• The Korean Journal of Mycology
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• v.33 no.1
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• pp.22-29
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• 2005

The main objectives of this research were to study the cultural and nutritional characteristics of Tricholoma matsutake and to establish its liquid culture system. The optimum growth of T. matsutake was observed in HA and TMM agar media. Similarly highest growth was observed in PDB and TMM liquid media. The optimal temperature for the mycelial growth was $25^{\circ}C$. The most suitable carbon source was dextrin among 12 different carbon sources tested. Yeast extract and peptone were best nitrogen sources among 17 different sources tested. The optimum mineral salts were $Fe_{2}(SO_{4})_{3}{\cdot}H_{2}O$ and KCl among 9 different sources tested. Shaking culture gave higher mycelial growth compared to stationary culture. Similarly, optimum medium amount for shaking culture was 100 ml per 250 ml flask. The highest mycelial growth was obtained when $5{\sim}7$ mycelial discs were inoculated in 100 ml of medium and incubated for $8{\sim}9$ weeks, respectively. The highest proportion of mycelial growth was observed at 40 : 1 ratio of medium to inoculum volume in 8 l air-lift fermenter.

• Journal of Korean Society of Forest Science
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• v.65 no.1
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• pp.43-47
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• 1984

Pinus rigida ${\times}$ P. taeda seedlings in a nursery was inoculated with basidiospores of Pisolithus tinctorius (Pt) either collected from Suweon, Korea or introduced from U.S.A. to compare the effectiveness of the spores from two different origins as mycorrhizal inocula. Nursery beds were fumigated with methyl bromide and 1g of spores was used to inoculate $1m^2$ of soil surface just before seed sowing. Seedlings inoculated with American Pt (#250 strain from Georgia, U.S.A.) were 15% taller than Korean Pt at the end of the first growing season. The seedlings from fumigation treatment only (no inoculation involved) was slightly taller (statistically unsignificant) than those with Korean Pt, but slightly smaller than those with American Pt. In a subsequent year experiment, the seedlings inoculated with American and Korean Pt after soil fumigation were 66% and 60% taller, respectively, than seedlings infected by natural fungi without soil fumigation, suggesting the dual effects of Pt and fumigation on the seedling growth. Therefore potential of Pt spores for an effective inoculum exists and selection of Pt strains which have adapted to specific local environments is needed to develop better sources of mycorrhizal inocula.

• The Korean Journal of Mycology
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• v.32 no.2
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• pp.95-100
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• 2004

The main objectives of the study were to investigate cultural characteristics of Phellinus linteus. The optimum culture media for mycelial growth of P. linteus were MYA (malt yeast agar) and SMS (soybean powder malt Sucrose). Similarly, optimum temperature and pH were $30^{\circ}C$ and 6.0, respectively. Malt extract (2%, v/v) and yeast extract (0.2%, v/v) were optimum carbon and nitrogen sources. Similarly, 0.1% $KH_2PO_4$ was optimum mineral salt. Highest mycelial growth was observed when C/N ratio was 10 : 1. Optimum inoculum amount for flask culture was $5{\sim}6$ mycelial discs (6 mm diameter) per 100 ml of liquid medium, Highest mycelial dry weight was obtained when cultured in 100 ml liquid medium in 300 ml shaking flask after 20 days of shaking culture, For mass liquid culture (8 l), flask culture was homogenized and used as an inoculum. Optimum culture period and aeration rate for 8l fermentation culture were 12 days and 2.0 vvm, respectively.

• Journal of Microbiology and Biotechnology
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• v.19 no.5
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• pp.462-467
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• 2009

Cyclosporin A (CyA) produced by Tolypocladium inflatum is a promising drug owing to its immunosuppressive and antifungal activities. From an industrial point of view, the necessity to obtain a suitable and economic medium for higher production of CyA was the aim of this work. The present study evaluated the effect of different fermentation parameters in solid state fermentation, such as selection of solid substrate, hydrolysis of substrates, initial moisture content, supplementation of salts, additional carbon, and nitrogen sources, as well as the inoculum age and size, on production of CyA by Tolypocladium inflatum MTCC 557. The fermentation was carried out at $25{\pm}2^{\circ}C$ for 9 days. A combination of hydrolyzed wheat bran flour and coconut oil cake (1:1) at 70% initial moisture content supported a maximum production of $3,872{\pm}156\;mg$ CyA/kg substrate as compared with $792{\pm}33\;mg/kg$ substrate before optimization. Furthermore, supplementation of salts, glycerol (1% w/w), and ammonium sulfate (1% w/w) increased the production of CyA to $5,454{\pm}75\;mg/kg$ substrate. Inoculation of 5 g of solid substrate with 6 ml of 72-h-old seed culture resulted in a maximum production of $6,480{\pm}95\;mg$ CyA/kg substrate.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.4
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• pp.58-68
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• 1999

