6.60 (T3) after 40 days. The water holding capacities (%) was 85.99~93.24% for T1, 85.26~93.89% for T2 and 89.11~94.67% for T3, all of which were slightly higher than those of other pork products. The shear force values of T2 were significantly higher (p<0.05) than those of the other pork products throughout the storage period. The TBARS and VBN values of T2 were significantly higher (p<0.05) than those of T1 and T3. With regard to microorganisms, all grilled pork samples was in good condition, showing 1.93~3.48 log10 CFU/g via total plate counts, and 1.74~3.48 log10 CFU/g for lactic acid bacteria throughout the storage period. Regarding sensory evaluation, the scores of overall acceptability in all products were above 5.0 points through 40 days of storage.

• Journal of Mushroom
• /
• v.13 no.2
• /
• pp.108-113
• /
• 2015

This study was carried out to investigate the feeding effects of dietary supplementation of fermented spent mushroom substrates (F-SMS) from Pleurotus eryngii with Bacillus subtilis CS21 and Saccharomyces cerevisiae on Hanwoo steers. The cellulase and xylanase producing bacteria, designated CS21, was isolated from freshly spent mushroom substrates from Pleurotus eryngii and used as probiotics to fermented spent mushroom substrates. Twenty Hanwoo steers were allocated into two feeding groups and assigned equally to two dietary treatments; Control (TMR) and TMR including 30% F-SMS (30% F-SMS TMR). Total gain and feed intake was significantly greater in the 30% F-SMS TMR than control (p<0.05), but carcass grades were not influenced by the experimental diets. Based on this study, fermented spent mushroom substrates from Pleurotus eryngii with B. subtilis CS21 and Saccharomyces cerevisiae is able to use as an ingredient feed in TMR for Hanwoo steers.

• Parasites, Hosts and Diseases
• /
• v.27 no.2
• /
• pp.101-108
• /
• 1989

This study was performed to observe the role of Pneumocystis carinii as an etiologic agent of interstitial pneumonia in immunocompromised hosts. Total 90 male Sprague-Dawley rats, approxi. mately 150-180 g, were used. Fifteen of them were used as control group and remaining 75 (5 groups) were as immunosuppression groups; group 1 received prednisolone (25 mg/kg twice weekly) only; group 2 Prednisolone and tetracycline (75 mk/kg/day) ; group 3 Prednisolone, tetracycline and trimethoprim-sulfamethoxasole (50~250 mg/kg/day) : group 4 prednisolone and trimethoprim-sulfamethoxasole; and group 5 prednisolone and griseofulvin (300 mg/kg/day) until death. The survival days of each group rat were calculated, and upon death their lungs were removed immediately and then stamp smears were prepared and stained by Giemsa or toluidine blue O. For histopathologic observation, lungs were fixed in 10% formalin, cut into sections and stained with Gomori's methenamine silvei, hematoxylin-rosin, and Brovkn & Brenn stain. The results obtained were as follows: 1. The mean survival time of each group rat was 19.3$\pm$5.2 days (group 1), 41.1$\pm$14.0 days (group 2), 50.5$\pm$18.4 days (group 3), 43.0$\pm$22.9 days (group 4) or 21.8$\pm$5.1 days (group 5). Significant differences were noted between group 1 and group 2(p<0.01), group 1 and group 3 (p<0.01), and group 1 and group 4 (p<0.01), which represented bacterial infections were most fatal in immunocompromised rats. Group 5 revealed no difference in the survival day from group 1, while significant differences were noted between group 2 and group 5(P<0.01), group 3 and group 5(p<0.01), and group 4 and group 5(p<0, 01), which represented little importance of fungal infection as the cause of death of the rats. 2. The first fatality due to p. carinii pneumonia occurred 17 days after the beginning of the immunosuppression. The occurrence rate of P. carinii pneumonia in the decreasing order was 92.9% (group 3), 80.0% (group 2 and group 5), 78.6% (group 4) and 33.3% (group 1). With regard to the pathological stage of P. carinii pneumonia, the stage 1 was 11.3%, the stage 2, 28.3%, and the stage 3, 60.4%. 3. Viewing from the duration of immunosuppression, bacterial pneumonia chieay appeared in 1 month, mixed infections (P. carinii and bacteria, or p. carinii and fungi) in 1~2 months, and pure P. carinii pneumonia after 2 months. The present study revealed that P. carinii pneumonia was the most important cause of death of immunocompromised rats later than 1 month after the start of immunosuppression.

