The role of the gut microbiota in colorectal cancer (CRC) development has garnered attention, highlighting probiotics as potential adjuncts in CRC prevention and treatment. In recent years, probiotics and their derivatives have demonstrated mechanisms that may contribute to anticancer properties. This study investigates the cytotoxic effects of Bifidobacterium bifidum KCTC 3357, Lacticaseibacillus rhamnosus KCTC 5033, Limosilactobacillus reuteri VA 103, Bacillus galactosidilyticus VA 107, and Lactococcus taiwanensis VE101 on CT-26 mouse colon carcinoma cells using live cells, heat-killed cells (paraprobiotics), and cell-free supernatants (CFS, postbiotics) through an MTT assay. The results indicate that live bacterial strains, such as KCTC 3357, VA 103, and VA 107, promoted CT-26 cell viability, while heat-killed cells and CFS exhibited dose-dependent cytotoxicity. Inactivated forms of KCTC 3357 and VE 101, as well as CFS at 10 mg/mL concentration of KCTC 5033, VA 103, and VE 101, showed the strongest antiproliferative effects. These findings suggest that non-viable probiotic derivatives, such as paraprobiotics and postbiotics, offer promising therapeutic potential for CRC, providing a safer and more stable alternative to live probiotics. However, further research is required to explore their mechanisms of action, in vivo efficacy, and potential clinical applications.

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.

본 연구에서는 하수처리 과정에서 분리된 항생제 내성균(Antibiotic Resistant Bacteria, ARB)을 제거하기 위해 박테리오파지와 차아염소산 나트륨(NaClO)을 결합한 병용 처리 기술을 응용하였다. ARB를 감염시키는 용균성 박테리오파지는 폐수 샘플에서 성공적으로 분리되었다. 이러한 박테리오파지와 NaClO를 순차적으로 적용한 결과, 5시간 이내에 ARB를 상당히 감소시킬 수 있었다. 환경 안정성 평가에서는 분리된 박테리오파지가 온도, pH, 독성 물질에 대한 노출 등 다양한 조건에서도 효과를 유지하는 것으로 나타냈다. 또한, 실험실 규모의 반응기 실험을 통해 단독 염소 소독과 비교했을 때, 결합 처리가 ARB를 효과적으로 억제하는 것을 확인할 수 있었다. 박테리오파지와 차아염소산 병용 처리는 유기물, 질소(N), 인(P)과 같은 영양소 제거 효율에 영향을 미치지 않았다. 이러한 결과는 박테리오파지를 기반으로 한 생물학적 제어법과 기존의 소독 방식을 결합하여 폐수 처리 공정(Wastewater treatment plant, WWTP)에서 효과적인 항생제 내성 박테리아 제어 방안을 제시할 가능성을 시사한다.

Endoplasmic reticulum (ER) stress, caused by the accumulation of misfolded or unfolded proteins, activates the unfolded protein response to maintain cellular homeostasis and is implicated in bacterial infections. This study investigated ER stress activation in THP-1-derived macrophages infected with oral bacteria Porphyromonas gingivalis , Prevotella intermedia , Aggregatibacter actinomycetemcomitans , and Streptococcus oralis at an multiplicity of infection of 50 for 4 hours. mRNA and protein expressions related to ER stress were analyzed by real-time polymerase chain reaction and Western blot, while pro-inflammatory cytokines were measured using enzymelinked immunosorbent assay. P. gingivalis induced the highest mRNA expression of XBP1 and PERK, whereas A. actinomycetemcomitans showed elevated GRP78, ATF6, IRE1α, ATF4, and CHOP. P. intermedia strongly expressed PERK, while S. oralis showed higher GRP78, PERK, ATF4, and CHOP expression. Protein analysis revealed S. oralis had the highest phosphorylation levels of eIF2α and IRE1α, while CHOP was most highly expressed in P. intermedia . Pro-inflammatory cytokine expression showed P. intermedia and P. gingivalis elicited the most TNF-α, while P. gingivalis induced the highest IL-1β levels. These findings suggest oral bacteria induce varying levels of ER stress, influencing the progression of oral infectious diseases. Targeting ER stress could offer therapeutic potential for managing inflammatory conditions like periodontitis.

