• The Korean Journal of Mycology
• /
• v.28 no.2
• /
• pp.73-80
• /
• 2000

This study was carried out to investigate the optimal mycelial growth and an artificial cultivation conditions of Pleurotus eryngii. The optimal medium for the mycelial growth and density was MYPA medium. The optimal temperature and pH for the mycelial growth were $25^{\circ}C$ and 6.0, respectively. The modified optimal medium composition were obtained to be soluble starch 3%(w/v), malt extract 0.25%(w/v), yeast extract 0.25%(w/v) and $CaCl_2{\cdot}2H_2O$ 0.05% (w/v). From the results of experiment on the nutritional requirements, the modified optimal medium was higher than MYP medium in mycelial production and growth yield (Yx/s) of Pleurotus eryngii. The optimal sawdust species of solid culture for the mycelial growth and density was Quercus spp. The optimal concentration of additives (rice bran and wheat bran) and moisture content for the mycelial growth were about 30%(v/v) and 70%(v/v), respectively. On the other hand, the optimal concentration of additives for the production of fruiting body was 20%(v/v) of rice bran.

• Microbiology and Biotechnology Letters
• /
• v.23 no.2
• /
• pp.236-242
• /
• 1995

Biological control of soilborne plant pathogens by the addition of antagonistic microorganisms to the soil may offer a practical supplement or alternative to existing disease management strategies that depend heavily on chemical pesticides. Soil amendment with antagonistic microbes was non-effective because of high cost, low efficacy, and inconvenient usage on the treatment course. Therefore, seed coating formulation for the application of biological seed treatments has been being to apply successful disease suppression for many important crops. The objectives of this study were to investigate the optimal condition for the spore production of biocontrol agent Bacillus subtilis YBL-7 and the liquid coating formulation that contained a suspension of a proper aqueous binder, as well as a ground fine solid particulate material. The maximum yield has been obtained from 60 hrs-old culture at 30$\circ$C in spore forming (SF) medium containing 0.8% nutrient broth, 0.05% yeast extract, 10$^{-1}$ M MgCl$^{2}$, 10$^{-4}$ M MnCl$^{2}$, 10$^{-5}$ M dipicolinic acid, and pH 6.5. The optimal condition of dried spore preparation was achieved when cells of B. subtilis YBL-7 was heat-dried with 50$\circ$C for 2 hrs.

• Microbiology and Biotechnology Letters
• /
• v.26 no.1
• /
• pp.40-44
• /
• 1998

A Penicillium strain which produces $eta$-galactosidase with high transgalactosylation activity, was isolated from soil and registered as Penicillium sp, KFCC 10888. When $eta$-galactosidase from Penicillium sp. KFCC 10855 reacted with 40% lactose, transgalactosylation ratio reached up to 70% at the 73% conversion of initial lactose. The biosynthesis of the enzyme in Penicillium sp. KFCC 10888 was not induced by lactose. The soybean meal was an effective component of the culture medium. The optimum pH and temperature for transgalactosylation were 4.0 and 55$^{\circ}C$, respectively. The production of galactooligosaccharides was in proportion to the initial lactose concentration. When the enzyme reacted with 40% lactose (pH 4.0) at 55$^{\circ}C$, the concentration of galactooligosaccharides increased up to 40% of total solid concentration.

• Korean Journal of Agricultural Science
• /
• v.7 no.1
• /
• pp.44-51
• /
• 1980

The population of indole-forming thermophile was obtained for the first time several samples of soil and compost manure. The population was highly enriched by successive transfer in the tryptophan liquid medium treated with antibiotics and dilution subculture cloning. Both indole-forming thermophile might be a Gram-negative bacterium hitherto unknown, but its pure culture has not yet been established due to the inability to grow on the solid media.

• Journal of Marine Bioscience and Biotechnology
• /
• v.16 no.1
• /
• pp.26-35
• /
• 2024

Chlorella has various biotechnological applications, including in the biomedical and pharmaceutical industries, because of its advantages, including rich nutrients, fast growth rate, easy cultivation, and high biomass. We used the Agrobacterium-mediated transformation method to express human GM-CSF and EGF proteins, which are widely used in regenerative medicine, cosmetics, and pharmaceutical materials in Chlorella. The codon-optimized hGM-CSF and hEGF genes were cloned into plant binary vectors and transformed into Chlorella vulgaris using the Agrobacterium-mediated coculture transformation method. After transformation, genomic DNA PCR was performed for each C. vulgaris line that was stably subcultured on an antibiotic-resistant solid medium to confirm the insertion of hGM-CSF and hEGF into the chromosome. Furthermore, PT-PCR and protein expression of hGM-CSF and hEGF in each transformed C. vulgaris were significantly increased compared to the untransformed Chlorella. This study suggests that high-value proteins, including hGM-CSF and hEGF, which are foreign genes of C. vulgaris, can be stably expressed through the Agrobacterium-mediated Chlorella transformation system.

