• Title/Summary/Keyword: floating bacteria

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Influence of denitrified biofloc water on the survival rate and physiological characteristics of Pacific white shrimp juveniles, Litopenaeus vannamei (바이오플락 탈질수가 어린 흰다리새우, Litopenaeus vannamei의 생존율 및 생리특성에 미치는 영향)

  • Kim, Su-Kyoung;Jang, Jin Woo;Jo, Yong Rok;Kim, Jun-Hwan;Kim, Su Kyoung
    • Korean Journal of Environmental Biology
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    • v.37 no.2
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    • pp.136-143
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    • 2019
  • This study investigates the effect of denitrified biofloc water on changes in the water quality parameters and the physiological characteristics of shrimps. Biofloc rearing water contains a large number of microorganisms and can rapidly stabilize the water quality and energy saving if reusable due to high water temperatures. Rearing water contain floating bacteria with both aerobic and anaerobic bacteria. Therefore, when the carbon source is added in limited air supply, the anaerobic state is activated and the denitrification process is possible. In this study, the denitrification water had the following properties: ammonia (6.9 mg L-1), nitrite (0.3 mg L-1), nitrate concentration (9.2 mg L-1), high pH (8.42) and alkalinity (590 mg L-1). The experimental group consisted of seawater (SW, control), a mixture of Seawater and denitrified biofloc water (DNW) in the ratio of 3:1, 1:1 and DNW only. All experiments were done in triplicate. As a result, the survival rate never changed even when 100% of the denitrification water was utilized. However, a body fluid analysis showed that creatine and BUN were increased due to index of stress and the tissue damage resulting from the high denitrified water content. Body fluid ions (Na+, K+, and Cl-) significantly decreased as the denitrified water content increased. It was recommended that the denitrification water be mixed with a certain ratio (less than 50%) in the future as it may affect the osmotic pressure control in shrimps.

A Study on the Effect of Photocatalyst Coating to Improve the Indoor Air Quality in Buildings (건축물 실내 공기질 향상을 위한 광촉매 코팅 효과에 관한 연구)

  • Park, Hyeon-Ku;Kim, Jong-Ho;Go, Seong-Seok
    • Journal of the Korean Society of Safety
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    • v.21 no.2 s.74
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    • pp.150-157
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    • 2006
  • Sick Building Syndrome (SBS) is an illness symptom such as irritation of eyes, skin eruption and vomit ing in newly constructed buildings. It is mainly due to the harmful gases from the materials installed in building such as Volatile Organic Compounds (VOCs), Semivolatile Organic Compounds (SVOCs), floating bacteria, fungi, fungal spores and viruses, human bioeffluents in many modem buildings. The general ways to improve the Indoor Air Quality (IAQ) are ventilating, utilizing eco-material without harmful gases and reducing or removing harmful gases through additional treatment to the building materials. This study aimed to improve the Indoor Air Quality(IAQ) by applying surface coating on the building materials and to make safe living environments through the analysis of air quality before and after surface coating treatment in buildings.

Microbial Colonization of the Aquatic Duckweed, Spirodela polyrhiza, during Development (수생식물 개구리밥 (Spirodela polyrhiza)과 미생물)

  • Kim, In-Sun
    • Applied Microscopy
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    • v.34 no.2
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    • pp.103-111
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    • 2004
  • Fresh specimens of the aquatic macrophyte, Spirodela polyrhiza, have been examined employing scanning and transmission electron microscopy. Observations revealed the occurrence of microbial colonization during development. Submerged parts of the small, free-floating S. polyrhiza body exhibited a variety of microorganisms such as bacteria, cyanobacteria, and diatoms throughout their development. However, immature and/or young plants normally demonstrated much less microbial colonization compared to mature plants. During the study, heavy colonization by the microorganisms was routinely encountered at maturity, especially in the fully developed abaxial fronds and root caps. The mucilaginous layer was shown along the root caps, and the microorganisms appeared to be either clustered or attached to this layer. In contrast, only moderate degrees of colonization were observed in the root, and little to no colonization was observable in the adaxial frond surface. Transmission electron microscopy clearly demonstrated the microbial colonization to be external in the S. polyrhiza specimen examined in the current study. The association between the microorganisms and S. polyrhiza has been considered non-harmful, as no frond senescence and almost no mechanical penetration of the plant by the microorganisms were noticed during the study.

