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.

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.

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.

우리나라 여러 해양환경 지역으로부터 확보한 370주의 해양세균, 균류, 미세조류로부터 기초생 리활성(항산화, 항염, 항균, 항암, 항바이러스)을 조사하여 채집지, 분리원, 종(種) 수준에서의 활성결과를 비교하였다. 해양세균의 경우, 일반적으로 유용성이 많이 알려진 Streptomyces 속 과 Bacillus 속에 속하는 균주들이 두드러진 강한 효능이 관찰되었고, 주로 해양퇴적물로부터 유용한 자원을 분리할 수 있었다. 해양균류와 미세조류의 경우에도 종 특이적으로 활성이 강 하게 나타나는 결과를 확인할 수 있었고, 효능 특이적으로 활성을 보이는 결과도 얻을 수 있었 다. 이러한 결과를 바탕으로 추후 특정질병에 선택적으로 효능을 보이는 화학물질 연구 또는 자원 기반 연구 수행 시 유용성을 전제로 한 자원 확보 전략 수립과 산업 활성화를 위한 전 략소재로 우선적 접근이 용이할 수 있는 연구결과라 생각된다. 또한, 이들 결과를 해양바이오 뱅크를 통한 분양소재로 활용함으로써 학계, 산업계에서 활용하여 해양바이오산업 활성화에 좀 더 빠른 접근을 도울 수 있다고 생각한다.

This study was carried out to examine the concentration and distribution characteristics of total airborne bacteria (TAB) and airborne mold in non-regulated public-use facilities. The arithmetic mean (AM) of the TAB in all facilities was 356.5 ± 419.3 CFU/m3, and the geometric means (GM) was 157.8 CFU/m3, which did not exceed the standard value of 800 CFU/m3. The highest concentration was 637.3 ± 372.0 CFU/m3 (GM: 534.9 CFU/m3) in the underground shopping mall. The AM of airborne mold in all facilities was 448.2 ± 429.6 CFU/m3 (GM: 285.4 CFU/m3), which did not exceed the standard value of 500 CFU/m3, but was close to it. In particular, subway station (AM: 661.5 ± 441.2 CFU/m3, GM: 540.0 CFU/ m3), large-scale store (AM: 587.6 ± 683.2 CFU/m3, GM: 297.8 CFU/m3), and private educational institute (AM: 528.8 ± 379.6 CFU/m3, GM: 373.7 CFU/m3) exceeded the standard. Operational taxonomic unit of 16S rDNA and ITS2 rDNA region was analyzed to profile bacteria and mold component in the air of the public-use facilities. As a result, Pseudomonas and Morganella are the major bacterial groups. Regarding mold, Aspergillus, Candida, Malassezia, and Penicillium are the major groups. Component of each airborne bacterial and mold groups varied depending on the type of public-use facilities.

Microbial proteases are more economical than plant- and animal-derived proteases due to their ease of production and high activity. This study aimed to optimize the production of proteases from fermentative food-derived microorganisms. Five strains with proteolytic activity among 50 Bacillus sp. were first screened. Two strains with high protease activity were identified: Bacillus amyloliquefaciens SRCM 102139 and Bacillus subtilis SRCM 104999. SRCM 102139 strain and SRCM 104999 strain had the highest protease activity in 0.8% glucose and 0.3% yeast extract, and in 0.8% starch and 0.1% soy peptone, respectively. The production of protease for two strains was optimized by the Central Composite Design (CCD) under response surface methodology. The optimal conditions for protease production in SRCM 102139 were 0.5% and 0.347%, pH 6.0, for carbon (glucose) and nitrogen (yeast extract springer 0202) sources, respectively, with a predicted value of 0.929 U/mL. Additionally, the optimal conditions for protease production in SRCM 104999 were 0.5% and 0.5%, pH 6.7, for carbon (starch) and nitrogen (soy peptone HSP-349) sources, respectively, with a predicted value of 0.431 U/mL. The actual protease activities of SRCM 102139 and SRCM 104999 under the established conditions were 0.926 U/mL and 0.428 U/mL, respectively, closely matching the predicted values.

한국의 전통 과자인 유과는 거의 모든 공정이 수작업으로 제조되기 때문에 공정 중 작업자 및 작업도구 등에 의한 교차오염으로 인한 안전문제가 제기되고 있다. 본 연구에서는 유과 제조 공정 중 찹쌀의 불림 단계에서 증가된 미생물을 제어하기 위하여 항균 활성이 있는 용액 9가지 용액(40% 자몽종자 추출물, 100% 계피 추출물, 70% 에탄올, 100% 식초, 0.2% 차아염소산나트륨, 40% 초산나트륨, 40% 탄산수소나트륨, 40% 사과산, 40% 구연산)을 이용하여 Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium, Bacillus cereus에 대해 항균 효과를 비교 확인하였다. Disk diffusion법을 통해 40% 사과산과 구연산에서 높은 항균 효과를 확인할 수 있었고, 추가로 항균용액의 농도, 처리방법 및 시간을 최적화한 결과 1% 사과산-구연산을 10분 동안 처리 시 세균 5종을 모두 사멸시켜 높은 항균효과를 확인할 수 있었다. 불림단계의 찹쌀에 1% 사과산-구연산으로 정치 및 교반하면서 10분 동안 세척하였을 때 일반세균과 대장균군의 수가 각각 4.0 Log CFU/g와 5.0 Log CFU/g씩 감소하였다. 이상의 결과로 볼 때 1% 사과산-구연산으로 불린 찹쌀에 대해 침지와 교반으로 10분 동안 처리함으로써 전통 유과 제조과정 중 쌀의 불림단계에서 증가된 미생물을 효과적으로 저감화 할 수 있음을 확인하였다.

