Earticle

Over a million tons of spent mushroom substrate (SMS) are generated as by-products of mushroom cultivation every year in Korea. Disposal of SMS by mushroom farmers is difficult, therefore, recycling solutions that do not harm the environment are necessary. SMS consists of mushroom mycelia and residues of fruiting bodies, containing a variety of bioactive substances, such as extracellular enzymes, antimicrobial compounds, and secondary metabolites. This paper reviews utility of SMS for bioremediation, controlling plant disease, and production of lignocellulytic enzymes, organic fertilizer, and animal feed.

We investigated the correlation between density of air and the infection rate of airborne microorganisms in mushroom cultivation facilities and found that the correlation was low in places where the infection rate during cultivation was less than 1%. The farms with an infection rate of 2~5% showed a high infection rate in the inoculation room in spring and summer seasons, and in the incubation room in autumn, and the farms with an infection rate of more than 6% showed infection in all the rooms regardless of the season. The farms where the Trichoderma sp. was investigated at the time of the mushroom cultivation showed the highest infection rates of 3.17%, 2.74%, and 2.64% in summer, spring, and autumn, respectively. The farms infected with Neurospora tetrasperma showed a lesser rate of infection than the ones infected with Trichoderma sp., and the highest infection rate of 0.56% was observed in summer. Based on these results, the type of infection could be classified into five groups, where type I was farms where the infection rate is less than 1% in all seasons. Three farms belonged to this type, and the infection rate in this type was lower than that in the other types.

To improve the productivity of shiitake mushroom (Lentinula edodes), seven different types of media for liquid spawn (denoted as “A” to “G”) were prepared with 0.3% soybean meal and varying sugar and glucose concentrations. During 14 days of incubation, the pH of the liquid culture gradually acidified with increasing incubation period. Additionally, there was a significant, but not prominent, difference in the degree of acidification depending on the sugar to glucose ratio. Liquid spawn culture “G,” which had the highest sugar content was the most acidic on the last day of incubation. Mycelium dry weight increased significantly with increasing incubation period, and there was no significant difference in mycelium dry weight irrespective of the sugar to glucose ratio even after 14 days of culture. The inoculation of liquid spawn in sawdust medium with an inoculation volume ≥ 45 mL and incubation period of 15 to 18 days were the optimal culture conditions. Productivity of fruit bodies in sawdust medium and mushrooms treated with liquid spawn was significantly higher compared to solid spawn treatment. The mushrooms treated with liquid spawn had better chewiness, and the free amino acid content, which is associated with savory taste, was higher in these mushrooms compared to those treated with solid spawn.

This study was conducted to develop a healthy functional food material using mycelial extract of Phellinus sp. Jangsoo and GMPL48007 were selected as suitable strains because of good mycelial growth and high functionality. The highest total polyphenols and reducing power were observed in the Jangsoo strain and the radical scavenging was shown in GMPL48007. Among grains media, whole-grain wheat had the highest extraction yield from mycelia of selected strains; especially, the GMPL48007 strain showed the highest content of beta-glucan.

Oyster mushrooms are an economically important crop, accounting for 35% of the total mushroom production in Korea. In this study, we developed a new cultivar of Pleurotus ostreatus, known as ‘Baekseon,’ which is characterized by a white pileus with a white stipe. It was bred by mating monokaryons isolated from white mutant oyster mushrooms that were naturally generated from ‘Gonji-7ho’ and ‘Wonhyeong-1ho’ at the Mushroom Research Institute, GARES, Korea in 2018. The optimum temperature for mycelial growth on potato dextrose agar medium was approximately 28-31 °C, and the optimum temperatures for primordia formation and growth of fruit bodies on sawdust media were 22 °C and 20 °C, respectively. The time required for the bottle-cultured mushrooms to complete spawn running, primordia formation, and growth of fruit bodies was 30 days, 4 days, and 4 days, respectively. The fruit bodies were bundle-shaped, the pilei were round type and white, and the stipes were white. The stipes were slender and longer than those of the control (‘Miso’). In the productivity test, the yield per bottle was 185 g/1100 mL, which was 45% greater than that of the control (‘Miso’). In the farm test, the yield per bottle for Farm A (Pyeongtaek) and Farm B (Yeoju) was 184 g/1100 mL and 178 g/850 mL, respectively. With regard to the physical properties of fruit bodies, the springiness, cohesiveness, gumminess, and brittleness of stipe tissue were 80%, 57%, 720 g, and 57 kg, respectively. These values were lower than those of the control (‘Miso’). To test the shelf life, the fruit bodies were wrapped with antifogging film and stored at 4 °C for 28 days and then at room temperature for 4 days; such conditions were sufficient for maintaining edibility.