An Analysis of the Current Status and Characteristics of Airborne Fungi in Indoor Air in Multi-Use Facilities Nationwide (전국 다중이용시설의 실내공기 부유 곰팡이의 현황 및 특성 분석)

  • Park, Yongsung;Kwon, Soonhyun;Park, Song-Yi;Kee, Sun-Ho;Yoon, Wonsuck
    • Journal of Environmental Health Sciences
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    • v.48 no.5
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    • pp.282-289
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    • 2022
  • Background: Airborne fungi are ubiquitous in the air and exposure to an airborne fungus can be a significant risk factor. The composition of fungi has been potentially important for human health, especially for respiratory diseases like asthma and atopic dermatitis. Therefore, we attempted to ascertain what kind of airborne fungi affect human health at a nationwide level. Objectives: This study was carried out to provide information on indoor fungi distribution at multi-use facilities throughout South Korea. Methods: We classified our data by region and public facility after collection, cultivation, and identification via the sequencing of the ITS (internal transcribed spacer) region. We investigated whether or not the proliferation of HaCaT cells was affected by the identified airborne fungi. Results: In our data, the most isolated airborne fungi by region were Penicillium spp (Seoul, Daegu), Periconia sp (Gyeonggi-do), Iprex sp (Gangwon-do), Phanerochaete sp (Busan), Bjerkandera sp (Gwangju), and Aspergillus sp (Jeju-do). In the public facilities, the most detected fungi were Cladosporium sp (public transport), Penicillium sp (apartment house, retail market, financial institution, karaoke room), Bjerokandera sp (underground parking lot, public toilet, medical institution), Periconia sp (retail store), and Fusarium sp (general restaurant). Next, we selected twenty airborne fungi to examine their cytotoxicity and proliferation of human skin cells. In this experiment, the proliferation of the cells was influenced by most of the identified fungi. In case of the cytotoxicity test, most genera except for Rhodotorula sp and Moesziomyces sp showed cytotoxicity in HaCaT cells. Conclusions: The distribution of mold in the indoor air in multi-use facilities in South Korea differs from region to region, and this is an indicator that should be considered in future health impact studies. In addition, as a result of culturing about 20 types of bacteria dominant in indoor air, it was found that most (90%) inhibit the growth of skin cells, which can be harmful to health. An in-depth study of the health effects of floating fungi is needed.

DISTRIBUTION OF AIRBORNE BACTERIA BY HANDPIECE AEROSOL CONDITIO (핸드피스 분무조건에 따른 부유세균 기균(氣菌) 의 분포)

  • Ko, Young-Han;Baik, Byeong-Ju;Kim, Jae-Gon;Yang, Yeon-Mi;Shin, Jeong-Geun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.35 no.4
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    • pp.628-634
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    • 2008
  • In recent years, cross-contamination has become one of the noticeable issues in dental clinic. Two major routes of contamination are the direct-contamination through blood and oral secretion and the indirect-contamination through dental office equipments. Especially, air-contamination through air-floating pollutant in a confined space like hospital, and also contamination through aerosol ejected from high-speed handpiece in a dental office was interested. The purpose of this study was to understand risk of bacterial infection through aerosol from handpiece in a dental office, which will help the practitioner with prevention of contamination during dental treatment. The main findings are as follows. 1. In a comparative test, the group using handpiece has higher bacterial number than the group not using handpiece with significant statistical difference(P<0.01). 2. The group using handpiece with rubber dam has lower bacterial number than the group using handpiecewithout rubber dam with significant statistical difference(P<0.01). 3. Comparing the group using drainage water with the group using distilled water as a handpiece water source results in 22.4 cfu and 17.0 cfu respectively but the difference is no statistically significant(P>0.05). 4. Measuring cfu at 0.5m and 1.5m distance, 0.5m distance showed higher bacterial number with statistical significance(P<0.01). 5. Classification of bacterial types showed the largest bacterial number came from gram-positive micrococcus(73.9%), and gram-negative micrococcus, gram-negative bacillus, and gram-positive bacillus follow in descending order.

