• 한국미생물·생명공학회지
• /
• 제50권2호
• /
• pp.255-269
• /
• 2022

Actinomycetes isolated from marine habitats represent a promising source of bioactive substances. Here, we report on the isolation, identification, productivity enhancement and application of the bioactive compounds of Streptomyces qinglanensis H4. Eighteen marine actinomycetes were isolated and tested for resistance to seven bacterial diseases. Using 16S rRNA sequencing analysis (GenBank accession number MW563772), the most powerful isolate was identified as S. qinglanensis. Although the strain produced active compound(s) against a number of Gram-negative and Gram-positive bacteria, it failed to inhibit pathogenic fungi. The obtained inhibition zones were 22.0 ± 1.5, 20.0 ± 1, 16.0 ± 1, 12.0 ± 1, 22.0 ± 1 and 24.0 ± 1 mm against Bacillus subtilis ATCC 6633, Escherichia coli ATCC 19404, Enterococcus faecalis ATCC 29212, Pseudomonas aeruginosa ATCC 9027, Candida albicans ATCC 10231 and Staphylococcus aureus ATCC6538, respectively. To maximize bioactive compound synthesis, the Plackett-Burman design was used. The productivity increased up to 0.93-fold, when S. qinglanensis was grown in optimized medium composed of: (g/l) starch 30; KNO₃ 0.5; K₂HPO₄ 0.25; MgSO₄ 0.25; FeSO₄·7H₂O, 0.01; sea water concentration (%) 100; pH 8.0, and an incubation period of 9 days. Moreover, the anticancer activity of S. qinglanensis was tested against two different cell lines: HepG2 and CACO. The inhibition activities were 42.96 and 57.14%, respectively. Our findings suggest that the marine S. qinglanensis strain, which grows well on tailored medium, might be a source of bioactive substances for healthcare companies.

• 대한본초학회지
• /
• 제29권5호
• /
• pp.45-53
• /
• 2014

Objectives : The purpose of the study is to test the antibacterial, anti-inflammatory and antioxidant effects of BPH, which is composed of Pini Densiflorae Nodi Lignum and Querci Acutissimae Fructus, Angelicae Gigantis Radix, Cnidii Rhizoma, Angelicae Dahuricae Radix, Angelicae Tenuissimae Radix. Method : Antibacterial and anti-inflammatory effects of BPH on Propionibacterium acnes, one of anaerobic bacteria species were evaluated by measuring the levels of 2,2-diphenyl-1-picrylhydrazyl (DPPH) elimination and lipid peroxidation. Result : When BPH was applied to CCD-986sk (Human normal fibroblast) to confirm the level of cytokine(tumor necrosis factor-alpha, interleukin-8), its level increased in proportion to that of BPH's concentration, which indicated dose-dependent relationship. Using the Disk diffusion to measure the bacterial growth inhibition zone varying BPH concentration, it was found that the antibacterial effect of BPH was less than that of erythromycin, the control group, but was higher than that of saline, and it increased with higher concentrations. In a liquid culture medium containing BPH, the growth rate of Propionibacterium acnes was decreased by more than 10% at 25% BPH. After adding P. acnes to THP-1 monocyte, and treated it with BPH, and measuring the concentration of TNF-a and IL-8, it was observed that the amount of TNF-alpha and IL-8 significantly decreased depending on the level of BPH concentration. The ability to eliminate DPPH increased with higher BPH concentration. The inhibition of lipid peroxidation was increased by BHT treatment in a dose-dependent manner. Conclusion : Using Propionibacterium acnes, an anaerobic bacteria, we confirmed that BPH has antibacterial, anti-inflammatory and antioxidant effects.

