• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.4
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• pp.354-359
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• 2009

The productivity of ultra-small rotifer, Synchaeta kitina was investigated at the exchange rate of culture water (10, 20, 30, 40 and 50%) and initial inoculation densities (250, 600 and 900 inds. per mL) in semi-continuous culture. Also, the possibility of mass culture was investigated in a 100 L culture tank. Tetraselmis suecica was used as the feed for S. kitina in all experiments. The production of S. kitina increased with an increase in exchange rate of culture water. The highest production ($82.0{\times}10^5$ inds.) was achieved at 40% exchange rate of culture water. The production of S. kitina increased with an increase of initial inoculation density during the first week and the highest total production ($17.4{\times}10^6$ inds.) was achieved at 900 inds. per mL of initial inoculation density. However, on the second week, all treatments were not significantly different in total production (P>0.05). During the two weeks, total production of S. kitina at 900 inds. per mL of initial inoculation density was higher than at 600 inds. of initial inoculation density, but there was no significant difference (P>0.05). In the 100 L culture tank, density of S. kitina was kept from 516 to 890 inds. per mL and S. kitina was daily harvested $15.5{\times}10^6$ to $26.7{\times}10^6$ during the experimental period. The production cost for 100 million rotifers in semi-continuous culture was 63,656 won. The results from this study indicate that the optimal exchange rate of culture water and initial inoculation density for the semi-continuous culture of ultra-small rotifer, S. kitina are 40% and 600 inds. per mL, respectively.

• Mycobiology
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• v.30 no.4
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• pp.208-212
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• 2002

For comparison of mycelial colonization of Phellinus linteus on logs, several techniques of inoculation were tested; sterilized short log inoculation, drilling inoculation and log-end sandwich inoculation. The mycelial colonization of P. linteus on logs was good in the treatment of sterilized short log inoculation, but poor in the traditional methods such as drilling inoculation and log-end sandwich inoculation. The initial mycelial growth and the full mycelial colonization of P. linteus in logs were the best in case of 20 cm logs under the condition of 42% moisture content. Also, the initial mycelial growth of P. linteus was accelerated over 12 hours of sterilization. Burying method of logs after $5{\sim}6$ months of incubation was the best for formation of basidiocarps of P. linteus. The formation of fruiting body of P. linteus was quite good in the cultivation house at $31{\sim}35^{\circ}C$ and over 96% of relative humidity.

• Mycobiology
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• v.36 no.2
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• pp.81-87
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• 2008

The optimal conditions for mycelial growth of Phellinus linteus ATCC 26710 were determined to be a log length of 20 cm, temperature of $30^{\circ}C$ and pH of 6.0. Mycelial growth was excellent on the mushroom complete medium, and was optimal when sucrose, man nose and glucose were supplied as carbon sources. Potassium nitrate and sodium nitrate as nitrogen sources supported good mycelial growth. To evaluate P. linteus mycelial colonization on logs, sterilized short log inoculation, drilling inoculation and log-end sandwich inoculation techniques were used. Only sterilized short log inoculation produced good mycelial colonization. Initial mycelial growth and full mycelial colonization were best on 20 cm logs having 42% moisture content. The initial mycelial growth of P. linteus was accelerated over 12hr of sterilization. Basidiocarp formation was optimal using a burying method of logs after $5{\sim}6$ months, and fruiting body formation was superior in cultivation house conditions of $31{\sim}35^{\circ}C$ and in excess of 96% relative humidity.

