In this study, Pleurotus ostreatus No.42 was cultured in glucose-peptone-yeast-wheat bran medium using a previously reported novel rotary draft tube bioreactor. Versatile peroxidase (VP), a lignin-degrading enzyme, was isolated from a pellet-type mycelium culture grown in the medium for seven days. The VP was purified by sequentially applying ultra-filtration, DEAESepharose CL-6B column, and Mono Q column. SDS-PAGE analysis revealed the molecular weight of VP to be 36.4 KDa with an isoelectric point of 3.65. The amino acid sequence was confirmed as VTCATGQTT. The purified VP was observed to possess the property of not only oxidizing Mn ions but also decomposing veratryl alcohol, a non-phenolic compound. The catalytic ability of VP is a subject for future research.

The development of automated bottle cultivation systems has facilitated the large-scale production of Pleurotus ostreatus, a commonly cultivated oyster mushroom species in South Korea. However, as the consumption of this product is decreasing and production quantities are exceeding demand, farmers are seeking various other mushroom types and cultivars. In response to this, we have developed a new oyster mushroom cultivar named 'Sena'. This high-yielding cultivar has a white pileus and excellent quality. The white oyster mushroom cultivars 'Goni' and 'Miso' were selected as parental strains from the genetic resources of the National Institute of Horticultural and Herbal Science’s Mushroom Division. By crossing their monokaryons, hybrids were developed and subjected to cultivation trials and characteristic evaluations to select the superior cultivar. The optimal temperature for 'Sena' mycelial growth is 25–30°C, with inhibition occurring at temperatures above 30°C, whereas the temperature for mushroom growth is 14–18°C. The mushrooms grow in clusters, with the white pileus having a shallow funnel shape. Optimal mycelial growth occurs in malt extract agar medium. When cultivated in 1,100 cc bottles, the 'Sena' cultivar had 35 available individuals, surpassing the number 16 available from the control cultivar 'Goni'. The yield per bottle also increased by approximately 157 g, a 24% increase over the control cultivar amount. When 300 g samples of harvested mushrooms were packed and stored at 4°C in a cold storage facility for 28 days, the weight loss rate of ‘Sena’ was approximately 4.22%, lower than that of 'Goni'. Moreover, the changes in pileus and stipe whiteness (measuring 6.99 and 8.33, respectively) were also lower than those of the control cultivar. Since the appearance of a white cap is crucial for quality assessment, the 'Sena' cultivar is superior to the 'Goni' cultivar in terms of both weight and quality after undergoing lowtemperature storage.

We conducted an on-site application study at the livestock cooperative fertilizer plant to compare the composting period, temperature change, moisture content, and chemical properties between livestock manure compost using sawdust as a moisture regulator with those using spent oyster mushroom substrate. The composting period, moisture content, and fertilizer composition of compost containing spent oyster mushroom substrate did not differ from that of conventional compost mixed with sawdust after the first and second fermentation and post-maturation stages, it was suitable as a material for manufacturing livestock manure compost. The spent oyster mushroom substrate also lower the production cost of livestock manure compost by replacing the more expensive sawdust. The developed technology is expected to contribute towards the utilization of by-products of the oyster mushroom harvest while simultaneously producing high quality livestock manure compost.

The oyster mushroom is a widely cultivated edible mushroom in Korea. It is a regionally specialized crop in Gyeonggi-do, where 68% of the national production is produced. The present study was conducted to develop a new, highquality cultivar with stable cultivation. ‘Manseon’ is a new variety of oyster mushroom suitable for bottle culture. It was produced by mating monokaryons isolated from ‘HB-18’ and ‘P15159-16’. The optimal temperature for ‘Manseon’ mycelial growth was 26–29 °C on potato dextrose agar (PDA) medium and for primordia formation and the growth of fruit bodies the optimal temperature was 18–19 °C on sawdust medium. Spawn running required 30 d, primordia formation required 4 d, and fruit body growth in the bottle culture required 4 d. Regarding the characteristics of the fruit bodies, the pilei were round and dark grayish brown, stipe color was white, and stipe shape was short and thick. The yield per bottle was 192.7 g/1,100 cc, which was 9% higher than that of the control strain (Suhan-1ho). The physical properties of springiness, cohesiveness, gumminess, and brittleness of stipe tissue were 87.9%, 77.4%, 445.1 kgf, and 389.6 kgf, respectively.

