• Food Science and Preservation
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• v.15 no.1
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• pp.99-104
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• 2008

To utilize non-heat treated alcoholic by-products of brown rice (Goami) as food sources, the quality characteristics changes according to the treatment conditions of cellulase were evaluated. Results showed that the increase of hydrolysis temperature correspondingly increased the soluble solids and total sugar amounts in the by-products of Goami, and total dietary fiber amount was found to be around 0.67% Reducing sugar concentration was the highest at the hydrolysis temperature of $70^{\circ}C$. Maltooligosaccharides amounts were detected to be the highest at the hydrolysis temperature of $80^{\circ}C$ and were also, maltopentose and maltopentose were found. In the soluble solid, total dietary fiber, reducing sugar and total sugar according to the cellulase concentration, the content of hydrolysates with enzyme were higher than control, and the content of hydrolysates with enzyme was similar (6.30 and 0.69% 3,600 and 5,500 mg% respectively). The content of maltooligosaccharides was increased with the increase of enzyme concentration, and the content was similar at more than 0.6%(w/w) of enzyme concentration. The soluble solids and total dietary fiber by hydrolysis time were found to be 6.25% and 0.70%, respectively at more than 60 min. of hydrolysis. The content of reducing sugar, total sugar and maltooligosaccharides were increased with the increase of hydrolysis time, and the content was similar at more than 120min. of hydrolysis (3,800, 5,680 and 1,950 mg% respectively). Based upon these results, the byproducts of Goami are expected to be valuable as various food sources showing the highest dietary fiber and maltooligosaccharides contents by the hydrolysis at $80^{\circ}C$ for 120 min. with the addition of 0.6%(w/w) of cellulase.

• Journal of the Korean Society of Clothing and Textiles
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• v.32 no.6
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• pp.882-889
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• 2008

Three fabrics, 100% silk, nylon and cotton each, were dyed with a lichen dye solution prepared by a fermentation method under conditions of varying dyebath pH and temperature. To verify the effect of chitosan on fabric dyeing, the 100% cotton fabric was treated with a chitosan solution before dyeing. The K/S, CIE $L^*$, $a^*$, $b^*$, ${\Delta}E$ and Munsell values of the dyed samples were measured. Colorfastness of each sample was also investigated. The maximum K/S value was measured at 520nm wavelength for the dyed silk fabric and at 480nm for the dyed cotton and nylon. The K/S values for the dyed silk fabric were much greater than those of the other fabrics. The dyed silk fabric showed a red tone on the Munsell color system, and the dyed nylon and cotton fabrics a yellowish red tone. Dye affinity to fabrics was better in a neutral or acidic dyebath. As dyeing temperature increased, K/S values increased for the dyed nylon and cotton fabrics but not for the silk. Dyeability of cotton fabrics could improve by Chitosan treatment. As for most natural dyes, colorfastness of all dyed samples was poor. The silk fabric showed an excellent dry cleaning fastness of Grade 5.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.3
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• pp.214-222
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• 2012

Several acidogenesis batch tests, and BMP (Biochemical Methane Potential) with food waste leachate was tested at various organic loading rates (OLRs) on the mesophilic ($35^{\circ}C$) and thermophilic ($55^{\circ}C$) conditions. In acidogenesis batch test, VS removal efficiencies were 27.3% and 30.6% at $35^{\circ}C$ and $55^{\circ}C$, respectively. Removal efficiency of VS at $55^{\circ}C$ was higher than that at $35^{\circ}C$. With decrease in VS, SCOD increased as reaction time increased. Solubilization efficiency of VS were 27.4% and 33.4% at each reaction temperature within 4 days acid fermentation. Methane yield were 461 and 413 $mLCH_4/gVS$ at mesophilic and thermophilic BMP test, respectively. SCOD solubilizations in the themophilic acid fermenter showed 8~17% higher than those in the mesophilic fermenter. COD removal efficiency showed higher in the mesophilic acid fermenter at low organic loading rate. While at high organic loading rate, it was higher in the thermophilic acid fermenter. VS removal efficiency was higher at the mesophilic temperature, however, it decreased at OLR higher than 6 kg $COD/m^3{\cdot}day$. On the contrary, VS removal efficiency did not decrease but maintain at thermophilic temperature. The amount of methane gas generated from mesophilic methanogenesis digester was 12.6, 21.6, 27.4 L/day at OLR of 4, 5, 6 $COD/m^3{\cdot}day$, respectively. The amount of methane gas generated from themophilic methanogenesis digester was 14.3, 20.6, 25.2 L/day at each OLR, respectively, which is about 15~20 L/day lower than those generated at mesophilic digester.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.186-191
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• 2006