• The Plant Pathology Journal
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• v.39 no.2
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• pp.220-227
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• 2023

Rose crown gall caused by Agrobacterium tumefaciens is a major disease that damages the production of cutroses in Korea. The effective prevention methods for this disease include the use of resistant varieties. This study was conducted to evaluate the resistance of 58 Korean cultivars and six foreign cultivars to crown gall disease with nodal explants in vitro. Among 180 A. tumefaciens strains, pathogenic strain RC12 was selected as an inoculant strain. The strain RC12 was identified based on characteristics of some selective media, pathogenicity test, and polymerase chain reaction analysis. Forty rose cultivars formed tumors on explants inoculated with A. tumefaciens RC12. However, 24 cultivars, including 22 Korean cultivars and 2 foreign cultivars, showed resistance to A. tumefaciens RC12 without forming any tumors. Six cultivars with tumor formation rates of over 30% formed initial tumors within 23 days after inoculation. Six cultivars with low tumor formation rates of around 5% formed initial tumors after 28 days of inoculation. It was found that gall formation rate was highly correlated with the initial gall formation period. Thus, the relationship between the period of gall formation and the rate of gall formation could be useful for assessing resistance to crown gall disease. In vitro inoculation methods could be used to evaluate resistance of cut-rose cultivars to crown gall diseases.

• Plant Disease and Agriculture
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• v.5 no.2
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• pp.90-94
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• 1999

Effect of inoculum concentration inoculation method and plant age on development of clubroot disease of Chinese cabbage seedling were examined in growth chambers. Root galls were developed at the concentration of 105 resting spore or above per ml of incoulum and as the inoculum concentration became higher rate of development of root galls was faster. In the plants with root gall development fresh weight of above ground parts was reduced to 30-44% of that of healthy plants but root weight increased by 4-10 times. Growth of diseased plants was greatly reduced as compared to healthy plants. Planting in the diseased soil as a inoculation method was most effective for disease development showing uniform infections but time of initial root gall development was delayed by root soaking inoculation. Some plants inoculated by soil drenching method did not develop root galls. However root gall enlargement after its initial formation did not differ greatly among inoculation methods. Nine-day-old seedlings showed poor development of root gall but 16-days-old seedlings was found to be most adequate for inoculation for gall development.

• Microbiology and Biotechnology Letters
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• v.36 no.3
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• pp.233-239
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• 2008

A new approach to the solubilization of excess activated sludge by the inoculation of lactic acid bacteria was studied to reduce the amount of sludge produced in the activated sludge treatment process. Aerobic microorganism in sludge was lysed in anaerobic condition and the cytoplasmic substance eluted was utilized as a carbon source by lactic acid bacteria. On the basis of sludge solubilization efficiency, Lactobacillus brevis and Leuconostoc mesenteroides subsp mesenteroides were selected the best candidates among five kinds of Lactobacillus sp. and seven kinds of Leuconostoc sp. The sludge solubilization efficiency by heterofermentative lactic acid bacteria was more efficient than that of homofermentative bacteria. Initial value of soluble COD (sCOD) was 1050 mg/L at the initial inoculation time increased to 3070 mg/L (192% solubilization) at 96 h of the incubation time. The inoculation of lactobacillus brevis to the sludge resulted in 2824% increase in sCOD value after 96 h of incubation than the control experiment. Leuconostoc mesenteroides subsp mesenteroides showed 152% increase of solubilization and 30% increase of S-COD/T-COD on 96 h of incubation time. Considering the increase of S-COD by the inoculation of Leuconostoc sp. on 24 h, 10% inoculation of lactic acid bacteria to the sludge was most effective.

• The Plant Pathology Journal
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• v.24 no.3
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• pp.352-356
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• 2008

Root discs of 4-year-old ginseng, Panax ginseng C. A. Meyer, were inoculated with the higher($10^8$ colonyforming units(CFU)/ml) and lower($10^6\;or\;10^5$ CFU/ml) initial inoculum levels of a plant-growth promoting rhizobacterium(PGPR), Paenibacillus polymyxa GBR-1 to examine rot symptom development and bacterial population changes on the root discs. At the higher inoculum level, brown rot symptoms developed and expanded on the whole root discs in which the bacterial population increased continuously up to 4 days after inoculation. In light and electron microscopy, ginseng root cells on the inoculation sites were extensively decayed, which were characterized by dissolved cell walls and destructed cytoplasmic contents. However, no rot symptoms were developed and the bacterial population increased only during the initial two days of inoculation at the lower inoculum level($10^6$ CFU/ml) of P. polymyxa GBR-1. At the lower inoculum level($10^5$ CFU/ml), boundary layers with parallel periclinal cell divisions, structurally similar to wound periderm, were formed internal to the inoculation sites, beneath which the cells were intact containing numerous normal-looking starch granules and no disorganized cell organelles, suggesting that these structural features may be related to the suppression of symptom development, a histological defense mechanism.

