• Title/Summary/Keyword: Extracellular organic matter

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Formation of Assimilable Organic Carbon from Algogenic Organic Matter

  • Kim, Ji-Hoon;Chung, Soon-Hyung;Lee, Jing-Yeon;Kim, In-Hwan;Lee, Tae-Ho;Kim, Young-Ju
    • Environmental Engineering Research
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    • v.15 no.1
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    • pp.9-14
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    • 2010
  • The objective of this study was to assess the variation in the concentration of assimilable organic carbon (AOC) in a drinking water resource, and investigate the characteristics of AOC derived from algae. The seasonal change in AOC at the Kamafusa dam corresponded to changes in the algal cell number. In order to understand the relationship between AOC and algae in a water resource and water purification plant, two kinds of laboratory experiment were performed. The algal culture experiment showed that extracellular organic matter (EOM) that was released during the growth of Phormidium tenue with M-11 medium led to significant increases in the AOC concentration, but no significant variation in the AOC concentration was observed with CT medium containing a high dissolved organic carbon concentration. The chlorination experiment showed that the AOC included in EOM was not easily removed by chlorination, although the AOC included in intercellular organic matter released from the algal cells by chlorination was removed under conditions where residual chlorine was detected.

Characteristics of Formation of Chlorination Disinfection By-Products in Extracellular Organic Matter of Various Algal Species (다양한 조류종들의 세포외 유기물질에서의 염소 소독부산물 생성 특성)

  • Son, Hee-Jong;Park, Hong-Ki;Hwang, Young-Do;Jung, Jong-Moon;Kim, Sang-Goo
    • Journal of Environmental Science International
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    • v.24 no.4
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    • pp.541-547
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    • 2015
  • Formation of disinfection by-products (DBPs) including trihalomethans (THMs) and haloacetic acids (HAAs) from chlorination of six different species (Chlorella vulgaris, Scenedesmus sp., Anabaena cylindrical, Microcystis aeruginosa, Asterionella formosa and Aulacoseira sp.) of algal extracellular organic matter (EOM). The EOM characteristics evaluation of six algal species reaching at the stationary phase in the growth curve showed most of its SUVA254 showed below 1 and this means hydrophilic organic matter is much higher than hydrophobic organic matter. Chloroform formation potential (CFFP), dichloroacetic acid formation potential (DCAAFP) and trichloroacetic acid formation potential (TCAAFP) were mainly composed of THMFP and HAAFP in the EOM of various algal species. In the case of THMFP/DOC and HAAFP/DOC values, EOM of blue-green algae has appeared highest and EOM of green algae and diatom in order. THMFP/DOC was higher than HAAFP/DOC in EOM of blue-green algae. In comparison of formation potential by unit DOC composed of HAAFP in algal species EOM, DCAAFP/DOC was 1.5 times to 7.5 time higher than TCAAFP/DOC in the EOM of blue-green algae, while DCAAFP/DOC was found to be relatively high compared to TCAAFP/DOC in the EOM of green algae and diatom.

Differences in Biogeochemical Properties and Microbial Activities in Stream Segments with Changes in Land-use Type

  • Kim, Jinhyun;Jang, Inyoung;Lee, Hyunjin;Kang, Hojeong
    • Ecology and Resilient Infrastructure
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    • v.2 no.3
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    • pp.247-254
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    • 2015
  • Changes in land-use type can affect soil and water properties in stream ecosystems. This study examined the effects of different land-use types on biogeochemical properties and microbial activities of a stream. We collected water and sediment samples in a stream at three different sites surrounded by varying land-use types; a forest, a radish field and a rice paddy. Nitrogen contents, such as nitrate, nitrite and total nitrogen in the stream water body, showed significant differences among the sampling sites. The highest nitrogen values were recorded at the site surrounded by cropland, as fertilizer runoff impacted the stream. Soil organic matter content in the sediment showed significant differences among sites, with the highest content exhibited at the forest mouth site. These differences might be due to the organic matter in surrounding terrestrial ecosystems. Microbial activities determined by extracellular enzyme activities showed similar values throughout all sites in the water body; however, the activities in the sediments exhibited the highest values near the forest site and mirrored the soil organic matter content values. From these results, we conclude that different land-use types are important factors affecting water and sediment properties in stream ecosystems.

