• Journal of Microbiology and Biotechnology
• /
• v.11 no.3
• /
• pp.428-434
• /
• 2001

A viscous substance producer strain BS62, which was isolated from conventional Chungkookjang, was examined for its productivity of levansucrase and levan during soybean fermentation at $37{\circ}C$. After one day of cultivation, the enzyme activity reached the highest level, 8 units $ml^{-1}$. Extracts of fermented soybeans were precipitated by ethanol and hydrolyzed by either 0.1 N HCl or invertase, and the hydrolyzates were analyzed using thin layer and ion chromatographies. Fructose was the only sugar detected. This suggest that fructose was derived from the levan produced by the strain BS62 during soybean fermentation. The aerobic, endospore-forming bacterium BS62 was identified as a Bacillus subtilis sp., based on the composition of its cellular fatty acids and phylogeny, which was determined by its 16S rDNA sequence.

• Journal of Life Science
• /
• v.23 no.1
• /
• pp.102-109
• /
• 2013

To isolate GABA-producing microorganisms, 1,500 strains were isolated from different Chungkookjang samples and screened. From these strains, 20 were selected for further analyses based on a protease and slime-producing activity test. The MC 31 strain showed the highest GABA concentration in Chungkookjang and was used in this study. MC 31 was identified as Bacillus subtilis by an API 50CHB kit and 16S rDNA sequences analysis and named as B. subtilis MC 31. B. subtilis MC 31 showed exponential growth up to 12 hours at $37^{\circ}C$ in LB broth, and it reached a stationary phase after 24 to 36 hours of incubation. B. subtilis MC 31 showed maximum GABA content at 72 hours after incubation at $40^{\circ}C$.

• Korean Journal of Food Science and Technology
• /
• v.38 no.4
• /
• pp.548-553
• /
• 2006

The aim of this study was to produce Chungkookjang-a food produced through fermentation with Bacillus licheniformis E1-that contains an increased concentration of a bacterial biological response modifier (B-BRM). Unfortunately, sensory studies have indicated that B. licheniformis E1-fermented Chungkookjang is unacceptable for commercial use. We isolated another bacterial strain from this food product: B. subtilis S2. The optimum time and temperature for Chungkookjang fermentation with B. licheniformis E1 and B. subtilis S2 were 48 hr and $40^{\circ}C$, respectively. Sensory studies showed that Chungkookjang fermented by both B. licheniformis E1 and B. subtilis S2 was more acceptable than B. licheniformis E1 only. The amino nitrogen and crude protein content of the product were 359 mg% and 45.6% respectively. Additionally, it was confirmed that the proliferation of mouse splenic lymphocytes increased significantly, when the cells were treated with the BRM from Chungkookjang fermented using the mixture of bacterial strains in vitro. These results suggest that the enriched Chungkookjang may help patients who are medically in need of potentiation of lymphocytes proliferation.

• Microbiology and Biotechnology Letters
• /
• v.18 no.4
• /
• pp.423-428
• /
• 1990

Three strains among 8 isolates from the fermented chungkookjang were shown the strong phytase productivities. The phytase activities in manufacturing chungkookjang with thrse bacteria were maximized after incubating at 35-$40^{\circ}C$, pH 7.0 for 5 day. The contents of same amino acids and riboflavin were increased in chungkookjang manufactured with these phytase-producing bacteria and the rate of phytic acid degradation was much higher in chungkookjang manufactured with a single or mixed cultures of these bacteria than in traditional chungkookjang.

• Microbiology and Biotechnology Letters
• /
• v.26 no.3
• /
• pp.226-231
• /
• 1998

The medium optimization was investigated to maximize the production of fibrinolytic enzyme by Bacillus subtilis KCK-7 isolated from Chungkookjang, which could hydrolyze the fibrin produced through the blood coagulation mechanism in human body. The simultaneous addition of 5% soluble starch and 0.5% cellobiose to the medium as carbon sources resulted in the highest production of the fibrinolytic enzyme. Likewise, the optimized composition of medium appeared to be 0.5% peptone, 0.3% beef extract, 0.5% cellobiose, 5% soluble starch, 2% raw soybean meal and 0.02% Na$_2$HPO$_4$. In addition, the fibrinolytic enzyme production by Bacillus subtilis KCK-7 reached to the maximum level after the cultivation for 48 hr, using the optimized medium.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.31 no.2
• /
• pp.204-210
• /
• 2002

