• Journal of Applied Biological Chemistry
• /
• v.51 no.6
• /
• pp.307-314
• /
• 2008

To explore the optimal conditions for the removal of $H_{2}S$ gas by biofiltration, various conditions, including inlet $H_{2}S$ concentration, flow rate, moisture, and cell number, were examined. Heterotrophic bacteria were isolated from the compost of the animal excreta. A strain that effectively removed $H_{2}S$ was selected and identified as Rhodococcus rhodochrous B261 by analysis of its 16S rDNA sequence. A cell number of $10^{7}\;cfu/g^{-}compost$ was sufficient to dominate the microbiota, and an effective removal was observed at $H_{2}S$ gas concentrations below 220 mg/L. The moisture content of 33-38% was suitable for activation of the microbial activity and delaying the desiccation. Higher flow rates resulted in lower removal rates of the $H_{2}S$ gas. Under the conditions of $10^7\;cfu/g^{-}compost$, $H_{2}S$ gas concentrations of 220 mg/L, and moisture content of 33-38%, the inlet $H_{2}S$ gas concentrations of 120 and 400 mg/L were completely removed for 34 and 12 days, respectively. The amount of sulfur removed was $2.99{\times}10^{-9}H_{2}S-S/cell$, which was suggested as the amount of sulfur removed by a single cell. The biofilter consisting of the compost and R. rhodochrous B261 could be suitable for a long-term biofilteration for the removal of $H_{2}S$ and other malodorous compounds.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.7 no.1
• /
• pp.67-77
• /
• 1999

The biodegradation of algae coagulated with poly aluminum chloride(PAC) was investigated by using the thermophilic oxic process. The compositions of coagulated algae were 83.5% of water content, 24.6% of ash, 32% of organic carbon with in total solid, respectively. In present study, food waste oil was used for the increment of calorie of mixtures in order to accelate the microbial activity. As a result, the maximum temperature of mixtures was higher than $50^{\circ}C$ when the mixing ratio of food oil was over 10%. However the temperature indicated the lower than $50^{\circ}C$ when conditions of no mixing with waste food oil, and 5% of mixing ratio. Therefore, the optimum condition was 10% of the mixing ration at $217l{\cdot}m^{-3}{\cdot}min^{-1}$ of air supply rate. The conversion efficiency of carbon was highest as 92% at the optimum condition. And then water was evaluated from imxture without accumulation at 10% of mixing ratio. The thermophilic oxic process well conducted that is good process for the treatment of waste algae without effluents however it has to consider the retreatment of accumulated aluminum in the reactor.

• Journal of Applied Biological Chemistry
• /
• v.52 no.4
• /
• pp.163-169
• /
• 2009

A total of 155 microbial strains were isolated from the Korean traditional soybean paste based on their morphological features on the growth of agar plate. Among the isolated strains, a total of 28 strains were capable of hydrolyzing isoflavone glycoside to isoflavone aglycone efficiently in the soybean paste. Finally, two strains, K123-1 and SI, were selected because of their resistance to 15% NaCl and ability to convert isoflavone glycoside to isoflavone aglycone efficiently during the fermentation of soybean paste. The isolated strains K123-1 and SI were identified to be Pichia guilliermondii and Candida fermentati, respectively, using the partial 26S rDNA sequence analysis and phylogenic analysis. Pichia guilliermondii K123-1 and Candida fermentati SI converted daidzin to daidzein up to 96% and 95%, respectively, and genistin to genistein up to 92% when soybean pastes were fermented at $30^{\circ}C$ for 20 days with a single isolated strain. Pichia guilliermondii K123-1 and Candida fermentati SI were able to grow in the presence of 15% NaCl on both liquid medium and agar plate. We think that Pichia guilliermondii K123-1 and Candida fermentati SI might be one of good candidates for making functional soybean paste because they are isolated from the Korean traditional soybean paste and have a good ability to convert isoflavone glycosides to isoflavone aglycones and a high salt tolerance.

• Food Science and Preservation
• /
• v.17 no.2
• /
• pp.301-306
• /
• 2010

We identified microorganisms causing skin disease in slaughtered chickens. Ten microbial strains were isolated from skin wound regions on the back and legs of chickens. Fatty acid composition analysis of the cell membranes of isolated bacteria identified five isolates of Shigella sonnei, Proteus mirabilis (2), and Escherichia coli (2). In addition, 16S rRNA sequencing indicated that S. sonnei (99%), P. mirabilis (99%), and E. coli (99%) were the strains responsible for skin wounds in chickens. Therefore, these three species may be the major pathogenic bacteria causing skin wounds on the back and legs of chickens.

• Journal of Environmental Science International
• /
• v.6 no.1
• /
• pp.61-67
• /
• 1997

Heavy metal adsorption by microbial cells is an alternative to conventional methods of heavy metal removal and recovery from metal-bearing wastewater The waste Sac-chuomyces cerevisiae is an inexpensive, relatively available source of biomass for heavy metal biosorption. Biosorption was investigated by free and immobilized-S. cerevisiae. The order of biosorption capacity was Pb>Cu>Cd with batch system. The biosorption parameters had been determined for Pb with free , cells according to the Freundlich and Langmuir model. It was found that the data fitted reasonably well to the Freundlich model. The selective uptake of immobilized-S. cerevisiae was observed when all the metal ions were dissolved in a mixed metals solution(Pb, Cu, Cr and Cd). The biosorption of mixed metals solution by immobilized-cell was studied in packed bed reactor. The Pb uptake was Investigated in particular, as it represents one of the most widely distributed heavy metals in water. We also tested the desorption of Pb from immobilized-cell by us- ing HCI, $H_2SO_4$ and EDTA.

