• Journal of the Korean Society of Marine Environment & Safety
• /
• v.30 no.1
• /
• pp.20-31
• /
• 2024

This study was conducted to investigate the changes in the structure of benthic communities resulting from aquaculture activities and to assess the benthic health status of surface sediment in Gangjin Bay, a region known for concentrated shellfish aquaculture on the southern coast of Korea. Survey stations were divided into longline culture, bottom culture, and non-cultivation areas. The spatiotemporal distribution of physiochemical factors such as the grain size, water temperature, salinity, and total organic carbon in Gangjin Bay showed no significant differences between sampling stations. However, the species number, density, and diversity were relatively lower at the sampling stations in the bottom culture areas than at the other stations throughout the entire survey period. Cluster analysis and principal coordinates analysis also clearly distinguished the benthic communities in the bottom culture areas from those in the other sampling areas. At the sampling stations in the longline culture and non-cultivation areas, Scolectoma longifolia and Sigambra tentaculata, which are indicator species of organically enriched areas, appeared as dominant species. However, excluding some stations influenced by physical factors such as the water depth and current speed, the occupancy rate was not high. The health assessment results, conducted using the fisheries environment assessment method, revealed good conditions with Grades 1 and 2 across the entire area. However, an examination of the spatiotemporal changes in benthic communities and the benthic health index indicated that the benthic environment in the bottom culture areas was affected by physical disturbances.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.4 no.1
• /
• pp.26-31
• /
• 1999

The advantages of the organism Streptomycs griseus HUT 6037 is that the chitinase and chitosanase using chitinaceouse substrate are capable of hydrolyzing both amorphous and crystalline chitin and chitosan. We attempted to investigate the optimization of induction protocol for high-level production and secretion of chitosanase and the influence of chitin and partially deacetylated chitosan sources (75∼99% deacetylation). The maximum specific activity or chitinase has been found at 5 days cultivation with the 48 hours induction time using colloidal chitin as a carbon source. To investigate characteristic of chitosan activity according to substrate, we used chitosan with various degree of deacetylation as a carbon source and found that this strain accumulates chitosanase in the culture medium using chitosanaceous substrates rather than chitinaceous substrates. The highest chitosanase activity was also presented on 4 days with 99% deacetylated chitosan. The partially 53% deacetylated chitosan can secrete both chitinase and chitosanase which was defined as a soluble chitosan. The specific activities of chitinase and chitosanase were 0.89 at 3 days and 1.33 U/mg protein at 5 days, respectively. It indicate that chitosanase obtained from S. griseus HUT 6037 can hydrolyze GlcNAc-GlcN and GlcN-GlcN linkages by exo-splitting manner. This activity increased with increasing degree of deacetylation of chitosan. It is the first attempted to investigate the effects of chitosanase on various degrees of deacetylations of chitosan by S. griseus HUT 6037. The highest specific activity of chitosanase was obtained with 99% deacetylated chitosan.

• Korean Journal of Soil Science and Fertilizer
• /
• v.45 no.2
• /
• pp.185-191
• /
• 2012

This study was performed to screen fallow crops during winter period for improvement of soil quality and utilizing as mulching material in watermelon cropping system during winter period. Five fallow crops, mainly, hairy vetch, barley, rye, oat and wheat, were sown in early November. They were mowed for covering the soil surface instead of polyethylene (PE) film before watermelon planting in early April the following year. The highest absorbed nutrients and dry matter yield were found in rye. Bulk density in plots with fallow crop was lower than control plot. There was observed no significant differences among the fallow crops. However, porosity was the lowest in control plot. Soil EC reduced to 12%, 13%, 14%, 16% and 22%, respectively, by cultivation of hairy vetch, oat, wheat, barley and rye. Microbial biomass carbon and dehydrogenase activities were higher in soil treated with gramineous crops, such as barley, rye and oat. The growth of watermelon was more affected by regeneration of fallow crop than the occurrence of weed, especially in plots treated with rye or oat. Also, the fruit damage by aphid was found severe in these treatment plots. The fruit yield in plots treated with hairy vetch and barley was increased 5.7% and 2.6%, respectively, compared to that of PE films. The present experiment findings implied that these fallow crops had significant beneficial effects on improvement of soil qualities and could be utilized for mulching materials in watermelon cropping system.