The quality characteristics and sensory evaluation of chungkookjang were investigated. The samples were prepared and fermented by the inoculation of Bacillus strains; B. subtilis, B. natto and B. licheniformis as a single starter, and mixed culture of B. natto and B. licheniformis on the industrialized model system. It was shown that microbial growth, protease activity, contents of amino-and ammonia-nitrogen and contents of organic acid were higher in B. subtilis inoculated sample, and were lower in B. licheniformis inoculated one. General quality characteristics of sample inoculated by mixed culture of B. natto and B. licheniformis took a middle position between each B. natto and B. licheniformis inoculated one. Fifty eight species of odor components were identified. Ethanol, 3-methyl-1-butanol, acetic acid, benzaldehyde and alkyl pyrazines were identified in all samples and most of other flavor components were strain specific. The contents of unpleasant smell components, alkyl pyrazines and benzaldehyde, were lower in B. licheniformis inoculated sample. The sensory evaluations showed that chungkookjang manufactured from mixed culture of B. natto and B.licheniformis was most acceptable. Therefore, results indicated that chungkookjang manufactured from mixed culture of B. natto and B. licheniformis induced better sensory quality than that of the control.

• Applied Biological Chemistry
• /
• v.41 no.2
• /
• pp.119-124
• /
• 1998

In this study, the bacteria which could hydrolyze the fibrin produced through the blood coagulation mechanism in the human body, were isolated from Chungkookjang. The KCK-7 strain was selected among the isolated bacteria as the best strain for fibrinolytic activity. It was spore forming and Gram positive. $C_{150}$ anteiso fatty acid and $C_{150}$ iso fatty acid were 40.85% and 19.47%, respectively as major component among its cellular fatty acid composition. It showed the similarity of 63.6%, compared with standard strain. It was thus identified to be Bacillus subtilis according to Bergey's manual of systematic bacteriology and its fatty acid profiles af Gas chromatography. The optimum culture temperature and pH were $37^{\circ}C$ and 8 for the production of fibrinolytic enzyme by Bacillus subtilis KCK-7.

• Journal of Applied Biological Chemistry
• /
• v.54 no.1
• /
• pp.1-6
• /
• 2011

${\gamma}$-PGA(poly-${\gamma}$-glutamic acid) is an unusual anionic polypeptide that is made of D- and L-glutamic acid units connected by amide linkages between ${\alpha}$-amino and ${\gamma}$-carboxylic acid groups. ${\gamma}$-PGA has been isolated from many kinds of organisms. Many Bacillus strains produce ${\gamma}$-PGA as a capsular material of an extracellular viscous material. It is safe for eating as a viscosity element of fermented soybean products such as Chungkookjang and Natto. It is biodegradable, edible and nontoxic toward humans and the environment and its molecular weight varies from ten thousand to several hundred thousand depending on the kinds of strains used. Therefore, potential applications of ${\gamma}$-PGA and its derivatives have been of interest in the past few years in a broad range of industrial fields such as food, cosmetics, medicine, water-treatment, etc. In this study, a bacterium, Bacillus subtilis GS-2 isolated from the Korean traditional seasoning food, Chungkookjang could produce a large amount of ${\gamma}$-PGA with high productivity and had a simple nutrient requirement. Based on carbon utilization pattern and partial 16S rRNA sequence analysis, the GS-2 strain was identified as B. subtilis. The determination of purified ${\gamma}$-PGA was confirmed with thin layer chromatography (TLC), high performance liquid chromatography (HPLC), fourier transform infrared (FT-IR) spectra, and $^1H$-nuclear magnetic resonance ($^1H$-NMR) spectroscopy.

• Food preservation and processing industry
• /
• v.6 no.1
• /
• pp.8-15
• /
• 2007

• Food Science and Preservation
• /
• v.17 no.3
• /
• pp.410-417
• /
• 2010

Several extracellular protease-producing bacteria were isolated from Chungkookjang, a traditional Korean food of fermented soybeans, on skim milk agar plates. Among these bacteria, strain D14 exhibited the highest production (15.2 U/mL) and specific activity (40.0 U/mg protein) of extracellular protease activity as assessed on growth in a protease induction medium composed of 1% (w/v) soluble starch, 1.5% (w/v) skim milk, 0.5% (w/v) yeast extract, and 2% (w/v) NaCl. The bacterium was identified as Bacillus subtilis based on morphological and physiological characteristics and 16S rDNA sequence. A BLAST search of 16S rDNA sequences revealed that the isolate was most closely related to Bacillus subtilis subsp. subtilis strain NCIB 3610. The 16S rDNA sequence homology was 99.9%. Our isolate produced the highest level of protease when grown in a protease induction medium containing 1% (w/v) sorbitol and 0.5% (w/v) yeast extract. Fructose and glucose reduced enzyme production to 12.7% and 35.9%, respectively, of the level seen when the strain was grown in medium containing soluble starch. Soytone also reduced enzyme production to 61.4% of the level noted when the strain was grown in medium containing yeast extract.