Effects on the Stability of Aerobic Granular Sludge (AGS) at Different Carbon/Nitrogen Ratio (C/N비 변화가 호기성 그래뉼 슬러지의 안정성에 미치는 영향)

  • Kim, Hyun-Gu;Ahn, Dae-Hee
    • Journal of Environmental Science International
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    • v.28 no.9
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    • pp.719-727
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    • 2019
  • In this study, the effect on the stability of Aerobic Granular Sludge (AGS) with different Carbon/Nitrogen (C/N) ratios was investigated. The C/N ratios were controlled to 10.0, 7.5, 5.0, and 2.5 using the sequencing batch reactor, and the results showed that the removal efficiency of organic matter and total nitrogen decreased simultaneously with the decrease of C/N ratio. The removal efficiency of organic matter and total nitrogen at C/N ratio of 2.5 was 70.7% and 52.3% respectively. In addition, the AGS/mixed liquor suspended solids (MLSS) ratio showed a tendency to decrease from 85.7% to 73.7%, while the sludge volume index showed a tendency to increase from 82 mL/g to 102 mL/g as the C/N ratio decreased. At the same time, the apparent deviation of polysaccharide (PS) content in extracellular polymeric substances was observed, and polysaccharides/protein (PS/PN) ratio decreased from 0.62 to 0.31 as the C/N ratio decreased. Optical microscope observations showed that the reduction in C/N ratio caused the growth of filamentous bacteria and significantly affected the stability of AGS.

The relation between sewage sludge solubilization and extracellular polymeric substances (하수슬러지 가용화와 체외고분자물질(EPS)간의 관계)

  • Jeon, Byeong-Cheol;Nam, Se-Yong
    • Journal of the Korea Organic Resources Recycling Association
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    • v.27 no.4
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    • pp.43-49
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    • 2019
  • In order to investigate the relation between sewage sludge solubilization and extracellular polymeric substances(EPS) during alkaline-ultrasonic pretreatment, SCOD/TCOD ratio, solubilization rate, VSS/TS ratio, VSS reduction rate, LB-EPS(Loosely-Bound EPS) and TB-EPS(Tightly-Bound EPS) were measured. At the condition of TS 1.0% and pH 12, solubilization rate increased by 27.7%, LB-EPS as Carbohydrate and Protein increased by 14.6 and 13.3 mg/L/g TS, respectively. Withal, VSS decreased by 26.7% and TB-EPS as Carbohydrate and Protein were extracted by 15.7 and 21.9 mg/L/g TS, respectively. Consequently, the concentrations of organic matter and LB-EPS increased and the trends appeared similarly. In addition, the concentrations trend of decreasing solid matter and extracted TB-EPS also appeared similarly.

Electroencephalography (EEG) based Toxicity Test of Algae Organic Matter on Zebrafish (조류기인 유기물질의 제브라피쉬에 대한 뇌파측정기반 독성평가)

  • Oh Sehyun;Jang hyeongjun;Cho Yunchul
    • Journal of Korean Society on Water Environment
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    • v.39 no.3
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    • pp.223-230
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    • 2023
  • Harmful algae blooms have become a serious environmental problem in major river basins in Korea. They are known to produce various algal organic matters (AOMs) including intracellular organic matters (IOMs) and extracellular organic matters (EOMs). Generally AOMs cannot be easily removed by coagulation/flocculation process in conventional drinking water plants. AOMs produced by blue-green algae also include various toxins such as Microcystins, Anatoxin-a, and Saxitoxin known to have harmful effects on living organisms in aquatic environment. In this study, toxic effects of EOMs produced by three different algae species (Microcystis sp., Anabaena sp., and Oscillatoria sp.) on zebrafish were investigated using electroencephalography (EEG) recording method, a technology for recording brain activity. Electroencephalographic changes in zebrafish revealed that a low EOM had a negative effect on zebrafish compared to both Anabaena sp. and Oscillatoria sp. at 30 ppm EOM exposures. This result might be due to Microcystins present in EOMs produced by Microcystis sp. As a result of power spectrum density anallysis, exposure to EOMs produced by Microcystis sp. caused a state of vigilance in zebrafish. This EEG based toxicity test can be used to examine effects of harmful materials at low levels on living organisms in an aquatic system.

Seasonal Fluctuations of Heterotrophic Activity and Bacterial Extracellular Enzyme Activity in Paldang Lake (팔당호에서 종속영양 활성도의 계절적 변화 및 세균의 세포외 효소활성)

