• Journal of Korean Society on Water Environment
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• v.20 no.3
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• pp.236-240
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• 2004

Autohydrogenotrophic denitrification of high nitrate concentration contaminated wastewater in a batch-scale biofilm reactor has been investigated. High nitrate concentration decreased as pH increased from 7.01 to 9.45. The high nitrate concentrations continuously decrease from $150mg.l^{-1}$ to $0mg.l^{-1}$. Nitrite concentrations increase at about two-thirds way through the denitrification process and thereafter it decreases with time. Autohydrogenotrophic denitrification of high nitrate concentration is passible to use drinking water as well as wastewater, and to deal with wastewater treatment by hetrotrophic denitrification.

• Korean Journal of Plant Tissue Culture
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• v.26 no.2
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• pp.115-119
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• 1999

The single node cuttings of sweet potato (cv. Mokpo #29) plantlets maintained in vitro were cultured with (MF+) or without membrane filter (MF-) under photomixotrophic (PM), hetrotrophic (HT) and autotrophic (AT) conditions. Shoot length was the greatest (11.9cm) in 3$0^{\circ}C$ (HT) treatment and it was the shortest (3.4 cm) in $25^{\circ}C$ (PM) treatment. Nodal explants cultured in 3$0^{\circ}C$ treatment looked more vigorous than those of $25^{\circ}C$ in appearance, and node number was the greatest (10.5 per plantlet) among the treatments. But plantlets grew in 3$0^{\circ}C$ (HT) treatment were observed all overgrown. The size in leaf area was about 2 times greater and shoot length was about 2 times shorter in PM than in HT condition. Percent dry matter of shoots was 5.9% (HT) and 7.4% (PM) in $25^{\circ}C$ treatment and 6.1% (HT) and 7.4% (PM) in 3$0^{\circ}C$ treatment. Plantlets cultured in the MF+ treatments were less succulent than those cultured in the MF- treatment. Vitrified plantlets were examinated 14.8% (both $25^{\circ}C$ and 3$0^{\circ}C$) in PM condition and 22.2% ($25^{\circ}C$) and 31.5% (3$0^{\circ}C$) in HT condition. Sucrose was necessary for the survival of in vitro plantlets. In the sucrose-free medium, explants cultured in the MF- had turned yellow and were dead after 30 days of culture. But explants cultured in the MF+ were alive and produced plantlets with shoot and root (AT). On the other hand, the survival of explants on the MS basal medium (sucrose-free and hormone-free) depended entirely upon the MF attachment.

• ALGAE
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• v.30 no.4
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• pp.281-290
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• 2015

We explored phagotrophy of the phototrophic ciliate Mesodinium rubrum on the cyanobacterium Synechococcus. The ingestion and clearance rates of M. rubrum on Synechococcus as a function of prey concentration were measured. In addition, we calculated grazing coefficients by combining the field data on abundance of M. rubrum and co-occurring Synechococcus spp. with laboratory data on ingestion rates. The ingestion rate of M. rubrum on Synechococcus sp. linearly increased with increasing prey concentrations up to approximately 1.9 × 10⁶ cells mL^-1, to exhibit sigmoidal saturation at higher concentrations. The maximum ingestion and clearance rates of M. rubrum on Synechococcus were 2.1 cells predator^-1 h^-1 and 4.2 nL predator^-1 h^-1, respectively. The calculated grazing coefficients attributable to M. rubrum on cooccurring Synechococcus spp. reached 0.04 day^-1. M. rubrum could thus sometimes be an effective protistan grazer of Synechococcus in marine planktonic food webs. M. rubrum might also be able to form recurrent and massive blooms in diverse marine environments supported by the unique and complex mixotrophic arrays including phagotrphy on hetrotrophic bacteria and Synechococcus as well as digestion, kleptoplastidy and karyoklepty after the ingestion of cryptophyte prey.