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.

This study examined the impact of two bacterial strains, H05E-12 and H05R- 04, on alleviating non-irrigation-induced stress and its subsequent effects on the fruit productivity of sweet pumpkin plants. When subjected to non-irrigation-induced stress, the lipid peroxidation, proline, total phenol, and total soluble sugar content significantly decreased in plants treated with either H05E-12 or H05R-04 compared to the control. In a greenhouse experiment under non-irrigated conditions, H05E-12-treated plants exhibited higher stomatal conductance than the control, although there was no significant change in the soil plant analysis development (SPAD) value due to treatment. Upon re-watering, an increase in fruit diameter was observed in H05E-12-treated plants, and the L-ascorbic acid content in the fruit also showed a significant increase compared to the control. The H05E-12 strain was identified as Kushneria konosiri. To the best of our knowledge, this is the first report detailing the beneficial effects of K. konosiri on the alleviation of non-irrigation-induced stress and the promotion of plant growth in sweet pumpkin plants.

In this study, we examined the antagonistic effects of sprout-borne lactic acid bacteria (LAB) on Salmonella enterica serovar Enteritidis. This antagonism is promoted as a means of controlling contamination during sprout production and provides additional LAB for consumers. We isolated a total of 24 LAB isolates in nine species and five genera from seven popular vegetable sprouts: alfalfa (Medicago sativa), clover (Trifolium pratense), broccoli (Brassica oleracea ssp. italica), vitamin (B. rapa ssp. narinosa), red radish (Raphanus sativus), red kohlrabi (B. oleracea var. gongylodes), and Kimchi cabbage (B. campestris var. pekinensis). Based on 16S rRNA gene sequences, the LAB species were identified as Enterococcus casseliflavus, E. faecium, E. gallinarum, E. mundtii, Lactococcus taiwanensis, Leuconostoc mesenteroides, Pediococcus pentosaceus, and Weissella cibaria, and W. confusa. A total of 16 LAB isolates in seven species including E. faecium, E. gallinarum, E. mundtii, L. taiwanensis, L. mesenteroides, P. pentosaceus, and W. cibaria showed antagonistic activity toward S. enterica. The growth inhibition of sprout LAB on S. enterica was confirmed by co-culture. Unexpectedly, sprout LAB failed to suppress the growth of S. enterica in alfalfa sprouts, whereas all LAB strains stimulate S. enterica growth even if it is not significant in some strains. The findings of this study indicate that S. enterica-antagonistic LAB are detrimental to food hygiene and will contribute to further LAB research and improved vegetable sprout production.

Rapid and accurate detection of pathogenic bacteria is crucial for various applications, including public health and food safety. However, existing bacteria detection techniques have several drawbacks as they are inconvenient and require time-consuming procedures and complex machinery. Recently, the precision and versatility of CRISPR/Cas system has been leveraged to design biosensors that offer a more efficient and accurate approach to bacterial detection compared to the existing techniques. Significant research has been focused on developing biosensors based on the CRISPR/Cas system which has shown promise in efficiently detecting pathogenic bacteria or virus. In this review, we present a biosensor based on the CRISPR/Cas system that has been specifically developed to overcome these limitations and detect different pathogenic bacteria effectively including Vibrio parahaemolyticus, Salmonella, E. coli O157:H7, and Listeria monocytogenes. This biosensor takes advantage of the CRISPR/Cas system's precision and versatility for more efficiently accurately detecting bacteria compared to the previous techniques. The biosensor has potential to enhance public health and ensure food safety as the biosensor’s design can revolutionize method of detecting pathogenic bacteria. It provides a rapid and reliable method for identifying harmful bacteria and it can aid in early intervention and preventive measures, mitigating the risk of bacterial outbreaks and their associated consequences. Further research and development in this area will lead to development of even more advanced biosensors capable of detecting an even broader range of bacterial pathogens, thereby significantly benefiting various industries and helping in safeguard human health