  • 김상진
    • Korean Journal of Microbiology
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    • v.31 no.1
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    • pp.93-98
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    • 1993
  • To investigate the organic matter transformation in aquatic environment, seasonal fluctuations of heterotrophic activity and microbia] extracellular enzyme activity were studied in Paldang Lake, Korea. The turnover time in the water column and the sediment at the station I fluctuated between 3 -I ,300 hrs and 17-170 hrs for glucose, 5 -1.900 hrs and 15-240 hrs for protein hydrolysate and 4-350 hrs and 15-230 hrs for acetic acid, respectively, indicating that the seasonal turnover time of organic substrates fluctuated drastically. The respiration ratios of glucose. protein hydrolysate and acetate were 23-32%, 38-41% and 22-28% in the water column and 34%, 61% and 41% in the sediment. respectively. These results showed that the respiration ratios in the sediment were higher than those in the water column regardless of kinds of organic substrates. The bacterial extracellular enzyme activities of $\alpha$-glucosidase. $\beta$-glucosidase, N-acetyl-$\beta$-D-glucosaminidase and aminopeptidase were 32-44%. 31-32%, 18-34% and 61-67% in the water column, and 34%. 40%, 23% and 65% in the sediment. respectively.

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Evaluation of Extracellular Enzyme Activity of Fungi from Freshwater Environment in South Korea (담수환경에서 분리한 곰팡이의 세포외분해효소 활성 탐색)

  • Hye Yeon Mun;Yoosun Oh;Jaeduk Goh
    • The Korean Journal of Mycology
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    • v.51 no.4
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    • pp.265-276
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    • 2023
  • This study aimed to isolate and characterize fungi from freshwater environments in South Korea and evaluate their extracellular enzyme activities. Fungal strains were collected from various freshwater sources and identified using phylogenetic analysis. The isolated fungi included known aquatic hyphomycetes and previously unreported species. Extracellular enzyme, including those of protease, amylase, lipase, cellulase, laccase, and chitinase, activities were evaluated. Among the isolated strains, several showed high enzyme activity, suggesting their potential role in organic matter decomposition in freshwater ecosystems. This research expands our knowledge of the diversity and enzyme activities of the fungi in freshwater environments, contributing to our understanding of their ecological roles.

Effects of elevated CO2 on organic matter decomposition capacities and community structure of sulfate-reducing bacteria in salt marsh sediment

  • Jung, Soo-Hyun;Lee, Seung-Hoon;Park, Seok-Soon;Kang, Ho-Jeong
    • Journal of Ecology and Environment
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    • v.33 no.3
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    • pp.261-270
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    • 2010
  • Increasing atmospheric $CO_2$ affects the soil carbon cycle by influencing microbial activity and the carbon pool. In this study, the effects of elevated $CO_2$ on extracellular enzyme activities (EEA; ${\beta}$-glucosidase, N-acetylglucosaminidase, aminopeptidase) in salt marsh sediment vegetated with Suaeda japonica were assessed under ambient atmospheric $CO_2$ concentration (380 ppm) or elevated $CO_2$ concentration (760 ppm) conditions. Additionally, the community structure of sulfate-reducing bacteria (SRB) was analyzed via terminal restriction fragments length polymorphism (T-RFLP). Sediment with S. japonica samples were collected from the Hwangsando intertidal flat in May 2005, and placed in small pots (diameter 6 cm, height 10 cm). The pots were incubated for 60 days in a growth chamber under two different $CO_2$ concentration conditions. Sediment samples for all measurements were subdivided into two parts: surface (0-2 cm) and rhizome (4-6 cm) soils. No significant differences were detected in EEA with different $CO_2$ treatments in the surface and rhizome soils. However, the ratio of ${\beta}$-glucosidase activity to N-acetylglucosaminidase activity in rhizome soil was significantly lower (P < 0.01) at 760 ppm $CO_2$ than at 380 ppm $CO_2$, thereby suggesting that the contribution of fungi to the decomposition of soil organic matter might in some cases prove larger than that of bacteria. Community structures of SRB were separated according to different $CO_2$ treatments, suggesting that elevated $CO_2$ may affect the carbon and sulfur cycle in salt marshes.

Influences of Invasive Plant on Extracellular Enzyme Activities in Riparian Ecosystems (하변토양의 미생물체외효소활성에 미치는 칩입성 식물의 영향)

  • Park, Soon-Young;Kim, Jae-Keun;Kang, Ho-Jeong
    • Journal of Wetlands Research
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    • v.14 no.1
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    • pp.47-57
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    • 2012
  • We have measured soil enzyme activities, which represent the rates of organic matter decomposition, in four riparian ecosystems in Korea. ${\beta}$-glucosidase, N-acetylglucosaminidase, phosphatase and arylsulfatase activities were determined in five occasions over a year period in soils of control plots and plots with invasive plants, namely Sicyos angulatus and Humulus japonicus. Significantly higher enzyme activities were found in soils with invasive plant in barren land, but the difference was season and enzyme-specific. Although it was not universal changes, the invasive plants appeared to accelerate organic matter decomposition in some disturbed riparian ecosystems.