Earticle

Mushroom is well known for a safe food for a long time and, what is more, has a lot of useful characteristics related on the pharmacological activities. It is expected to be one of the most important functional food due to its diverse bioactive compounds. Especially, medical potentiality on immunomodulator and antitumor continues to be focused. Recent research trend and commercialization of functional healthy food using mushroom and its bioactive compounds will be herein introduced. Industrialization of mushroom functional substances will be also discussed.

This experiment was carried out to examine physiological and cultural characteristics of two strains ASI 19003, 'Poplar field-cap mushroom' Agrocybe cylindracea, and ASI 19016, 'Chaxingo' A. chaxingu, at the bottle cultivation which have very similar morphological characteristics in genus Agrocybe. There was significant difference between the physiological and cultural characteristics of ASI19003 and ASI19016. The optimal temperature for the hyphal growth was 28℃ in the strain ASI19003 and 30℃ in ASI19016. The optimal pH was not different in two strains and these strains grew well at pH 5.5∼7.0. But the optimal pH in the submerged culture was 5.5 in ASI19003 and 5.0 in ASI19016. Especially, hyphal growth of the strain ASI19016 was very poor at pH 6.0∼7.3. The optimal carbon source for the growth was lactose in the strain ASI19003 and fructose in ASI19016, and nitrate sources were asparagine, alanine, and glycine in the strain ASI19003, and ammonium tartrate, asparagine, glycine, and alanine in ASI19016, respectively. The periods of incubation and fruiting body formation in the bottle cultivation during the spring were 27 and 13 days in the strain ASI19003, 29 and 17 days in ASI19016. The yields of fruit body were 114 g per bottle (850 ㎖ volume) in the strain ASI19003 and 100 g in ASI19016. In the summer, the periods of hyphal incubation and fruiting body formation were 29 and 11 days in the strain ASI19003, 30 and 12 days in ASI19016. The color of the cap in the ASI19003 strain according to temperature increase during the fruit body development become more pale, but the strain ASI19016 kept dark color relative to ASI19003. The fruiting body formation of the strain ASI19016 was faster than that of ASI19003. Accordingly, the cultivation of A. cylindracea ASI19003 during the spring, fall and winter, and A. chaxingu ASI19016 during the summer can keep high quality and stable supply all year round of these mushrooms.

The stromatal forms of T. fuciformis and the mycelia of Hypoxylon sp. were collected. The DNA sequence in the ITS region of the 5.8S ribosomal genes of isolated strain KG103 was very similar to that of T. fuciformis AF042409 with a homology of over 98% in the EMBL/GenBank database through BLAST searching. A second isolate, No KG201, one of the symbiotic strains for cultivating T. fuciformis also exhibited high homology with Annulohhypoxylon stygium AJ390406. Potato Dextrose Medium exhibited the best mycelial growth of 14 ㎜/14 days and 85 ㎜/14 days for T. fuciformis and its symbiotic fungi, respectively. Optimum culture conditions for the micelial growth were pH 5 at 25℃. For the optimization of artificial cultivation of T. fuciformis in bottle with sawdust medium, several conditions such as type of sawdust, supplements, pH, moisture content, and incubation temperature were investigated. T. fuciformis and symbiotic fungi showed fast mycelial growth on corn cob media (77 and 52%) followed by oak tree sawdust and cotton seed meal. The optimal temperature for mycelial growth of T. fuciformis and symbiotic fungi on corn cob media was 25 ℃ at 55% of moisture content.

The optimization of submerged culture conditions for mycelial growth and exopolysaccharide (EPS) production in an edible mushroom Tremella fuciformis were studied in shake flasks and bioreactors. The temperature of 28℃ and pH 8 in the beginning of fermentation in agitated flasks was the most efficient condition to obtain maximum mycelial biomass and EPS. The optimal medium constituents were as follows (g l-1): glucose 20, tryptone 2, KH2PO4 0.46, K2HPO4 1 and MgSO4H2O 0.5. The fungus was cultivated under various agitation and aeration conditions in a 5L stirredtank bioreactor. The maximum cell mass and EPS production were obtained at a relatively high agitation speed of 200 rpm and at an aeration rate of 2 vvm. The flow behavior of the fermentation broth was Newtonian and the maximum apparent viscosity (35 cP) was observed at a highly aerated condition (2 vvm). The EPS productivity in an airlift reactor was higher than that in the stirred-tank reactor. The EPS was protein-bound polysaccharides consisted of mainly mannose, xylose, and fructose. The molecular weights of EPS were determined to be 1.3~1.5×106.

This study was carried out to investigate the growth inhibition of Propionibacterium acnes by mycelial culture broth of Paecilomyces japonica in the Mulberry leaf extract. The growth inhibition effect of P. japonica mycelial culture broth against P. acnes in various concentration of Mulberry leaf extract was the most effective in 3% Mulberry leaf extract. The inhibition effect of P. japonica mycelial culture broth against P. acnes according to the culture time was the moust effective after 25 days mycelial cultivation. As the treating amount of the mycelial culture broth was increased, the growth inhibition effect against P. acnes was increased gradually. The growth inhibition effect of mycelial culture broth against P. acnes according to the time of heat treatment was active by 45min at 100℃, while it was inactive more than 60min at 100℃. This result suggested that the antibacterial materials are possible to be glycoside or peptides. Taken together P. japonica mycelial culture in the Mulbarry leaf extract has a possibility to be an element of skin -care cosmetics regulating the acnes.

Studies were processed to confirm the difference of the shiitake productivity according to different spawn shapes(sawdust, plug-shaped and liquid spawns) on middle-temperature type strain. A tendency of fruiting was similar among three treatments, and treatments inoculated with plug-shaped spawn and liquid spawn produced over 50 % of total yield until 2nd flushing period and 80 % of total yield until 4th flushing period. In investigation of deformed fruitbodies, all of three treatments occurred until 2nd flushing period. However, in rate of deformed fruit-bodies, treatment inoculated with liquid spawn was lower than others. In investigation of yield, the amount produced on treatment inoculated with liquid spawn was 411 g per medium and it was highest among treatments. And the amount of fruit-bodies over 10 g was higher than others. Also, the number of fruit-bodies between sawdust and plug-shaped spawn was different, but each weight of fruit-bodies among three treatments was not different.