This study aims to report the results for the analysis of the growth environment by applying smart farm technology to “Chunchu No 2” farmers in order to develop an optimal growth model for precision cultivation of bottle-grown oyster mushrooms. The temperature, humidity, carbon dioxide concentration, and illumination data were collected and analyzed using an environmental sensor installed to obtain growth environment data from the oyster mushroom cultivator. Analysis of the collected temperature data revealed that the temperature at the time of granulation was 19.5oC after scraping, and the mushroom was generated and maintained at about 21oC until the bottle was flipped. When the fruiting body grew and approached harvest time, mushrooms were harvested while maintaining the temperature between 14oC and 18oC. The humidity was maintained at almost 100% during the complete growth stage. Carbon dioxide concentration gradually increased until 3 days after the beginning of cultivation, and then increased rapidly to almost 5,500 ppm. From the 6th day, carbon dioxide concentration was gradually decreased through ventilation and was maintained at 1,600 ppm during harvest. Light intensity of 8 lux was irradiated up to day 6 after seeding, and growth was then continued while periodically irradiating 4 lux light. The fruiting body characteristics of “Chunchu No 2” cultivated in the farmhouse were as follows: pileus diameter of 26.5 mm and thickness of 4.9 mm, stipe thickness of 8.9 mm, and length of 68.7 mm. The fruiting body yield was 166.8 g/850 ml, and the individual weight was 12.8 g/10 units.

This study sought to identify the optimum substrate composition for the stable bottle cultivation of Sparassis latifolia. The main substrate was fermented larch sawdust. Six nutrient sources were mixed at a maximum volume ratio of 20%. The fresh weight of fruit body was the highest at 128.5 g for GMSL69033 and 126.6 g for ‘Neoul’ in the treatments of beet pulp and corn flour in a volume ratio of 15:5. In addition, the total cultivation period was 94 days, which was shorter than that required for other treatments. The selected substrate characteristics were pH 4.7, C:N (carbon to nitrogen) ratio of 106:4, moisture content of 70%, and air filling porosity of 38%. We plan to develop new income items through research on mycelial incubation and fruit body growth conditions.

This study aimed to develop a new method of Lentinula edodes cultivation to reduce labor and waste disposal. To identify the optimum container for L. edodes cultivation, box, bottle, and bag containers were assessed for their effects on the cultural characteristics and mushroom yield. Among the three approaches, box-cultivation with 7 kg of substrate had the shortest browning period (42 days) and resulted in the highest mushroom yield (1,253 g). Contrastingly, bottle-cultivation was unsuitable for cultivation due to low production of the fruiting bodies and poor quality. Further studies on the box-cultivation approach will be required for commercial applications of L. edodes.

In this study, we analyze the antioxidant and anti-inflammatory activities of various extracts of Cryptoporus volvatus. Three extracts were prepared using hot-water, 70% ethanol, and 70% methanol. Compared to the hot-water and 70% methanol extracts, the 70% C. volvatus ethanol extracts showed significantly higher DPPH radical scavenging activities (76.1%), nitrite scavenging activities (29.5%), and total polyphenol content (9.17 mg GAE/g). The DPPH radical and nitrite scavenging activities of C. volvatus both correlated significantly with the total polyphenol content. The Pearson’s correlation coefficient of DPPH radical and nitrite scavenging activities with total polyphenol content were r = 0.744 (p<0.05) and r = 0.921 (p<0.01), respectively. To test their anti-inflammatory effects, nitric oxide production and cell viability were measured by performing nitric oxide (NO) and MTT assays on lipopolysaccharide-treated RAW 264.7 cells. The NO production levels of the 70% ethanol extract-treated cells were slightly lower than those of the others. In our MTT assay, the hot-water extracts showed higher cell viabilities (81.4%) than those of 70% ethanol and 70% methanol extracts. The ?-glucan content of C. volvatus was 37.8%. From the results of this study, it is suggested that C. volvatus, an easily accessible wild mushroom, has potential to be used in the development of medicines, cosmetics, and functional health foods.

