• Korean Journal of Environmental Biology
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• v.31 no.4
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• pp.302-307
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• 2013

Microbial fermented cellulose gel, citrus gel (CG), was successfully fabricated to porous foam by radiation treatment and freeze drying. The chemically induced radiation was used to create highly porous foam and further freeze drying of the CG produced tough foams with interconnected open pores for use in tissue engineering. The microstructure of the CG foam was controlled by varying the irradiation dose and quenching temperature with pore size ranging from several microns to a few hundred microns. Tensile strength and Gurley value of the CG foam were influenced by irradiation dose. These radiation induced CG foams are promising scaffolds for tissue engineering.

• Mycobiology
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• v.32 no.4
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• pp.170-172
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• 2004

The efficiency of acid, enzyme and microbial pretreatment of rice bran was compared based on the content of cellulose, hemicellulose, reducing sugars and xylose in the substrate. An isolate of Aspergillus niger or a strain of Trichoderma viride(MTCC 800) was employed for microbial pretreatment of rice bran in solid state. Acid pretreatment resulted in the highest amount of reducing sugars followed by enzyme and microbial pretreatment. A. niger showed a higher rate of hydrolysis than T. viride. The rice bran hydrolysate obtained from the different methods was subsequently fermented to ethanol either by Zymomonas mobilis(NCIM 806) or by Pichia stipitis(NCIM 3497). P. stipitis fermentation resulted in higher ethanol(37% higher) and biomass production($76{\sim}83%$ higher) than those of Z. mobilis. Maximum ethanol production resulted at 12h in Zymomonas fermentation, while in Pichia fermentation, it was observed at 60h. Microbial pretreatment of rice bran by A. niger followed by fermentation employing P. stipitis was more efficient but slower than the other microbial pretreatment and fermentation.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.220-224
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• 2002

Alaska pollock roe is mainly used for the production of salt-seasoned and fermented seafood (Myungran-jeot). Alaska pollock roes with broken egg membrane are usually discarded as a waste product. In this study, the broken roes of Alaska pollock were salt-seasoned and stuffed into cellulose casing for commercial production. The chemical and microbial changes of the broken roes of Alaska pollock stuffed into cellulose casing fermented at 5 and $25^{\circ}C$, respectively, were analyzed at different ripening periods. On 5 week fermentation, pH decreased down to 5.60 and 5.10 at 5 and $25^{\circ}C$, respectively, but the amounts of lactic acid, amino-nitrogen, and volatile basic nitrogen increased continously as ripening period increased, higher at 25 than $5^{\circ}C$. The amounts of amino-nitrogen, 620 and 780 mg/100 g, were the highest on 3 week fermentation at $5^{\circ}C$ and on 1 week at $25^{\circ}C$, respectively. The numbers of total viable cell and lactic acid bacteria, $3.1{\times}10^6$ and $3.1{\times}10^5\;CFU/g$ at $5^{\circ}C$, and $1.9{\times}10^7$ and $2.8{\times}10^6\;CFU/g$ at $25^{\circ}C$, respectively, were the highest on 2 week fermentation.

• Microbiology and Biotechnology Letters
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• v.6 no.1
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• pp.1-8
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• 1978

In order to develop the processes for the production of fermented feed from cellulosic agricultural by-product, cereal straw, by th action of cellulolytic fungus, the properties of the cellulolytic enzyme produced by Trichoderma sp. KI 7-2 was studied. A higher enzyme activity was obtained in the culture added by 1％ rice or barley straw powder than in the culture of pure cellulose. The crude enzyme was prepared by precipitating from 20∼60％ saturated ammonium sulphate of the culture supernatant. The optimum conditions for the enzyme reaction were temperature of of 50$^{\circ}C$ and pH 4.2. The crude enzyme was static at 50$^{\circ}C$ for two hours and at pH between 4 and 6. These properties were adopted for the fermented feed production, and several production. Thus, several processes of semisolid culture were devicced to up grade tile fermented feed and to develop into the acceptable quality.

• The Korean Journal of Mycology
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• v.40 no.4
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• pp.235-243
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• 2012

We studied the effect of fermented Rhus verniciflua stem bark (FRVSB) extract (used in herbal med-icine by Koreans) on the microbial growth and enzyme activity of 12 soybean-fermenting microorganisms, including Bacillus spp., lactic acid bacteria, yeast, and other harmful bacteria. The ethanol and methanol extracts of FRVSB inhibited the growth of Bacillus subtilis, Bacillus licheniformis, Bacillus cereus, and Zygosaccharomyces rouxii, and in the disk diffusion assay, their inhibition zone diameters were 11.06-12.23, 12.32-18.38, 11.47-11.84, and 13.59-14.21 mm, respectively. The water extract did not show any inhibitory effect. In fact, the water extract addition enhanced the growth of B. subtilis and B. licheniformis by 1.3-4.5 fold and that of B. cereus by 1.2-1.4 fold. However, the water extract did not affect the growth of Lactobacillus plantarum, Lactobacillus mesenteroides, Saccharomyces cer-evisiae, and Escherichia coli. The addition of water extract increased the amylase and protease activity of B. subtilis and B. licheniformis.