This experiment was to investigate decoloization characteristics of E1 effluents from the bleaching plant of pulp mill with three white-rot fungi(Trametes versicolor, Ganoderma appanatum and Pleurotus ostreatus).In addition, the effect of carbon and nitrogen resources was discussed on its decolorization. The color removal of E1 effluent during shaking and stationary cultures were 72% and 80%, respectively. Stationary culture was more effective on decolorization of E1 effluent compared to the shaking culture. The optimum inoculum weight was 1.0g based on dry weight of mycelia . The decolorization medium I showed 88% of the color removal of E1 effluent with in one day cultivation of T.versicolor and P.ostreatus . Color removal was increased from 87% to 90%. T.versicolor and P.ostreatus by the addition of 0.5% glucose. By addition of nitorgen sources(ammonium sulfate and ammonium choride), medium was much higher than that of carbon source. With 0.1% ammoniumm sulfate, P.ostreatus and T.versicolor showed 94% and 92% of the color removal within one day of cultivation , respectively. On decolorization medium II, T.versicolor and P.ostretus were 94% of oclor removal with addition of carbon source. The addition of nitrogen source was much more efficient than that of carbon source. With 0.1% amminium chloride, T.versicolor and P.ostreatus showed 95% of its color removal . The decolorization medium II was higher color removal than medium I, and also MnP and laccase were produced. However, the decolorization medium I produced a little MnP and laccase activity. It could be suggested that MnP and laccase may play an important role in decolorization of E1 effluent.

• Journal of Ginseng Research
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• v.28 no.3
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• pp.149-156
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• 2004

The objectives of this study were to investigate the morphology of mycorrhizal roots, and the effects of root age and soil texture on the mycorrhizal infection in ginseng (Panax ginseng C. A. Meyer) growing in Korea. Ginseng roots at ages of two to six years were collected from fields in late June. Their infection by arbuscular mycorrhizal fungi(AMF) was studied by clearing the roots and staining fungal hyphae with trypan blue. Root infection varied greatly depending on the developmental stages of young roots. Young tertiary roots, in diameter of smaller than 0.8 mrn, formed during the current growing season had root hairs and were frequently and in some cases heavily infected by AMF. Hyphal coils and arbuscules were abundant, while vesicles were rarely observed. Older secondary or tertiary roots in diameter of bigger than 1.0 mm with fully differentiated primary xylem formed during the previous growing season had no root hairs, and were not infected at all. The rates of mycorrhizal infection in the young tertiary roots were not affected by the age of the ginseng plants, suggesting that fungal populations might have not much changed during the aging of the cultivated fields up to six years. The differences in the infection rates among the different ages of ginseng were caused by differences in the amount of young tertiary roots in the samples. Soil texture, either sandy loam or clay loam, did not affect the rate of root infection. There were large variations in the infection rates among the different farms and locations within a farm. It strongly suggested that infection rates of the ginseng roots by AMF would be influenced by the practice of the farmers, possibly by avoiding consecutive planting, introduction of new topsoil, and the ways of handling the soil before transplanting the ginseng, such as fumigation or sterilization that might have affected indigenous inoculum sources of the AMF.

• Animal Bioscience
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• v.36 no.2
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• pp.238-247
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• 2023

Objective: Recently, indigenous Korean grass Sasa quelpaertensis Nakai (SQ) has garnered much interest as a roughage source for livestock to mitigate its adverse effects on habitat diversity. Thus, the objective of the present study was to evaluate the ruminal fermentation, palatability, and nutrient digestibility of SQ for Korean native beef cattle (Hanwoo) using in vitro rumen fermentation, in situ rumen degradability, and in vivo feeding trials. Methods: Using in vitro tests with rumen fluid as the inoculum for 48 h, ruminal fermentation of SQ was evaluated and compared with that of other roughage sources commonly used in Korea (i.e., rice straw, Timothy hay, and Italian ryegrass [IRG]). Additionally, an in situ trial 96 h was performed using three cannulated Hanwoo steers. Further, an in vivo trial was performed using eight Hanwoo steers to compare the palatability of SQ with rice straw in total mixed ration (TMR) and forage-concentrate separate feeding conditions. Finally, an in vivo digestibility trial of SQ fed as TMR of two particle sizes was performed with four Hanwoo steers. Results: In vitro and in situ trials revealed that SQ was comparable or superior to rice straw in terms of the ruminal fermentation characteristics of pH, gas production, total volatile fatty acid content, and effective ruminal dry matter digestibility (DMD), although its fermentability was lower than that of Timothy hay and IRG. In the palatability test, steers showed a greater preference for SQ when given as TMR. The total tract DMD of SQ fed as TMR was 75.9%±1.37%, and it did not differ by particle size. Conclusion: The feed value of SQ as a roughage source for Hanwoo steers is comparable or superior to that of rice straw, particularly when provided as TMR.