• 한국생물공학회:학술대회논문집
• /
• 2000.11a
• /
• pp.241-244
• /
• 2000

Continuous $H_2$ production from CO and water was studied in a trickle bed reactor(TBR) using Rhodopspedomonas palustris P4. To achieve high cell density, R. palustris P4 were cultivated by a fed-batch culture mode under chemoheterotrophic and aerobic condition, and final cell concentration was 13 g/L. TBR could provide sufficient residence time for CO to contact with cell suspension circulating TBR. The maximum CO uptake rate was found to be 16 mmol/L/hr at gas retention time of 50 min and CO partial pressure of 0.4 atm. In our correlation of the experimental data with mathematical model of TBR, the TBR operation with P4 was found to be lie in an intermediate state between mass transfer limitation and kinetic limitation. Due to the high cell density as well as hydrogen production activity in this study, TBR operation showed a superior performance to other previous reports on microbial hydrogen production.

• KSBB Journal
• /
• v.26 no.6
• /
• pp.505-512
• /
• 2011

Psolarea corylifolia extract that contains bakuchiol is known to have anti-microbial, anti-inflammatory and anti-scarring effects. In this study, a vesicles such as liposome, niosome, and transfersome were produced to encapsulate P. corylifolia extract and measured their stability and physiochemical property. The skin permeation and partitioning of P. corylifolia extract in the vesicles were elucidated in nude mouse skin by using Franz diffusion cells after topical application for 24 h. After storage at 25, 40, $70^{\circ}C$, and light, the stability of bakuchiol incorporated into the vesicles was maintained for 30 days. The optimal concentration of P. corylifolia extract entrapped into the vesicles was found to be 5~10%. From the physicochemical studies, after storage at 4, 25, and $40^{\circ}C$, the viscosity and particle size of the vesicles remained in 30~80 cP and the nanosize range for 6 months, respectively. From the permeation experiments, niosome showed a higher amount of bakuchiol permeated through the mouse skin compared to liposome and transfersome after 24 h. From these results, niosome and transfersome could be a good bioavailability enhancement system (BAES) for P. corylifolia extract to improve the skin permeation and stability.

• KSBB Journal
• /
• v.13 no.1
• /
• pp.77-82
• /
• 1998

Glutathione(L-$\gamma$ -glutamyl-L-cysteinylglycine, GSH) produced by microbial enzymes was separated by a liquid chromatography. In order to select a resin which would bind GSH efficiently, a batch adsorption experiment was carried out with GSH solution and various resins at pH 8.0 GSH bound to Q-sepharose and QAE-sephadex among anion exchange resins, but the latter was found not to be suitable because of the reduction of resin volume at high salt concentration. Preliminary experiments using a standard solution were carried out to separate GSH. GSH and $\gamma$ -glutamylcysteine were separated from the other constituents by applying step gradient of salt(NaCl) concentration. GSH was successfully separated from $\gamma$ -glutamylcysteine by applying Tris buffer containing 35mM NaCl. Chromatographic separation behaviors for the enzymatic product was similar to that for the standard solution. Separation yields of GSH from the standard solution and enzymatic product solution were 72.6% and 84.4%, respectively.

• KSBB Journal
• /
• v.16 no.6
• /
• pp.527-532
• /
• 2001

Trichlooethylene (TCE) has become a widespread contaminant in air, soil, and underground water due to extensive industrial used and improper disposals. Since TCE is a suspected carcinogen and constitutes public health concerns, many treatment systems have been investigated to remove this hazardous waste. One of the most premising reactor systems for the treatment of TCE is trickling biofilter (TBF), in which monooxygenase (MO), the corresponding enzyme for initiating primary substrate oxidation, fortuitously degrades TCE via cometabolism. TCE, however, is not easily treated by simple TBF. This is mainly due to the toxicities of TCE and its degradation products to microbial film in TBF. In this paper, recent progresses on the development of bioreactor system for the treatment of TCE, especially gas-phase TCE, are reviewed. The potentials of novel biofilm reactor systems were also discussed for the long-term continuous treatment of TCE.

• KSBB Journal
• /
• v.14 no.6
• /
• pp.682-687
• /
• 1999

Virginiae butanolide C(VB-C) is one of the butyrolactone autoregulators, which triggers the production of virginiamycin in Streptomyces virginiae. In order to investigate the function of VB-C as inducer in other strains, Streptomyces erythraeus was used as a test strain(parent). VB-C binding receptor gene was introduced into S. erythraeus(transformant) and the production of VBs and specific VB-C binding protein were analysed in parent and transformant. When 300ng/ml of the synthetic VB-C was added at 0, 20, 44 h cultivation of the parent and at 44 h cultivation of the transformant, the initial production times a antibiotics were shortened by more than 8 and 6 h, respectively. The transformant showed strong antibiotic activity against B. subtilis. These results suggest that the VB-C might have an ability to induce the production of secondary metabolites in S. erythraeus.