• Journal of Biosystems Engineering
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• 제43권2호
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• pp.110-118
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• 2018

Purpose: In this study, the potential for biogas production, degradation rates, and lag-phase of diauxic growth of carbohydrate-based material, which is one of the proximate compositions, were investigated. Methods: This study was conducted using starch as a carbohydrate-based material. In experimental condition 1, the biogas potential of carbohydrate-based material was measured. In experimental condition 2, the effect of feed to microorganism ratio (F/M ratio) on lag-phase of diauxic growth from carbohydrate-based material was tested. Biochemical methane potential tests were performed at five different feed to microorganism ratios (0.2, 0.4, 0.6, 0.8, and 1.0) under mesophilic conditions. The biogas production patterns, lag-phase, total volatile fatty acids to total alkalinity ratio (TVFA/TA ratio), and time required for 90 percent biogas production were used to evaluate biogas production based on the biochemical methane potential tests. Results: In experimental condition 1, unlike previous studies, biogas was produced in the TVFA/TA ratio ranging from 1.131 to 2.029 (approximately 13-19 days). The methane content in the biogas produced from the digesters was 7% on day 9 and increased rapidly until approximately day 27 (approximately 72%). In experimental condition 2, biogas yield was improved when the feed to microorganism ratio exceeded 0.6, with an initial lag-phase. Conclusions: Even if the TVFA/TA ratio was greater than 1.0, the biogas production was processed continuously, and the $CO_2$ content of the biogas production was as high as 60%. The biogas yield was improved when the F/M ratio was increased more than 0.6, but the lag-phase of carbohydrate-based material digestion became longer starting with high organic loading rate. To clarify the problem of the initial lag-phase, our future study will examine the microbial mechanisms during anaerobic digestion.

• 유기물자원화
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• 제22권4호
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• pp.54-61
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• 2014

본 연구는 Bacillus sp.와 Actinomyces sp.을 포함하는 미생물배양액, 일본산입상미생물 및 미국산입상미생물 등의 기능성성분을 포함하는 기능성비료의 시비가 크리핑벤트그래스의 잔디생육과 토양 대취분해에 미치는 영향에 대해 조사하였다. 처리구는 비료의 종류에 따라 대조구(CF), 미생물배양액(M), 미생물배양액과 가축분뇨발효액비(M-L), 미생물배양액과 가축분뇨발효액비 및 아미노산액비(M-L-A), 일본산 입상미생물(JGM), 미국산 입상미생물(USGM)였다. 시험 전후 토양분석결과, pH는 시험 후에 전보다 모든 처리구에서 약간 증가하였고, 시험 종료 후 처리구간의 토양화학성은 비슷하여 공시비료의 시비는 토양환경에 거의 영향을 미치지 않았다. 잔디생육 조사결과, 엽색지수와 엽록소지수는 관행구와 비교할 때, 처리구에서 높았고, 관행구과 처리구들사이에는 조사시기별 변화경향은 비슷하나 M-L-A와 M-L처리구에서 약간 높게 나타났다. 잔디뿌리는 M-L에서 더 길었다. 대취함량 조사결과, 관행구와 비교할 때, 처리구에서 감소하였고, 관행구와 처리구들사이에는 M처리구가 관행구보다 대취분해에 효과적이었다. 본 연구 결과, Bacillus sp.와 Actinomyces sp.을 함유하는 배양미생물 처리는 다른 미생물제제에 비하여 크리핑벤트그래스의 뿌리생육과 토양 내 대취분해를 촉진하여 잔디품질을 향상시키는 잔디성장촉진 기능이 있는 비료임을 알 수 있었다.

• 한국버섯학회지
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• 제21권3호
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• pp.154-159
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• 2023

표고 톱밥재배용 무포자 품종의 육성을 위해 수집균주 중 우량계통의 단포자 교배를 통해 육성된 '대담'의 주요 특성은 다음과 같다. '대담'의 균사생장 적온은 22~.25℃, 발이 및 생육온도는 16~18℃이었으며, 자실체 형태는 평반구형이며 갓을 형성하지 않는 무포자품종이다. '대담'은 배양기간이 21일, 갈변기간 96일로 대조품종('화담')과 유사하였고, 발이기간은 5일, 생육기간은 9일로 전체 재배기간은 134일로 같았다. '대담'의 개체중은 32.4g으로 대조품종과 유사하였고, 유효개체수는 6.8개로 대조품종 보다 1.3개 낮았으며, 총수량은 222g으로 대조품종의 266g에 비해 낮았다. '대담'의 자실체는 대조품종 대비 갓이 두껍고, 갓 직경은 다소 작았으며, 대의 굵기는 작고 긴 특성을 보였다. '대담'의 배지형태별 생산성 분석결과, 1.2kg 원통형 배지에서 생물학적 효율이 26.7%로 3kg 봉형배지보다 높았으며, '하나참'와 비교 시 재배기간이 40일 짧고 수량도 유사하여, 단기 재배용 품종으로 활용이 가능할 것으로 생각된다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권10호
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• pp.1411-1416
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• 2004

