• ALGAE
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• v.28 no.3
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• pp.289-296
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• 2013

For the quantitative detection of algal toxin, microcystin, a chemiluminescence immunochromatographic assay method was developed. The developed system consists of four parts, chemiluminescence assay strip (nitrocellulose membrane), horse radish peroxidase labeled microcystin monoclonal antibodies, chemiluminescence substrate (luminol and hydrogen peroxide), and luminometer. The performance of the chemiluminescence immunochromatographic assay system was compared with high performance liquid chromatography (HPLC) detection. The detection limit of chemiluminescence immunochromatographic assay system is several orders of magnitude lower than with HPLC. The chemiluminescence immunochromatography and HPLC results correlated very well with the correlation coefficient ($r^2$) of 0.979.

• Journal of Microbiology and Biotechnology
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• v.27 no.4
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• pp.808-815
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• 2017

We demonstrated the quantitative detection of a toxin-producing Microcystis aeruginosa (M. aeruginosa) strain with the laboratory protocol of the NanoGene assay. The NanoGene assay was selected because its laboratory protocol is in the process of being transplanted into a portable system. The mcyD gene of M. aeruginosa was targeted and, as expected, its corresponding fluorescence signal was linearly proportional to the mcyD gene copy number. The sensitivity of the NanoGene assay for this purpose was validated using both dsDNA mcyD gene amplicons and genomic DNAs (gDNA). The limit of detection was determined to be 38 mcyD gene copies per reaction and 9 algal cells/ml water. The specificity of the assay was also demonstrated by the addition of gDNA extracted from environmental algae into the hybridization reaction. Detection of M. aeruginosa was performed in the environmental samples with environmentally relevant sensitivity (${\sim}10^5$ algal cells/ml) and specificity. As expected, M. aeruginosa were not detected in nonspecific environmental algal gDNA over the range of $2{\times}10^0$ to $2{\times}10^7$ algal cells/ml.

• Journal of Environmental Science International
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• v.9 no.3
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• pp.267-273
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• 2000

In order to understand the impact for decomposition of blue-green algae Microcystis on water quality, the algae were cultivated with collection of natural population during approximately one month, when water-bloom of Microcystis dominated at August 31, 1999 in the lower part of the Okchon Stream. The enrichment of inorganic NㆍP nutrients didn't in algal assay and the effect of Microcystis on water duality was assessed from the variation of nutrients by algal senescence. Microcystis population seemed to play a temporary role of sink for nutrients in the water body. Initial algal density of Microcystis was 2.3×10/sup 6/ cells/㎖. When Microcystis population died out under light condition, algal NㆍP nutrients between 9∼12 days affected to increase of biomass after reuse by other algal growth as soon as release to the ambient water. However, cellular nutrients under dark condition were almost moved into the water during algal cultivation. NH₄, NO₃ and SRP concentration were highly increased with 160, 17 and 79 folds, respectively relative to the early. As a result, the senescence of Microcystis population seemed to be an important biological factor in which cause more eutrophy and increase of explosive algal development by a lot of nutrients transfer to water body. There are significantly observed an effort of reduce for production of inner organic matters such a phytoplankton as well as load pollutants from watershed in side of the water quality management of reservoir.

• Journal of Environmental Science International
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• v.15 no.10
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• pp.961-966
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• 2006

An algal assay procedure using an indigenous phytoplankton assemblage was tested to estimate the propagation of red tide phytoplankton species and determine the optimal time interval at which to measure growth yield in eutrophic marine waters where red tides frequently occur. Various red tide phytoplankton species were propagated on a large scale by adding nitrogen or phosphorous. This procedure was useful for estimating the limiting nutrient, elucidating the mechanisms underlying red tides, and determining the levels of increases in organic matter in eutrophic coastal waters. The algal assay using indigenous C. polykrikoides showed that this species did not always propagate, apparently because of very low concentrations of trigger elements that are necessary for its growth, rather than as a result of other environmental characteristics, e.g., water temperature or stress from sampling. In the winter, when water temperatures are lower than in spring, summer, or autumn, maximum propagation and the limiting nutrient could be estimated by measuring phytoplankton biomass at 2 - 3-day intervals. However, in the other seasons, when water temperatures are higher, phytoplankton biomass should be measured at 2-day intervals. In particular, daily monitoring will be required to determine precise growth yields in warm seasons.

• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.6
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• pp.418-421
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• 2000

A new direct colorimetric assay of microcystin in water and algal samples is proposed consisting of two procedures as follows: 1) the elimination of phosphorus in the sample and concentration of microcystin using a C(sub)18 cartridge, 2) the detection of the released phosphorus by the ascorbic acid method and determination of protein phosphatase (PP) inhibition by microcystin. The optimum amounts of phosphorylase ${\alpha}$ and PP-1 in 50 ${\mu}$L concentrated sample were 50$\mu\textrm{g}$/50${\mu}$L buffer and 1.0unit/50${\mu}$L buffer, respectively, for the best assay. The pH for the maximum activity of PP-1 was 8. The minimum detectable concentration for this method was about 0.02$\mu\textrm{g}$/L, which is sufficient to meet the proposed guideline level of 1$\mu\textrm{g}$ microcystin/L in drinking water. Consequently, it would seem that the proposed direct colorimetric assay using PP is a rapid, easy, and convenient method for the detection of microcystin in water and algal samples.

• Journal of Microbiology and Biotechnology
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• v.16 no.10
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• pp.1613-1621
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• 2006

Isolation and identification of algal lytic bacteria were carried out. Nine strains of algal lytic bacteria were isolated by the double-layer method using Anabaena flos-aquae as a sole nutrient. The isolate, AFK-13, showing the highest algal lytic activity was identified as Sinorhizobium kostiense based on the l6S rDNA sequence. The algal lytic experiments of the culture supernatants of AFK-13 demonstrated that the bacterial cell growth reached a maximum at 36-h culture, but the supernatant of 72-h culture exhibited the highest activity. Components among the extracellular products in the crude enzyme of the supernatant from S. kostiense AFK-13 culture were responsible for degradation of cell walls of Anabaena flos-aquae. Algal lytic assay tests of the culture supernatants suggest that the main substances for algal lytic activity could be proteinaceous. The activity of glucosidase was observed highly by polysaccharolytic analysis using the crude enzyme from S. kostiense AFK-13, whereas activities of galactosidase, mannosidase, rhamnosidase, and arabinosidase were also detected in low levels. The molecular weights (MW) of ${\alpha}-\;and\;{\beta}$-glucosidases were estimated to be approximately 50-100 kDa by the ultrafiltration method.

• Journal of Environmental Science International
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• v.4 no.5
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• pp.469-479
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• 1995

The increase of population and industrial activities had brought into eutrophication in the Nakdong river. A remarkable acceleration of eutrophication brought about serious problems for water supply. Therefore, for the purpose of conservation of water quality in the Nakdong river it is necessary to control nutrients. MBOD method was use to evaluate algal growth limiting factor and algal growth potential in the Nakdong river from June to August 1994. The modified biochemical oxygen demand(MBOD) depends on the amount of available inorganic nutrient and organic substrate during 5 day incubation in the dark at 2$0^{\circ}C$. The MBOD assay depends on inorganic nutrients such as P and N as well as reduced carbon and called the MBOD, the MBOD-P, and the MBOD-N, respectively. The results of bioassay by MBOD(Modified BOD) method showed that the MBOD, MBOD-P and MBOD-N value were found to be in the ranges of 3.8~96.0 mg$O_2$/l, 5.6~94.0 mg$O_2$/l and 42.0~220 mg$O_2$/l, respectively. And the the bioassay value was found to be the highest in Koryong area and the lowest in Waekwan area throughout the Nakdong river. The variations of MBOD-P and MBOD-N value showed similar tendencies to the variations of phosphorus and nitrogen value, respectively. By MBOD method, the relationships of MBOD, MBOD-P and MBOD-N value were MBOD ≒ MBOD-P 《 MBOD-N. The MBOD value was nearly equal to the MBOD-P value, and the MBOD-N value was 3 to 20 times more than the MBOD-P value, approximately. Therefore, in the Nakdong river, phosphorus was the limiting factor for algal growth during summer season. The algal growth potential as the concentration of chlorophyll-a in the summer was maximum 5 times more than standing crop as it.