In the present study, an attempt has been made to produce hybrid yeast strains of different useful and dominant characteristics. The hybrid yeast strains were produced by electrofusion and their genetic analysis were performed by RAPD-PCR (random amplified polymorphic DNA-polymerase chain reaction). The protoplast of Saccharomyces cerevisiae KCTC 7904 and Zygosaccharomyces rouxii KCTC 7966 were obtained above 92% when treated with lyticase at $30^{\circ}C$ for $60{\sim}90$ min after the pretreatment of $1{\sim}2%$ 2-mercaptoethanol at $30^{\circ}C$ for $15{\sim}20$ min. The fusant was produced from paired protoplast stage under the electric pulse at high frequency conditions (1.5 MHz/50 pV, 615 $V/256\;{\mu}sec$) within glass-platinum made electrofusion chamber. Changes in RAPD patterns in mother cells and hybrid cells proved that the fusant contains two types of yeast gene originated from its parent. Furthermore, fermentation characters exhibits by the fusant cell confirmed its genetic changes. These results suggest that genetically stable hybrid yeast strains of economic importance can be produced by electrofusion technique and these electrofused yeast cells have an enormous impact in biotechnology and biomedicine.

• Journal of the Mineralogical Society of Korea
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• v.20 no.4
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• pp.357-366
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• 2007

Microorganisms participate in a variety of geochemical processes such as weathering and formation of minerals, leaching of precious metals from minerals, and cycling of organic matter The objective of this study was to investigate biogeochemical processes of iron leaching from magnetite ore by iron-reducing bacteria isolated from intertidal flat sediments, southwestern part of Korea. Microbial iron leaching experiments were performed using magnetite ore, Shinyemi magnetite ore, in well-defined media with and without bacteria at room temperature for a month. Water soluble Fe and Mn during the leaching experiments were determined by ICP analysis of bioleached samples, and the resulting precipitated solids were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The extent of iron leaching from magnetite in the aerobic conditions (Fe = 15 mg/L and Mn = 3.41 mg/L) was lower than that in the anaerobic environments (Fe = 32.8 mg/L and Mn = 5.23 mg/L). The medium pH typically decreased from 8.3 to 7.2 during a month incubation. The Eh of the initial medium decreased from +144.9 mV to -331.7 mV in aerobic environments and from -2.3 mV to -494.6 mV in anaerobic environments upon incubation with the metal reducing microorganisms. The decrease in pH is due to glucose fermentation producing organic acids and $CO_2$. The ability of bacteria to leach soluble iron from crystalline magnetite could have significant implications for biogeochemical processes in sediments where Fe(III) in magnetite represents the largest pool of electron acceptor as well as to use as a novel biotechnology for leaching precious and heavy metals from raw materials.

• Food Science of Animal Resources
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• v.30 no.3
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• pp.435-442
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• 2010

The study analyzed the effects of salt concentration [high salt (HS) and low salt (LS)] and sodium nitrite ($NaNO_2$), which are typically utilized in Korean processing facilities, on fatty acid composition, free amino acids, microbial counts and sensory characteristics of processed dry-cured ham. Four different treatments were considered: three hams (11.30 kg) salted with 92 g/kg salt (w/w) (HS), three hams (10.65 kg) treated with HS and 100 ppm $NaNO_2$ (HS+$NaNO_2$), three hams (11.42 kg) salted with 62 g/kg salt (w/w) (LS), and three hams (10.62 kg) treated with LS and 100 ppm $NaNO_2$ (LS+$NaNO_2$). Fatty acid composition analysis revealed significantly (p<0.05) higher saturated fatty acid and lower (p<0.05) unsaturated fatty acid in the HS+$NaNO_2$ group compared with the other groups. Glutamate, alanine and lysine free amino acids were higher than the other free amino acids. The processing conditions did not significantly affect the free amino acids of biceps femoris muscles, except for the proline content (p>0.05). In sensory evaluation, the fermentation aroma of the LS group was higher than that of the HS group. The aerobic counts consistently ranged from from $2.3{\times}10^2$ to $1.11{\times}10^4$ CFU/g. Escherichia coli including strain O157:H7, Staphylococcus aureus, and Salmonella spp. were not detected.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.926-934
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• 2006

The base for preparing oyster hydrolysate-added yogurt was consisted of whole milk (1,000 mL), skim milk (44.05 to 42.05 g), enzymatic oyster hydrolysates powder (OHP, 0 to 2.0 g) and pectin. The yogurt base was fermented with 7 kinds of starter cultures (3% based on yogurt volume), such as Lactobacillus acidophilus, lactobacillus bulgaricus, lactobacillus casei, Lactobacillus fermentum, Lactobacillus pentosus, Streptcoccus thermophilus and the mixed starters (L. bulgaricus and S. thermophilus) at optimal temperature. Processing condition and quality characteristics of the yogurt were evaluated by analyzing pH, titratable acidity, viscosity, viable cell count, functional properties and sensory evaluation. The results suggested that the optimal conditions for preparing the good quality yogurt revealed the mixed starters (L. bulgaricus and S. thermophilus) for starter culture, 1.0 g of 3 kDa hydrolysate for amount, and 5.5 hrs for fermentation time. The good quality yogurt showed 4.31 for pH, 1.07% for titratable acidity, 469 cps for viscosity and $4.9{\times}10^8\;CFU/mL$ for viable cell count. The hydrolysate-added yogurt was 2 times higher in ACE inhibitory and antioxidant activities than commercial yogurt, and kept good quality during storage of 15 days at $5^{\circ}C$.