This study aimed to obtain basic information on the indoor environmental hygiene of non-disinfected libraries used for paper records preservation in the Nara Repository of National Archives, Korea. Microorganisms were investigated in dust samples collected from bookshelves of five libraries using the swab method. Bacterial concentration ranged from 6 CFU/m2 up to 1,730 CFU/m2 . A total of 11 bacterial species belonging to five genera were identified, with Bacillus being the predominant genus. Some bacterial species forming colonies with pigmentation on TSA media were also present. No bacterial species capable of producing cellulases were found. However, one species that could have harmful effects on human health was discovered. For fungi, concentration ranged between 6 CFU/m2 to 1,660 CFU/m2, and a total of six fungal species belonging to five genera were found. Some fungal species forming pigmented colonies on PDA media were also present. Additionally, three species that could have harmful effects on human health were identified. This study’s data suggests that microbial contamination in the dust is relatively low, but the dust in the bookshelves of non-disinfected libraries at the Nara Repository requires management. This is the first report conducted on microorganisms in the dust of bookshelves at the National Archives in Korea.

식품공전 시험법은 식품기초규격 적부 판정, 수거검사의 적부판정, 수입식품의 적부판정 등의 판단근거가 되기 때문 에 식품산업에서 매우 중요하다. 본 연구는 도시락, 밀키트, 된장에 오염된 일반세균, 대장균군, 효모, 곰팡이, 대장균을 분리하기 방법으로 사용되는 평판배지법, Petrifilm법, Compact Dry법을 이용해 각각의 세균을 분리하였고, 회수율을 비교 하였다. 식품 내 자연균총(일반세균, 효모/곰팡이, 대장균군) 검출은 평판배지 PCA, PDA, DCLA와 Petrifilm AC, YM, CC의 성능을 Compact Dry TC, YMR, CF와 비교하였다. 인 위접종한 대장균(E. coli)의 경우는 평판배지 EMB, Petrilfilm EC, Compact Dry EC의 검출능을 비교하였다. 본 실험결과, 일반세균, 대장균군, 대장균의 검출에서 Compact Dry법은 기 존의 평판배지법 및 건조배지법과 비교하여 식품 내 각각의 세균수를 계수하는데 유의적 차이를 보이지 않았다(P>0.05). 또한, 평판배지법과 Compact Dry간의 상관관계 및 Petrifilm 과 Compact Dry간의 상관관계 역시 1에 가까운 높은 값을 확인하였다. Compact Dry법은 미생물 분석을 위해 배지 준 비 과정이 필요 없으며, 접종 후 자체 확산이 가능하여 사 용하기 쉽고, 공간을 효율적으로 사용할 수 있으므로 기존 의 배지를 사용하는 방법에 비해 많은 장점을 제공하였다. 따라서 식품 중 일반세균, 대장균군, 대장균의 검출을 위한 Compact Dry법(Compact Dry TC, CF, EC)은 기존의 식품공 전 상 등재된 다른 건조필름법을 대체 가능한 것으로 판단된다.

To develop farm-made high effective vinegar, this study prepared apple vinegar using four kinds of acetic acid bacteria isolated from a natural fermentation liquid of ‘Cheongsoo’ grapes and analyzed vinegar samples fermented 93% apple juice and 7% alcohols at 30℃ for 20 days. To accomplish this, quality characteristics such as pH, total acidity, reducing sugar, organic acid, color, total polyphenol contents, and antioxidant activity contents were determined. The pH decreased while total acidity of all samples gradually increased during fermentation period. The vinegar with AP 21 strain tended to increase the total acidity quicker than other stains. Reduced sugar content remained high until the last fermentation day. Furthermore, reduced sugar contents of all vinegars increased as fermentation progressed by decomposing sucrose present in apples. When physiological activities were compared, apple vinegars fermented with AP 21 and 30 strains had higher total polyphenol and flavonoid contents than other samples. However, there was no significant difference in antioxidant activity between samples. These results indicate that strain 21 is the most suitable starter as acetic acid bacteria for producing farm-made vinegar.