• Journal of the Korean association of regional geographers
• /
• v.18 no.1
• /
• pp.101-117
• /
• 2012

The purpose of this research is to propose a plan on migration policy based on features, through analyzing the migration adaption process and the farming life of the back-to-countryside population throughout the nation. For this, survey has been conducted to find out urban-to-rural migrants' motives and characteristics. The major reason for the migration was the household's financial condition, and the most of migration decisions were made by either one's spouse or parents. The migration fund was primarily spent in early agricultural activities and it was the neighbors who aided them the most whilst teaching them many farming techniques. Some government-supported policies are being highly demanded regarding the lower level of income (than urban life) and difficulties of raising cultivation funds; these two things are what migrants consider as the most inconvenient and suffering matters in farming life. Many surveyee have responded that they would constantly stay in the rural area and continue on their life as a farmer, giving a promising prospect for future farmland life. Based on these trends and features, development strategy regarding elaborate settlement plan of urban-to-rural migration is necessary.

• Biotechnology and Bioprocess Engineering:BBE
• /
• v.10 no.4
• /
• pp.296-303
• /
• 2005

A strain named as HJ35 was isolated from the skin of sixty-five men and fourteen women for acne therapy, in order to find an effective antimicrobial agent against Propionibacterium acnes. Isolate HJ35 was identified as Enterococcus faecium based on 16 rDNA sequence and produced enterocin HJ35 having antimicrobial activities against most lactic acid bacteria, En­terococcus spp., Staphylococcus aureus, S. epidermidis, Clostridium perfringens, some bacilli, Mi­crococcus flavus, Listeria monocytogenes, L. ivanovii, Escherichia coli, Pseudomonas fluorescens and Propionibacterium acnes, in the modified well diffusion method. Especially, enterocin HJ35 showed a bactericidal activity against Propionibacterium acnes P1. The antimicrobial activity of enterocin HJ35 was disappeared completely with the use of protease XIV. But enterocin HJ35 activity is very stable at high temperature (up to $100^{\circ}C$ for 30 min), in wide range of pH (3.0${\~}$9.0), and by treatment with organic solvents. The apparent molecular mass of enterocin HJ35 was estimated to be approximately 4${\~}$4.5 kDa on detection of its bactericidal activity after SDS-PAGE. In batch fermentation of E. faecium HJ35, enterocin HJ35 was produced at the mid­log growth phase, and its maximum production was obtained up to 2,300 AU/mL at the late stationary phase. By employing fed-batch fermentation, the enhanced production of enterocin HJ35 was achieved up to 12,800 AU/mL by feeding with 10 g/L glucose or 6 g/L lactate.

• Korean journal of food and cookery science
• /
• v.9 no.4
• /
• pp.266-271
• /
• 1993

In order to investigate the traditional value of Ewhaju (traditional wine) and to establish the brewing condition, studies on of traditional background and field inquiry were carried out. Scientific evaluation and possibility of revealation of Ewhaju were searched by the experiments of microbial and enzymatic properties of brewed Ewhaju and Nuruk by traditional method. In flora of microorganisms in Nuruk of Ewhaju, Aspergillus oryzae and Hansenula sP. were isolated, and, showed a level of 1.2$\times$$10^6$ CHU/g, respectiveln but other microorganisms were not grown in diluted cultivation test. The a-and f-amylase activity of Nuruk were 30.74 and 34.4, respectively and their activities of two amylases were 19.28 and 18.8 at first stage of brewing, 21.21 and 19.80 at 100 day after brewing, and 20.25 and 19.90 at one year aged Ewhaju, respectively. The brewed Ewhaju could be remained with high quality long period without teat treatment or addition of preservatives, also, stored Ewhaju contains remarka-bly high activity of amylases which might contribute to digestion.

• Journal of Korean Society of Rural Planning
• /
• v.22 no.3
• /
• pp.131-142
• /
• 2016

Urban agriculture, which can be defined as agriculture performed in a city, is suggested as an alternative solution to restore deserted community and expand green land in city area through cultivation activities. In Korea, 'Urban Agriculture Promotion and Support Act' was enforced from May 2012. In addition, in the same year, Seoul Metropolitan Government declared 'the beginning of urban agriculture era,' established municipal ordinance, and increased budget to actively support urban agriculture. As a result, urban agriculture practices have been increasing every year. Yet, the way of developing urban agriculture in a uniform way of expanding green land has led to difficulties of securing proper spaces. Accordingly, 'roof top' spaces have gained attention. This study analyzes rooftop garden, one of the spaces of carrying out urban agriculture, from the publicness perspective. The study selected a case study of a public rooftop garden in Mullae-dong, Yeongdeungpo-gu, investigated present conditions and usage features of the garden, and explored the conditions to be a 'public' roof top garden. Through theoretical analysis, both physical and non-physical indicators were derived for analysis framework; physical aspects- accessibility, locality, openness, comfortness, and non-physical aspects- subjectivity, cooperativeness, and a sense of community. The results of this study are as follows. First, openness and locality scores were the highest, and comfortness scored the lowest, in ensuring the publicness of Mullae roof top garden. Second, non-physical indicators had stronger effect than physical indicators on rooftop garden users' awareness on publicness and building a garden community. In conclusion, in order to vitalize roof top garden, users should be engaged from the very first planning stage of building a garden, opening hours should not be limited, and more importance should be put on users to subjectively manage the operation of rooftop garden than merely creating a physical environment.