• 한국축산식품학회지
• /
• 제22권1호
• /
• pp.66-71
• /
• 2002

예천산 프로폴리스는 ethanol과 butanol 분획물이 S.typhimurium과 B. subtilis에 강한 항미생물 활성을 보였으며, 용매별로는 butanol, ethyl acetate, chloroform 분획물의 순이었다. C. utilis와 A. niger에는 모든 분획물이 항균활성을 나타내지 않았다. 농도별 균생육 억제 시험 결과, E. coli의 경우 예천산은 0.4mg/ml에서 초기에 균증식이 억제되었으며 영월은 0.25mg/ml에서 12시간 이후 균증식이 완전히 억제되었다. S. aureus의 경우, 영월과 예천산 프로폴리스가 0.25와 0.30mg/ml에서 완전히 균증식을 억제시켰다. P. aeruginosa의 경우, 예천산 프로폴리스는 0.20mg/ml에서 12시간 이후 균생장 억제를 보였으며, 영월산 프로폴리스는 0.20mg/ml에서 균생장이 완전히 억제되었다. S. typhimurium의 경우, 영월산은 0.20, 0.25mg/ml에서 균증식이 거의 억제되었으며, 예천산은 0.40mg/ml에서 균증식이 거의 억제되었다. MIC는 예천산 프로폴리스가 P. aeruginosa가 >0.2mg/ml로 가장 낮았고 S. aureus 0.25mg/ml, S. typhimurium > 0.35mg/ml 순이었다. 영월산은 P. aeruginosa가 0.15mg/ml로 가장 낮았으며 E. coli, S. aureus 및 S. typhimurium이 0.25mg/ml, B. subtilis 와 C. utilis는 각각 0.3, 0.4mg/ml 이었다.

• Journal of Periodontal and Implant Science
• /
• 제44권6호
• /
• pp.266-273
• /
• 2014

Purpose: We previously reported that human serum significantly reduces the invasion of various oral bacterial species into gingival epithelial cells in vitro. The aims of the present study were to characterize the serum component(s) responsible for the inhibition of bacterial invasion of epithelial cells and to examine their effect on periodontitis induced in mice. Methods: Immortalized human gingival epithelial (HOK-16B) cells were infected with various 5- (and 6-) carboxy-fluorescein diacetate succinimidyl ester-labeled oral bacteria, including Fusobacterium nucleatum, Provetella intermedia, Porphyromonas gingivalis, and Treponiema denticola, in the absence or presence of three major serum components (human serum albumin [HSA], pooled human IgG [phIgG] and ${\alpha}1$-antitrypsin). Bacterial adhesion and invasion were determined by flow cytometry. The levels of intracellular reactive oxygen species (ROS) and activation of small GTPases were examined. Experimental periodontitis was induced by oral inoculation of P. gingivalis and T. denticola in Balb/c mice. Results: HSA and phIgG, but not ${\alpha}1$-antitrypsin, efficiently inhibited the invasion of various oral bacterial species into HOK-16B cells. HSA but not phIgG decreased the adhesion of F. nucleatum onto host cells and the levels of intracellular ROS in HOK-16B cells. N-acetyl-cysteine (NAC), a ROS scavenger, decreased both the levels of intracellular ROS and invasion of F. nucleatum into HOK-16B cells, confirming the role of ROS in bacterial invasion. Infection with F. nucleatum activated Rac1, a regulator of actin cytoskeleton dynamics. Not only HSA and NAC but also phIgG decreased the F. nucleatum-induced activation of Rac1. Furthermore, both HSA plus phIgG and NAC significantly reduced the alveolar bone loss in the experimental periodontitis induced by P. gingivalis and T. denticola in mice. Conclusions: NAC and the serum components HSA and phIgG, which inhibit bacterial invasion of oral epithelial cells in vitro, can successfully prevent experimental periodontitis.

