Plastics are widely used in industries in human society and because of their structural stability, degradation is a serious global issue. To estimate the degradation of plastic, 31 edible mushrooms were cultured with the selected plastic films (polyethylene [PE], polystyrene [PS], and poly(ethylene terephthalate) [PET]) for 3 months at 25 °C. Measuring the weight of the films showed that four species of mushrooms, namely Porostereum spadiceum, Ganoderma lucidum, Coprinellus micaceus, and Pleurotus ostreatus, exhibited the highest degrees of plastic degradation. In addition, the mushrooms and fungi that exhibited the most significant plastic degradation were cross-cultured to promote this degradation. As a result, cross-cultivation of G. lucidum and Aspergillus niger showed a weight loss of 2.49% for the PET film. For the PS film, Aspergillus nidulans showed a weight loss of 4.06%. Cross-cultivation of A. nidulans and C. micaceus, which showed a weight loss of 2.95%, was noted as an alternative for PS biodegradation, but is harmful to humans. These bio-degradation effects of edible mushroom will contribute to the development of alternatives for eco-friendly plastic degradation.

As a member of ectomycorrhizal fungi, Tricholoma matsutake has a symbiotic relationship with its host, Pinus densiflora. To cultivate T. matsutake artificially, the co-cultivation of T. matsutake mycelia and bacteria from shiro was introduced. In this study, bacteria were isolated from soil samples in Bonghwa-gun, and seven bacterial isolates (B22_7_B05, B22_7_B06, B22_7_B07, B22_7_B08, B22_7_B10, B22_7_B13, and B22_7_B14) promoted the growth of T. matsutake mycelia (147.48, 232.11, 266.72, 211.43, 175.17, 154.62, and 177.92%, respectively). Sequencing of the 16S rRNA region of the isolated bacteria was performed. B22_7_B05 and B22_7_B10 were identified as Bacillus toyonensis, B22_7_B06 and B22_7_B08 as Paenibacillus taichungensis, B22_7_B07 and B22_7_B14 as P. gorilla, and B22_7_B13 as P. odorifer. These bacterial isolates were associated with the shiro community and are expected to contribute to the cultivation of T. matsutake.

Tricholoma matsutake is a traditional favorite food in East Asia, cultivated in fairy rings called “shiro,” which are found near Pinus densiflora. For effective artificial cultivation of Tri. matsutake, microorganisms from symbiotic fairy rings are co-cultivated. In this study, one bacterial isolate (Y22_B35) and two fungal isolates (Y22_F64 and Y22_F68) displayed growth-promoting effects on Tri. matsutake mycelium (158.47, 125.00, and 122.26% enhanced growth, respectively). For identification, 16S rRNA or ITS regions from the microorganisms¡¯ genomes were sequenced. Other sequences, including BenA, CaM, and RPB2 were sequenced in the fungal isolates. The bacterial isolate Y22_B35 was identified as Bacillus cereus. Y22_F64 and Y22_F68 were identified as Umbelopsis nana and Aspergillus parvulus, respectively. To identify the effects of the dominant microorganisms on Tri. Matsutake cultivation, metagenomic analyses were performed. Discovery of these Tri. matsutake mycelium growth-promoting microorganisms and metagenomics analyses are expected to contribute to our understanding of Tri. matsutake fruiting body growth and construction of biomimicry.

본 연구는 대도시에서 미세먼지 없는 학교 부지를 찾는 Model Eliciting Activity (이하 MEA) 활동을 통해 고 등학교 학생들의 문제 해결 특성을 조사하기 위한 것이다. 5차시로 개발된 MEA 활동에 79명의 고등학교 2학년 학생 들이 참여 하였으며, MEA 활동지를 주요 데이터로 수집하였다. 학생들이 작성한 활동지의 개방형 질문에 대한 답을 기반으로 학생들의 문제 해결 모델을 귀납적 및 질적 방법으로 분석하였다. 먼저 학생들이 다른 데이터보다 어떤 데이 터를 우선적으로 사용했는지 순서를 분석한 후 주어진 데이터 세트를 어떻게 상호 연결하여 순서를 결정하는지 분석하 였다. 분석결과 학생들은 미세먼지 배출량이 많은 곳을 기피하기 위해 미세먼지 배출농도, 산업단지 분포 등 미세먼지 와 직접적으로 관련된 데이터를 먼저 활용하는 경향이 있음을 알 수 있었다. 흥미롭게도 MEA 활동에서 고등학생의 문 제 해결 특성은 매우 다양하여 76명의 학생이 총 61가지 유형의 문제 해결 모델을 제작한 것으로 나타났다. 문제를 해 결하기 위해 동일한 순서의 데이터를 사용하는 학생의 최대 수는 6명으로 학생들의 문제 해결 방법은 매우 다양함을 보여준다. 그러나 공통적으로 미세먼지 농도가 높은 곳을 제외하는 방법으로 미세먼지 배출과 직접적으로 관련된 데이 터를 먼저 선택하는 특성을 보였다.