• The Korean Journal of Mycology
• /
• v.32 no.2
• /
• pp.134-137
• /
• 2004

This study was carried out to determine the optimum culture conditions for Phellinus spp. known as white rot fungi showing anti-cancer activity. The optimum solid medium for mycelial growth at $25^{\circ}C$ was potato dextrose agar medium and optimum pH range was $6.0{\sim}8.0$, while all species showed reduced or no growth at pH 4.0. Most species showed good growth at $25{\sim}30^{\circ}C$. Out of 10 species of Phellinus examined, P. biscuspidatus was the best growing fungus in the range of pH $6.0{\sim}7.0$ based on mycelial density. Three species such as P. biscuspidatus, P. johnsonianus and P. lloydii could be grouped in mesophile fungi, showing $30{\sim}35^{\circ}C$ optimum temperature.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.48 no.1
• /
• pp.38-43
• /
• 2003

Immature and mature embryos of 18 Korean wheat genotypes were cultured in vitro to develop an efficient method of callus formation and plant regeneration, and to compare the responses of both embryo cultures. Immature and mature embryos were placed on a solid agar medium containing the MS salts and vitamins, 30g/l maltose, 2 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D), and amino acids. The developed calli were maintained on regeneration medium containing MS salts and B5 vitamins, 20 g/l sucrose, and the combination of two plant growth regulators, 6-benzylaminopurine (BAP) and indole-3-acetic acid (IAA). Immature embryos in most genotypes showed high efficiency of callus induction except three genotypes; Eunpamil, Chunggemil, and Namhaemil, and significant differences among the genotypes. Plant regeneration of calli induced from immature embryos showed high efficiency in Geurumil (56.5%), Tapdongmil (50.5%), Gobunmil (45.5%), and Urimil(42.2%). The analysis of variance showed significant differences for regeneration frequency among the genotypes. Mature embryos showed low callus induction frequency compared with that in immature embryos, and significant differences among the genotypes. Plant regeneration of calli induced from mature embryos showed high efficiency in Keumkangmil (33.33%), Tapdongmil(28.13%), and Geurumil (27.78%). The analysis of variance showed significant differences for plant regeneration frequency among the genotypes.

• Journal of Plant Biotechnology
• /
• v.32 no.1
• /
• pp.37-44
• /
• 2005

Microspores were isolated from pepper (Capsicum annuum L.) anthers by using a micro-blender and cultured in modified NLN medium at $25^{\circ}C$. The influence of pretreatment period at $32^{\circ}C$, adding the 2-hydroxynicotinic acid to a pretreatment medium, and co-pretreatment anthers with microscopes on the induction of embryo were examined. Globular and torpedo embryos were observed from 3 weeks after culture. Embryo development was not synchronized within culture. After 4 weeks in culture, in addition to globular and torpedo embryos, cotyledonary embryos were observed. Normal cotylodonary embryos developed into plantlets when transferred to a solid hormone free B5 medium containing $2\%$ sucrose. Embryo yields were significantly higher after 1- and 2-day pretreatment at $32^{\circ}C$. However the development of embryo ceased at the globular or heart stage. In contrast, embryo yields were lower after 3- to 6-day pretreatment at $32^{\circ}C$ and embryo developed at the cotyledonary stage. After adding the 2-hydroxynicotinic acid to anther pretreatment solution, embryo yields were slightly increased. However most embryos occurred were at the globular or heart stage. Co-pretreatment of microspores with anthers was deleterious for embryo induction and development. AS far as we know, this is the first report of success in obtaining high frequency of embryogenesis and plantlets formation from isolated microspores of pepper. Although the culture conditions have to be optimized further, this promising microspore culture system can be used for genetic transformation, selection for dominant and recessive traits as well as for the production of homozygous doubled haploid plants.

• Journal of Korean Society of Forest Science
• /
• v.101 no.1
• /
• pp.158-162
• /
• 2012

The acclimatization of in vitro propagated plants is an important step to produce vigorous plants for clonal forestry and in vitro micro-environment may affect the growth in ex vitro condition. To monitor in vitro environmental effects on the growth in ex vitro condition, several culture systems such semi-solid medium(SS), temporary immersion bioreactor(TIB) and continuous immersion bioreactor(CIB) culture types were tested to compare for the growth of acclimated plants of Liriodendron tulipifera. Results suggested that morphological characters, stomatal conductance, evapotranspiration and chlorophyll contents of acclimated plants were affected by the different of in vitro culture conditions. CIB type of culture was resulted to the lowest value in the biomass of acclimated plants. Net photosynthsis rate of CIB was the same level as those of SS and TIB. However, stomatal conductance, evapotranspiration and $CO_2$ partial pressure in the intercellular air space were lower than those of SS and TIB. The amounts of chlorophyll a, b and carotenoids were also lower than those of the other two culture systems. TIB, showing a little lower or higher value than SS in many growth character, is recommended rather than CIB to produce healthy yellow poplar plants in ex situ condition.

• KSBB Journal
• /
• v.26 no.3
• /
• pp.229-236
• /
• 2011

An efficient screening method was developed for rapid selection of a few overproducers of itaconic acid (IA) among the great many mutants derived from mother strains of Aspergillus terreus. For this purpose, an attempt was made to reveal the relationships of the growth rate and sporulation of each mutant on PDA solid medium with its IA productivity in the final liquid production-culture. As a result, it was possible to classify the mutated strains into 5 groups (from [A] to [E] group) according to theirmorphologies (i.e., growth rate and sporulation extent) on the PDA slants. Notably, most of the high-yielding mutants of IA were observed to belong to [A]group which had the properties of the highest growth rate and sporulation among the 5 groups, whereas the mutant groups of [C], [D] and [E] with the contrasting morphological features showed significant reductions in their IA productivities. From these results, it was concluded that the probability of selecting IA overproducing mutants could be remarkably enhanced when the mutated colonies showing faster growth rates are firstly selected on the PDA plate, and then further screening process is performed on the basis of the sporulation extents of the mutants selected. Consequently, through the application of the strategy developed in this study, costs and time involvedin the labor-intensive task of strain improvement could be reduced to a great extent, because the time-consuming liquid culture processes did not need to performed for the unfavorable mutants belonging to the groups other than group [A].