• Journal of Mushroom
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• v.19 no.2
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• pp.103-108
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• 2021

This experiment investigates the characteristics of microorganisms isolated from a medium during cultivation process and reveals the relationship between these microorganisms and the growth of Agaricus bisporus. The domestically grown strains of Agaricus bisporus displayed a higher inhibition growth rate against microorganisms isolated from straw, chicken manure, and medium than imported strains. As for inhibition of mycelial growth among mushroom cultivars of the microorganisms separated by each fermentation step from the mushroom medium, the domestic cultivar, 'Saedo,' grew more vigorously among other cultivars. As the fermentation progressed, it was confirmed that inhibitation of microorganisms against Agaricus bisporus was weakened. A total of 21 strains of microorganisms that promote mushroom growth were isolated in the 4th turning process, and the microorganisms isolated from the mushroom medium affect the growth and as yield of the mushroom through secretory substances.

• Journal of Mushroom
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• v.16 no.2
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• pp.96-102
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• 2018

Sparassis latifolia is one of the most expensive mushrooms in Korean market owing to its high ${\beta}$-glucan content and immunoactivity. However, because of the long cultivation period and high contamination rates, it has low production efficiency. Therefore, we first need to establish the optimum conditions for liquid spawn production to increase its production efficiency. As a result of experiments, molasses culture medium was selected for mycelial growth. Also, the optimum sugar content for molasses and amount of aeration used were approximately 8 Brix% and 0.3~0.6 vvm, respectively. Mycelial dry weight increases, while the medium decreases, as the incubation period increases. Therefore, to achieve maximum production efficiency, the incubation period of 9 to 11 days is appropriate.

• Journal of Mushroom
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• v.16 no.2
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• pp.61-64
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• 2018

This study was carried out to investigate the management characteristics and growth performance of L. edodes from the cooling stage to incubation. Bags of different heights and weights are available for bagging. When the medium size of $17{\times}13cm$ was used and the size of the inoculation hole was changed from 1/3 to 2/3, the browning period was shortened to 30 days. Mycelial growth was evaluated according to the cooling temperature after sterilization. It was observed to be the highest at 122 mm/15 days at $10^{\circ}C$ and 114 mm/15 days and 117 mm/15 days at $15^{\circ}C$ and $20^{\circ}C$, respectively. The contamination rate of the sawdust media before inoculation was measured as 0, $4.5{\times}10$, $1.3{\times}10^2$, $4.0{\times}10^3cfu$ at $5^{\circ}C$, $10^{\circ}C$, $15^{\circ}C$, and $24^{\circ}C$ respectively. The average of $1.6{\times}10^8$ colony forming units (cfu) of microorganisms was observed in the sawdust that had been piled for six months outdoors. In summer, the sawdust has to be used immediately after mixing. The sterilized medium had an average of $4{\times}10^3cfu$ of microorganisms at $24^{\circ}C$ and $1.3{\times}10^2cfu$ at $15^{\circ}C$. After 15 days of inoculation in vitro, the growth conditions of the sawdust was the best at 132 mm, followed by grain and liquid. When inoculated with liquid spawn, the moisture content of the substrate should be adjusted between 50% and 55% in advance.

• Korean Journal of Microbiology
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• v.32 no.3
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• pp.192-197
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• 1994

Pseudomonas fluorescens which is able to utilize malonate as a sole carbon source was found to contain a novel 60 kb plasmid, which encodes the genes for the proteins to assimilate malonate, including malonate decarboxylase and acetyl-CoA synthetase. The evidence is as follows: The Pseudomonas cured with mitomycin C was unable to grow on malonate-medium as well as it lost plasmid. The plasmid isolated from the Pseudomonas could be introduced into E. coli strain JM103 and DH1 by transformation. The transformed E. coli was able to grow on malonate-medium and could transmit its plasmid back to the cured P. fluorescens by conjugation. The existence of the plasmid in the transformed E. coli was confirmed by hybridization with a labeled probe prepared from 12 kb segment of the plasmid. Dot hybridization showed that the copy number of the plasmid in the transformed E. coli is at least 13 times higher than in the wild type P. fluorescens. The two key enzymes, malonate decarboxylase and acetyl-CoA synthetase, were inducible by malonate in the transformed E. coli.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.115-120
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• 2004