본 연구는 어린이집 급식설비 손잡이의 식중독 세균 오 염도를 측정하고, 분리 균주의 독소 유전자와 항생제 내 성을 분석하여 급식설비 손잡이에 의한 집단식중독을 예 방을 위한 과학적 기반을 마련하고자 하였다. 실험 대상 은 전라남도 일부 지역 어린이집 101곳의 냉장고, 냉동고, 자외선 살균기 손잡이, 총 303개를 대상으로 하였다. 어린 이집 냉장고, 냉동고 손잡이에서 B. cereus 4 균주(1.3%) 가 검출되었고 어린이집 냉장고 손잡이에서 S. aureus 2 균주(0.7%)가 검출되었다. B. cereus와 S. aureus의 독소유 전자를 분석한 결과 B. cereus 4개 균주 모두에서 nheA, nheB, nheC, entFM, cytK가 검출되었으나, S. aureus의 2 개 균주의 경우 모두 sea, seb, sec, sed, see, seg, seh, sei, sej 독소유전자가 불검출되었다. B. cereus에서 설사를 유 발하는 장독소가 검출되어 B. cereus에 의한 식중독 발생 가능성이 상존하는 것으로 판단되었다. B. cereus와 S. aureus의 항생제 감수성을 실험한 결과 B. cereus 4 균주 에서 AM, FEP 등 β-lactam계 항생제에 내성을 나타내었 고 S. aureus 균주 모두 AM, P 항생제에 내성을 나타내 었다. S. aureus 균주는 OX 항생제에 각각 중간 내성 1 균주와 감수성 1 균주를 나타내었으나 MRSA는 검출되지 않았다. 이러한 결과를 종합하여 볼 때 어린이집 급식설 비 손잡이의 교차오염으로 인한 식중독 발생을 예방하기 위해 급식설비 손잡이에 대한 주기적인 살균 등 위생관리 방안을 강화해야할 것으로 판단되었다.

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.

이탄 토양으로부터 분리된 세균의 유기물 분해능, 항균 활성 및 식물생육촉진능을 확인하고 다 기능성 유용 미생물을 확보하고자 하였다. 분리된 48 균주를 대상으로 β-glucosidase, cellulase, amylase, protease 생성능을 확인한 결과, SH-23, SH-26, SH-29 그리고 SH-33 균주가 우수 균주로 선발되었다. 선발된 유기물 분해 우수 세균 4 균주는 식물병원성곰팡이(Botrytis cinerea, Rhizoctonia solani, Fusarium oxysporum, Colletotrichum acutatum)에 대한 항진균 활성을 나타내었다. 유기물 분해능이 우수하고 식물 병원성 곰팡이에 대해 항진균 활성을 나타낸 SH-26 균주를 최종 우수균주로 선발 하였다. 선발된 SH-26 균주의 16S rRNA 유전자 염기 서열을 결정한 결과, Pseudomonas knackmussii HG322950 B13T, Pseudomonas citronellolis BCZY01000096 NBRC 103043T, 그리고 Pseudomonas delhiensis jgi.1118306 RLD-1T 와 100%의 상동성을 나타내었다. Pseudomonas sp. SH-26 균주는 siderophore 생성능, 질소고 정능과 Indole-3-acetic acid 생성능이 있는 것으로 확인되었다.