Dental caries is an infectious disease that is caused by the interaction between the host, the diet, and a diverse microbial community. This study illustrated the anticariogenic effects of THYJ-15 against Streptococcus mutans, a major agent of dental caries. THYJ-15 was identified as Latilactobacillus sakei subsp. sakei through 16S rRNA sequencing, with a similarity of 99.72% to L. sakei subsp. sakei JCM 1157T. The cell-free supernatant of L. sakei subsp. sakei THYJ-15 observed MIC values of 10 mg/mL and MBC values of 20 mg/mL against S. mutans KACC 16833T. The cell-free supernatant of L. sakei subsp. sakei THYJ-15 showed significant inhibitory effects on biofilm formation, acid production and glucosyltransferases(GTFs) production against S. mutans. As a results, it was confirmed that L. sakei subsp. sakei THYJ-15 is a lactic acid bacterium possessing notable anticariogenic effects. Accordingly, L. sakei subsp. sakei THYJ-15 is expected to have great potential to be used as a basic substance for dental caries treatment caused by S. mutans.

Dental caries is an infectious disease accompanied by the destruction of teeth. It is a multifactorial disease caused by the interaction between microbes in dental plaque and food, with cariogenic Streptococcus mutans being one of the primary causes. In this study, the antimicrobial and antibiofilm activities of Lactiplantibacillus plantarum THK-j112 isolated from Kimchi, a traditional fermented food, against S. mutans were investigated. Furthermore, this paper also showed the possibility of developing this strain. After analyzing the 16S rRNA sequence, strain THK-j112 was named L. plantarum THK-j112 as it shared 99.93% similarity with L. plantarum ATCC 14917T. Both L. plantarum THK-j112 and L. plantarum ATCC 14917T demonstrated MIC values of 5 mg/mL and MBC values of 10 mg/mL against S. mutans KACC 16833T. The study confirmed that L. plantarum THK-j112 exhibited significant concentration-dependent inhibitory effects on biofilm formation, acid production, and glucosyltransferases(GTFs) production. Regarding hemolytic activity, Bacillus cereus ATCC 14579T, used as a positive control, was confirmed to cause hemolysis, whereas L. plantarum THK-j112 did not cause this phenomenon. Additionally, except for gentamicin, the antibiotic resistance test revealed a lower value than the MIC cut-off value for each antibiotic, indicating no resistance. Based on the findings, L. plantarum THK-j112 is expected to be useful in the food industry, such as functional food, as a lactic acid bacterium with antimicrobial and antibiofilm effects.

The purpose of this study was to examine changes in serving frequency of elementary school meal before and after the COVID-19 pandemic. Number of menus provided in June and July of 2019 and 2020 were compared for 300 elementary schools in Korea. As a result, the serving frequency of la carte and dessert was increased after COVID-19. In addition, frequencies of main dishes such as pork cutlet, chicken, sweet and sour pork, hamburger steak, and so on using processed food were increased after COVID-19. Because of the longer serving time due to staggered serving, cook's working time for serving meals became longer. Therefore, it was judged that the number of servings of processed food was increased rather than the menu with a large amount of preprocessing work. Moreover, among desserts, fruits showed increased serving frequency. Serving frequencies for juice and dairy products were also increased. However, increased servings of juice and dairy products could increase sugar intake. Thus, a careful plan for menu composition is needed to provide balanced nutrients to students under emergency situations such as an infectious disease.

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.