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Nutritional Properties by Composting Process of Algae Biomass as Soil Conditioner (조류 바이오매스를 이용한 토양개량제의 퇴비화 과정에 따른 영양성분 특성)

  • Ahn, Chang-Hyuk;Lee, Saeromi;Park, Jae-Roh
    • Journal of Environmental Impact Assessment
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    • v.28 no.6
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    • pp.604-615
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    • 2019
  • In this study, we produce a new type of the algae soil conditioner(ASC) using discarded algae biomass through a composting process and evaluate its nutritional characteristics. As the main ingredient, the ASCs used algae biomass collected through the coagulation-floating method and made by adding a variety of additional supporting materials (sawdust, pearlite, oilcake etc.). ASCs were divided into 0% in blank, 11.7% in ASC1, 21.6% in ASC2, 37.6% in ASC3, 59.5% in ASC4, and composted during 127 days. ASCs showed a sharp increase in temperature by aerobic microbial reaction, and 6~7 high and low temperature peaks were observed. As a result of physicochemical analysis, mineralization proceeded according to decomposing the organic matter and there was a marked increase not only in macronutrients (TN, P2O5, K2O), but also in secondary macronutrients (CaO, MgO). The microbial community change was found in stage 1 (bacteria, filamentous fungi) → stage 2 (actinomycetes, bacteria) → stage 3 (Bacillus sp.), depending on the maturation process. It was estimated that microbial transition was closely related to temperature change and nutritional behavior. The quality of soil conditioner can be determined according to the maturity of compost process, and it was determined that effective microbial activity could be induced by controlling algae biomass below 59.5% in this study. In conclusion, we found out the possibility of manufacturing and utilizing soil conditioner recycled algae biomass and if further technological development is made on the basis it can be used as an effective soil conditioner.

Control of Microorganisms in School Refectories and Kitchens Using Ozone Water and Ozone Gas (오존수 및 오존가스를 이용한 학교급식에서의 미생물 제어)

  • Choi, Jin-Kyung;Shin, Il-Shik;Kim, Dae Uk;Kim, Hee-Yun
    • Korean Journal of Food Science and Technology
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    • v.47 no.5
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    • pp.586-592
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    • 2015
  • This study was performed to determine optimum approaches for control of microorganisms in school refectories and kitchens. A reduction of more than 5.0 log CFU/mL was noted for Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus, and Streptococcus mutans after treatment with 5 ppm ozone water for 60 s. Treatment of different vegetables with ozone water for 5 min showed bactericidal effects with 2-4 log reduction of viable cell number; the bactericidal effects differed according to the kinds of vegetables. The viable cell number on kitchen apparatus and tableware was not detected by ozone water treatment for 60 s. In addition, the count of the bacteria floating in the air in refectories and kitchens decreased 2.0 log CFU/1,000 L air to 0-1 CFU/1,000 L air on treatment with 45 ppm ozone gas for 12 hr. Therefore, ozone water and ozone gas may be good candidates as antimicrobial agents that can be used to improve sanitary conditions in school refectories and kitchens.

Effects of High Pressure on Quality Stability of Fresh Fruit Puree and Vegetable Extracts During Storage (고압처리가 신선 과채음료의 저장기간 중 품질 안정성에 미치는 영향)

  • Kim, Young-Kyung;Lee, Yong-Hyun;Iwahashi, Yumiko
    • Food Science and Preservation
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    • v.17 no.2
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    • pp.190-195
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    • 2010
  • Pressure, used as a minimal processing technology in the food industry, is a valuable tool ensuring microbiologically safe, shelf-stable fruit and vegetable production. Pressure could be used to deliver a greater variety of minimally processed products, as demanded by today's consumers. Weevaluated the effect of <400 MPa pressure, applied during chilling, on fresh fruit purees (strawberry, kiwi, aloe, and pomegranate) and vegetable extracts (from carrot and spinach) during cold storage (<$10^{\circ}C$) for 15-20 days. Samples were prepared in a processing facility in which total plate counts of falling and floating bacteria were controlled at $1{\times}100-10^1$ CFU/plate and $1{\times}10^2-10^3$ $CFU/m^3$ under conditions of $21-25^{\circ}C$ and 55-60% relative humidity. The aerobic plate counts of raw materials were less than $1{\times}10^3$ CFU/g. Evaluation parameters included microbiological safety, vitamin content, and sensory qualities. Although the overall quality of non-treated samples deteriorated with storage time at $10^{\circ}C$, samples pressurized at 250-350 MPa at $5-7^{\circ}C$ for 10 min showed less change, with no significant difference in microbiological safety, vitamin content, or sensory quality. The use of pressure extended the shelf-life during storage at $10^{\circ}C$.