• Journal of Environmental Science International
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• v.13 no.9
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• pp.807-817
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• 2004

The modified biochemical oxygen demand (MBOD) were conducted to evaluate the water quality and fertility in the Mangyeong river from november 2002 to april 2003. MBOD method was used to evaluate algal growth potentials and their limiting factors. MBOD depends on the amount of available inorganic nutrient and organic substrate during 5-day incubation in the dark condition at $20^{\circ}C.$ The MBOD assay depends on inorganic nutrients such as phosphorus and nitrogen as well as reduced carbon as called MBOD, MBOD-P, and MBOD-N, respectively. The concentration of pollutants were in the range of 3.08～48.36 mg/L for COD. The concentration of nutrients were in the range of 0.37～111.62 mg/L for dissolved inorganic nitrogen (DIN) and 0.00～1.03 mg/L for dissolved inorganic phosphorus (DIP). The results of MBOD bioassay showed that the MBOD, MBOD-P and MBOD-N values were 15～173 mg $O_2/L,$ 13～165 mg $O_2/L$ and 66～175 mg $O_2/L$ ranges, respectively. The MBOD values are found to be the highest in Iksan River and the lowest in Hari River throughout the Mangyeong River. The relationships of MBOD, MBOD-P and MBOD-N in MBOD method were generally found in MBOD$\risingdotseq$ MBOD-P$\risingdotseq$MBOD-N. But the result of Gosan was appeared to MBOD$\risingdotseq$MBOD-N > MBOD-P. The MBOD-N value was higher 3 to 5 times than the MBOD-P value in the Gosan station. The algal growth potentials expressed as the concentration of chlorophyll-a were maximum 20 times more than algal biomass in the water column.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.5
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• pp.457-464
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• 2001

Algal growth potential (AGP) assay using Cochlodinium polykrikoides was conducted in Saryang Island coast where C. polykrikoides red tide occurred annually from July to October 1998. The effects of macro- and micro-nutrients on the growth of C. polykrikoides were specifically evaluated by the algal assay method. Two different types of growth response of C. polykikoides for the addition of nutrients were clearly obseued. For both before and after C. polykrikoides occurrence, the growth of C. polykikoides was significantly stimulated by the addition of either nitrate or ammonium of $50{\mu]M$ with phosphate of $5{\mu}M$. The addition of a single nutrient had no clear effect on the growth of C. polyhikoides and the addition of trace metals, vitamins, and EDTA etc. did not stimulate the algal growth, also. This result indicates that both N and P potentially limited the growth of C. polyhikoides in this period. However, during a bloom of C. polyhikoides, the growth was unlikely to be stimulated by the addition of both macro- and micro-nutrients. At that time the nutrient concentration of Saryang Island coast was $24.33{\mu}M$ for ammonium, $1.61{\mu}M$ for phosphate, and $0.58{\mu}M$ for nitrate, respectively. The concentrations of nutrients increased, on average, 8.2-fold for ammonium and 4.8-fold for phosphate, decreased 3.3-fold for nitrate compared to both before and after the red tide. This result shows that the growth of C. polykikoides was not limited by the nutrients during the bloom in September. Therefore, our results suggest that the C. polykrikoides red tide may outbreak especially when the water is fertilized due to the increased N and P.

• Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.269-273
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• 2014

Coralline algae, the algal whitening phenomenon-causing seaweeds, are characterized by calcareous deposits in the cell wall. The viability of the coralline algae Lithophyllum yessoense and Corallina pilulifera was quantitated using a triphenyltetrazolium chloride assay and eight calcification inhibitors. Among these inhibitors, ferric citrate showed the strongest inhibition of coralline algae viability. The concentrations of ferric citrate conferring 50% inhibition were 1.7 and 3.8 mM for L. yessoense and C. pilulifera, respectively. Thus, at a specific concentration and in a localized area, ferric citrate may be used to prevent the blooming of coralline algae.