Earticle

In this study, to produce Flammulina velutipes mushroom liquid spawn efficiently and effectively the effects of explosive aeration (supplying air with tiny bubbles) of the liquid culture medium on carbon dioxide concentration and residual sugar content in the medium on carbon dioxide concentration and residual sugar contentin the medium were measured. Carbon dioxide concentrations were measured at the outlet of the incubator. On the third day the explosive aeration greatly increased mycelial growth of the liquid spawn, and carbon dioxide concentration also greatly increased but decreased after 5 days. Free sugar contents in the liquid culture consistantly decreased up to 7 days and thereafter was not detected. The weight of the mycelia were maintained similar levels after 3 days. Total nitrogen content in the liquid medium constantly decreased during the 11days of explosive aeration. The content of free sugars in 7 days of culture was the lowest level, thus the inoculum incubated for 6~7 days was thought to be the most effective. Carbon dioxide concentration measurement at the outlet of the container during the liquid spawn incubation required low cost but was efficient to estimate the degree of mycelial growth to be used as a simple indicator.

This study was carried out to investigated optimum mixing ratio of Korean natural Lindera glauca for production of functional oyster mushroom. Total nitrogen and carbon source of Lindera glauca was 0.16% and 40.9%, respectively and C/N ratio was 215. Total nitrogen source and pH of substrate mixed with Lindera glauca was 2.8~3.0 and 4.8~5.0, respectively. The contents of P2O5, CaO, MgO and Na2O were increased by increasing Lindera glauca, but there was no significant difference in K2O content. Mycerial growth was faster at Lindera glauca treatments than that of control. Yields of fruiting body was the highest at Lindera glauca 20%, and dimeter and thick of pileus were increased according to increase of Lindera glauca addition ratio. The L value of pileus was the highest at the Lindera glauca 10% during mushroom harvest, but there was no significant difference in the a-value and the b-value.

Ventilation effects of bottles(1,100㎖) for culturing Flammulina velutipes on its mycelial growth and mushroom production were investigated. The degree of ventilation were controlled with hole positions, upper and under, and hole sizes in the bottle lids. The ventilation effects were measured with the contents of carbon dioxide, free sugars, chitin, moisture in the bottles and with the amount of produced mushrooms from the bottles. Carbon dioxide concentrations within the culturing bottles at exponential mycelial growth period vertex were relatively high in the bottles with lids without both a sponge and an aeration hole, and in those with a smaller hole. Free sugar contents in the mycelia were the highest in those with a 47mm hole on both sides, and in those with 26~33mm holes only underside. Chitin content was the highest in those with a 26mm hole only underside. On the other hand, the lids with 42mm~47mm holes on the both sides greatly lost water and decreased the mushroom production. In conclusion, the most efficient ventilation hole sizes on the lids for bottle(1,100㎖) cultivation of Flammulina velutipes using 1,100㎖ polypropylene bottle were 19mm on both sides of the lid and 26mm on only underside. They produced more mushrooms than the control by 6~9 %.

Studies were made to optimize the media composition and cultural condition for mycelial growth of Agrocybe cylindracea. Sawdust spawn of media composition for optimal growth was found to be pine sawdust combination of 30% wheat bran and poplar sawdust combination of 20% corn bran were the best of the optimal combination. The optimal concentration of white sugar was 1.0~1.5%. The nitrogen sources was found to be yeast extract and soybean powder. Also, optimal concentration were 0.7g/ℓand 0.1g/ℓ, respectively. The mineral sources of optimal medium compositions were MgSO4·7H2O 0.3g/ℓ, KH2PO4 0.5g/ℓand K2HPO 1.2g/ℓ. Optimal amount of inoculum for cultivation of A. cylindracea were 20~25g/850㎖ and 25㎖/850㎖ in the sawdust spawn and liquid spawn, respectively.

We conducted an analysis by comparing the nutritional contents of Auricularia auricula-judae(black), Auricularia polytricha and Auricularia auricula-judae (brown). In nutritional contents of three strains of Auricularia spp., four free sugars, seven organic acids and 24 amino acids were detected. Auricularia auricula-judae (black) was highly contained free sugar, organic acid and amino acid. There was the most prevalent Vitamin D2 content in Auricularia auricula-judae (black) of Auricularia spp. Dietary fiber of three strains showed contents of about 60% but were not significantly different. ß-glucan contents of Auricularia auriculajudae (brown) contained the highest contents with 25.21±0.37% and showed significant differences between Auricularia polytricha and Auricularia auricula-judae (black). Total polyphenol contents of Auricularia polytricha showed the highest contents, followed by Auricularia auricula-judae (brown) and Auricularia auricula-judae (black).

This study was carried to identify a correct species and asses genetic diversity within the same species of Polyporus spp. preserved in Division of applied Microbiology. Contaminated isolates showed different growth rates, morphology and color of hyphae. We have reconstructed the phylogenetic tree of a select group of Polyporus spp. using nucleotide sequences of the internal transcribed spacer region(ITS) region. The phylogenetic tree was constructed by using the neighbor-joining method. PELF primers of 20-mer were used to assess genetic diversity of preserved isolates. Sequence analysis showed that three strains were different species and four strains were identified completely different nomenclature. According to the analysis of ITS sequences, the genus Polyporus clustered into five distinct group, most of which correlated with species-groups identified by RAPD method. Four isolates included strain PM02 showed high similarity with P. arcularius, four isolates included strain PM03 high similarity with P. alveolaris, three isolates included strain PM01 high similarity with P. tuberaster, and PM 06 and PM04 high similarity with P. brumalis and P. squamossus. Isolates were collected in the United States(PM10, PM11) was identified as P. alveolarius and P. arcularius. RAPD analysis of genetic polymorphisms of genus Polyporus showed a very different band patterns. As the result of RAPD and ITS region sequences analysis for preserved isolates, it seems likely that 6 isolates of Polyporus spp. may be need to reclassify or eliminate from preserved catalogue.

In this study, whether Giemsa staining solution can accurately determine bacterial contamination of liquid spawn for Flammulina velutipes in a short period of time was investigated. Giemsa solution staining cells of blood, bone marrow, lymph node, malaria parasites, rickettsia et al. was prepared by dissolving basic methylene azul and methylene blue, and acidic eosine in methyl alcohol-glycerine. Supernatant samples of Flammulina velutipes liquid spawn cultured under explosive aeration were placed on a slide, mixed with Gimesa solution and examined with optical microscope after staining. In 40 to 60 seconds bacterial cells were distinguishable from soybean meal residual and hyphal cell fragments. Thus we conclude that microscopy using Gimesa staining solution is a quick, simple and accurate method for the mushroom growers to effectively use to detect bacterial contamination of the liquid spawn.