• Microbiology and Biotechnology Letters
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• v.7 no.2
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• pp.91-95
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• 1979

Ethanol and Xylose were produced from cellulosic agricultural waste such as rice straw and corn cob by a single-step simultaneous hydrolysis-fermentation process utilizing semi-solid culture of Trithoderma as enzyme source and Saccharomyces yeast. By this process all the hexoses prduoced by the enzyme were converted to ethanol leaving pentoses which are not fermented by the yeast. By processing 50 g of rice straw, 18 ml of ethanol and 2.7 g of xylose were produced and 50 g corn cob produced 3.8 ml of ethanol and 10.8 g of xylose. Alkali-treatment of rice straw showed little effects on the productivities of ethanol and xylose. The possible reasons are discussed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.4
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• pp.322-331
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• 2017

This study was conducted to evaluate the changes of pH, dry matter digestibility (DMD), $NH_3-N$ concentrate, gas production and volatile fatty acid (VFA) through in vitro fermentation by adding horse feces to various juice pomaces fermented with Bacillus, yeast and lactic acid bacteria. The pH range of fermented fluid with juice pomaces was 6.4-7.1, indicating that the digestion by microbial fermentation was normal. Juice pomaces adopted will be helpfully used to assist with digestion by microbes in intestines because approximately $10^9CFU/m{\ell}$ microbes were grown after 48 hours in fermented fluid. DMD rate gradually increased from 12 hours. It was 39.19% in pomaces of apple, 38.22% in grape, 37.02% in carrot, 36.2% in citrus and 34.35% in mixture respectively after 48 hours. $NH_3-N$ concentrate was not changed significantly as it was maintained at $1.5mg/100m{\ell}$ level in the entire treatment group from beginning of fermentation until 12 hours, but increased rapidly from 24 hours. Amount of gas produced was lowest in the mixture and increased rapidly after 12 hours. Total VFA increased from 24 hours and was highest at 48 hours. It was suggested that dry matter digestion was processed while fermented juice pomaces kept proper pH during in vitro digestion, and cellulose degrading microorganisms could act actively in the caecum and colon of horses.

• Microbiology and Biotechnology Letters
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• v.9 no.2
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• pp.65-69
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• 1981

As a process to utilize agricultural residues, simultaneous hydrolysis-fermentation (SSF) was compared with fermentation of enzymic hydrolyzate using koji cultures of Trichoderma sp. KI 7-2 and a thermotolerant yeast Saccharomyces cerevisiae NCYC 716. Cellobiose was not detected in SSF broth whilst 15 mg/$m\ell$ of the disaccharide was found in enzymic hydrolysate of rice straw using the same enzyme source. It was found that converting glucose to ethanol in SSF process reactivated the cellobiase activity, which is inhibited by the accumulation of glucose in enzymic hydrolysis process. Cutting milled rice straw was fermented as effectively as ball milled one in SSF process. From tile results discussions are made on the product inhibition mechanism of cllulolytic enzyme system.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.829-835
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• 2004

A fibrinolytic enzyme has been found in several bacteria isolated from fermented food. This study was carried out to investigate the purification and characteristics of the fibrinolytic enzyme produced by Bacillus subtilis KCK-7 originated from Chungkookjang. The fibrinolytic enzyme was purified to homogeneity from the culture supernatant using ammonium sulfate fractionation and chromatographies on DEAE-cellulose and on Sephadex G-100. The final specific activity of the purified enzyme increased 11.0-fold, and the protein amount in the purified enzyme was about 16% of that in the culture supernatant. The molecular weight of the purified enzyme was estimated to be about 45,000 by SDS-PAGE. The optimum pH and temperature for the enzyme activity were pH 7.0 and $60^{\circ}C$, respectively. The enzyme activity was relatively stable up to $60^{\circ}C$ over the pH range of 7.0-10.0. The fibrinolytic enzyme activity increased by $Ca^{2+}$ and $Cu^{2+}$, whereas it was inhibited by $Hg^{2+}$ and $Ba^{2+}$. In addition, it was severely inhibited by PMSF and DFT. It is suggested that the purified enzyme was a serine protease for the fibrinolysis. The purified enzyme could completely hydrolyze fibrin in vitro within 8 h. Hence, it is suggested that the purified enzyme can be put into practice as an effective thrombolytic agent.

• Journal of Microbiology and Biotechnology
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• v.32 no.8
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• pp.967-975
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• 2022

Kombucha mutualistic community (KMC) is composed by acetic acid bacteria and yeasts, producing fermented tea with health benefits. As part of the BIOlogy and Mars EXperiment (BIOMEX) project, the effect of Mars-like conditions on the KMC was analyzed. Here, we analyzed metagenome-assembled genomes (MAGs) of the Komagataeibacter, which is a predominant genus in KMC, to understand their roles in the KMC after exposure to Mars-like conditions (outside the International Space Station) based on functional genetic elements. We constructed three MAGs: K. hansenii, K. rhaeticus, and K. oboediens. Our results showed that (i) K. oboediens MAG functionally more complex than K. hansenii, (ii) K. hansenii is a keystone in KMCs with specific functional features to tolerate extreme stress, and (iii) genes related to the PPDK, betaine biosynthesis, polyamines biosynthesis, sulfate-sulfur assimilation pathway as well as type II toxin-antitoxin (TA) system, quorum sensing (QS) system, and cellulose production could play important roles in the resilience of KMC after exposure to Mars-like stress. Our findings show the potential mechanisms through which Komagataeibacter tolerates the extraterrestrial stress and will help to understand minimal microbial composition of KMC for space travelers.