The present study was carried out to investigate the concentration and species diversity of airborne fungi in thermophilic mushroom cultivation houses. Fungal concentration measurements were performed in April and May 2022 for a Pleurotus ostreatus cultivation house, in July and August 2023 for a Pleurotus sajor-caju and Agaricus blazei cultivation house, and in June, July and August 2023 for a Pleurotus pulmonarius, Pleurotus sajor-caju and Calocybe indica cultivation house. The airborne fungal concentration was 2.95 × 102 CFU/m3~105CFU/m3, above 105CFU/m3, and 1.12 × 103 CFU/m3~ 9.17 × 103 CFU/m3 in the three cultivation houses, respectively. A total of 8 genera and 22 species of airborne fungi were isolated from three mushroom cultivation houses. 5 genera and 7 species were identified from P. ostreatus cultivation house. Furthermore, 4 genera 6 species were found from A. blazei and C. indica cultivation house. In addition, 5 genera and15 species were isolated from P. pulmonarius, P. sajor-caju and C. indica cultivation house. Among the fungi isolated, the class of Eurotiomycetes was the most common. Among the 22 fungal species, Aspergillus flavus, A. ochraceus A. sydowii, A. tubingensis, A. westerdijkiae, Penicillium brevicompactum, P. citrinum, and P. steckii have been reported as harmful species to mushrooms, food, and human.

Airborne bacteria in mushroom growing environments are a potential risk of contamination in commercial mushroom production. Controlling contamination in mushroom farms requires understanding the bacterial ecology in the cultivation environment. This study was conducted to investigate the concentration and species diversity of floating bacteria in a thermophilic mushroom cultivation room. Temperature, humidity, temperature, humidity, and bacterial concentration measurements were performed in April and May 2022 for a Pleurotus ostreatus cultivation house, in July and August 2023 for a Pleurotus sajor-caju and a Agaricus blazei cultivation house, and in June, July and August 2023 for a Pleurotus pulmonarius, Pleurotus sajor-caju and Calocybe indica cultivation house. The airborne bacterial concentration was 5.27 × 103~105 CFU/m3, 3.81 × 102 ~1.37 × 103 CFU/m3, and 2.55 × 102 ~1.37 × 102 CFU/m3 in the three cultivation houses, respectively. A total of 23 genera and 37 species of airborne bacteria were isolated from the three mushroom cultivation houses. 12 genera and 18 species were identified from P. ostreatus cultivation house. Furthermore, 4 genera and 4 species were found from A. blazei and C. indica cultivation house. In addition, 11 genera and 18 species were isolated from P. pulmonarius, P. sajor-caju and C. indica cultivation house. Among the bacteria isolated, the Bacilli class was the most common, followed by Gammaproteobacteria. Among the 37 bacterial species, it was determined that Bacillus cereus, B. licheniformis, Cedecea neteri, Exiguobacterium acetylicum and Raoultella terrigena could negatively affect humans or foodstuff. Cedecea neteri is also known to cause diseases among mushrooms.

To understand microorganism effects on wild mushroom fruiting bodies, we investigated the fungi in hyphosphere soil supporting wild mushroom species Cortinarius violaceus, Amanita hemibapha, Laccaria vinacelavellanea, and Amanita verna found in the Gotjawal area of Jeju Island. Fungal species identification based on morphological traits and molecular analysis of ITS, LSU rDNA, and -tubulin gene sequences resulted in isolation and identification of eleven fungal species previously unrecorded in Korea. These newly-recorded species are: Arthrinium kogelbergensis, Kalmusia longisporum, Keithomyces carneum, Neopyrenochaeta cercidis, Penicillium ranomafanaense, Phomatodes nebulosa, Pyrenochaeta nobilis, Tolypocladium album, Talaromyces kendrickii, Talaromyces qii, and Umbelopsis gibberispora, and their morphological characteristics and phylogenetic positions are described.

