• The Plant Pathology Journal
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• v.33 no.3
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• pp.264-275
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• 2017

The spent mushroom substrate (SMS) of Lentinula edodes that was derived from sawdust bag cultivation was used as materials for controlling Phytophthora blight disease of pepper. Water extract from SMS (WESMS) of L. edodes inhibited mycelial growth of Phytophthora capsici, suppressed Phytophthora blight disease of pepper seedlings by 65% and promoted growth of the plant over 30%. In high performance liquid chromatography (HPLC) analysis, oxalic acid was detected as the main organic acid compound in WESMS and inhibited the fungal mycelium at a minimum concentration of 200 mg/l. In quantitative real-time PCR, the transcriptional expression of CaBPR1 (PR protein 1), CaBGLU (${\beta}$-1,3-glucanase), CaPR-4 (PR protein 4), and CaPR-10 (PR protein 10) were significantly enhanced on WESMS and DL-${\beta}$-aminobutyric acid (BABA) treated pepper leaves. In addition, the salicylic acid content was also increased 4 to 6 folds in the WESMS and BABA treated pepper leaves compared to water treated leaf sample. These findings suggest that WESMS of L. edodes suppress Phytophthora blight disease of pepper through multiple effects including antifungal activity, plant growth promotion, and defense gene induction.

• Korean Journal Plant Pathology
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• v.10 no.3
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• pp.197-210
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• 1994

This experiment was carried out to study the cause of degeneration and rot of cultivated mushroom. Among 597 bacterial isolates derived from the rots of Button mushroom (Agaricus bisporus), Oyster mushroom (Pleurotus ostreatus) and Oak mushroom (Lentinus edodes) collected from markets of 5 cities (Seoul, Suwon, Taegu, Pohang and Pusan) in Korea (1991~1993), 111 bacterial isolates (18.5%) were proved as pathogenic bacteria. These pathogenic bacteria causing bacterial rots of cultivated mushrooms were identified as Pseudomonas tolasii, P. agarici, and Eriwinia sp., and the main causal bacteria were P. tolaasii. P. fluorescens and Klebsiella plenticola were confirmed as saprophytic non-pathogenic bacteria. One hundred fifty nine isolates (Group No. 39) of the 486 saprophytic bacterial isolates were classified as P. fluorescens, and this species was most often found rot area of cultivated mushrooms. P. tolaasii, the causal organism of bacterial blotch, was classified into two groups; One group can be differentiated from the other by the formation of white precipitation band by white line reacting organisms of Pseudomonas Agar F media. P. tolaasii attacked the cultivated mushrooms relatively well at lower incubation temperature such as 5$^{\circ}C$, but P. agarici rarely attack at below 1$0^{\circ}C$. The temperature for the infection commercial cultivated mushrooms by P. agarici was higher than that of P. tolaasii. Optimum temperature for the infection of mushrooms by P. tolaasii and P. agarici were 2$0^{\circ}C$ and $25^{\circ}C$, respectively.

• Journal of Physiology & Pathology in Korean Medicine
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• v.27 no.2
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• pp.239-245
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• 2013

In in vitro study, the anti-platelet aggregation effect of Shiitake mushroom extract was examined by measuring the collagen induced platelet aggregation and the DPPH radical scavenging. In in vitro study, anti-thrombotic effect of Shiitake mushroom extract was examined using the carotid artery thrombosis rat model. Carotid artery thrombosis rat model was made by 35% $FeCl_3$ treatment. After that, we investigate thrombus weight and blood flow. In platelet aggregation test, the extract significantly inhibited platelet aggregation in a concentration dependent manner(p<.001). Also, extract increased DPPH radical scavenging activity in a concentration dependent manner. Extract significantly inhibited thrombus weight to compare with control group. And blood passage time were shorter in the Shiitake mushroom extract supplemented groups than in control group. These results provide experimental evidence that Shiitake mushroom can be used to prevent platelet aggregation and thrombosis, then could apply the clinical diseases such as cardiovascular disease, and so on.

