This study aimed to examine the major domestic and foreign regulations related to the production of organic products. The production and consumption of organic products have been expanding due to the increase in consumer demand for safe food, as well as improved certification procedures and industry trends. In case of organic mushrooms, there were 405 certified farms nationwide in 2021, with a cultivation area of 3,886,628 m2 and a planned production of 6,011 tons. Jeollanamdo has 221 farms, a cultivation area of 2,923,402 m2, and a certification plan for 2,132 tons. Shiitake mushrooms are ranked first with 369 farms, a cultivation area of 3,805,636 m2, and a certification plan for 3,576 tons, representing 91% of the farms, 98% of the cultivation area, and 60% of the certification planning.
Pleurotus ostreatus is a globally cultivated mushroom crop. Cap color is a quality factor in P. ostreatus. However, cap color can spontaneously mutate, degrading the quality of the mushroom on the market. Early detection and removal of mutant strains is the best way to maintain the commercial value of the crop. To detect the cap color mutant Gonji7ho, molecular markers were developed based on insertion/deletions (InDels) derived from the comparison of mitogenomes of Gonji7ho and Gonji7hoM mushrooms. Sequencing, assembly, and comparative analysis of the two mitogenomes revealed genome sizes of 73,212 bp and 72,576 bp with 61 and 57 genes or open reading frames (ORFs) in P. ostreatus Gonji7ho and Gonji7hoM, respectively. Fourteen core protein-encoding genes, two rRNA, and 24 tRNA with some OFRs were predicted. Of the 61 genes or OFRs in the wild type, dpo, rpo, and two orf139 were missing (or remnant) in the mutant strain. Molecular markers were developed based on the sequence variations (InDels) between the two mitogenomes. Six polymorphic molecular markers could detect the mutated mitochondria by PCR. These results provide basic knowledge of the mitogenomes of wild-type and mutant P. ostreatus, and can be applied to discriminate mutated mitochondria.
This study was conducted to reduce the phenomenon of the biased cultivation of certain mushroom varieties and to develop a competitive variety of Grifola frondosa. We developed the first Korean white commercial mushroom strain, ‘Bakyeon’, by crossing monokaryons derived from brown strains. We have collected and tested the characteristics of mushrooms from domestic and international genetic resources since 2018. We bred the unique domestic variety, ‘Bakyeon’, which has the following characteristics. The optimal temperature for mycelial growth was 25~28oC and the optimal temperature for fruit body growth was 16~18oC. The new variety was similar to the control variety (Daebak) in terms of the pileus, which formed a pine cone shape, and the number of days of cultivation. The yield was 94.1 g/bottle, which was 23% lower than the 108.5 g/bottle yield of the control variety. When incubating the parent and control varieties, the replacement line was clear. Moreover, polymerase chain reaction analysis of mycelial DNA resulted in different band patterns between the parent and control varieties, confirming the hybrid species.
This study was conducted to establish an appropriate period of use of sawdust spawn at low temperatures and a nutrient supplement medium for cultivation of Lentinula edodes ‘Hwadam’. Of the nutrient supplements, the total yield of rice bran (5%) + corn flour (5%) treatments were 673.3 g, which was higher than rice bran (551.6 g) and wheat bran (546.7 g) treatments, respectively. As shown by the growth of Lentinula edodes ‘hwadam' during to the sawdust spawn storage period (at 4oC), the period of spawn running, browning, fruiting body formation, and development was 27 d, 81 d, 5 d, and 11-13 d, respectively, regardless of the length of the storage period at 4 oC. After 3 months of storage of sawdust spawn, the number of fruiting bodies and yield decreased as the storage period increased. Therefore, the period of use of sawdust spawn (at 4 oC) for the stable production of fruiting bodies of Lentinula edodes ‘Hwadam’ was a maximum of 3 months.