• 한국동물위생학회지
• /
• 제44권3호
• /
• pp.169-174
• /
• 2021

Mastitis is an inflammatory condition of the mammary gland, most often caused by bacterial infections, resulting in significant economic losses to the dairy industry. Antimicrobial resistance has been of great concern because of the extensive clinical use of antibiotics. For this reason, the development of new compounds as an alternative treatment to bovine mastitis is needed. Bee venom has been widely used as an oriental treatment for several inflammatory diseases and bacterial infections. The aim of the present study was to evaluate the antimicrobial activity of bee venom on bacteria isolated from bovine mastitis. A total of 107 isolates from bovine mastitic milk samples collected in 2019 and 2020 in Jeonbuk province. All bacterial isolates were tested for susceptibility to bee venom of the honey bee (Apis mellifera). In order to obtain comprehensive antibacterial activities of the bee venom, we measured the minimal inhibitory concentration (MIC) of the bee venom against bacterial strains. Bee venom showed significant inhibition of bacterial growth of Gram-negative bacteria Citrobacter spp., Escherchia coli, Klebsiella spp., Pseudomonas spp., Serratia spp. and Raoultella with MIC values of 96, 81, 72, 230, and 85 ㎍/mL, respectively, and Gram-positive bacterial Enterococcus spp., Staphylococcus spp. and Streptococcus spp. with MIC values of 29, 21 and 16 ㎍/mL, respectively. The results indicated that the MIC values were different depending on the bacterial strains, and those of Gram-positive bacteria were lower than those of Gram-negative bacteria for bee venom. These findings suggested that bee venom could be an effective antimicrobial treatment for bovine mastitis; however, further research is necessary to evaluate the mechanism underlying the antimicrobial action, its effectiveness/safety in vivo and effective application for therapeutic use.

• 대한의생명과학회지
• /
• 제13권1호
• /
• pp.47-53
• /
• 2007

Due to wide abuse of antibiotics both in human and livestock use, the advent and spread of multidrug resistant (MDR) pathogens becomes a serious health problem all over the world. Since the development of new antibiotics is at a standstill in pharmaceutical industry, the choice of therapeutic antibiotics is getting narrower. In this study, in an effort to search new antibiotics, the antimicrobial activity of Paenibacillus DY1 isolated from Korean soil was characterized on its growth inhibition spectrum against various health threatening MDR strains, with its stability and chemical structure. Extracellular culture filtrate of Paenibacillus DY1 effectively inhibits the growth of all the tested MDR enteropathogenic Eshcherichia coli, enterohemolytic E. coli, and enterotoxigenic E. coli strains, at a similar level to that on the nonresistant control E. coli strains. It showed significant growth inhibition effect against the causative agents of class one legal communicable disease, MDR Salmonella typhi, MDR Salmonella paratyphi A, food poisoning bacteria, MDR Salmonella typhimurium, and other MDR Salmonella spp. The growth of all of 10 different MDR Shigella spp. strains and 6 different Vibrio spp. strains tested was also inhibited. The antimicrobial activity of Paenibacillus DY1 was well preserved after heat treatment, and was also stable in both alkaline and acidic environment. The antimicrobial activity was partially purified with Diaion HP20 column and TLC. By NMR study, the putative structure of the activity was postulated as an alkane having hydroxyl groups.

• Journal of Microbiology and Biotechnology
• /
• 제17권4호
• /
• pp.586-593
• /
• 2007

Seed coating by a phenazine-producing bacterium, Pseudomonas chlororaphis O6, induced dose-dependent inhibition of germination in wheat and barley seeds, but did not inhibit germination of rice or cucumber seeds. In wheat seedlings grown from inoculated seeds, phenazine production levels near the seed were higher than in the roots. Deletion of the gacS gene reduced transcription from the genes required for phenazine synthesis, the regulatory phzI gene and the biosynthetic phzA gene. The inhibition of seed germination and the induction of systemic disease resistance against a bacterial soft-rot pathogen, Erwinia carotovora subsp. carotovora, were impaired in the gacS and phzA mutants of P chlororaphis O6. Culture filtrates of the gacS and phzA mutants of P. chlororaphis O6 did not inhibit seed germination of wheat, whereas that of the wild-type was inhibitory. Our results showed that the production of phenazines by P. chlororaphis O6 was correlated with reduced germination of barley and wheat seeds, and the level of systemic resistance in tobacco against E. carotovora.