• The Korean Journal of Mycology
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• v.41 no.4
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• pp.248-254
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• 2013

A Gram-negative bacterium was isolated from mushroom media that markedly reduces the level of extracellular toxins (i.e., tolaasins) produced by Pseudomonas tolaasii, the most destructive pathogen of cultivated mushrooms. The HC1 strain was selected as detoxifying tolaasin by bioassay on potato and it was identified Pseudomonas sp. by the cultural, morphological and physiological characteristics, and analysis of the 16S rRNA. The isolated bacterium is saprophytic but not parasitic nor pathogenic to cultivation mushroom. The isolated bacterium for P. tolaasii cell, was sufficient for detoxification in vitro. Inoculation of the isolated bacterium prevents the development of bacterial disease in Pleurotus ostreatus, Flammunia velutipes and Agaricus bisporus. Control efficacy of brown blotch of strain HC1 treatment was 69, 68 and 55% on Agaricus bisporus, Flammulina velutipes and Pleurotus ostreatus, respectively. The suppressive bacterium may be useful in future for the development of biocontrol system and the construction of genetically modified edible fungi resistant to the disease caused by P. tolaasii.

• Journal of Food Hygiene and Safety
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• v.16 no.3
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• pp.232-240
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• 2001

One hundred twenty five bacterial isolates were obtained from the brown blotch-diseased oyster mushrooms collected from markets. Among them, 45 were determined as pathogenic bacteria and white line forming organisms(WLFO) were 6 strains and white line reaction organisms (WLRO) were 6 strains. All of the white line forming isolates were identified as Pseudomonas tolaasii which is a known pathogen of brown blotch disease of oyster mushroom by GC-MIS(Gas chromatography-microbial identification system). Six of the white line reacting organisms were identified as P. chlomraphis, P. fluorescens biotype A and type C. The rest of them were P gingeri, P. agarici, P. fluorescens biotype B, P. chloroyaphis, non-pathogenic P. tolaasii, P. putida biotype A and B etc. For spectrum of activity of tolaasin, culture filtrates from pathogenic isolates were examined by browning of mushroom tissue and pitting of mushroom caps. The weak pathogenic bacteria didn't induce browning or pitting of mushroom tissue. On the other hand, strong pathogenic isolates showed browning and pitting reaction on mushroom. An extracellular toxin produced by P. tolaasii, was investigated. The hemolysis activity test of 6 strains identified as P. tolaasii were 0.8∼0.9 at 600 nm and 3 strains of WLRO were 0.9∼1.0 and Pseudomonas app. were 1.0∼1.2. Observation of fresh mushroom tissue using confocal laser scanning microscopy was carried out for images of optical sectioning and vertical sectioning. Also images of brown blotch diseased oyster mushroom tissue after contamination P. tolaasii was obtained by CLSM.

• Journal of Mushroom
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• v.8 no.4
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• pp.157-160
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• 2010

Agaricus blazei Murill is a important medicinal mushroom for a powerful immune system builder and tonic. Currently, it is known about a new disease phenomenon that appears to be occurring on a number of mushroom farms. We described a straightforward approach in which molecular methods was used to survey the presence of potentially endo- and epiphytic bacteria infected with the Agaricus blazei. The 16S rDNA was amplified with universal eubacterial primers directly from pure cultures of Agaricus blazei mycelium and fruit body. The 16S rDNA sequences were almost identical (96 to 97% similarity), and phylogenetic analysis placed them in a single unique rRNA branch belong to the uncultural bacterium phylogroup. PCR detection of uncultural bacterium in the malformed tissues of Agaricus blazei were carried out by using 16S rRNA sequenced specific probe. It was strongly amplified at the malformed pileus region of fruit body and also spore print was impossible.