The present study aimed at selecting a cost-effective substrate for king oyster mushroom based on the growth characteristics of fruiting body for use as a basic resource to ensure stable production on farms. Compositional analysis of substrates manufactured with different materials in each process revealed that the total carbon content was 42.24–48.22% higher and the total nitrogen content was 1.7–2.29% higher in the processed lot than in the control (i.e., substrate used by the farmhouse; 40.86% and 1.39%, respectively). Meanwhile, the carbon-to-nitrogen ratio was the highest in the control (27.9% vs. 19.12–27.88% in the processed lot). When cultured for 28 days, the mycelium growth was 11.5 and 11.3 mm in substrates 1 and 6, respectively, indicating the fastest growth; meanwhile, the values were 10.1–10.3 mm in the control and substrate 11, showing a similar tendency. Mycelial density did not differ significantly among the processed lots. Yield per bottle was higher in substrates 8 (205.95 g/bottle), 7 (178.51 g/bottle), and 11 (170.63 g/bottle) than in the control (152.2 g/bottle). Fruiting body quality was comparable to controls in all processed lots. Overall, economic effects, such as substrate material prices, should be analyzed, and stability evaluations, such as residual pesticide and harmful microorganisms, should be undertaken along with further detailed examination to ensure safe and stable production on farms.

본 연구는 조사료 원료인 마늘 껍질의 사료적 가치와 메탄 발생량을 조사하기 위해 in vitro 발효 실험을 수행하였다. Garlic husk를 제외하고 국내에서 널리 사용되는 4가지 조사료 원료(Oat hay, Annual ryegrass, Timothy, Tall fescue)를 실험의 처리구로 구성하였다. In vitro 48 시간 발효 후 건물 소화율, 섬유소 소화율, 암모니아태 질소, 휘발성 지방산, pH, 메탄 발생량을 평가하였다. 가스 발생량은 3, 6, 9, 12, 24, 36 및 48 시간에 각각 측정되었다. 최종 가스 발생량에서 Oat hay가 유의적으로 가장 높았다(p<0.01). Garlic husk는 처리구 중 가장 높은 메탄 발생량을 나타내었다(p<0.01). Garlic husk의 건물 소화율은 Oat hay보다 유의적으로 낮았지만 Annual ryegrass, Timothy, Tall fescue보다 높았다(p<0.01). 섬유소 소화율은 Annual ryegrass에서 가장 낮았다(p<0.01). 총 휘발성 지방산 생성량은 Oat hay에서 가장 높았고(p<0.01), Garlic husk, Timothy, Tall fescue는 유사하였다. 본 연구의 in vitro 발효 성상과 메탄 발생량을 고려할 때, Garlic husk는 국내 주요 조사료를 대체할 영양적 가치를 포함하고 있으나 메탄 저감 효과는 미미할 것으로 추정된다.

모바일 환경의 발달은 사람들이 SNS를 대인 커뮤니케이션 채널로 의존하도록 만들고 있으며 SNS를 통해 타인의 상태에 대한 논평을 하거나 언급하는 성 향을 형성하면서 이용자들간의 관계를 형성하거나 유지하도록 하는 중요한 역할을 담당하기도 한다. 한 개인이 다른 특정한 개인과 지속적인 정서적 유대를 가지는 경향을 애착이라 하는데, 특정 미디어나 브랜드를 이용하는 과정에서 애착이 발생한다는 연구가 나타났다. 이에 본 연구에서는 대인관계의 중요한 역할을 담당하고 있는 SNS와 이용자의 애착정도를 살펴보고 애착 관계에 따라 사회적 자기효능감과 대인관계 만족도에 미치는 영향을 살펴보고자 하였다. 이를 위해 온라인을 통해 203명의 SNS 이용자를 대상으로 설문을 실시하였다. 그 결과 SNS의 하위요인 중 안정감과 분리불안 요인 사회적 효능감과 대인 관계 만족도에 통계적으로 유의미한 영향을 미치는 것으로 조사되었다. 안정감의 경우 긍정적인 영향을 미치고 있었으며, 분리불안은 부정적인 영향을 미치는 것으로 조사되었다. 분리불안의 부정적인 영향은 SNS중독 연구들과 비슷한 연구 경향성을 보이고 있다. 하지만 안정성 측면에서 긍정적인 영향을 미치고 있어 SNS 이용 동기인 관계 측면에서의 긍정적인 영향관계를 살펴볼 수 있는 연 구 결과라 할 수 있다.