본 연구에서는 영종도에 위치한 인천과학고등학교 주변에 서식하는 개미와 개미집 근권토양을 두 차례에 걸쳐 채취한 것을 활용하여 토양미생물 순수분리 및 동정을 진행하였다. 채취된 개미의 더듬이의 모양, 털의 위치 및 분포 등의 형태학적 동정 및 DNA extraction을 통한 분자생물학적 동정을 통하여 채취한 개미를 Camponotus japonicus으로 결론하였다. 토양미생물을 연속희석법을 이용하여 확인한 결과 채취한 개미집 세 곳에서 각각 12, 18, 10개의 종이 동정되었다. 개미집 근권토양의 비옥도가 상대적으로 높다는 선행연구를 바탕 으로 ‘분리한 토양미생물이 다양한 유기물 분해 효소활성을 보일 것’이라는 가설을 세웠고, 이를 확인하기 위해 분별배지를 제작하여 디스크 확산법을 진행하였다. 실험 결과 개미집 근권 토양에서 분리된 균주가 일반 토양에 서 분리된 균주에 비해 높은 효소활성을 보임을 확인하였으며 개미집 근권 토양 미생물의 불용성인산 가용화능 이 우수함을 확인하였다. 이후 위 실험들을 바탕으로 개미집 근권 토양 미생물이 식물 생장을 촉진시켜 미생물을 접종한 토양에서의 식물의 건조 질량이 증가하였음을 확인하였다.

Nutrient acquisition by insect herbivores affect all aspect of the the lifespan of individauls. For seed-sucking insect herbivores, they face challenges with nutrient acquisition due to requirement for extra-oral digestion of seed contents into a readily-ingestible state. In this study, we demonstrated environmentally-transmitted Caballeronia insecticola allow seed-sucking R. pedestris to overcome challenges with extra-oral digestion. Through the evaluation, first, we found symbiotic insects exhibited enhanced feeding efficiency by consuming significantly larger amount of food per feeding attempt compared to apo-symbiotic insects (P<0.05). Then, we observed feeding behavior modification in the symbiotic insects from the behavior tracking evaluation. Symbiotic insects displayed dichotomic behavior which can be generally divided into early focused feeding and later subdued resting periods. By contrast, apo-symbiotic insects displayed unordered behavior by frequent switches between feeding and walking behavior.

Humans have lived in relationship with bees for a very long time. In addition, as essential pollinators, Bee also contribute to biodiversity by promoting the reproduction of various plant species, and play an important role in global food security. Therefore, strong and thriving bee populations are essential for maintaining healthy ecosystems and sustaining food production systems. However, the population of these bees is currently rapidly decreasing due to various causes such as climate change, abnormal temperatures, infectious diseases, and predators. In this presentation, we will learn about the microorganisms that affect bees, including bacteria and fungi, among the various causes of the decline in the bee population, and study their control.

Hymenobacter 속(genus)은 Bacteroidota 문(phylum), Hymenobacteraceae 과(family)의 대 표 속(type genus)이다. 이 속에 속하는 세균들은 붉은색 색소를 함유하는 그람 음성 간균으로서, 자연 계의 다양한 환경에서 분리되고 있다. 본 연구에서 붉은색 색소를 함유하는 그람 음성 간균이 경남 창 원시 소재 창원대학교 교내의 연못에서 분리되었고, 이 세균은 균주 B2로 명명되었다. 균주 B2를 계통 분석 및 생화학적으로 분석한 결과, Hymenobacter 속에 속하는 것으로 밝혀졌다. 이 세균의 16S rRNA 유전자 염기서열을 genbank의 BLAST로 분석해 본 결과, 다른 어떠한 세균과도 16S rRNA 유전 자 염기서열의 상동성이 새로운 미생물로 인정되는 기준인 98.7%보다 낮은 것으로 나타났다. 균주 B2 의 지방산을 분석해 본 결과, 주된 지방산은 summed feature 3(C16:1 ω7c and/or C16:1 ω6c, 22.8%), iso-C15:0(16.2%), anteiso-C15:0(12.9%), C16:1ω5c(12.4%) 및 summed feature 4 (iso-C17:1 I/anteiso-C17:1)(9.5%)인 것으로 밝혀졌는데, 결과적으로 균주 B2의 지방산 함량은 다른 Hymenobacter 종들의 지방산 함량과 뚜렷한 차이가 있는 것을 알 수 있었다. 이 세균의 16S rRNA 유전자 염기서열 은 genbank에 accession number OQ318247로 등록되었다.