창원시의 3개 지점(남천, 창원천, 청운지)에서 물 시료를 채취하고, 채취한 시료로부터 genomic DNA를 분리하였다. 분리된 DNA와 class A extended-spectrum beta-lactamase(ESBL) 유전 자 5가지(blaOXA-1, bl aSHV, blaTEM, blaCTX-M-1, blaCTX-M-9)를 target으로 하는 primers를 사용하여 quantitative PCR을 수행하였다. 시료를 채취한 지점별로 ESBL 유전자들의 수와 비율에서 확연한 차이 가 있음을 알 수 있었다. 남천의 경우 DNA 30ng당 ESBL 유전자가 1.93×106 copy나 존재하는 데에 반해 창원천의 경우에는 1.47×105 copy 그리고 청운지에는 9.5×103 copy 밖에 존재하지 않았다. 흐르 는 하천인 남천과 창원천에서는 각 ESBL 유전자들의 비율에서 큰 차이가 없었다. 즉, 남천에서는 blaOXA-1 유전자가 65.3%, blaCTX-M-1 유전자가 33.6%를 차지하여서 이 두 유전자가 전체 ESBL 유전자 의 99% 가까이를 차지하고 있었다. 창원천에서도 blaOXA-1 유전자가 64.1%, blaCTX-M-1 유전자가 19.1%를 차지하므로 이 두 유전자가 전체의 83% 이상을 차지하고 있었다. 하천과 다르게 폐쇄된 환경 인 청운지 연못에서는 내성세균들의 총량 자체가 다른 두 하천에 비해서 월등하게 적었다. 또한 내성 세균의 비율도 달라서 blaCTX-M-1 유전자가 전체의 87.5%, 그리고 blaCTX-M-9 유전자가 9.8%를 차지하 고 있었다.

To isolate aerobically and identify the diversity of halophilic bacteria in the soil around two ports, Daepopogu and Hwasun Port, on Jeju island, a total 46 halophilic bacteria strains were isolated and phylogenetically analysed. The isolated strains were divided into 3 phyla, 8 families, 16 genera and 23 species. The main taxa was the Bacilli class, which included 50.0% of the strains with 3 families, 10 genera and 15 species of Bacillaceae, Exiguobacterium_f and Planococcaceae. The second taxa was the Gammaproteobacteria class, which included 45.7% of the strains with 4 families, 5 genera and 7 species of Aeromonadaceae, Halomonadaceae, Marinobacteraceae and Vibrionaceae. The isolated strains were tested for hydrolytic enzymes, amylase, lipase and protease activity, and 31 strains showed activity of at least one enzyme. Furthermore, auxin activity was determined in 7 strains. This study showed that the isolated strains have possible applications in the food and agricultural industries and have importance as a genetic resource in Korea.

The rapid development of biotechnology has increased the importance of microorganisms or their genetic information. Thus, the Nagoya Protocol on access to genetic resources and the fair and equitable sharing of benefits arising from their utilization was established, and countries are working to secure industrially and academically useful bioresources to deal with the agreement. In the case of Korea, because 67% of bioresources are imported from abroad, we are required to secure domestic bioresources as well. The number of isolated foodborne illness-causing microorganisms is predicted to invrease based on the incresing number of outbreaks of foodborne illness each year. Consequently, appropriate long-term preservation methods are necessary to secure the isolated microorganisms for the purpose of research and resourcification. Therefore, the long-term preservation methods for bacteria, fungi, viruses, and protozoa were investigated in this study, from domestic and international bioresource banks, and the functions of the cryoprotectants were reviewed and discussed. This review should be informative in the preservation of microorganisms and contribute to the development of biotechnology.