The objective of this work was to isolate a microorganism, able to produce high lactate dehydrogenase (LDH) activity, for use as a microbial feed additive. The LDH is an important enzyme for lactate conversion in the rumen, thereby possibly overcoming lactic acidosis owing to sudden increases of cereal in the diets of ruminants. In the present study, various bacterial strains were screened from a variety of environments. Among the isolated microorganisms, strain FFy 111-1 isolated from a Korean traditional fermented vegetable food called Kimchi showed the highest enzyme activity, along with retaining strong enzyme activity even in rumen fluid in vitro. Based on morphological and biochemical characteristics as well as compositions of cellular fatty acids plus API analyses, this strain was identified as Lactobacillus sp. The optimum temperature and pH for growth were found to be 30$^{\circ}C$ and pH 6.5, respectively. A maximum cell growth of 2.2 at $A_{650}$ together with LDH activity of 2.08 U per mL was achieved after 24 h of incubation. Initial characterization of FFy 111-1 suggested that it could be a potential candidate for use as a direct-fed microbial in the ruminant animals.

• 한국미생물·생명공학회지
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• 제19권6호
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• pp.543-547
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• 1991

토양으로부터 호알칼리성 미생물을 분리하여 동정 한 결과, Bacillus속의 특성을 나타내어 Bacillus sp. SH-8로 명명하였다. Bacillus sp. SH-8은 초기 pH 9.0이상의 알칼리에서만 생육이 가능하였으며 중성 pH에서는 불가능하였다. Bacillus sp. SH-8로부터 U.V.조사에 의해 중성배지에서도 생육이 가능한 변이주를 분리하여 Bacillus sp. SH-8M으로 명명하였으며, 초기 pH 6.9부터 11.0까지 생육이 가능하였다. 따라서 이들 두 균주는 pH 변화에 따른 생육과 효소생산을 비교, 검토하는데 적합한 균주로 생각된다.

• Journal of Life Science
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• 제9권2호
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• pp.76-81
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• 1999

216 microorganisms which able to degrade wasted lubricant were isolated in the region of contaminated with wated lubricant such automobile repair shops, garages and gas stations in Taejon. Most activated strain among them is selected and used in this research. The microorganism in identified as Acinetobacter lwoffii 16C-1, which shows active growth and hydrocargon utilization withnormal alkane such as tetradecane, hexadecane and octadecane, and do not grow aromatic hydrocargons, cycloalkane, and branched alkane. In addition, A. lwoffii 16C-1 has resistance to heavy metals such as Ba, Li, Cr, and Mn more than 6.4mg/ml, and showed negligible tolerance against antibiotics. Effects of environmental conditions including concentration of wasted lubricnt, pH, NaCl concentration, nitrogen source and phosphate on microorganism growth and emulsification were studied. 2% of wasted lubricant, pH 7.0, 0-1% of NaCl, 0.2% of peptone, and 0.01% of K2HPO4 is turn out to be optimum condition. By the analysis of remaining oils, almost of hydrocarbons added to the media are removed by A. lwoffii 16C-1 at 30$^{\circ}C$ after 2 days of culture, which showed excellent oil degradation characteristics.

• 성인간호학회지
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• 제29권3호
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• pp.278-289
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• 2017

Purpose: This study was designed to investigate whether there were differences among three oral care protocols on participants' oral health status (oral status, dry mouth, halitosis, saliva pH, microorganism growth in oral cavity) and tooth stain. The three protocols were: 1) oral solution of 4% normal saline, 2) 0.1% Chlorhexidine and 3) Tantum. Methods: A nonequivalent control group pretest-posttest design was utilized. A total of 55 elderly patients residing at long-term care facilities(19 in the 4% normal saline group, 17 in the 0.1% Chlorhexidine group, 19 in the Tantum group) received oral care daily for four weeks. Data were analyzed using SPSS/WIN 22.0 program. Results: The halitosis (${\chi}^2=10.71$, p=.005) and saliva pH (${\chi}^2=6.84$, p=.033) scores were significantly improved after the oral care with 4% normal saline. Conclusion: These findings indicate that if elderly patients in long-term care facilities have complaint of the discomfort of using Chlorhexidine or Tantum, 4% normal saline is as effective at the other two. This can also be cost effective as there were no differences among the protocols in oral status, dry mouth, tooth stain or microorganism growth in oral cavity.