• Journal of Sericultural and Entomological Science
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• v.44 no.2
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• pp.74-81
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• 2002

The optimal conditions for mycelial growth of P. linteus ASI 26011 were 25-30$^{\circ}C$ and pH 6.0, respectively. The mycelial growth of P. linteus was excellent on MCM medium. In case of carbon sources, the mycelial growth of P. linteus was best on the culture media that were contained with sucrose, mannose and glucose. Potassium nitrate and sodium nitrate were good for the mycelial growth of P. linteus as a nitrogen source. For comparison of the mycelial colonization of P. linteus on logs, several techniques of inoculation were tested; the sterilized short log inoculation, drilling inoculation and log-end sandwich inoculation. The mycelial colonization of P. linteus on logs was good in the treatment of sterilized short log inoculation, but poor in the traditional methods such as drilling inoculation and log-end sandwich. The initial mycelial growth and the full mycelial colonization of P. linteus were the best on 20 cm logs under the condition of 42% of moisture content in log. Also the initial mycelial growth of P. linteus was accelerated over 12 hours of sterilization. Burying method of logs after 5-6 months of incubation was the best for formation of basidiocarp of P. linteus. The formation of fruiting body of P. linteus was quite good in the cultivation house at the 31-35$^{\circ}C$ and over 96% of relative humidity.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.700-703
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• 2001

The influence of process conditions on highly branched glucooligosaccharides production by mixed culture of Leuconostoc mesenteroides ATCC 13146 and Lipomyces starkeyi ATCC 74054 was studied. We divided the batch culture fermentations into two groups according to inoculation method. One-point inoculation was performed by coinoculation of L. mesenteroides and L. starkeyi at the ration of 10 to 1, and two-point inoculation by L. mesenteroides inoculation first and L. starkeyi inoculation after L. mesenteroides grew to the end of the log phase of growth. Two-point inoculation improved the yield of oligosaccharide by 1.5 to 20 fold more than one-point inoculation. In this process, the highest yield of oligosaccharides (48% of theoretical yield) and productivity (0.85 g/l/h) were obtained with starch as an initial substrate for L. starkeyi growth. The estimated composition of the end product consisted of 31.5% oligosaccharides, 17.6% dextran, and 46.5% mannitol.

• Journal of Microbiology and Biotechnology
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• v.29 no.9
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• pp.1434-1443
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• 2019

Although chemical oxygen demand (COD) is an important issue for wastewater treatment, COD reduction with microalgae has been less studied compared to nitrogen or phosphorus removal. COD removal is not efficient in conventional wastewater treatment using microalgae, because the algae release organic compounds, thereby finally increasing the COD level. This study focused on enhancing COD removal and meeting the effluent standard for discharge by optimizing sludge inoculation timing, which was an important factor in forming a desirable algae/bacteria consortium for more efficient COD removal and higher biomass productivity. Activated sludge has been added to reduce COD in many studies, but its inoculation was done at the start of cultivation. However, when the sludge was added after 3 days of cultivation, at which point the COD concentration started to increase again, the algal growth and biomass productivity were higher than those of the initial sludge inoculation and control (without sludge). Algal and bacterial cell numbers measured by qPCR were also higher with sludge inoculation at 3 days later. In a semi-continuous cultivation system, a hydraulic retention time of 5 days with sludge inoculation resulted in the highest biomass productivity and N/P removal. This study achieved a further improved COD removal than the conventional microalgal wastewater treatment, by introducing bacteria in activated sludge at optimized timing.