• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.4
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• pp.339-347
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• 2000

An algicidal bacterium, Micrococcus sp. LG-5 against the harmful dinoflagellate, Cochlodinium polykrikoides was isolated. The optimal conditions for the highest algicidal activity of bacterial culture filtrate showed in the range of $20{\~}30^{\circ}C$, at pH 7.0 and $3.0{\%}$ of NaCl concentration. In addition, $IC_(50)(mean of 50{\%} inhibitory concentration)$ of the culture filtrate against C. polykrikoides after incubation of 5 days was $0.482{\%}$. To investigate heat and pH stability of the culture filtrate of Micrococcus sp. LG-5, the culture filtrate ($pore size, 0.1 {\mu}m$) was heated to $121^{\circ}C for 15 min$ and adjusted pH from 2.0 to 10.0. There were no significant changes in algicidal activity by heat treatment and the pH change between pH from 5.0 to 10.0. The algicidal substances produced from Micrococcus sp. LG-5 were mainly detected in the fraction of $10,000{\~}1,000$ MWCO (molecular weight cut-off). The culture filtrate of Micrococous sp. LG-5 showed antimicrobial activity against Enterococcus faecalis, Escheiichia coli, Uebsiella pneunioniae and Vibrio altinolyticus, but did not show against Pseudomonas aeminosa, P. Buorescens, Salmonella typhi, Staphylococcus aureus, V. cholerae and V parahaemolyicus. The culture filtrate of Micrococcus sp. LG-5 was examined against 16 phytoplankton species and showed the algicidal activity against Ajexandzium tuarense, Eutreptiella Drnnastin, Gymnodinium catenatum, G. mikimotoi, G. sanguineum, eyodinium impuaicum, Heterocapsa triquetra, Heterosipa akashiwo, Prorocentrum micans and Pyraminonas sp.. However no algicidal effects of Micrococcus sp. LG-5 were observed against Chlamydomonas sp., Cylindrotheoa closterium, P. mininum, P. triestimum, Pseudonieschia sp. and Sczipuiella trochoidea. On the other hand, algicidal activity on the tested marinelivefood was not detected except for Isochrysis galbana. In addition, physiological responses of cultured olive flounder (Paralichthys oliraceus) exposed to $1 and 10{\%}$ of the culture filtrate of Micrococcus sp. LG-5 were measured. There were no clear changes in AST, GGT, creatinine, urea, total cholesterol, total protein, albumine, $Mg^(+2), Ca^(+2), Na^+, K^+, and Cl^-$. These results indicate that olive flounders were not affected when they were exposed to the culture filtrate of Micrococcus sp. LG-5.

• Korean Journal of Poultry Science
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• v.34 no.2
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• pp.91-97
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• 2007

To evaluate the physiological status of laying flocks, the blood chemistry values were measured and analyzed in various ages under different feeding conditions. Total 671 birds from 48 Hyline brown hens flocks from 13 different poultry farms were bled at the ages of day(s) 1, 11, 21, 50, 80, 120, 180, 240, 300, 400, and 500. The 17 blood chemistries including glucose, lipids, proteins, enzymes, electrolytes and metabolic by-products were measured with an autoanalyzer. Blood glucose showed the highest at the hatching day not relate with the dietary carbohydrates and energy, but tended to decrease during the rest of growth stage in hens. Total blood protein, albumin and globulin increased depending on the ages even though dietary protein was decreased. Blood lipid was greatly changed at different growth stages. Cholesterol was the highest at hatching period and maintained consistently until the 120 days of age. It was increased in birds after 180 days of age. HDL was also highest in hatchery, but decreased greatly after 180 days of age. However, TG was the lowest at one day old, but was increased up to 10 times after 180 days of age compared to that of one day old. The enzyme activities were different. AST, ALT, and GGT showed comparatively contained consistently, whereas amylase was slowly decreased. Blood P, Na, K and Cl showed consistency, but Ca content was increased upto two times of the one day of age. The results from this study showed that the blood chemistry values were affected by the general metabolic status of the host with ages not by feeding conditions. Further, the standard data of age-dependent blood chemistry values in the laying flocks were obtained, which can be utilized for early detection of the changes in the physiological status occurred by the infectious or metabolic diseases. The results of these analyses seemed to be useful to increase the productivity of laying flocks through rapid and proper veterinary medical treatments.