Optimization Test of Plant-Mineral Composites to Control Nuisance Phytoplankton Aggregates in Eutrophic Reservoir (부영양 저수지의 조류제거를 위한 기능성 천연물질혼합제의 최적화 연구)

  • Lee, Ju-Hwan;Kim, Baik-Ho;Moon, Byeong-Cheon;Hwang, Soon-Jin
    • Korean Journal of Ecology and Environment
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    • v.44 no.1
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    • pp.31-41
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    • 2011
  • To optimize the natural chemical agents against nuisance phytoplankton, we examined algal removal activity (ABA) of Plant-Mineral Composite (PMC), which already developed by our teams (Kim et al., 2010), on various conditions. The PMC are consisted of extracted-mixtures with indigenous plants (Camellia sinensis, Quercusacutissima and Castanea crenata) and minerals (Loess, Quartz porphyry, and natural zeolite), and characterized by coagulation and floating of low-density suspended solids. A simple extraction process was adopted, such as drying and grinding of raw material, water-extraction by high temperature-sonication and filtering. All tests were performed in 3 L plastic chambers varying conditions; six different concentrations ($0{\sim}1.0\;mL\;L^{-1}$), six light intensities ($8{\sim}1,400\;{\mu}mol\;m^{-2}s^{-1}$), three temperatures ($10{\sim}30^{\circ}C$), four pHs (7~10), five water depths (10~50 cm), and three different waters dominated by cyanobacteria, diatom, and green algae, respectively. Results indicate that the highest ABA of PMC was seen at $0.05\;mL\;L^{-1}$ in treatment concentrations, where showed a reduction of more than 80% of control phytoplankton biomass, while $1,400\;{\mu}mol\;m^{-2}s^{-1}$ in light intensity (>90%), $20{\sim}30^{\circ}C$ temperature (>60%), 7~9 in pH (>90%), below 50 cm in water depth (>90%), and cyanobacterial dominating waters (>80%), respectively. Over the test, ABA of PMC were more obvious on the algal biomass (chlorophyll-${\alpha}$) than suspended solids, suggesting a selectivity of PMC to particle size or natures. These results suggest that PMC agents can play an important role as natural agents to remove the nuisant algal aggregates or seston of eutrophic lake, where occur cyanobacterial bloom in a shallow shore of lake during warm season.

Brief Introduction of Research Progresses in Control and Biocontrol of Clubroot Disease in China

