• Korean Journal of Soil Science and Fertilizer
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• v.16 no.2
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• pp.188-194
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• 1983

A Pot experiment was conducted to find out the effects of NPK fertilizers and soil amendments on the symbiotic nitrogen fixation and yield of soybean inoculated with Rhizobium japonicum in newly reclaimed upland soil with very low fertility. The results are summarized as follows; 1. Application of PK fertilizer and soil amendments such as lime, and rice straw in combination with micronutrients (Zn, B, Mo) increased the amounts of symbiotic $N_2$ fixation in soybean. 2. The inoculation of Rhizobium japonicum with application of soil amendments increased the yield of soybean by 4% to 10% due to enhanced $N_2$ fixation. 3. In case of improvement of newly reclaimed hilly soil in order to obtain the high yield of soybean, simutaneous application of soil amendments with inoculation of R. janconican should the highest yield.

• The Korean Journal of Mycology
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• v.12 no.2
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• pp.53-58
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• 1984

This experiment was performed to select the most suitable species of oyster mush­room for cultivation during summer season in Korea. The selection was made based upon mycelial growth on the ricestraw substrates, fruiting under hot weather conditions during the summer season in Korea and potential high productivity using six cultures from South-east Asia. The newly selected strain of Pleurotus sajor-caju (ASI 2070) grew well on the rice straw substrates and produced the higher yields of sporophores than other cultures tested. The primordia of the mushroom were formed between 10 to $35^{\circ}C$. The optimal temperature for fruiting ranged from 20 to $25^{\circ}C$.

• The Korean Journal of Mycology
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• v.6 no.2
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• pp.25-30
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• 1978

Present experiments were conducted to determine the possibility of cultivation of 9 edible wild species selected among the higher fungi growing in Korea. In the investigation on the mycelial growth according t6o the different media, the mycelial growth of Coprinus comatus was fast on the CSA medium, when malt extract was added to the basal medium PSA, the mycelial of Lapista nuda and Auricularia auricula-judae was fast in growth and density. In the spawning, the mycelial growth of Pholiota squarrosa on the oak tree's sawdust, Pleurotus cornucopiae on the broad-leaves' sawdust, and Coprinus comatus on the compost was respectably fast and also it shown to be possibility of artificial cultivation owing to their carporphore budding when Coprinus comatus and Lepiota alborubescens cultivated on the rice straw, Auricularia auriculajudae and Pleurotus cornucopiae on the sawdust of the popla and Pholiota squarrosaon the sawdust of the oak tree.

• Microbiology and Biotechnology Letters
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• v.20 no.1
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• pp.14-19
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• 1992

The xylanase producing microorganisms occurring on rotten woods were selectively isolated on the modified Czapek-Dox medium supplemented with 0.5% xylan as a sole carbon source. Among more than three-hundred isolates of xylanase producing microorganisms, only two bacterial isolates were turned out to be more potent xylanase producer than the reference strain of xylanase producer, Aureobaszdium pullulans NRRL Y-2311. The exo-xylanase producer, bacterial isolate No. 33 was identified as a strain of Pseudomonas sp. on the basis of morphological and biochemical characterizations as well as cellular fatty acid composition. Optima of pH and of temperature for enzyme reactions of xylanase were 5.5 and $50^{\circ}C$ respectively. The enzyme was stable in a range of pH 5.0~7.0 and below $45^{\circ}C$. Among the number of carbohydrate substrates, xylose was turned out to be a potent inducer of Pseudomonas sp. No.33 exo-xylanase. Among the raw materials tested, rice straw was the best material for xylanase production by Pseudomonas sp. strain No. 33.

• Toxicological Research
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• v.34 no.2
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• pp.163-172
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• 2018

Air pollution is increasing, along with consumption of fossil fuels such as coal and diesel gas. Air pollutants are known to be a major cause of respiratory-related illness and death, however, there are few reports on the genotoxic characterization of diverse air pollutants in Korea. In this study, we investigated the mutagenic activity of various particles such as diesel exhaust particles (DEP), combustion of rice straw (RSC), pine stem (PSC), and coal (CC), tunnel dust (TD), and road side dust (RD). Ultra-fine particles (UFPs) were collected by the glass fiber filter pad. Then, we performed a chemical analysis to see each of the component features of each particulate matter. The mutagenicity of various UFPs was determined by the Ames test with four Salmonella typhimurium strains with or without metabolic activation. The optimal concentrations of UFPs were selected based on result of a concentration decision test. Moreover, in order to compare relative mutagenicity among UFPs, we selected and tested DEP as mutation reference. DEP, RSC, and PSC induced concentration-dependent increases in revertant colony numbers with TA98, TA100, and TA1537 strains in the absence and presence of metabolic activation. DEP showed the highest specific activity among the particulate matters. In this study, we conclude that DEP, RSC, PSC, and TD displayed varying degrees of mutagenicity, and these results suggest that the mutagenicity of these air pollutants is associated with the presence of polycyclic aromatic hydrocarbons (PAHs) in these particulate matters.

