• Bulletin of the Korean Chemical Society
• /
• v.32 no.7
• /
• pp.2243-2248
• /
• 2011

Carbon-based solid acid catalyst was found to be highly efficient, eco-friendly and recyclable heterogeneous catalyst for the multicomponent reaction of dimedone, aromatic aldehydes, and a nitrogen source (ammonium acetate or aromatic amines) under solvent-free conditions, giving rise to 1,8-dioxodecahydroacridines in high yields. The present methodology offers several advantages, such as a simple procedure with an easy work-up, short reaction times, high yields, and the absence of any volatile and hazardous organic solvents.

• The Korean Journal of Mycology
• /
• v.19 no.1
• /
• pp.47-53
• /
• 1991

Metaboilc parameters were obtained from the measurment of productivities of carbon dioxide on the sawdust medium. The productivites of carbon dioxide obtained during fourteen days' incubation were employed for the fungal biomass, representing the fungal growth, and applied for understanding the physioligical parameters on the sawdust medium. The role of rice bran, commonly employed in the conventional spawn medium was speculated to be three kinds of nutrients of starch, nitrogen source, and and minerals. Biologically, the role of rice bran was considered to be the fast growing agents which led to prevention of other microorganisms.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.402-402
• /
• 2012

Bundles of single-walled carbon nanotube (SWCNTs) were grown using catalytic layer supported by self-assembled monolayers (SAMs). Amine-SAMs were introduced on SiO2/Si substrate (SAMs/Si) there then iron nanoclusters solution was dropped on it through spin-coating (Fe/SAMs/Si). This catalytic template was used to grow CNTs and the synthesized carbon material was confirmed the bundles of dense SWCNTs with incorporation of ca.1% nitrogen. The SAMs has played an active role to support catalytic layer and also acted as a source of N-dope onto SWCNTs in CVD.

• Microbiology and Biotechnology Letters
• /
• v.10 no.2
• /
• pp.109-115
• /
• 1982

A Corynebacterium sp. capable of utilizing diaminododecane (DAD) were isolated from the soil by enrichment culture. Among 9 different kinds of substituted alkanes containing CN, NH$_2$, Cl, and SH groups (monoteminally or diterminally substituted) tested as carbon source, the isolate, designated as DAD 2-2. utilized DAD, putrescine dihydrochloride, dodecanethiol, dodecane and lautylamine. Thioanisole, decanedithiol, dicyanooctane, laurylcyanide, and dichlorodecane were not utilized. When emulgen 950 was added to the medium, the growth of DAD 2-2 was greatly accelerated. Isolated DAD 2-2 grown in the medium with DAD as carbon source formed ethyl $\alpha$-ketoglutarate. Metabolic product of DAD 2-2 grown in a medium without nitrogen source was different from that of grown in a medium with NH$_4$NO$_3$. When glucose, putrescine, n-dodecane and other alkane derivatives were tested in place of DAD, isolate DAD 2-2 yielded products different from those they formed with DAD suggesting specificity of DAD as a carbon source.

• 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.

• The Korean Journal of Food And Nutrition
• /
• v.13 no.2
• /
• pp.171-175
• /
• 2000

Microbial proteases have certain unique characteristics, and are now widely used in food, leather, detergent, and pharmaceutical industries. Thermophilic Actinomyces producing the protease was isolated from soil in Wonju city. This strain was able to grow and produce protease at the culture temperature of 50$^{\circ}C$. The maximum protease production was obtained when 0.5% soluble starch and 0.4% yeast extract were used as carbon and nitrogen source, respectively. The other culture condition for the maximal productivity of the protease was 0.1% K2HPO4, and 0.05% CaCl2 at initial pH 8.0 for 48 hours.