우리는 솔수염하늘소(Monochamus alternatus) 장에 존재하는 공생미생물들을 분리하였다. 그중 다양한 식물 들을 대상으로 성장 촉진 효과가 보고된 세균을 단일배양 분리하였다. 이 세균은 16S rRNA sequencing을 통하여 Enterobacter roggenkampii로 동정되었다. 우리는 분리된 E. roggenkampii에 대하여 genomic sequencing을 수행하 였고 유전학적 특성을 확인하였다. 우리는 E. roggenkampii가 식물의 성장을 촉진할 수 있는 다양한 유전자들을 가지고 있는 것을 확인하였고 그 중 IAA-Asp hydrolase 유전자를 가지고 있음을 알 수 있었다. 동시에, 분리된 E. roggenkampii와 같은 속의 세균을 대상으로 다양한 API kit와 기질 첨가 배지를 이용하여 생화학적 특성을 비교하였다. 향후 IAA-Asp 가수분해효소를 생산하는 잠재적인 식물 생장 촉진 비료 미생물로 등록하여 다양한 작물을 대상으로 생장 촉진 효과를 확인할 것이다.

우리는 길앞잡이(Cicindela chinensis)의 장에서 다양한 공생 미생물들을 분리하였다. 그중 다양한 곰팡이 성장 을 억제하는 세균을 동정하였고 “Ch-1”이라 명명하였다. 우리는 Ch-1 균주를 사용하여 10종의 식물 병원성 곰팡 이와 2종 곤충 병원성 곰팡이의 생장 억제를 확인하였다. 또한 8종의 항생제에 대한 저항성을 확인하였다. 동시 에, 본 균주의 genomic sequence를 수행하였고 유전적, 생화학적, 생리적 특성을 조사하였다. Ch-1균주는 특허등 록과 친환경 미생물제제로 등록하였고 향후 생물학적 방제제로써 활용될 수 있을 것으로 판단한다.

Riptortus pedestris is known to acquire their symbiotic bacteria, Caballeronia insecticola, from soil environments in every generation. The symbionts have been demonstrated to affect behavioral and physiological traits of the host insect such as the enhancement of development. In particular, symbiotic effects on female adults could directly entail changes in their population growth. Therefore, we investigated a suite of symbiotic effects of C. insecticola on behaviors and fitness-related parameters of female R. pedestris. Overall, symbiotic females showed an behavioral enhancement in both feeding efficacy and movement capacity including walking and flight. In addition, the survival rates under exposure to overwintering conditions and insecticide resistance level were significantly higher in symbiotic females than the aposymbiotic. Finally, although symbiotic females exhibited shorter longevity, their fecundity was found higher compared to the apo-symbiotic.

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.

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.

To increase industrial applicability of Astragalus membranaceus (AM) as immunostimulating materials, hot-water extract (AME) was prepared from AM and fermented with Kimchi-lactic acid bacteria (Lactobacillus sakei & Leuconostoc mesenteroides) to prepare fermented AM-postbiotics (FAME). Although FAME prepared from AM-postbiotics did not show a significant enhancement in macrophage stimulating activity compared to non-fermented AME, crude polysaccharide (FAME-CP) fractionated by EtOH precipitation from FAME showed significantly higher macrophage stimulating activity than AME-CP. Compared to AME-CP, FAME-CP showed dramatic changes in component sugar and molecular weight distribution. FAME-CP was a polysaccharide with a major molecular weight distribution of 113.4 kDa containing Man (44.2%), Glc (19.3%), Gal (10.2%), GalA (10.2%), and Ara (7.4%) as sugar components. FAME-CP with enhanced macrophage stimulatory activity not only increased expression levels of mRNA genes encoding macrophage-activated factors (iNOS, TNF-α, MCP-1, IL-6, and COX-2), but also led the nuclear translocation of activated p65 and c-Jun. In conclusion, crude polysaccharide from AM-postbiotics fermented with lactic acid bacteria could increase industrial applicability as a functional material with enhanced immunostimulating activity than AME-CP.