The present study was performed to investigate the effects of NH3-N and nitrifying microorganisms on the increased BOD of downstream of the Yeongsan river in Gwangju. Water samples were collected periodically from the 13 sampling sites of rivers from April to October 2021 to monitor water qualities. In addition, the trends of nitrogenous biochemical oxygen demand (NBOD) and microbial clusters were analyzed by adding different NH3-N concentrations to the water samples. The monitoring results showed that NH3-N concentration in the Yeongsan river was 22 times increased after the inflow of discharged water from the Gwangju 1st public sewage treatment plant (G-1-PSTP). Increased NH3-N elevated NBOD levels through the nitrification process in the river, consequently, it would attribute to the increase of BOD in the Yeongsan river. Meanwhile, there was no proportional relation between NBOD and NH3-N concentrations. However, there was a significant difference in NBOD occurrence by sampling sites. Specifically, when 5 mg/L NH3-N was added, NBOD of the river sample showed 2-4 times higher values after the inflow of discharged water from G-1-PSTP. Therefore, it could be thought other factors such as microorganisms influence the elevated NBOD levels. Through next-generation sequencing analysis, nitrifying microorganisms such as Nitrosomonas, Nitroga, and Nitrospira (Genus) were detected in rivers samples, especially, the proportion of them was the highest in river samples after the inflow of discharged water from G-1-PSTP. These results indicated the effects of nitrifying microorganisms and NH3-N concentrations as important limiting factors on the increased NBOD levels in the rivers. Taken together, comprehensive strategies are needed not only to reduce the NH3-N concentration of discharged water but also to control discharged nitrifying microorganisms to effectively reduce the NBOD levels in the downstream of the Yeongsan river where discharged water from G-1-PSTP flows.

A laboratory-scale experiment was conducted to evaluate the effect of supplementing commonly used effective microorganisms on the chemical properties of swine liquid manure. Effective microorganisms used in this study were Bacillus subtilis (1.3×109 colony-forming unit (CFU)/ml), Enterococcus faecium (1.9×1010 CFU/ml), Aspergillus oryzae (2.0×109 CFU/ml), Saccharomyces cerevisiae (6.4×109 CFU/ml), Rhodobacter sphaeroides (1.2×108 CFU/ml), and Streptomyces griseus (6.2×108 CFU/ml). Swine liquid manure collected and decanted from a swine farm was used in this study. Treatments included control (distilled water supplementation), Treatment 1 (T1) (mixed microbes, 109 CFU/ml), and Treatment 2 (T2) (mixed microbes, 107 CFU/ml). Microbial mix was supplemented every 3.5 days and aerated six times (15 min each) a day to facilitate compositing. Ten ml of sample was collected at 2-, 4-, 6-, and 7-week intervals for the measurement of pH, ammonia-N, volatile fatty acid (VFA), total nitrogen, total phosphorus, and total potassium. At seven weeks, samples were further collected to analyze biochemical oxygen demand (BOD) and chemical oxygen demand (COD). Ammonia-N was significantly (p<0.05) decreased in T1 and T2 by 36% and 30%, respectively, compared with control (23%). VFAs including butyrate, iso-butyrate, valerate, iso-valerate, and caproate were not detected in T1 from the four-week aerated sample. The BOD and COD were significantly (p<0.05) decreased in T1 by 96% and 58%, respectively. In conclusion, ammonia-N, VFA, BOD, and COD, known as odor indicators, were decreased in T1 and T2 compared with control, suggesting that effective microorganisms are useful for compositing swine liquid manure

달래의 전처리 방법을 통해 미생물 저감과 품질 유지 효과를 알아보기 위해 물리적인 처리로는 손 세척 1분, 버블 세척, Ultrasonication 처리를 50oC와 60oC의 온도에서 각각 1분, 3분, 5분 동안 세척하였고, 화학적 처리에서는 유기산인 푸마르산과 아세트산 용액 1.5%와 2% 농도에서 각각 1분, 3분, 5분 동안 침지 처리하였다. 미생물과 품질 분석 결과 물리적 처리에서는 버블 세척 3분이 곰팡이 저감에 효과적이었으나 일반세균 저감 효과는 적었고, Ultrasonication 60oC, 5분 처리에서 미생물 저감 효과가 가장 높았으나 색도의 a값이 증가하는 경향을 보여 녹색이 약해졌다. 화학적 처리에서는 acetic acid에 비해서 fumaric acid에서 일반세균과 곰팡이의 저감 효과가 높았으며, fumaric acid 1.5% 용액에서 3분 처리의 저감효과가 가장 높았다. 달래의 미생물 저감 효과가 좋은 버블세척 3분 (B3), fumaric acid 1.5%, 3분 처리(F153), 두 가지 방법을 조합한 병합(BF) 처리를 실시하고 9일 동안 4oC에서 저장하며 품질 특성을 비교해 본 결과, 일반세균보다는 곰팡이 저감에 더 효과적이었으며, 일반세균은 BF가 곰팡이는 F153에서 미생물 감소 효과가 있었다. 색변화에 있어 BF 처리의 ΔE값이 가장 낮았으며, 유기산 처리에서 색변화를 보여 F153에서 녹색이 약해졌다. 최대응집력 변화 알뿌리 보다는 녹색 줄기에서 현격히 나타났는데 저장 9일 차에 F153처리에서 녹색 줄기의 경도가 가장 높게 유지되었고 (P<0.05), 알뿌리 부분은 물리적 방법인 버블 세척 시 6일 차부터 다른 처리에 비해 낮아졌다(P<0.05). 달래의 미생물 저감과 품질의 유지를 고려할 때 전처리 방법으로는 fumaric acid 1.5%용액으로 3분 처리 시 미생물 저감 효과와 색·최대응집력의 특성 유지가 우수하였고, 3일 이내 의 유통기간이라면 병합 처리도 효과적인 방법으로 적용 할 수 있음을 알 수 있었다.