• Microbiology and Biotechnology Letters
• /
• v.28 no.6
• /
• pp.341-348
• /
• 2000

Selection of high producer strain, optimization of production medium and cultivation in bioreactor system were carried out in order to produce an antifungal substance, PAFS in large amounts which sources and 41 kinds of nitrogen sources, a synthetic medium consisting of fructose(70 g/1) and ammonium sulfate (10g/l) and a complex medium including galactose(30g/l), fructose(20g/l) and cottonseed flour(35g/l) were determined as opti-mized media for PAFS production. In bioreactor studies examining physiological characteristics of the pro- ducer microorganism with the complex medium, typical pattern of diauxic growth was observed as demonstrated by the result that fructose was not used before almost exhaustion on readily utilizable carbon source, galactose. When galactose was supplemented additionally during the fermentation period. PAFS pro-ductivity did no increases any more, indicating that large portion of the added galactose was used for cell growth instead of biosynthesis of the secondary metabolite. It was deduced that PAFS production could be enhananced by employing fed-batch operation in order to overcome the apparent phenomenon of catabolite repression and /or inhibition.

• Korean Journal of Environmental Biology
• /
• v.36 no.4
• /
• pp.680-686
• /
• 2018

Nitrogen fertilizers, hairy vetch, and slow-release complex fertilizers were applied to the soil during the cultivation of crops. The impact of these factors on $N_2O$ emission was quantitatively assessed and the GHGs reduction effect comprehensively evaluated. Among the three factors, the significant factors affecting $N_2O$ emission were mineral nitrogen>soil moisture>temperature. Yield and fertilizer utilization efficiency were highest in the slow-release complex fertilizer treatment. There was no significant difference in $N_2O$ emissions between the slow-release complex fertilizer treatments and the NPK+hairy vetch treatments. Comprehensive results showed that slow-release complex fertilizers treatment has high yield and fertilizer utilization efficiency but low $N_2O$ emission.

• Journal of Environmental Health Sciences
• /
• v.25 no.3
• /
• pp.7-12
• /
• 1999

Bioremediation is the technology to harness nature's biodegradative capabilities to remove or detoxify pollutions that threaten public health as environmental contaminants. Composting may become one of major bioremediation technologies for treating soils contaminated with petroleum if the fate of contaminants during composting is better understood Most composting research of petroleum was primarily focused on removing contaminant by optimizing composting conditions. Accordingly, laboratory feasibility studies may be useful to establish a realistic basis in co-composting complex substrate such as petroleum hydrocarbons. The purpose of this study was to assess the optimal conditions of kerosene biodegradation following supplementation with nutrient amendments under simulated composting conditions. Although it increased the growth of bacterial consortium, addition of co-substrates 0.5%(w/v) such as acetic acid, citric acid, glucose, and malic acid was not beneficial. Combination of nitrogen and phosphorous source enhanced kerosene biodegradation and reduced VOC evolution. These results showed that kerosene was able to utilize in bioremediation technology.

• Transactions of the Korean hydrogen and new energy society
• /
• v.22 no.4
• /
• pp.451-457
• /
• 2011

Purple non-sulfur (PNS) bacterium $Rhodobacter$ $sphaeroides$ KD131 was studied with the aim of achieving maximum hydrogen production using various carbon and nitrogen sources at different pH conditions. Cells grew well and produced hydrogen using $(NH_4){_2}SO_4$ or glutamate as a nitrogen source in combination with a carbon substrate, succinate or malate. During 48h of photo-heterotrophic fermentation under 110$W/m^2$ illumination using a halogen lamp at $30^{\circ}C$, 67% of 30mM succinate added was degraded and the hydrogen yield was estimated as 3.29mol $H^2$/mol-succinate. However, less than 30% of formate was consumed and hydrogen was not produced due to a lack of genes coding for the formate-hydrogen lyase complex of strain KD131. Initial cell concentrations of more than 0.6g dry cell weight/L-culture broth were not favorable for hydrogen evolution by cell aggregation, thus leading to substrate and light unavailability. In a modified Sistrom's medium containing 30mM succinate with a carbon to nitrogen ratio of 12.85 (w/w), glutamate produced 1.40-fold more hydrogen compared to ammonium sulfate during the first 48h. However, ammonium sulfate was 1.78-fold more effective for extended cultivation of 96h. An initial pH range from 6.0 to 9.0 influenced cell growth and hydrogen production, and maintenance of pH 7.5 during photofermentation led to the increased hydrogen yield.

• Journal of Mushroom
• /
• v.13 no.3
• /
• pp.207-211
• /
• 2015

To investigate the usefulness of Kenaf(Hibiscus cannabinus L.) as mushroom culture media source, we analyze physical condition and contents of nutritional components. The water absorption rate of Kenaf bast was 578% and it was 95% higher than that of poplar sawdust's. This was caused by Kenaf's porous cellular structure. so it could give more moisture and oxygen to cultured mushroom. Total carbon contents of Kenaf was 91.4%, it was quite higher than that of poplar sawdust, wheat bran and rice bran. Total nitrogen content was 1.76% and C/N ratio was 51.9. The content of NFE(Nitrogen free extract) was 46.6% and it was similar with rice bran. Cellulose content was higher than poplar but lignin content was lower. specially hemicellulose and pectin complex which more digestible carbon source to mushroom was 3.7% higher than poplar. Mineral component and amino acid contents were also maintained high compared with poplar. Fe was 4.2 times, P 3.2 times, K 2.2 times more and Ca was higher 16 mg/kg than poplar. The content of amino acid was quite more higher than poplar sawdust but lower than chaff. Consequently Kenaf had a good trait for basic support material in mushroom culture media and also had a good character as nutritional source.

• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.3
• /
• pp.206-213
• /
• 2014

Nutrients such as phosphorus and nitrogen have been widely known as important source of algal appearance in eutrophic water. In order to prevent lake eutrophication, it is required to remove these nutrients not only presented in the lake water, but also released from the sediment. In order to solve this problem this study, the trivalent lanthanum ions and ammonia Nitrogen ($NH_4{^+}-N$) for the adsorption capacity of a zeolite support as it combines the lake water has dissolved in the nutrient removal, as well as deposits in the eluted in the continuously adsorbing the complex to develop and study was to inhibit the growth of algae. In experimental results, lanthanum complexes when the adsorption characteristics were evaluated $PO_4{^{3-}}-P$ and the $NH_4{^+}-N$ removal was confirmed that has an excellent ability, when it applied lake water the time of Chl-a and the turbidity decreased. In this study, these results suggest that the lanthanum complexes produced inhibitory effects on algae in the lake water is determined to excellent. Further, when applied to a complex of lanthanum in lake water to a standard 48 hours Acute Toxicity Method of toxicity were measured, and the results for the toxic effect was not observed.

• Korean Journal of Ecology and Environment
• /
• v.56 no.4
• /
• pp.339-347
• /
• 2023

Dissolved organic matter (DOM) is a key component in the biogeochemical cycling in freshwater ecosystem. However, it has been rarely explored, particularly complex river watershed dominated by natural and anthropogenic sources, such as various effluent facility and livestock. The current research developed a new analytical method for TOC/TN (Total Organic Carbon/Total Nitrogen) stable isotope ratio, and distinguish DOM source using stable isotope value (δ¹³C-DOC) and spectroscopic indices (fluorescence index [FI] and biological index [BIX]). The TOC/TN-IR/MS analytical system was optimized and precision and accuracy were secured using two international standards (IAEA-600 Caffein, IAEA-CH-6 Sucrose). As a result of controlling the instrumental conditions to enable TOC stable isotope analysis even in low-concentration environmental samples (<1 mgC L^-1), the minimum detection limit was improved. The 12 potential DOM source were collected from watershed, which includes top-soils, groundwater, plant group (fallen leaves, riparian plants, suspended algae) and effluent group (pig and cow livestock, agricultural land, urban, industry facility, swine facility and wastewater treatment facilities). As a result of comparing characteristics between 12 sources using spectroscopic indices and δ¹³C-DOC values, it were divided into four groups according to their characteristics as a respective DOM sources. The current study established the TOC/TN stable isotope analyses system for the first time in Korea, and found that spectroscopic indices and δ¹³C-DOC are very useful tool to trace the origin of organic matter in the aquatic environments through library database.

• Microbiology and Biotechnology Letters
• /
• v.13 no.4
• /
• pp.339-344
• /
• 1985

Cephalosporin C(CPC) inhibited the growth of Cephalosporium acremonium M-113, a potent CPC producer derived from C acremonium ATCC 20339. Similar inhibitory effects of CPC were also observed in growth of C. acremonium ATCC 20339 and ATCC 14553. Minimum inhibitory concentrations (MIC) of CPC on the growth of conidia and hyphae of C. acremonium M-113 were 200-500 and 3000-4000$\mu\textrm{g}$/$m\ell$ respectively in synthetic medium. MIC values were increased in complex media. The inhibitory effect of CPC was due to CPC-exerted inhibition of amino acids uptake by the cells. 3'-Group of CPC might be important in its inhibitory action. In audition, CPC itself could be utilized by the cells as a nitrogen source under nitrogen limited condition.

• Journal of Korean Society for Atmospheric Environment
• /
• v.30 no.4
• /
• pp.319-326
• /
• 2014

Exhaust gas emitted as a result of the incomplete combustion of biomass in charcoal kilns includes odor compounds as well as other air pollutants such as particulate matters, sulfur and nitrogen oxides, and carbon monoxide. A number of offensive odor compounds affect quality of life. In this study, odor emissions were investigated from biomass burning in a pilot-scale charcoal kiln and a commercial-scale kiln. Complex odor from emission source reached up to 10,000 dilutions to threshold during the study period. Combustion fume was found to contain reduced sulfur compounds, aldehydes, and volatile organic compounds. Hydrogen sulfide and methyl mercaptan were the major odorants which highly contributed to the offensive odor.

• Archives of Pharmacal Research
• /
• v.19 no.3
• /
• pp.173-177
• /
• 1996

The Pneumococcus, Streptococcus pneumoniae, has an ample polysaccharide (PS) capsule that is highly antigenic and is the main virulence factor of the organism. The capsular PS is the source of PS vaccine. This investigation was undertaken to optimize the culture conditions for the production of capsular PS by type 4 pneumococcus. Among several culture media, brain heart infusion (BHI) and Casitone based medium were found to support luxuriant growth of pneumococcus type 4 at the same level. Therefore in this study, the Casitone based medium was used to study optimization of the culture condition because of BHI broth's high cost and complex nature. The phase of growth which accomodated maximum PS production was exponential phase. Concentrations of glucose greater than 0.8% did not enhance growth or PS production. Substitution of nitrogen sources with other resources or supplementation of various concentrations of metal ion (with the exception of calcium, copper, and magnesium ions) had adverse effects on growth and PS production. On the other hand, low level aeration and supplementation of 3 mg/l concentration of asparagine, phenylalanine, or threonine were beneficial for increased PS production. The synergistic effect of all the favorable conditions observed in pneumococcal growth assays provided a two-fold cumulative increase in capsular PS production.