• Journal of Korean Society of Rural Planning
• /
• v.20 no.1
• /
• pp.77-89
• /
• 2014

This study intends to establish a system to investigate and analyze various impacting factors to Rural Housings such as the relationship of characteristics of Rural Housings located in a Rural Village to the Village and a Unit Housing, to the External and Internal Spaces inside the Unit Housing and the Village, and to Living Characteristics of the Residents and Space from an integrated point of view. The results of this study are largely summarized as following four kinds. Rural Housing Survey System can be largely classified into three stages, and they are a Preliminary Survey, Basic Survey and In-depth Survey. Along with these, the scope of the survey contents can be divided into a survey result by a unit of village, of land, of housing, and of resident's opinion survey. Secondly, the surveys by village unit are on location properties, Village Identity, Street Network, Land Use, Landscape Features and Public Facilities, and consist of Literature, Discussion and Field Survey. Thirdly, the land Unit Surveys are on a Driveway, Gate Location, Housing Placement, Outer Space Design in a Yard and Outer Space Use Characteristics, and consist of Questionnaire and Field Surveys. For the fourth, the Housing Unit Surveys are on an Internal Space Design and Placement, and consist of Questionnaire and Field Surveys. Finally, the Resident Questionnaire Survey consisted of Entire Discussion Survey and a Household one, and then the Entire Survey was on the Village's History, Village's Characteristics, Cultivation Characteristics and Community Activities while an individual one was on Main Living Characteristics, Satisfaction and Utilization Characteristics.

• Microbiology and Biotechnology Letters
• /
• v.31 no.3
• /
• pp.257-263
• /
• 2003

The cellulases production in solid state fermentation (SSF) of Trichoderma harzianum FJ1 with high cellulases productivity using cellulosic wastes was investigated. Physical and chemical conditions of the fermentation, such as moisture content, initial pH, and composition of mixed substrate (wine waste, rice straw, and soybean flour) on FPase (Filter paper activity) production were examined. The enzyme production was optimized in the conditions of moisture content of 70%, pH 5.0, 3$0^{\circ}C$, and 1:1:1 composition of mixed substrate containing wine waste, rice straw, and soybean flour. The highest activities of FPA, CMCase, Xylanase, $\beta$-glucosidase, and Avicelase in the optimized culture conditions were 15.2, 69.1, 83.9, 29.2, and 4.2 unit/g-SDW in 5 day cultivation, respectively. Economical and efficient production of cellulolytic enzymes by T harzianum FJ1 using cellulosic wastes in solid state fermentation will contribute to the biological saccharification of cellulosic wastes with enormous potential resource value in future.

• Journal of Microbiology and Biotechnology
• /
• v.13 no.3
• /
• pp.415-421
• /
• 2003

A bacterium, Pseudomonas fluorescens 2112, that is antagonistic against a red-pepper blight-causing fungus, Phytophthora capsici, was isolated from the local soil of Gyongju, Korea. This strain formed an orange-colored clear halo zone on chrome azurol S (CAS) blue agar, suggesting the production of a siderophore in addition to an antifungal antibiotic. The optimal culture conditions for siderophore production by P. fluorescens 2112 were 30-h cultivation at $25^{\circ}C$ and pH 6.5 in King's B medium. The presence of $20{\mu}g/ml\;of\;Fe^3+$ ion or EDDHA promoted the production of siderophore in King's B medium. The siderophore was purified from culture broth by CM-Sephadex C-25 and Sephadex G-25 column chromatographies. The UV spectra of the purified siderophore was the same as that of pyoverdins or pseudobactins. The molecular mass was 1,958 Da determined by FAB-rlass spectrometer, and the amino acid composition analysis showed that the purified siderophore consisted of glycine/threonine/serine/glutamic acid/alanine/lysine with the molar ratio of 3:2:1:1:1:1, DL-Threo-${\beta}$-hydroxyaspartic acid and $N^{\delta}$-hydroxyornithine, two of the essential constituents of pyoverdin, were also found. The purified siderophore pyoverdin showed strong in vitro and in vivo antagonistic activities against phytophthora blight-causing P. capsici. Especially in an in vivo pot test, the siderophore protected red-pepper Capsicum annum L. very well from the attack of P. capsici. These results indicated that the purified siderophore of P. fluorescens 2112 played a critical role in the biocontrol of the red-pepper blight disease, equivalent to treatment by P.fluorescens 2112 cells.