We investigated the standard cultivation substrate for Sparassis latifolia “Neowul” bred in Jeollabuk-do Agricultural Research and Extension Services. Cultivation characteristics and yield were assessed by varying the kind of sawdust and additives, and the mixing ratio. The cultivation period in larch sawdust was the shortest at 97 days. The yield was excellent (143.6 g). The findings indicated that larch is a tree species appropriate for the cultivation of S. latifolia. When the additives were varied, the yield and productivity (53.1%) were highest (116.6 g) for the wheat bran treatment. Thus, wheat bran would be an additive appropriate for culturing S. latifolia. Concerning the use of different mixing ratios, larch sawdust:beet-pulp:wheat bran ratios of 80:15:5 and 85:10:5 resulted in yields of 114.4 g and 111.4 g, and productivity of 52.5% and 51.8%, respectively. These yield and productivity values were not statistically different. Thus, the standard cultivation substrate for S. latifolia can comprise larch sawdust, beet pulp, and wheat bran at a ratio of 80:15:5 or 85:10:5. The carbon/nitrogen (C/N) ratio assumed to be appropriate for the cultivation of S. latifolia was 184 –223. Pinheading would be difficult below a C/N substrate ratio of 105. Thus, the C/N ratio of the media, as well as the pH, would be vital factors affecting pinheading during S. latifolia cultivation.
Eco-friendly materials, such as alternative vegan materials using various fungal resources, are being actively researched to reduce environmental pollution and facilitate a healthy lifestyle. The fungal mycelium-based mushroom mycelium mat is one such emerging material. In this study, the commonly used mushroom mycelium culture method was modified to reduce the time required to produce the mycelium mat, lower the possibility of contamination, and improve the properties and quality of the mat. Shortening the period required for the previously used primary bag culture and secondary mat production culture. A culture method in which the bag culture was omitted was attempted using a mycelium mutated by gamma irradiation to the mycelium of Trametes orientalis. In addition, various nutrients were added to the fungal solution to observe the change in physical properties of the fungal mat. High-quality mycelium mats were produced in the experimental group containing 1.5% CaCO3 in sawdust medium, and the period was also reduced by more than 10 days compared to the existing production method. In the future, for mass producing mycelium mats, additional selection of medium components and optimization of culture conditions are essential.
The consumption of Flammulina velutipes mushroom imported from Korea has been associated with the cases of listeriosis in the United States, Canada, and Australia. We investigated the effect of sanitizing the plastic wrapper (used in packaging F. velutipes) with slightly acidic electrolyzed water (SAEW) and ultraviolet C waterproof light-emitting diode (UVC-WLED) on reducing the Listeria monocytogenes. Further, the effect of UVC-LED on L. monocytogenes growth in F. velutipes at different storage temperatures (2, 4, and 10oC) was determined. The combined (SAEW+UVC-W-LED) treatment for 5–10 min reduced 99.9% of bacterial population from the contaminated plastic wrapper. In addition, the UVC-LED treatment for 3 min reduced the L. monocytogenes concentration in F. velutipes by 0.47 log CFU/g. Moreover, the growth of L. monocytogenes in the treated mushrooms was slower than that of the untreated (control) ones. L. monocytogenes concentration in F. velutipes increased over 3 log CFU/g at 2oC and 10oC for 60 and 10 days, respectively. The growth of L. monocytogenes at the bottom of mushrooms was faster than that at the top at both the temperatures. These results indicate that the combined SAEW+UVC-WLED treatment of plastic wrappers and the UVC-LED treatment of mushrooms can be used as potential hurdle technologies to control the risk of L. monocytogenes in mushrooms prior to packaging at farms.
Pleurotus eryngii, a white rot fungus, produces two extracellular lignin-degrading enzymes, laccase and manganese peroxidase (MnP). Owing to these enzymes, P. eryngii efficiently degrades synthetic chemicals such as azo, phthalocyanine, and triphenyl methane dyes. In this study, we investigated the degradation processes of four aromatic dyes, congo red (CR), methylene blue (MB), crystal violet (CV), and malachite green (MG), by P. eryngii under solid and liquid culture conditions. CR and MG were the most quickly degraded under solid and liquid culture conditions, respectively. However, compared to CR, CV, and MG, MB was not degraded well under both culture conditions. The activities of ligninolytic enzymes (laccase and MnP) were also investigated. Laccase was identified to be the major enzyme for dye degradation. A positive relationship between decolorization and enzyme activity was observed for CR, MB, and CV degradation. In contrast, decolorization of MG ensued after high enzyme activity. These results indicate that the degradation process differs between MG and the other aromatic dyes. Therefore, P. eryngii could be a potential tool for the bioremediation of synthetic aromatic dye effluent.