A Gram (-), rod-shaped bacterium in size of 1.3∼$1.8{\times}0.35{\mu}m$ inhibiting the growth of cyanobacterium (Ana-baena cylindrica) was isolated and designated NG-2 in this manuscript. This isolate showed positive reactions for catalase and oxidase, and optimal growth conditions of 35∼TEX>$40<^{\circ}C$ and pH 9.0. In a mixed-culture of A. cylindrica and the isolate, each microorganism grew inverse-proportionally, and the cyanobacterial vegetative cells almost completely disappeared within 24 hours. NG-2 lysed A. cylindrica only under light, which means that lytic activity of NG-2 was dependent on the photosynthetic activity of host. When observed under phase contrast microscope, the isolate lysed vegetative cells of A. cylindrica in scattered state in a liquid medium, whereas het-erocysts have not been lysed. When cyanobacterial cell walls have been lysed partly, NG-2 attatched around A. cylindrica filament and formed colony, then encouraged complete lysis of cyanobacterial cells. The isolate showed similar lytic activity in natural water as in an artificial medium. And lytic activity of NG-2 was enhanced when attached on expandable polystyrene bead.

• Journal of Mushroom
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• v.12 no.3
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• pp.216-219
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• 2014

Studies were made to optimize the media composition in bag culture and conducted to determine the possibility of artificial cultivation of Auricularia auricula. Sawdust spawn of media composition for optimal growth were found to be oak-sawdust 80%combination of 20% popla-sawdust were the best of the optimal combination. And optimal substrate combination were found to be cotton-seed meal combination of 10% wheat bran 5% mixed were the best of combination. The duration of spawn run period and primordial formation period on bag(1.2 kg) were 50 days and 7 days, respectively. The weight of fruiting body and the yield(100ea, 1.2 kg) of fresh fruit-body were 24 g and 45,000 g, respectively.

• Ocean and Polar Research
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• v.37 no.1
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• pp.61-71
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• 2015

Eicosapentaenoic acid (EPA) produced from marine organisms is widely used in nutraceuticals. Monodus subterraneus and Nannochloropsis oceanica, which are representative freshwater and marine Eustigmatophyceae, respectively, are known to have a high content of protein and lipid, particularly, EPA. In this study, to compare the growth and nutritional composition of M. subterraneus and N. oceanica, they were cultured in autotrophic and mixotrophic conditions with JM and f/2 medium, respectively, at $25^{\circ}C$. In addition, $80{\mu}mol\;photons\;m^{-2}s^{-1}$ with 24-hour and 12-hour light was provided, with the addition of 2% glucose to the medium for the mixotrophic culture. With regard to growth, M. subterraneus showed 10 times higher biomass in a mixotrophic culture than in an autotrophic one. However, no significant difference was observed for N. oceanica between the two culture methods. With respect to nutritional composition, M. subterraneus cultured autotrophically had a higher protein and lipid content, particularly EPA, than that cultured mixotrophically, but no significant difference was found in the two cultures of N. oceanica. Furthermore, M. subterraneus cultured autotrophically with continuous light showed higher nutritional composition, particularly EPA, than N. oceanica. In conclusion, the mass culture of freshwater M. subterraneus is much easier and more economical than marine N. oceanica. In addition, production of EPA will be economically improved if mixotrophic culturing of M. subterraneus is first conducted to maximize the biomass, and then secondary autotrophic culturing is performed.

• Journal of Mushroom
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• v.14 no.1
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• pp.14-20
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• 2016

This study was conducted to establish replacement the corncob used in winter mushroom bottle cultivation. Corncob is unstable quality in moisture content or total nitrogen(T-N) content. Fruit body yields according to the ratio of cassava stem chips mixing were compared. After treatment-1 and treatment-2, fruit body yields increased by 8.8% and 5.4% and raw material cost decreased by 7% and 19%. The results showed that cassava stem chips could replace 33% to 67% of corncob for winter mushroom bottle cultivation.

• Journal of Mushroom
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• v.15 no.3
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• pp.104-110
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• 2017

In order to determine the possibility of artificial cultivation of Ganoderma lucidum, a study was carried out to optimize the medium composition used for bed culture. Sawdust spawn of medium composition for optimal growth was found to be the combination of 75% oak-sawdust, 10% cotton-seed meal, and 15% beet pulp. The optimal conditions for the formation of fruiting bodies were shown to be a temperature of $28-30^{\circ}C$, light intensity of 1,000-1,500 lux, and $CO_2$ concentration of 1%.

• Journal of Mushroom
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• v.10 no.4
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• pp.174-178
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• 2012

This study were carried out to analyze nutritional ingredients of pre-inoculation and post-harvest Flammulina velutipes media. pH, moisture content, total carbon(T-C), total nitrogen(T-N), crude protein, crude fiber, and crude fat content on the 8 raw materials using Flammulina velutipes bottle cultivation medium, and after sterilization(pre-inoculation) and post-harvest medium was analyzed. This result is expected to be utilized as the basis for recycling post-harvest media.