Volvariella bombycinais an edible mushroom commercially cultivated in Korea and other countries. In this study, the culture characteristics and optimal growth conditions of milky mushroom strains were determined. The growth temperature and pH range of V. bombycinawas extensively investigated between 15 and 35oC and pH 3–11. For efficient cultivation, 20 types of nutrient sources were selected, specifically, 21 carbon sources, 6 organic nitrogen sources, 7 inorganic nitrogen sources, 13 amino acids, 9 organic acids, and 13 inorganic salts. The impact of each of the selected nutrition sources and their concentration on growth was investigated. The optimum temperature and pH were determined to be 30oC and pH 8.0, respectively. The optimum concentration of medium elements required for mycelial growth of V. bombycinawas determined to be as follows: carbon source, 0.7% Soluble starch; organic nitrogen source, 0.7% Soytone; inorganic nitrogen source, 1.0% (NH4)2C4H4O6; amino acid, 0.1% cysteine; organic acid, 0.07% lactic acid; and inorganic salt, 0.07 mM CaCl2.

This study was carried out to investigate how airborne bacteria are distributed under different temperature conditions while cultivating oyster mushrooms by setting the indoor temperature of the cultivation room to 10°C, 15°C, 20°C, 25°C, and 30°C. The surveys were conducted in April and May, respectively. Airborne bacterial concentrations were distributed in the range of 1.61 × 102 ~ 3.67 × 102 CFU/m3 in April and 5.47 × 102 ~ 7 × 103 CFU/ m3 in May. In May, the indoor air quality maintenance standard (8.0 × 102 CFU/m3) was exceeded in the 10°C, 20°C, and 25°C cultivation rooms. Bacterial concentrations increased significantly in May compared to April. Bacterial concentrations were different between the cultivation rooms at different temperatures. The difference was more pronounced in May than in April. A total of 15 genera and 20 species were isolated from the indoor air of the oyster mushroom cultivation rooms. Overall, it was most abundant in Actinomycetia. Among the species identified, Agrobacterium radiobacter, Brevundimonas vesicularis, Kocuria palustris, K. salsicia, Lysinibacillus fusiformis, and Sphingobacterium siyangense are known to affect human health. This is the first report of airborne bacteria in cultivation rooms at different temperatures used for oyster mushroom cultivation. The results of this study are expected to be used as basic data to understand the indoor environment of thermophilic mushroom cultivation facilities.

The biological efficiencies of promising Pleurotus spp. were evaluated. Pleurotus ostreatus, Pleurotus tuberregium,and Pleurotus sajor-cajuwere investigated at temperatures of 22oC, 20oC, and 18oC to determine their ability to adapt to temperatures that are likely to be found in subtropical regions. The experiment was conducted using a substrate comprising Popular sawdust 60% + cotton seed 20% + beet pulp 20% under a relative humidity of 65%. The results indicated that there were significant differences in terms of biological efficiency between the species: P. tuber regium 128.84% at 22oC, P. ostreatus 108.41% at 22oC, and P. sajor-caju is 80% at 20oC. The common temperatures at which all species showed the highest biological efficiencies were 22oC and 20oC. Therefore, the production of the evaluated species was equal to or surpassed biological efficiencies reported in tropical environments, thereby demonstrating a potential opportunity to adapt to tropical environments without compromising quality standards.

This study was conducted from October 2014 to May 2015 to explore forage production and feed values of Italian ryegrass, Rye and whole crop barley as winter forage crops in the Southern region of Korea. The experimental location was over 10 points for each species and each sampling point area was 1 m² (Width: 1 m × Length: 1 m). Air mean temperature and rainfall in the Southern region of Korea during the experimental period was 6.95 ± 5.75℃ and 70.45 ± 54.68 mm, respectively. Fresh forage yield of Italian ryegrass, the most cultivated forage in the Southern region of Korea, was 44.4 ± 7.0 ton/ha. The percentage of dry matter for whole crop barley was 28.9 ± 7.0%. Crude protein (CP) was higher in Italian ryegrass (10.7 ± 5.3%) while total digestible nutrient (TDN) had the highest value in whole crop barley. Crude protein was not significantly different by location. However, the neutral detergent fiber (NDF), acid detergent fiber (ADF) and total digestible nutrient value of forage from Jeonbuk province were higher than in forage from Gyeongnam province.