In this study, we aimed to compare the mycelial growth of Pleurotus ostreatus after medium supplementation with various amino acids at different concentrations to select the optimal medium nutrient composition for mycelial growth. The mycelial growth of P. ostreatus was investigated after adding four amino acids (tryptophan, threonine, methionine, and lysine) at 0.5% or 1% to the medium.The rate of P. ostreatus mycelial growthwas faster in the potato dextrose agar (PDA) medium supplemented with threonine at 0.5% or 1% than that of the control, whereas it was inhibited by tryptophan treatment. Supplementation of sawdust mediumwith all amino acids, except tryptophan, at 0.5% did not alter the mycelial growth, compared to the controls. However, addition of any amino acid to sawdust medium at a higher concentration (1%) inhibited the mycelial growth. The laccase acitivity of P. ostreatus mycelium cultured in PDA medium was the highest when threonine was added, and the lowest when tryptophane was added, consistent with the results of the mycelial growth. Therefore, the addition of threonine, methionine, or lysine to PDA medium at a concentration of 0.5-1%was effective for increasing the mycelial growth of P. ostreatus; however, it inhibited mycelial growth insawdust medium, suggesting that the effects of amino acids dependedon the medium nutrient composition.

This study was conducted to investigate the growth and antioxidant activity of Pleurotus ostreatus mycelia grown in medium supplemented with Aronia. The diameter and dry weight of the mycelia were increased in the medium supplemented with Aronia compared with the untreated medium. The total polyphenol content of mycelia grown in medium supplemented with Aronia and untreated medium was 6.54 mg GAE/g and 5.77 mg GAE/g, respectively. The 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of mycelia grown in medium supplemented with Aronia and untreated medium was 61.81% and 49.65%, respectively. Moreover, the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity of mycelia grown in medium supplemented with Aronia and untreated medium was 59.83% and 52.66%, respectively. These results confirmed that P. ostreatus mycelial growth and antioxidant activity were increased when Aronia was added to the culture medium.

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 find out the optimal solvent extraction method [Distilled water (DW), 70% ethanol, 99% ethanol] of mushrooms, including Pleurotus ostreatus (Jacq.) Que, Pleurotus eryngii and Flammulina velutipes and improve their usability as natural antioxidants. To analyze antioxidant activities in each mushroom, total polyphenol, flavonoid contents, 2,2-Diphenyl-1-picrylhydrazyl (DPPH), 2,2?-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical (ABTS+) and fluorescence recovery after photobleaching (FRAP) were measured. All mushrooms showed the highest total polyphenol contents in DW mushroom extract (p<0.001). Total flavonoid contents were the highest in P. eryngii and F. velutipes DW and 70% ethanol mushroom extracts (p<0.05). All mushrooms showed the highest activities using DPPH and FRAP assays in the DW extraction method (p<0.001). P. ostreatus (Jacq.) Que and P. eryngii showed the highest ABTS+ radical scavenging activity in the DW extraction method, and F. velutipes showed the highest activity in the 70% ethanol extraction method (p<0.001). As a result of comparing IC50 values of DPPH and ABTS+ radicals and FRAP EC50 values, the DW P. ostreatus (Jacq.) Que extract showed high antioxidant activities (p<0.001). Pearson's correlation between total polyphenol contents and antioxidant activities showed a positive correlation in all mushrooms (p<0.01). Therefore, extraction of the mushrooms with DW can enhance the extraction of effective bioactive substances and antioxidant activity.

리그닌 분해효소의 생산은 나선형 리본이 있는 새로운 형태의 회전식 통풍관 생물 반응기(RTB)를 사용하여 느타리(Pleurotus ostreatus) No.42에 의해 실시하였다. 락게 이즈(laccase)의 최대 생산량은 배양 3일 후 약 8,200 U/ bioreactor 수준에 도달한 후 감소하였다. 반면에, 망간퍼 옥시데이즈(MnP)의 최대 생산은 6일 배양 후 약 8,400 U/bioreactor의 수준에 도달하였다. 그러나 이 발효조에서 리그닌퍼옥시데이즈(LiP)는 검출되지 않았다. 그 결과 회전식 통풍관 생물 반응기(RTB)가 리그닌 분해효소를 대규모 생산을 위해 성공적으로 생산할 수 있음을 보여주었다. 이 발효기에서 망간퍼옥시데이즈의 정제 과정은 Sepharose CL-6B, Superdex 75 prep grade 및 Mono-Q에 대한 크로마토그래피를 포함하여 정제하였다. 이 주요 효소는 sodium dodecyl sulfate-polyacrylamide 겔 전기영동(SDS-PAGE)에서 분자량 36,400, pI 3.95의 등전점(IEF)으로 각각 확인되었다. 이 발효기의 주요 효소 N-말단 서열은 정치 및 진탕배양과 같은 다른 배양조건에서 보고된 MnP3 효소와 동일하였다.