• Journal of Soil and Groundwater Environment
• /
• v.8 no.4
• /
• pp.27-35
• /
• 2003

The study site located in an industrial complex has a Precambrian age gneiss as a bedrock. The poorly-developed, disturbed soils in the study site have loamy-textured surface soil (1 to 2 m) and gravelly sand alluvium subsurface (2 to 6 m) on the top of weathered gneiss bedrock. The depth of the groundwater table was about 3.5 m below ground surface and increased toward down-gradient of the site. The hydraulic conductivity of transmitted zone (gravelly coarse sand) was in the range of 5.0${\times}$10$\^$-2/∼1.85${\times}$10$\^$-1/ cm/sec. The fine sand layer was in the range of 1.5${\times}$10$\^$-3/ to 7.6${\times}$10$\^$-3/ cm/sec. and the reclaimed upper soil layer was less than 10$\^$-4/ cm/sec. Toluene, ethylbenzene, and xylene (TEX) was the major contaminant in the soil and groundwater. The average depth of the soil contamination was about 1.5 m in the gravelly sand alluvium layer. At the depth interval 2.4∼4.8 m, the highest contamination in the soil is located approximately 50 to 70 m from the suspected source areas. The concentration of TEX in the groundwater was highest in the suspected source area and a lesser concentration in the center and southwest parts of the site. The TEX distribution in the groundwater is associated with their distribution in the soil. Microbial isolation showed that Pseudomonas flurescence, Burkholderia cepacia, and Acinetobactor lwoffi were the dominant aerobic bacteria in the contaminated soils. The analytical results of the groundwater indicated that the concentrations of dissolved oxygen (DO), nitrate, and sulfate in the contaminated area were significantly lower than their concentrations in the none-contaminated control area. The results also indicated that groundwater at the contaminated area is under anaerobic condition and sulfate reduction is the predominant terminal electron accepting process. The total attenuation rate was 0.0017 day$\^$-1/ and the estimated first-order degradation rate constant (λ) was 0.0008 day$\^$-1/.

• Korean Journal of Food Science and Technology
• /
• v.36 no.3
• /
• pp.385-392
• /
• 2004

Physicochemical and sensory characteristics of commercial Oiji, Korean pickled cucumbers (six commercial and three traditionally made products) were investigated. Saltiness values for commercial and traditionally made products were 3.424-4.47 and 3.92-7,23%, and acidity and pH were 3.43-3.85 and 0.39-0.75%, respectively, Commercial products showed lower L and higher b values than traditionally made products. Redness of both products ranged from -1.47 to -3.71. Numbers of total microbial, lactic acid bacteria, and yeast in traditionally made products ($1{\times}10^{7}-1.3{\times}10^{9},\;4{\times}10^{6}-4.7{\times}10^{8},\;and\;1.3{\times}10^{6}-3{\times}10^{8}\;cfu/mL,\;respectively$), were higher than those of commercial products ($1{\times}10^{4}-2{\times}10^{7},\;1{\times}10^{4}-6{\times}10^{6},\;and\;1{\times}10^{4}-6{\times}10^{6}cfu/mL\;respectively$). Texture analysis revealed fracturability (2,103-3,010 g) and hardness (409-890 g) varied among the products above. Overall acceptability scores of commercial products C1 and C2 were highest at 7.6-8.0 compared to other products (p<0.05). From the principal component analysis, the first principal component (PC1, 79.94%) and the second principal component (PC2, 19.94%) could describe the majority of the variability. Commercial product C1, C2, C3, and C7 having high negative loadings on the PC2 axis are closely related to over-all acceptability, over-all taste, savory taste and hardness. From Pearson correlation analysis, hardness and chewiness correlated positively with saltiness, whereas over-all acceptability, positively correlated with savory and overall taste, respectively (p<0.05).

• Microbiology and Biotechnology Letters
• /
• v.33 no.1
• /
• pp.16-23
• /
• 2005

In order to develop a new microbial fungicide using endophytic bacteria for the control of anthracnoses occurring on various crops, a total of 260 bacterial strains were isolated from fresh tissues of 5 plant species. After they were cultured in broth medium, their antifungal activities were tested for in vivo antifungal activity against cucumber anthracnose caused by Colletotrichum orbiculare. As the results, liquid cultures of 28 strains showed potent antifungal activities more than $90\%$ against cucumber anthracnose. At 3-fold dilutions of liquid cultures, 18 strains inhibited the development of cucumber anthracnose of more than $70\%$. They were further tested for in vivo antifungal activity against red pepper anthracnose caused by C. coccodes and in vitro antifungal activity against C. acutatum, a fungal agent causing red pepper anthracnose. Among 18 strains, a bacterial strain EB215 isolated from cucumber roots displayed the most potent antifungal activity against Colletotrichum species. It was identified as Burkholderia cepacia based on its physiological and biochemical characteristics, Biolog test and 16S rDNA gene sequence. It also controlled effectively the development of rice blast (Magnaporthe grisea), rice sheath blight (Corticium sasaki), tomato gray mold (Botrytis cinerea), and tomato late blight (Phytophthora infestans). Studies on the characterization of antifungal substances produced by B. cepacia EB215 are in progress.

