Wood ear mushroom (Auricularia heimuer) is one of the most popular mushrooms in Korea. Bacteria in the air can act as contaminants of mushroom media, mushroom pathogens, and sources of food poisoning in the indoor environment of mushroom cultivation houses. Therefore, cultivation houses require proper management to maintain mushroom production, quality and hygiene. This study was conducted to evaluate the properties of airborne bacterial species isolated from wood ear mushroom cultivation. Nine species of indoor-airborne bacteria were tested against wood ear mushroom cultivars using confrontation assay on PDA. Among 9 species, Bacillus subtilis DUCC18238 showed the strongest inhibition effect on the mycelial growth of nine wood ear mushroom cultivars and the inhibition rate for 7 of them was more than 30%. In addition, B. subtilis DUCC18238 inhibited the mycelial growth of 11 out of 18 wild mushroom species, 7 out of 8 phytopathogenic fungi, and 5 out of 5 Trichoderma species, respectively. The results of this study show that the management of airborne bacteria in the indoor environment of wood ear mushroom cultivation houses is necessary.

This study was carried out to get information on the concentration and species of airborne fungi in wood ear mushroom (Auricularia heimuer) cultivation houses. Air samplings were conducted at three wood ear mushroom farms located in Iksan and Wando in 2022. Two out of the three cultivation houses exceeded the Ministry of Environment’s recommended indoor air quality standards for fungi concentration in multi-use facilities. A total of 12 genera and 15 species of airborne fungi were isolated and identified. There were species belonging to 6 genera at the genus level. Overall, the genus Cladosporium accounted for the majority with three species. Among the identified species, there were fungi that affect the human body, such as Aspergillus niger, Lichtheimia ramose, and Rhizomucor pusillus, as well as Alternaria alternata, Cladosporium ramotenellum, Cladosporium subuliforme, and Curvularia lunata, which cause diseases in plants. Penicillium brevicompactum was detected as a fungus affecting mushroom cultivation. This study is the first report in Korea on airborne fungi in wood ear cultivation houses and provides useful information for environmental hygiene management of cultivation houses.

Airborne bacteria are an important environmental factor that affects the hygiene of mushroom cultivation houses, as they can act as contaminants or pathogens in mushroom cultivation. To determine the distribution of airborne bacteria in the air of wood ear mushroom cultivation houses, air sampling and temperature and humidity measurements were conducted at three wood ear mushroom farms located in Iksan and Wando in 2022. Sampled air was analyzed to measure bacterial concentration levels and identify bacterial species. There was no significant difference in temperature and humidity changes detected between the three mushroom growing houses. Additionally, the concentration of bacteria in the air did not exceed 800 CFU/m², which is the maximum amount of airborne bacteria allowed by the Ministry of Environment’s indoor air quality maintenance standards. Eleven species of bacteria belonging to 11 genera were isolated and identified from air samples. These include five species of Micrococcales, four species of Bacilli, one species of Actinomycetia, and one species of Mycobacteriales. Of the 11 species identified, five are known to affect human health. However, no mushroom pathogens or species causing food poisoning were found.

Buckwheat leaves have the best antioxidant properties, including flavonoids, rutin, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging ability compared to common buckwheat and tartary buckwheat. The total dietary fiber content of the powder extracted by mixing buckwheat leaves and sea tangle was 30.5%. To manufacture bread containing mixed buckwheat flour, 10, 20, and 30% buckwheat flour was mixed in to produce buckwheat bread. The bread’s characteristics underwent significant changes with varying levels of buckwheat flour. As the buckwheat content increased, the size of the bread decreased, but its hardness, gumminess, and chewiness tended to increase. The sensory characteristics of the bread were not improved due to the addition of gluten in the case of bread mixed with 20% buckwheat flour. When the buckwheat flour content was mixed at 20%, and the mixed extract of buckwheat leaves and sea tangle were added at 0.4% and 1.0%, there was no significant difference in the appearance of the buckwheat bread. Still, regarding sensory properties, the preference was higher in the sample with 1.0% added buckwheat flour.

This study analyzed the relationship between distribution of Bolboschoenus planiculmis which is main food source of swans (national monument species) with environmental factors, discharge, rainfall, and salinity in Eulsuk-do from 2020 to 2023. The distribution area of B. planiculmis in Eulsuk tidal flat was 103,672 m2 in 2020, 95,240 m2 in 2021, 88,163 m2 in 2022, and 110,879 m2 in 2023, and represents a sharp decrease compared to the 400,925 m2 area recorded in 2004. From 2020 to 2023, the growth densities of B. planiculmis were 243.6±12.5 m-2, 135.45±7.38 m-2, 51.10±2.54 m-2, and 238.20±16.36 m-2, respectively, and the biomass was 199.89±28.01 gDW m-2, 18.57±5.12 gDW m-2, 6.55±1.12 gDW m-2, and 153.53±25.43 gDW m-2 in 2020, 2023, 2021, and 2022, respectively. Based on discharge during May~July, which affects plant growth, the left gate discharge of the estuary barrage from 2020 to 2023 was 62,322 m3 sec-1, 33,329 m3 sec-1, 6,810 m3 sec-1, and 93,641 m3 sec-1, respectively; rainfall was 1,136 mm, 799 mm, 297 mm, and 993 mm, respectively; and average salinity was 14.7±9.4 psu, 21.1±4.7 psu, 26.1±2.7 psu, and 14.5± 11.1 psu, respectively. In 2022, cumulative rainfall (978 mm, about 70% of the 30-year average) and discharge (43,226 m3 sec-1) decreased sharply, resulting in the highest mean salinity (25.46 psu), and the distribution area, density, and biomass of the B. planiculmis decreased sharply. In 2023, there was a rise in discharge with an increase in rainfall, leading to a decrease in salinity. Consequently, this environmental change facilitated the recovery of B. planiculmis growth.

Owing to its excellent nutritional value, eggs are among the most important components of the human diet. Gender and environmental factors, such as feed composition, may alter the nutritional profile and quality of eggs. Feed additives have recently been used to enhance the health and productivity of hens, which has resulted in the production of higher-quality eggs. The fungus Cordyceps militaris, a well-established source of traditional medicines, contains potential bioactive metabolites, which prompted us to examine the effects of C. militaris-supplemented diets on the quality of hens’ eggs. The hens of two species (Gallus gallus domesticus and Araucana) were fed with one of three different diets: a control diet and diets supplemented with 2% or 5% of C. militaris. Egg quality was determined by measuring the Haugh Unit, yolk color, and shell thickness. In addition, egg and shell densities together with the ratio of yolk to albumen were calculated. Eggshell thickness and yolk color were both enhanced by the addition of C. militaris, whereas Haugh Unit values were somewhat reduced. Egg size, eggshell weight, and yolk and albumen production were all enhanced by C. militaris supplementation. Notably, in hens fed the 2% C. militaris-supplemented diet, enhancement was more evident in the yolk than in the albumen. The overall quality of the egg yolk was enhanced when 2% C. militaris was added to the hens' diet, which led to increases in both yolk color and quantity. Eggshell thickness and weight were also higher among eggs laid by hens fed the supplemented diets. Although these effects differed depending on the chicken species, we established that, in general, C. militaris contributes to improving egg quality.