• Title/Summary/Keyword: microorganism growth

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Evaluation of the Degradation of Carbohydrate-based Material During Anaerobic Digestion for High-efficiency Biogas Production

  • Kim, Min-Jee;Kim, Sang-Hun
    • Journal of Biosystems Engineering
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    • v.43 no.2
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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.

Effects of Composted Liquid Manure and Microbial Agent Types on Growth and Thatch Decomposing of Creeping Bentgrass (가축분뇨발효액비와 미생물제제 종류별 시용에 따른 크리핑 벤트그래스의 생육과 토양중 대취분해에 미치는 영향)

  • Lim, Ji Yeon;Ham, Suon Kyu;Lee, Yeong Min;Cha, Young Gi
    • Journal of the Korea Organic Resources Recycling Association
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    • v.22 no.4
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    • pp.54-61
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    • 2014
  • This study was conducted to investigate the effect of Actinomyces sp. and Bacillus sp., United States granular microorganisms and Japan granular microorganisms on turfgrass growth and thatch decomposing of creeping bentgrass in golf course by measuring turf color index, chlorophyll index, thatch content of soil, root length, turf density and chemical properties and thatch content of soil. Fertilizer treatment was designed as follows; control(CF; compound fertilizer), microorganism medium(M; CF+M), microorganism medium and livestock manure fertilizer(M-L; CF+M+LMF), microorganism medium, livestock manure fertilizer and amino acid liquid fertilizer(M-L-A; MM+LMF+ALF), United States granular microorganisms(USGM; CF+USGM), Japan granular microorganisms(CF+JGM). Soil properties investigated after experiment was scarcely affected by applied fertilizers in root zone of creeping bentgrass. The turf color index and chlorophyll index of M, M-L, M-L-A, USGM, JGM treatment were higher than those of CF. The turfgrass root in M-L treatment was longer than others. The thatch content of soil in M treatment was longer than others. The thatch content of M was decreased than that of CF by 6.8%. These was suggested that application of M induced the development of quality and growth of creeping bentgrass by assisting turfgrass growth and thatch decomposing.

Characteristics of newly bred spore-less cultivar Lentinula edodes 'Daedam' for sawdust cultivation (표고 톱밥재배용 무포자 신품종 '대담' 육성 및 특성)

  • Jeong-Han Kim;Young-Ju Kang;Chae-Young Lee;Yeon-Jin Kim;Jun-Yeong Choi;Chan-Jung Lee;Tai-Moon Ha;Gab-June Lim
    • Journal of Mushroom
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    • v.21 no.3
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    • pp.154-159
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    • 2023
  • A new spore-less cultivar Lentinula edodes 'Daedam' was bred from monokaryotic strains of 'LE15401-24' and 'LE192118-10'. The optimum temperature for mycelial growth of 'Daedam' on potato dextrose agar was 22~25℃. Total cultivation period of the new cultivar, from inoculation to its first harvest, was 134 days, similar to that of the control cultivar 'Hwadam'. Total yield of 'Daedam' was 222g per 3kg substrate, and was lower than that of control cultivar(266.0g). The fruiting body of 'Daedam' had a thick and small pileus and a longer stem compare to control cultivar. As a result of a analyzing the productivity of 'Daedam' on the different substrate types, the biological efficiency was 26.7% in the 1.2kg cylindrical substrate(CS), which was higher than that of the 3kg rod-type substrate(RS). 'Daedam' had a similar yield compared to 'Hanacham' in first fruiting body production, but the cultivation period was 40 days shorter. Therefore, 'Daedam' can only harvest fruiting bodies once, it is thought that it can be used as spore-less oak mushroom cultivar for short-term cultivation instead of 'Hanacham' in mushroom farms.

Screening and Characterization of Lactate Dehydrogenase-producing Microorganism

  • Sung, Ha Guyn;Lee, Jae Heung;Shin, Hyung Tai
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.10
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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.

Isolation and Identification of Alkalophilic Microorganism and its Mutant Growing at Neutral pH (호알칼리성 미생물의 분리, 동정 및 중성에서 생육 가능한 변이주의 분리)

  • 심창환;신원철;유주현
    • Microbiology and Biotechnology Letters
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    • v.19 no.6
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    • pp.543-547
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    • 1991
  • An alkalophilic microorganism, SH-8, was isolated from soil samples. It was a Grampositive, catalase-positive, spore-forming and motile rod which was capable of growth in aerobic condition at the initial pH 9.0 or above up to 11.0 and between 15 and $42^{\circ}C$ The characteristics of this strain resembled those of the Bacillus group of bacteria. The mutant, Bacillus sp. SH- 8M, was selected from Bacillus sp. SH-8 by U.V. mutagenesis and was able to grow at pH 6.9 up to 11.0. These two strains will be suitable for the comparative study on growth and enzyme production at various pH conditions.

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Characteristics of Wasted Lubricant Degradation by Acinebobacter lwoffii 16C-1

  • Kim, Gab-Jung;Lee, In-Soo;Park, Kyeong-Ryang
    • Journal of Life Science
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    • v.9 no.2
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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.

Effects of Oral Care on the Oral Health Status and Tooth Stain by Oral Solution Types for Elderly Patients Staying at Long-term Care Hospitals (구강 용액에 따른 구강 간호 수행이 요양병원 입원 노인의 구강건강상태와 치아착색에 미치는 효과)

  • Bae, Jisuk;Park, Heeok
    • Korean Journal of Adult Nursing
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    • v.29 no.3
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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.

Antibacterial effect on leaf-extract from Nelumbo nucifera against oral microorganism (연잎 추출물의 구강미생물에 대한 항균 효과)

  • Huh, Man-Kyu;Kim, Hye-Jin
    • Journal of Korean society of Dental Hygiene
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    • v.14 no.1
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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.

A Study on the Reaction-Stoichiometry of Autotrophic Denitrification based on Growth Characteristic of Microorganism (미생물 성장 특성에 기초한 독립영양탈질의 화학양론식 연구)

  • Lee, Su-Won;Kim, Gyu-Dong;Choi, Young-Gyun;Kim, Dong-Han;Chung, Tai-Hak
    • Journal of Korean Society of Water and Wastewater
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    • v.18 no.2
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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.

Effect of Mugwort on the Extention of Shelf-Life of Bread and Rice Cake (쑥 첨가가 빵과 떡의 저장성 향상에 미치는 영향)

  • 김순임;김경진;정해옥;한영실
    • Korean journal of food and cookery science
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    • v.14 no.1
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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.

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