The anti-oxidant activities and β-glucan contents of wild mushrooms collected from Songnisan, Soi-myeon, Joryeongsan, and Ganghwado, Korea, were investigated. Among the wild mushroom extracts, Pycnoporus sanguineus (OK1071), Piptoporus soloniensis (OK1090), and Daedalea dickinsii (OK1094) extracts showed the highest DPPH and ABTS+ radical scavenging activities. The nitrite scavenging activity and total polyphenol content of the extract of P. sanguineus (OK1071) was 74.2% and 37.7 mg GAE/g, respectively, and these values were much higher than those of the other mushrooms analyzed in this study. The Pearson’s correlation coefficients of the DPPH radical and nitrite scavenging activities with the total polyphenol contents of the wild mushroom extracts were r = 0.758 (p < .01) and r = 0.951 (p < .01), respectively. The β-glucan contents of Lenzites betulina (OK1040), Trametes versicolor (OK1044), and P. sanguineus (OK1071) were 47.8%, 43.9%, and 41.8%, respectively, which were higher than those of the other mushrooms. Therefore, the wild mushrooms analyzed were confirmed to have excellent antioxidant activities and high β-glucan contents. Accordingly, the fundamental data provided in this study can be used to isolate useful compounds from these wild mushrooms.

Phallus impudicus var. impudicus L. is an edible mushroom that has long been used as folk medicine in China. The aim of this study was to evaluate the antioxidant, anti-cholinesterase, and inflammation inhibitory activities of a methanol extract of fruiting bodies of P. impudicus var. impudicus L. The extract exhibited good 1,1-diphenyl-2-picrylhydrazyl scavenging activity, excellent ferrous ion chelating activity, and moderate hydroxyl radical scavenging activity compared with BHT at 2.0 mg/ml. However, the reducing power of the extract was significantly lower than that the BHT positive control. Although the inhibitory activities of methanol extract on acetylcholinesterase and butyryl cholinesterase were significantly lower than the galanthamine positive control at the concentration tested, the inhibition of acetylcholinesterase and butyryl cholinesterase was 52.83% and 55.17%, respectively, at 1.0 mg/ml. The methanol extract also demonstrated excellent inhibition of inflammation-related activities, such as production of nitric oxide in lipopolysaccharide-induced RAW 264.7 macrophage cells and acute edema induced by administration of carrageenan on the hind paw of rats. The collective results suggest that the fruiting body of P. impudicus var. impudicus L. might be a good source of antioxidant, anti-cholinesterase, and anti-inflammation compounds.

This study was carried out to investigate the optimum level of cottonseed meal in bottle cultivation of oyster mushrooms. Mycelial growth was slightly slower than that of the control at a cottonseed meal level ≤10%. Pileus diameter and thickness were highest at 14%, and stipe diameter was highest at 12% cotton seed meal. The hardness of pileus and stipe was greatest at 16% cotton seed meal. L-values tended to be lower at low levels of cotton seed meal, but the a- and b-values showed no significant difference among the treatments. The yield of fruiting body was 147.2 g/850 ml in the control and slightly higher at 147.6 g/850 ml using 12% cotton seed meal.

Cultivation of brown mushrooms, rather than that of white variants is preferred by Korean mushroom farmers, as the former are resistant to diseases. However, brown mushrooms were cultivated only in selective eco-friendly agricultural farms due to lack of consumer awareness. After providing information about brown mushrooms to respondents through a 1-minute video clip, a survey was conducted on social network service (SNS) to assess recognition and preference for brown mushrooms. A food evaluation was then conducted among 200 people randomly selected from the survey respondents. Most respondents (83%) had not encountered brown button mushrooms previously, and 98% of the respondents were willing to buy these mushrooms because they were “curious about its taste” (44%). In the food evaluation, 32% of the respondents found the brown button mushrooms to be delicious, 28% reported a good flavor, and 31% described a good texture. In addition, we confirmed that 95% of respondents were interested in purchasing brown mushrooms after sampling. Therefore, in the present study, we evaluated public perception, preference, and taste of brown button mushrooms, and confirmed that availability of information on nutrition and benefits s of mushroom consumption could induce consumers to buy brown button mushrooms.