본 연구는 차나무식재지 토양에서 LB-CMC 한천배지를 이용하여 목질계 바이오매스 분해능이 우수한 미생물을 분리하고자 실시하였다. 그 결과 목질계 바이오매스분해에 우수한 활성을 보이는 3종의 박테리아를 분리하였다. 16S rRNA 유전자를 이용하여 3종의 박테리아를 동정한 결과 모두 Bacillus속에 속하였다. CMC zymogram 분석결과 Bacullus 3종 모두 약 44kDa의 셀룰레이즈가 존재하였다. Bacillus sp. CS1의 최적생장 온도는 37℃였으며, CMCase의 최대활성은 배양 36시간 후였고, xylanase는 배양 후 12시간에 최대활성을 보였다. CMCase와 xylanase의 최적 pH는 각각 5.0이었다. CMCase의 열안정성은 높았지만, xylanse는 열에 불안정한 것을 보였다. Bacillus sp. CS2의 최적 생장온도는 37℃였으 며, CMCase와 xylanaase의 활성은 배양 후 36시간이 가장 높았다. CMCase의 최적 온도와 pH는 각각 37℃와 pH 4.0이었지만, xylanaase의 최적 온도와 pH는 50℃와 pH 5.0이었다. CMCase와 xylanase는 비교적 열에 안정적이었다. Bacillus sp. CS3 최적 생장 온도는 37℃였으며, CMCase와 xylanase의 활성은 배양 후 36시간이 가장 높았다. CMCase 및 xylanase에 대한 최적의 온도와 pH는 37℃와 4.0이었다. CMCase의 열안정성을 보였지만, xylanase는 열에 불안정한 것을 보였다.

Large amounts of waste and wastewater from aquaculture have negatively impacted ecosystems. Among them, shrimp aquaculture wastewater contains large amounts of nitrogen contaminants derived from feed residues in an aerobic environment. This study isolated candidate strains from adult rockworms to treat shrimp aquaculture wastewater (SAW) in an aerobic environment. Among 87 strains isolated, 25 grew well at the same temperature as the shrimp aquaculture with excellent polymer degradation ability (>0.5 cm clear zone). Six isolates (strains AL1, AL4, AL5, AL6, LA10, and PR15) were finally selected after combining strains with excellent polymer degradation ability without antagonism. 16S rRNA sequencing analysis revealed that strains AL1, AL4, AL5, AL6, LA10, and PR15 were closely related to Bacillus paramycoides, Bacillus pumilus, Stenotrophomonas rhizophila, Bacillus paranthracis, Bacillus paranthracis, and Micrococcus luteus, respectively. When these six isolates were applied to SAW, they reached a maximum cell viability of 2.06×105 CFU mL-1. Their chemical oxygen demand (CODCr) and total nitrogen (TN) removal rates for 12 h were 51.0% and 44.6%, respectively, when the CODCr/TN ratio was approximately 10.0. Considering these removal rates achieved in this study under batch conditions, these six isolates could be used for aerobic denitrification. Consequently, these six isolates from rockworms are good candidates that can be applied to the field of aquaculture wastewater treatment.

This research focused on the isolation and characterization of the new strains which can be used as microbial resources for auxin production in the agriculture industry. For the isolation of the new microorganism in the gut of Larimichthys polyactis, a marine agar medium was used and 3 colonies were isolated. Through the 16S-based ID service, isolated strains were identified as 1 strain of Niallia circulans and 3 strains of Proteus mirabilis. Verifying the agriculture industrial values of these isolated strains, the productivity of auxin and activity of various enzymes such as amylase, lipase, and protease were confirmed. As a result, isolated 3 strains showed auxin activity and only protease activities which means the possibility of applying them to the production of effective microorganisms in the agriculture industry.