  • He, Yueqiu;Wu, Yixin;He, Pengfei;Li, Xinyu
    • 한국균학회소식:학술대회논문집
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    • 2015.05a
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    • pp.45-46
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    • 2015
  • Clubroot disease of crucifers has occurred since 1957. It has spread to the whole China, especially in the southwest and nourtheast where it causes 30-80% loss in some fields. The disease has being expanded in the recent years as seeds are imported and the floating seedling system practices. For its effective control, the Ministry of Agriculture of China set up a program in 2010 and a research team led by Dr. Yueqiu HE, Yunnan Agricultural University. The team includes 20 main reseachers of 11 universities and 5 institutions. After 5 years, the team has made a lot of progresses in disease occurrence regulation, resources collection, resistance identification and breeding, biological agent exploration, formulation, chemicals evaluation, and control strategy. About 1200 collections of local and commercial crucifers were identified in the field and by artificiall inoculation in the laboratories, 10 resistant cultivars were breeded including 7 Chinese cabbages and 3 cabbages. More than 800 antagostic strains were isolated including bacteria, stretomyces and fungi. Around 100 chemicals were evaluated in the field and greenhouse based on its control effect, among them, 6 showed high control effect, especially fluazinam and cyazofamid could control about 80% the disease. However, fluzinam has negative effect on soil microbes. Clubroot disease could not be controlled by bioagents and chemicals once when the pathogen Plasmodiophora brassicae infected its hosts and set up the parasitic relationship. We found the earlier the pathogent infected its host, the severer the disease was. Therefore, early control was the most effective. For Chinese cabbage, all controlling measures should be taken in the early 30 days because the new infection could not cause severe symptom after 30 days of seeding. For example, a biocontrol agent, Bacillus subtilis Strain XF-1 could control the disease 70%-85% averagely when it mixed with seedling substrate and was drenching 3 times after transplanting, i.e. immediately, 7 days, 14 days. XF-1 has been deeply researched in control mechanisms, its genome, and development and application of biocontrol formulate. It could produce antagonistic protein, enzyme, antibiotics and IAA, which promoted rhizogenesis and growth. Its The genome was sequenced by Illumina/Solexa Genome Analyzer to assembled into 20 scaffolds then the gaps between scaffolds were filled by long fragment PCR amplification to obtain complet genmone with 4,061,186 bp in size. The whole genome was found to have 43.8% GC, 108 tandem repeats with an average of 2.65 copies and 84 transposons. The CDSs were predicted as 3,853 in which 112 CDSs were predicted to secondary metabolite biosynthesis, transport and catabolism. Among those, five NRPS/PKS giant gene clusters being responsible for the biosynthesis of polyketide (pksABCDEFHJLMNRS in size 72.9 kb), surfactin(srfABCD, 26.148 kb, bacilysin(bacABCDE 5.903 kb), bacillibactin(dhbABCEF, 11.774 kb) and fengycin(ppsABCDE, 37.799 kb) have high homolgous to fuction confirmed biosynthesis gene in other strain. Moreover, there are many of key regulatory genes for secondary metabolites from XF-1, such as comABPQKX Z, degQ, sfp, yczE, degU, ycxABCD and ywfG. were also predicted. Therefore, XF-1 has potential of biosynthesis for secondary metabolites surfactin, fengycin, bacillibactin, bacilysin and Bacillaene. Thirty two compounds were detected from cell extracts of XF-1 by MALDI-TOF-MS, including one Macrolactin (m/z 441.06), two fusaricidin (m/z 850.493 and 968.515), one circulocin (m/z 852.509), nine surfactin (m/z 1044.656~1102.652), five iturin (m/z 1096.631~1150.57) and forty fengycin (m/z 1449.79~1543.805). The top three compositions types (contening 56.67% of total extract) are surfactin, iturin and fengycin, in which the most abundant is the surfactin type composition 30.37% of total extract and in second place is the fengycin with 23.28% content with rich diversity of chemical structure, and the smallest one is the iturin with 3.02% content. Moreover, the same main compositions were detected in Bacillus sp.355 which is also a good effects biocontol bacterial for controlling the clubroot of crucifer. Wherefore those compounds surfactin, iturin and fengycin maybe the main active compositions of XF-1 against P. brassicae. Twenty one fengycin type compounds were evaluate by LC-ESI-MS/MS with antifungal activities, including fengycin A $C_{16{\sim}C19}$, fengycin B $C_{14{\sim}C17}$, fengycin C $C_{15{\sim}C18}$, fengycin D $C_{15{\sim}C18}$ and fengycin S $C_{15{\sim}C18}$. Furthermore, one novel compound was identified as Dehydroxyfengycin $C_{17}$ according its MS, 1D and 2D NMR spectral data, which molecular weight is 1488.8480 Da and formula $C_{75}H_{116}N_{12}O_{19}$. The fengycin type compounds (FTCPs $250{\mu}g/mL$) were used to treat the resting spores of P. brassicae ($10^7/mL$) by detecting leakage of the cytoplasm components and cell destruction. After 12 h treatment, the absorbencies at 260 nm (A260) and at 280 nm (A280) increased gradually to approaching the maximum of absorbance, accompanying the collapse of P. brassicae resting spores, and nearly no complete cells were observed at 24 h treatment. The results suggested that the cells could be lyzed by the FTCPs of XF-1, and the diversity of FTCPs was mainly attributed to a mechanism of clubroot disease biocontrol. In the five selected medium MOLP, PSA, LB, Landy and LD, the most suitable for growth of strain medium is MOLP, and the least for strains longevity is the Landy sucrose medium. However, the lipopeptide highest yield is in Landy sucrose medium. The lipopeptides in five medium were analyzed with HPLC, and the results showed that lipopeptides component were same, while their contents from B. subtilis XF-1 fermented in five medium were different. We found that it is the lipopeptides content but ingredients of XF-1 could be impacted by medium and lacking of nutrition seems promoting lipopeptides secretion from XF-1. The volatile components with inhibition fungal Cylindrocarpon spp. activity which were collect in sealed vesel were detected with metheds of HS-SPME-GC-MS in eight biocontrol Bacillus species and four positive mutant strains of XF-1 mutagenized with chemical mutagens, respectively. They have same main volatile components including pyrazine, aldehydes, oxazolidinone and sulfide which are composed of 91.62% in XF-1, in which, the most abundant is the pyrazine type composition with 47.03%, and in second place is the aldehydes with 23.84%, and the third place is oxazolidinone with 15.68%, and the smallest ones is the sulfide with 5.07%.

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