• 한국치위생학회지
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• 제14권1호
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• pp.117-122
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• 2014

Objectives : The purpose of the study is to investigate the activities of Nelumbo nucifera leaf extracts on Streptococcus mutans, Streptococcus mitis, Streptococcus sobrinus, Porphyromonas gingivalis, Prevotella intermedia, and Treponema denticola. Methods : The inhibitory effect of lotus leaf extracts on the growth of oral bacteria was assessed in experiments with extracts from freshly harvested and pulverized lotus leaves and bacterial cultures of dental caries. Results : The results showed that N. nucifera extracts possess antimicrobial activity on all bacterial strains. The minimal inhibitory concentration (MIC) values varied from 4 mg/ml to 10 mg/ml against antimicrobial activity. The relative growth ratio (RGR) against of N. nucifera extracts were determined as 50% in concentration of 4.0 mg/ml. The extract of N. nucifera was effective in reducing on the glucosyltransferase (GTase) activity of six strains in vitro. Conclusions : Methanol extracts of lotus leaves showed antimicrobial effects on three bacterial species causing dental caries and three bacterial species causing periodontitis, as well as inhibitory effects on GTase activity.

• 상하수도학회지
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• 제18권2호
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• pp.121-127
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• 2004

It is necessary to supply external carbon source for enhancement of biological nitrogen removal from domestic wastewater with low influent C/N ratio. Sulfide was chosen as a cost effective electron donor and reaction stoichiometry for autotrophic denitrification was investigated by conducting bench-scale experiments in this study. Higher sulfur to nitrogen (S/N) ratio than the calculated value from theoretical reaction stoichiometry was required when the anoxic reactor was operated at open condition because dissolved oxygen introduced by surface aeration reacted with sulfide with ease. In addition, higher sulfate production and lower yield of microorganism could be observed under the same condition. It was possible to obtain reliable reaction stoichiometry for autotrophic denitrification by establishing pure anoxic condition. Linear relationship between bacterial growth and consumption of nitrate, sulfide, alkalinity, and sulfate production enabled to derive a relatively correct reaction stoichiometry for autotrophic denitrification when sulfide was used as an electron donor.

• 한국식품조리과학회지
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• 제14권1호
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• pp.106-113
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• 1998

The purpose of this study is to investigate the antimicrobial effect of mugwort (Artemisia asiatica Nakai) on the rice cake and bread preservation, and to identify their antimicrobial compounds. The mugwort extracts showed complete inhibition on the growth of Bacillus subtilis and Staphylococcus aureus at 250 $\mu\textrm{g}$/ml level. Antimicrobial activi쇼 of mugwort extract were stronger than that of commercial antimicrobial agent. Five % of sodium propionate solution showed complete inhibition on the growth of B. subtilis, E. coli and S. aureus, but L. plantarum was inhibited 50.87% at the same concentration. When various amounts of freeze-dried mugwort powder were added in sulgis (steamed rice cake), 3% ssooksulgi (mugwort powder added sulgi) had quite lower level of total bacterial count (5.5$\times$$10^/5 CFU/g) compared with the control group (1.4$\times$$10^/7 CFU/g) at ambient temp. (30$\pm$1$^{\circ}C$) after 72 hr. Three % addition of mugwort showed 2 days extention of shelf-life of rice cake. The sensory qualities of ssooksulgi has no significant difference in moistness, consistency, cohesiveness, afterswallowing and overall quality compared with control group. Ssooksulgi with 3% of mugwort powder had the best overall quality in sensory test. The methanol extract of 500 $\mu\textrm{g}$/ml of mugwort could lead the successful retardation of the growth of putrefactive microorganism during the incubation of rice cake at 37$^{\circ}C$ for 24 hr. On the other hand, coumarin (Sigma) had 54% inhibitory effect at 500 $\mu\textrm{g}$/ml level, and (E,E)-2,4-decadienal completely inhibited the growth of putrefactive microorganism of whitesulgi at 100 $\mu\textrm{g}$/ml level during the incubation at 37$^{\circ}C$ for 48 hr.48 hr.