• Journal of Microbiology and Biotechnology
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• v.8 no.2
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• pp.129-133
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• 1998

The white-rot fungi Phanerochaete chrysosporium ATCC 24725, Pleurotus ostreatus ATCC 32783, Lentinus edodes ATCC 24462, and Trametes versicolor ATCC 42530 were studied for their ability to degrade lignin, phenanthrene, and anthracene. Lignin in rice-straw was degraded by 14.4, 28.73, and 33.88% by P. chrysosporium, T. versicolor, and P. ostreatus, respectively. Approximately 12% and 83% of phenanthrene was degraded in 1 and 5 days, respectively, when the pre-grown mycelIium matrix of P. ostreatus. was incubated with 10 ppm of phenanthrene in modified Kirk's medium (nitrogen limited) at $25^{\circ}C$. Approximately 2%> and 61% of phenanthrene was degraded when the phenanthrene concentration was increased to 30 ppm. Similar trends were observed with phenanthrene using P. chrysosporium. Mycelial growth of T. versicolor was less inhibited at 30 ppm phenanthrene than for P. ostreatus and P. chrysosporium. Better degradation of phenanthrene by T. versicolor may be attributed to better mycelium growth. One hundred percent of 15 ppm anthracene was degraded in 10 days by both P. chrysosporium and T. versicolor. 40 ppm anthracene inhibited the mycelial growth of P. chrysosporium. lignin peroxidase activity, which was previously reported to be involved in initial phenanthrene oxidation, was also detected from the culture broth of the strains tested. The rates of lignin peroxidase production in the cultures were not consistent with the rate of PAH hydrolysis during incubation.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.303-310
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• 2016

In this study, doenjang samples were prepared with different types of salts (12%, w/w): purified salt (PS), 3-year aged solar salt (SS3), 1-year aged solar salt (SS1), and bamboo salt melted 3 times (BS). Whole-soybean mejus were fermented with starters consisting of 2 Bacillus strains, a yeast, and a fungus (starter doenjang), and control mejus were fermented with organisms present naturally in rice straw (non-starter doenjang). The whole-soybean mejus were dried, and then mixed with cooked soybeans and the respective salts. The doenjang samples were fermented for 13 weeks at 25℃. The protease (acid, neutral, and alkaline) activities, fibrinolytic activities, and antioxidant capacities of the samples were examined every week. BS doenjang showed the highest acid protease (6.46 ± 0.20 unit/g) and fibrinolytic activities (0.61 unit/ml). Among the starter doenjang samples, those made with SS and BS showed the highest total phenolic contents after 91 days of fermentation. For antioxidant activities, SS3 doenjang showed higher activities than the other doenjang samples, as evaluated by ABTS, DPPH, and FRAP assays. These results suggest that solar salt, especially aged for 3 years, is better than purified salt in terms of producing better functionalities of doenjang.

• Microbiology and Biotechnology Letters
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• v.44 no.3
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• pp.324-332
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• 2016

A bacterial strain capable of hydrolyzing xylan was isolated from fermented soybean paste obtained from a domestic Buddhist temple, using enrichment culture with rice straw as a carbon source. The isolate, named YB-1301, was identified as Bacillus safensis on the basis of its DNA gyrase subunit B gene (gyrB) sequence. The xylanase productivity of strain YB-1301 was drastically increased when it was grown in the presence of wheat bran or various xylans. In particular, the maximum xylanase productivity reached above 340 U/ml in the culture filtrate from LB broth supplemented with only birchwood xylan at shake-flask level. The xylanase production was significantly induced by xylans at the stationary growth phase in LB medium containing xylan, whereas only a small amount of xylanase was constitutively produced from cells grown in LB medium with no addition of xylan. Furthermore, xylanase biosynthesis was induced more rapidly by the enzymatically hydrolyzed products of xylan than by the non-hydrolyzed xylan. In addition, the xylanase in the culture filtrate of B. safensis YB-1301 was found to have optimal activity at 55℃ and pH 6.5–7.0.

• Journal of Microbiology and Biotechnology
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• v.26 no.9
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• pp.1533-1541
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• 2016

Samples of doenjang (a fermented soybean paste) were prepared with different types of salts; purified salt (PS), 3-year-aged solar salt (SS3), 1-year-aged solar salt (SS1), and bamboo salt (BS, 3^rd processing product). For starter doenjang samples, selected starters comprising two bacilli, one yeast, and one fungus were inoculated, whereas for non-starter doenjang samples, microorganisms present in rice straw were inoculated after enrichment. The doenjang samples were fermented for 13 weeks at 25℃. During the fermentation period, SS and BS doenjang samples showed higher bacilli counts as well as much lower yeast counts than PS doenjang. At 13 weeks, yeast counts of starter doenjang samples were 7.75, 5.69, 6.08, and 4.74 log CFU/g for PS, SS3, SS1, and BS doenjang, respectively. For non-starter doenjang samples, counts were 7.17, 5.05, 5.92, and 4.54 log CFU/g for PS, SS3, SS1, and BS doenjang, respectively. SS and BS promoted growth of bacilli but inhibited growth of yeasts compared with PS. Debaryomyces hansenii was the dominant yeast in PS doenjang, whereas Candida guilliermondii and Pichia sorbitophila were dominant in SS and BS doenjang. In the sensory evaluation, SS and BS doenjang scored better than PS doenjang. In conclusion, SS and BS seem better than PS for production of high-quality doenjang.

• Journal of Food Hygiene and Safety
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• v.32 no.3
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• pp.171-178
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• 2017

This study evaluated the protective effect of Chungkookjang (CKJ) extract, a Korean traditional fermented soybean product made from Bacillus species in rice straw and boiled soybean, and one of its main flavonoids, genistein, against Trp-P-1 induced cytotoxicity and DNA damage in HepG2 cells. CKJ and genistein exhibited protective effect against Trp-P-1 induced cytotoxicity and Trp-P-1 induced DNA single strand breaks. CKJ and genistein inhibited Trp-P-1 induced CYP1A1 and CYP1A2 transcription in HepG2 cells. Our results indicated that CKJ and genistein have the protective effect against Trp-P-1 induced cytotoxicity and DNA damage. Via inhibiting expression of CYP1A1 and CYP1A2. CKJ can be used as a promising functional food material that prevents the genotoxicity induced by carcinogens produced by the heat treatment of foods such as heterocyclic amines (HCAs) that cause genomic instability.