• Journal of Food Hygiene and Safety
• /
• v.30 no.1
• /
• pp.28-34
• /
• 2015

This study is to investigate microbiological hazards which can be used as fundamental data to adequately control leeks hazards and develop leeks GAP model for those who want to get GAP system. The microbiological investigations on cultivation environments (soil and water), crops (leeks), personal hygiene (workers' hands, clothes and gloves) and working tools (boxes) have been conducted for one year, so the period was classified under non-cultivation, cultivation, and post harvest. Total bacteria was detected from soil (4.0~6.7 log CFU/g), leeks (4.6~5.1 log CFU/g), hands (ND~3.3 log CFU/hand) and gloves ($ND{\sim}5.4\;log\;CFU/cm^2$) while nothing was detected from the other samples. The coliform contamination of leeks (4.8~5.0 log CFU/g) was more high than that of soil (3.9~4.2 log CFU/g). In case of foodborne pathogens, only B. cereus was detected at the level of 0.5~4.6 log CFU/g (or hand, $100cm^2$). Fungi was observed at the level of 2.1~3.8 log CFU/g (or hand, $100cm^2$) excepting water and some working tools. These results demonstrate that the contamination of leeks is comparatively higher than that of soil sample. The reason may be the cross-contamination by biological hazards presenting on soil. Therefore, it is necessary to properly control soil and fertilizer for safety against biological hazards.

• Korean Journal of Food Science and Technology
• /
• v.10 no.2
• /
• pp.215-223
• /
• 1978

In Korea, the annual production of watermelon and cantaloupe melon is around 110,000 to 170,000 Metric Tons, and as the fruit does not keep well, studies were conducted to determine the feasibility of preservation in the form of natural juice or lactic fermented juice. The results obtained in these studies are summarized as follows: (1) The average yield of juice obtained from watermelon was 56.2%, and from cantaloupe melon 65.8%, of the fresh weight. (2) The colloidal components of watermelon juice separated from the juice by sedimentation within 24 hours. Cantaloupe melon juice gave a stable colloidal dispersion. (3) No change in the colour of the juices was detected by sensory evaluation or instrumental methods after they were treated at $100^{\circ}C$ for 5 minutes. (4) The addition of canesugar to give a total solids content of 11/13 Brix gave juices which were preferred by most tasters. (5) Lactic fermentation of natural juices pasteurised at $90^{\circ}C$ for 5 minutes, and inoculated with a pure culture of lactic acid bacteria proceeded without interference from competing microorganisms. (6) Sensory evaluation of lactic fermented juices indicated that 60% of tasters found the juices as acceptable or better than commercial fruit nectars at present on the market. (7) Taste panels showed a preference for natural melon juices over the lactic fermented juices. (8) The peroxidase activity of cantaloupe melon juice was higher than that of watermelon juice, with juice extracted from the core of the fruit showing a higher activity than that from other portions of the tissue. (9) Two types of peroxidase, of differing heat stability were detected in both juices. The more heat stable peroxidase had a decimal reduction time of 40 minutes at $80^{\circ}C$ and a z value of $11^{\circ}C$.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.19 no.2
• /
• pp.115-120
• /
• 1999

This experiment was carried out to investigate the effects of additives on the quality of alfalfa(Medicago sativa L.) silage at the forage experimental field, National Livestock Research Institute, RDA, Suwon in 1996. The experiment was arranged in a randomized block design with three replications. The treatments consisted of different additives(control, formic acid, molasses, inoculant A and inoculant B). Crude protein(CP) and Nitrogen free extract(NFE) content of alfalfa silage with additives were higher compared with those obtained control, but Crude ash(CA) and Crude fiber(CF) content of control(11.5 and 39.6%) were higher than those of additive treated plots. ADF and NDF contents of control silage were the highest as 36.2 and 48.6%, respectively, and increased by 4% compared with those obtained before ensiling. The acidity(pH) of control was the highest(5.45), but the lowest in inoculant A(4.32). Inoculant teratment significantly reduced acidity of silage compared with control. DM content of control silage was the lowest but DM loss of control silage was higher than that of additive treated silage. Ammonia-N content was the highest at formic acid treatment and level of Lactobacillus was decreased at control and formic acid treated silage. Total organic acid and lactic acid content of inoculant A and inoculant B were higher than those of other treated plots. The results of this study indicate that the treatment of LAB(Lactic acid bacteria) could be recommended as producing high quality of alfalfa silage.