• Food Science and Preservation
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• v.19 no.6
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• pp.858-865
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• 2012

In this research, the soaking and steaming conditions of Korean wheat meju according to the degree of milling were investigated, and the quality characteristic was analyzed, for the manufacture of the standardized Korean wheat meju. As a result of the changes in weight, volume, moisture content, and moisture absorption amount, which indicate the physical properties of Korean wheat meju using 20% polished wheat, 50% polished wheat, whole wheat, and whole wheat flour, most of the wheat materials reached the equilibrium state after 4 hours of soaking. Also, the appropriate steaming time to complete the cooking of the wheat materials was found to be 10 min at $100^{\circ}C$, except for whole wheat. The 20 and 50% polished wheat materials were selected for Korean wheat meju based on the soaking and steaming results. The selected wheat materials were fermented using Aspergillus oryzae and Bacillus subtilis M1, respectively, and the quality properties and enzyme activities showed that A. oryzae would be effective for the manufacture of Korean wheat meju. Also, the 50% polished wheat showed higher total sugar content, reducing sugar content, and ${\alpha}$-amylase activity than the 20% polished wheat. Therefore, it is supposed that the fermentation of 50% polished wheat by A. oryzae would be appropriate for manufacturing superior Korean wheat meju.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.4
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• pp.325-335
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• 1985

Biogas production from agricultural wastes were summarized as follows: 1. Biogas Generation Characteristics of Various Manures and Residues a. Gas yield from crop residues like rice straw, rice hull, corn stalk and coconut husk can be improved by addition of animal manures. b. Gas yield from coconut husk can be improved through aerobic fermentation for at least one week before loading in the digester. c. Gas yield from fresh rice straw is better than from pre-fermented one, whether alone or in combination with animal manures. d. Initial study has shown that fresh azolla can be substituted for animal manures in manurerice straw combinations and gas yield derived based on unit volatile solids loaded is actually better than for manure-residue combinations. e. Gas production is highly sensitive to substrate pH and becomes almost nil at a pH of below 6. 2. Effect of ambient conditions and other factors on biogas production in a house hold-size digester. a. Results showed that compaction of rice straw in straw-manure combination can reduce gas yield compared with loosely mixed straw. b. The effective gas production period extended to 70 days using freshly threshed rice straw and fresh cattle manure as feed material. c. Underground and above ground digesters with shade have relatively more stable substrate temperature than aboveground exposed digesters. This relative temperature instability may likely be the reason for lower gas yield for the exposed aboveground digester loaded with loose straw-cattle manure substrate, compared with the underground digester with the same substrate. 3. Economic Analysis a. Based on prevailing costs of fuel, materials, and labor in the Philippines, biogas produced from the household size system is cheaper than either LPG or kerosene. b. If other benefits like organic fertilizer, pollution control and convenience are considered, biogas will surely be the best alternative fuel source.

• Journal of Life Science
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• v.29 no.1
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• pp.76-83
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• 2019

In this study, the optimal growth and poly(3-hydroxybutyrate) (PHB) biosynthesis of Pseudomonas sp. EML2 were established using waste frying oil (WFO) as a cheap carbon source. The fatty acid composition of WFO and fresh frying oil (FFO) were analyzed by gas chromatography. The unsaturated and saturated fatty acid contents of the FFO were 82.6% and 14.9%, respectively. These contents changed in the WFO. The compositional change in the unsaturated fatty acid content in the WFO was due to a change in its chemical and physical properties resulting from heating, an oxidation reaction, and hydrolysis. The maximum dry cell weight (DCW) and PHB yield (g/l) of the isolated strain Pseudomonas sp. EML2 were confirmed under the following culture conditions: 30 g/l of WFO, 0.5 gl of $NH_4Cl$, pH 7, and $20^{\circ}C$. Based on this, the growth and PHB yield of Pseudomonas sp. EML2 were confirmed by 3 l jar fermentation. After the cells were cultured in 30 g/l of WFO for 96 h, the DCW, PHB content, and PHB yield of Pseudomonas sp. EML2 were 3.6 g/l, 73 wt%, and 2.6 g/l, respectively. Similar results were obtained using 30 g/l of FFO as a carbon source control. Using the FFO, the DCW, PHB content, and PHB yield were 3.4 g/l, 70 wt%, and 2.4 g/l, respectively. Pseudomonas sp. EML2 and WFO may be a new candidate and substrate, respectively, for industrial production of PHB.