• The Plant Pathology Journal
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• v.36 no.1
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• pp.54-66
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• 2020

This study was conducted to evaluate usefulness of numerical weather prediction data generated by the Unified Model (UM) for plant disease forecast. Using the UM06- and UM18-predicted weather data, which were released at 0600 and 1800 Universal Time Coordinated (UTC), respectively, by the Korea Meteorological Administration (KMA), disease forecast on bacterial grain rot (BGR) of rice was examined as compared with the model output based on the automated weather stations (AWS)-observed weather data. We analyzed performance of BGRcast based on the UM-predicted and the AWS-observed daily minimum temperature and average relative humidity in 2014 and 2015 from 29 locations representing major rice growing areas in Korea using regression analysis and two-way contingency table analysis. Temporal changes in weather conduciveness at two locations in 2014 were also analyzed with regard to daily weather conduciveness (C_i) and the 20-day and 7-day moving averages of C_i for the inoculum build-up phase (C_inc) prior to the panicle emergence of rice plants and the infection phase (C_inf) during the heading stage of rice plants, respectively. Based on C_inc and C_inf, we were able to obtain the same disease warnings at all locations regardless of the sources of weather data. In conclusion, the numerical weather prediction data from KMA could be reliable to apply as input data for plant disease forecast models. Weather prediction data would facilitate applications of weather-driven disease models for better disease management. Crop growers would have better options for disease control including both protective and curative measures when weather prediction data are used for disease warning.

• Journal of Microbiology and Biotechnology
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• v.21 no.6
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• pp.627-636
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• 2011

A commercially important alkaline protease, produced by Bacillus sp. RRM1 isolated from the red seaweed Kappaphycus alvarezii (Doty) Doty ex Silva, was first recognized and characterized in the present study. Identification of the isolated bacterium was done using both biochemical characterization as well as 16S rRNA gene sequencing. The bacterial strain, Bacillus sp. RRM1, produced a high level of protease using easily available, inexpensive agricultural residues solid-state fermentation (SSF). Among them, wheat bran was found to be the best substrate. Influences of process parameters such as moistening agents, moisture level, temperature, inoculum concentration, and co-carbon and co-nitrogen sources on the fermentation were also evaluated. Under optimized conditions, maximum protease production (i.e., 2081 U/g) was obtained from wheat bran, which is about 2-fold greater than the initial conditions. The protease enzyme was stable over a temperature range of 30-$60^{\circ}C$ and pH 6-12, with maximum activity at $50^{\circ}C$ and pH 9.0. Whereas the metal ions $Na^+$, $Ca^{2+}$, and $K^+$ enhanced the activity of the enzyme, others such as $Hg^{2+}$, $Cu^{2+}$, $Fe^{2+}$, $Co^{2+}$, and $Zn^{2+}$ had rendered negative effects. The activity of the enzyme was inhibited by EDTA and enhanced by $Cu^{2+}$ ions, thus indicating the nature of the enzyme as a metalloprotease. The enzyme showed extreme stability and activity even in the presence of detergents, surfactants, and organic solvents. Moreover, the present findings opened new vistas in the utilization of wheat bran, a cheap, abundantly available, and effective waste as a substrate for SSF.

• Research in Plant Disease
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• v.23 no.1
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• pp.1-18
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• 2017

Pseudomonas syringae pv. actinidiae, the causal agent of bacterial canker, is currently causing severe economic losses to kiwifruit production worldwide. The pathogen has affected green-fleshed kiwifruit cutlivars and yellow-fleshed kiwifruit cultivars since 1988 and 2006 in Korea, respectively. In recent years, the biovar 3 strains of P. syringae pv. actinidiae were introduced through imported contaminated pollens and have rapidly spread to neighboring kiwiruit orchards by secondary infection, leading to outbreaks of bacterial canker and tremendous damages on yellow- and red-fleshed kiwifruit cultivars. In this review, we summarize the various management practices of bacterial canker of kiwifruit such as disease escaping, cultural practices, blocking of dissemination, early diagnosis, eradication of inoculum sources, chemical control, and trunk injection on the basis of our research works and field experiences and important research products conducted during the last three decades in the world. Finally, we propose a manual for the efficient management of the disease that can be practically utilized at the farmers' orchards in order to keep kiwifruit vines healthy in the future.