• Journal of Mushroom
• /
• v.21 no.1
• /
• pp.15-21
• /
• 2023

Volvariella bombycinais an edible mushroom commercially cultivated in Korea and other countries. In this study, the culture characteristics and optimal growth conditions of milky mushroom strains were determined. The growth temperature and pH range of V. bombycinawas extensively investigated between 15 and 35℃ and pH 3-11. For efficient cultivation, 20 types of nutrient sources were selected, specifically, 21 carbon sources, 6 organic nitrogen sources, 7 inorganic nitrogen sources, 13 amino acids, 9 organic acids, and 13 inorganic salts. The impact of each of the selected nutrition sources and their concentration on growth was investigated. The optimum temperature and pH were determined to be 30℃ and pH 8.0, respectively. The optimum concentration of medium elements required for mycelial growth of V. bombycinawas determined to be as follows: carbon source, 0.7% Soluble starch; organic nitrogen source, 0.7% Soytone; inorganic nitrogen source, 1.0% (NH₄)₂C₄H₄O₆; amino acid, 0.1% cysteine; organic acid, 0.07% lactic acid; and inorganic salt, 0.07 mM CaCl₂.

• Korean Journal of Medicinal Crop Science
• /
• v.7 no.1
• /
• pp.1-6
• /
• 1999

Basic informations for direct somatic embryo formation in Rehmannja glutinosa Lib. were obtained in 500ml erlenmyer flask. The ratio of ammonium to nitrate nitrogen of 825(mg/l) : 1900(mg/l) was proper condition for somatic embryo formation from stem and petiole explants and 3% sucrose was the most effective carbon source. Full strength MS medium with 2mg/l BA was better than LS medium for somatic embryogenesis. The initial pH 5.7 of medium(full strength MS with 2.0mg/l BA and 0.1mg/l NAA) was good for embryo production. Potassium ion was taken up rapidly within 2 weeks. while $Ca^{++}$ and $Mg^{++}$ ion contents were almost constant during culture period. Sucrose hydrolysis occurred throughout the culture, while glucose and fructose were absorbed simultaneously from the third week of culture.

• Korean Journal of Microbiology
• /
• v.21 no.4
• /
• pp.191-196
• /
• 1983

A Corynebacterium sp. capable of utilizing diaminododecane (DAD) were isolated from the soil by enrichment culture. Among 9 different kinds of substituted alkanes containing CN, $NH_2$, Cl, and SH groups (monoterminally or diterminally substituted) tested as carbon source, the isolate, designated as DAD 2-3, utilized DAD, putrescine dihydrochloride, dodecane and laurylamine. Dodecanethiol, thioanisole, decanedithiol, dicyanooctane, laurylcyanide,and dichlorodecane were not utilized. When emulgen 950 was added to the medium, the growth of DAD 2-3 was slightly accelerated. Isolate DAD 2-3 grown in the medium with DAD as carbon source formed .alpha.-ketoglutaric acid. Metabolic product of DAD 2-3 grown in a medium without nitrogen source was different from that of grown in a medium with $NH_4NO_3$. When glucose, putrescine, n-dodecane and other alkane derivatives were tested in place of DAD, isolate DAD 2-3 yielded products different from those they formed with DAD suggesting specificity of DAD as a carbon source.

• Journal of Korean Society on Water Environment
• /
• v.36 no.6
• /
• pp.581-591
• /
• 2020

In this study, two types of reactors were operated to examine the properties of methanol uptake under the high-rate denitrification process. In a sequencing batch reactor, the denitrifying activity was enriched up to 0.80 g-N/g-VSS-day for 72 days. Then, the enriched denitrifying sludge was transferred to a completely stirred tank reactor (CSTR). At the final phase on Day 46-50, the nitrogen removal efficiency was around 100% and the total nitrogen removal rate reached 0.097±0.003 kg-N/㎥-day. During the continuous process, the sludge settling index (SVI30) was stabilized as 118.3 mL/g with the biomass concentration of 1,607 mg/L. The continuous denitrifying process was accelerated by using a sequencing batch reactor (SBR) with a total nitrogen removal rate of 0.403±0.029 kg-N/㎥-day with a high biomass concentration of 8,433 mg-VSS/L. Because the reactor was open to ambient air with the dissolved oxygen range of 0.2-0.5 mg-O2/L, an increased organic carbon requirement of 5.58±0.70 COD/NO3--N was shown for the SBR in comparison to the value of 4.13±0.94 for the test of the same biomass in a completely anaerobic batch reactor. The molecular analysis based on the 16S rRNA gene showed that Methyloversatilis discipulorum and Hyphomicrobium zavarzinii were the responsible denitrifiers with the sole organic carbon source of methanol.