• Ocean Science Journal
• /
• 제40권2호
• /
• pp.91-100
• /
• 2005

Bioassay using the marine bacteria, Vibrio fischeri and rotifer, Brachionus plicatilis, and chemical analyses were conducted to assess the toxicity of the various sewage sludges, one of the major ocean dumped materials in the Yellow Sea of Korea. Sludge elutriates extracted by filtered seawater were used to estimate the ecotoxicity of the sludge. Chemical characterization included the analyses of organic contents, heavy metals, and persistent organic pollutants in sludge. Bacterial bioluminescent inhibition (15 min), rotifer mortality (24 hr) and rotifer population growth inhibition (48 hr) assay were conducted to estimate the sludge toxicity. EC50 15 min (inhibition concentration of bioluminescence after 15 minutes exposed) values by Microtox(R) bioassay clearly revealed different toxicity levels depending on the sludge sources. Highest toxicity for the bacteria was found with the sludge extract from dyeing waste and followed by industrial waste, livestock waste, and leather processing waste. Clear toxic effects on the bacteria were not found in the sludge extract from filtration bed sludge and rural sewage sludge. Consistent with Microtox(R) results, rotifer neonate mortality and population growth inhibition test also showed highest toxicity in dyeing waste and low in filtration bed and rural sewage sludge. High concentrations of persistent organic pollutants (POPs) and heavy metals were measured in the samples from the industrial wastes, leather processing plant waste sludge, and urban sewage sludge. However, there was no significant correlation between pollutant concentration levels and the toxicity values of the sludge. This suggests that the ecotoxicity in addition to the chemical analyses of various sludge samples must be estimated before release of potential harmful waste in the natural environment as part of an ecological risk assessment.

• Restorative Dentistry and Endodontics
• /
• 제38권2호
• /
• pp.65-72
• /
• 2013

Objectives: To evaluate the inhibitory effect of ursolic acid (UA)-containing composites on Streptococcus mutans (S. mutans) biofilm. Materials and Methods: Composite resins with five different concentrations (0.04, 0.1, 0.2, 0.5, and 1.0 wt%) of UA (U6753, Sigma Aldrich) were prepared, and their flexural strengths were measured according to ISO 4049. To evaluate the effect of carbohydrate source on biofilm formation, either glucose or sucrose was used as a nutrient source, and to investigate the effect of saliva treatment, the specimen were treated with either unstimulated whole saliva or phosphate-buffered saline (PBS). For biofilm assay, composite disks were transferred to S. mutans suspension and incubated for 24 hr. Afterwards, the specimens were rinsed with PBS and sonicated. The colony forming units (CFU) of the disrupted biofilm cultures were enumerated. For growth inhibition test, the composites were placed on a polystyrene well cluster, and S. mutans suspension was inoculated. The optical density at 600 nm ($OD_{600}$) was recorded by Infinite F200 pro apparatus (TECAN). One-way ANOVA and two-way ANOVA followed by Bonferroni correction were used for the data analyses. Results: The flexural strength values did not show significant difference at any concentration (p > 0.01). In biofilm assay, the CFU score decreased as the concentration of UA increased. The influence of saliva pretreatment was conflicting. The sucrose groups exhibited higher CFU score than glucose group (p < 0.05). In bacterial growth inhibition test, all experimental groups containing UA resulted in complete inhibition. Conclusions: Within the limitations of the experiments, UA included in the composite showed inhibitory effect on S. mutans biofilm formation and growth.

• 농약과학회지
• /
• 제20권1호
• /
• pp.41-46
• /
• 2016

Acidovorax avenae subsp. citrulli에 의해 발생하는 수박 과일썩음병은 수박재배지역에 문제병해이다. 수박 과일썩음병 방제를 위해 시판되는 살세균제로 방제효과 조사하였다. 고체배지를 이용한 생장억제효과를 검정한 결과, 옥솔린산 수화제, 옥시테트라사이클린 수화제 등에서 과일썩음병균 생장억제효과가 나타났다. 총 4종의 살세균제를 사용하여 종자침지, 유묘기에 발생한 수박 과일썩음병 방제효과를 검정한 결과, 종자침지에서는 옥시테트라사이클린 수화제가 90% 이상의 방제효과를 보였고, 유묘기에 발생한 수박 과일썩음병 방제에는 아시벤졸라-에스-메틸+만코제브 수화제가 90% 이상의 방제효과를 보였다. 온탕침지 처리법으로도 병든 수박종자에 발생하는 수박 과일썩음병 감염율을 효과적으로 낮출 수 있는데, 그 처리조건은 $50{\sim}55^{\circ}C$에서 20~30분간 처리하는 것이다. 이러한 결과들은 수박재배농가와 육묘재배인이 사용 가능한 방법으로 수박 과일썩음병의 효율적인 방제법이 확립되는데 도움이 될 것으로 판단된다.