• Journal of Mushroom
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• v.8 no.3
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• pp.122-130
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• 2010

Common mushroom production per area has been decreased and are up to less than 50% of the 1980 production. To determine the main reasons for the decrement, we performed this study. Two main reasons, which are mushroom disease and the low compost quality because of mechanized compost making, were assessed. In mechanized mushroom farms, nitrogen concentration in compost was lower than recommended and total compost quantity was about 100-150 $kg/3.3m^2$, which was also lower than usual. Our study revealed that higher nitrogen concentration (about 1.5%) in compost gave better production. Also, use of large amount of compost appeared to increase the mushroom production, although more insects and disease problems were observed. The relationships between the presences of microorganisms and occurrence of diseases were assessed by monitoring the microorganism densities near the mushroom farms. Higher number of microorganisms were observed near the mushroom farm area, compared to control region, Daechon beach. Most contaminating molds were found in the circulating fans, tunnel and culture room floor. The bacterial isolates were collected from the air in mushroom culture room and killed with 0.005% Benzalkonium solution, indicating treatment of Benzalkonium are the effective methods to sanitize the mushroom culture room.

• Journal of Mushroom
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• v.12 no.3
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• pp.220-225
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• 2014

This study was conducted to set the proper sterilization standards of casing soil for the stable production of button mushroom(Agaricus bisporus) from mushroom disease that occurs in infection of casing soil material. Changes of aerobic bacteria are increased as the longer grow-out period and sharply increased after second flushes. Fluorescence Psuedomonas showed high density at high sterilization temperature and $100^{\circ}C$ treatment has extremely high density at 30 min and 60 min in casing 22 days. Density of thermophilic actinomyces is sharply increase from casing with soil and the highest density at 22 days of casing and rapidly decrease after first flushes. Sterilizing temperature of casing soil affects quality and quantity of button mushroom. Treatment of 60 min, 90 min at $80^{\circ}C$ and 30 min at $100^{\circ}C$ produced the highest mushroom yields, especially mushrooms yields of A grads were the highest at treatment of 90 min at $80^{\circ}C$. Treatment of 60min at $100^{\circ}C$ products many yields, however, this treatment has low economic feasibility for its yields. Sterilizing temperature of casing soil has an effect on generating diseases and insect pests. Treatment of 60 min, 90 min at $80^{\circ}C$ and 30 min $100^{\circ}C$ showed lower incidence than the other treatment. Although treatment of 30 min at $100^{\circ}C$ causes low diseases and mushroom fly damage, it has low mushroom yields. Furthermore, although treatment of 60 min at $100^{\circ}C$ has high mushroom yields, it causes high diseases and mushroom fly damage. Therefore the best conditions for the sterilization of casing soils was 60 min and 90 min at $80^{\circ}C$.

• Journal of Mushroom
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• v.21 no.3
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• pp.140-144
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• 2023

The objective of this study was to achieve biological control of green mold disease in Pyogo mushrooms using antagonistic microorganisms. Bacillus subtilis BSM320 cells inhibited mycelial growth by 48-60% against three Trichodermaisolates including T. hazianumisolated from the substrates of Lentinula edodes, showing their antifungal activity.The bacteria were cultured to a high density of 4.2 × 10⁹±113.7 cfu/mlin aqueous extract of composted spent mushroom substrates of L. edodes containing 1% glucose and showed a higher growth rate than that observed when using the commercial medium, Luria-Bertani broth. The bacterial culture showed a 75% protective effect without damaging the mushroom fruiting bodies. These results suggest that B. subtilis BSM320culture is suitable for biological control of green mold disease during mushroom cultivation.

• Journal of Mushroom
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• v.13 no.2
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• pp.97-102
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• 2015

This study was conducted to investigate optimum conditions for mass production of antagonistic microbes Pseudomonas azotoformans HC5. P. azotoformans HC5 is a potent biological control agent to control brown blotch disease caused by Pseudomonas tolaasii. This markedly showed the antagonistic activity against P. tolaasii, the most destructive pathogen of cultivated mushrooms. To define the optimum conditions for the mass production of the P. azotoformans HC5, we have investigated optimum culture conditions and effects of various nutrient source on the bacterial growth. The optimum initial pH and temperature were determined as pH 6.0 and $15^{\circ}C$, respectively. The optimal concentration of medium elements for the growth of pathogen inhibitor bacterium was determined as follows: 0.6% adonitol, 1.5% yeast extract, 0.8% $NH_4H_2PO_4$, 5mM $MgSO_4$, and 0.2% asparagine.