Samples were collected from planktonic habitats of the fresh and brackish waters in Korea from August 2016 to May 2018. As a result, three genera and nine species were newly recorded in Korea. The unrecorded indigenous genera were Anathece, Chondrocystis and Geminocystis, and nine species were Anabaenopsis arnoldii, Anathece smithii, Chondrocystis dermochroa, Coelosphaerium aerugineum, Eucapsis microscopica, Geminocystis herdmanii, Microcystis panniformis, Synechococcus nidulans and Woronichinia karelica. Anathece smithii, Coelosphaerium aerugineum, Eucapsis microscopica, Microcystis panniformis and Synechococcus nidulans had been reported to inhabit freshwater, but these were found in brackish water in this study. Microcystis panniformis, which is a potential genus for causing green-tide, is taxonomically valuable in Korea.

Phytoplanktons were collected from various environments including small marshes, small ponds, reservoirs and brackish water from March 2017 to November 2017. In this study, five species of family Scenedesmaceae were newly recorded in Korea. The genus Desmodesmus was newly reported in Korea. The newly recorded species are Scenedesmus nanus, S. praetervisus, Desmodesmus costato-granulatus, D. lunatus and D. spinulatus. S. nanus and S. praetervisus are known to occur in freshwater, but they were found in the brackish water in this study.

Samples were collected between August 2016 and May 2017 at Sangju-si, Gyeongsangbuk- do, Jeju-do, and Uljin-gun, Gangwon-do. As a result, one genus and six species were newly recorded in Korea. The unrecorded indigenous genus was Borzia, and the six species were Anagnostidinema acutissimum, Komvophoron bourrellyi, Hydrocoleum stankovicii, Borzia trilocularis, Phormidium tinctorium and Pseudanabaena lohchoides. Phormidium tinctorium and Pseudanabaena lohchoides had been reported to inhabit freshwater, but in this study, these were found in brackish water. It had also been reported that B. trilocularis trichomes are composed of up to 8 cells, but in this study, a maximum of 10 cells was observed.

Polyhedrin is the major component of the nuclear viral occlusions produced during replication of the baculovirus Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). To enhance the production efficiency of foreign protein in baculovirus expression system, the effects of various polyhedrin fragments were investigated by fusion expressing them with the enhanced green fluorescent protein (EGFP). Recombinant viruses were generated to express EGFP fused with polyhedrin fragments based on the previously reported minimal region for self-assembly and the KRKK nuclear localization signal (NLS). The marked increase of EGFP by these fusion expressions was confirmed through protein and fluorescence intensity analyses. Among the fusion-expressed protein in nucleus and cytoplasm, the most hyper-expression was observed in the fusion of amino acids 19 to 110 and 32 to 59 of polyhedrin. Also these fragments, some degradation of only the fused polyhedrin was observed in the fusion of amino acids 19 to 85 and 32 to 85. The production of E2 protein, which is a major antigen of classical swine fever virus, was dramatically increased by fusion expression with polyhedrin amino acids 19 to 110, and its preliminary immunogenicity was verified using experimental guinea pigs. The production of luciferase was approximately two folds increased by fusion expression with polyhedrin amino acids 32 to 59, and its activity was measured using Luminometer. This study suggests a new option for higher expression of useful foreign recombinant protein using the partial polyhedrin fusion expression in baculovirus.

To enhance the production efficiency of foreign protein in baculovirus expression system, the effects of polyhedrin fragments were investigated by fusion expression them with the enhanced green fluorescence protein (EGFP). Recombinant viruses were generated to express EGFP fused with polyhedrin fragments based on the minimal region for self-assembly and the KRKK nuclear localization signal (NLS). The increase of EGFP production by fusion expressions was confirmed through protein and fluorescence intensity analyses. The importance of nuclear localization for enhanced production of EGFP was shown by the mutation of the NLS within the fused polyhedrin fragment. Among the fusion expressed protein in cytoplasm, the most hyper-expression was observed in the fusion of amino acids 32 to 59 of polyhedrin. Polyhedrin fragment fusion expression with classical swine fever virus E2 protein also resulted hyper-enhanced expression of E2 protein. However, the fusion expression of porcine circovirus ORF2 with polyhedrin fragment did not show significant enhance of ORF2 production. These results suggested that the enhancement of foreign protein production when fused with polyhedrin is caused by the enhanced stability of expressed protein.

Polyhedrin is the major component of the nuclear viral occlusions produced during replication of the baculovirus Autographa californica multicapsid nuclear polyhedrosis virus (AcMNPV). To enhance the expression level of baculovirus vector system, we constructed several fusion vectors using various fragments of the polyhedrin. The polyhedrin fragments were genetically fused to the enhanced green fluorescent protein (eGFP) under the control of polyhedrin promoter, and their expressions were analyzed in Sf21 insect cells. Expression of the fusion protein was identified by SDS-PAGE and Western blot analysis using anti-GFP and anti-Polyhedrin. The expression level of eGFP was markedly increased by the fusion of partial polyhedrin. Also, the fluorescence intensity of fusion proteins was higher than that of non-fusion protein. Confocal laser scanning microscopy demonstrated that fusion proteins were localized to the cytosol or nucleus of insect cells. In additional, the glycoprotein E2 (gE2) of classical swine fever virus (CSFV) expressed by the these vectors was dramatically increased and its immunogenicity was proofed using experimental animal guinea pigs that were immunized with the partial polyhedrin containing gE2. This study provides a new option for the higher expression of useful foreign recombinant protein by using the partial polyhedrin in BEVS.

The Classical Swine Fever Virus (CSFV) is a member of the Pestivirus genus of the Flaviviridae. The polyprotein composed of eight nonstructural and four structural proteins (nucleocapsid protein C and three envelope glycoprotein E0, E1 and E2). E2, the most immunogenic of the CSFV glycoproteins, induces a protective immune response in swine. The objective of this study was to enhance production of E2 protein by fusion with partial polyhedrin of nucleopolyhedrovirus in insect cells. We generated various E2 form by fusion with different combinations of the partial polyhedrin and deletion of the C-terminal transmembrane region (TMR). Expression of the E2 protein was identified by SDS-PAGE and Western blot analysis using anti-CSFV E2 monoclonal antibodies. The fusion expression of an E2 protein with the partial polyhedrin markedly increased expression levels. Also, expression of E2 proteinlacking TMR region was higher than that of intact E2 protein. As a result, the fusion expression of E2 protein lacking the C-terminal TMR with partial polyhedrin was significantly increased in insect cells. These suggest that the fusion of target foreign protein with partial polyhedrin could enhance significantly the production of target protein.

The Classical Swine Fever Virus (CSFV) is a member of the Pestivirus genus of the Flaviviridae. The genome of CSFV is a positive single-stranded RNA molecule 12.3 kb and contains a single large open reading frame (ORF). The polyprotein composed of eight nonstructural and four structural proteins (nucleocapsid protein C and three envelope glycoprotein E0, E1 and E2). E2, the most immunogenic of the CSFV glycoproteins, induces a protective immune response in swine. To determine the characteristics of the CSFV, LOM strain, we investigated the nucleotide sequence of the glycoprotein E0, E1 and E2. Comparison of the LOM with the other strains revealed nucleotide sequence identity ranging from 97 to 98%. Expression of the glycoprotein E2 was identified by SDS-PAGE and Western blot analysis using anti-CSFV E2 monoclonal antibodies in Sf21 cells. The expression levels of glycoprotein E2 were observed from day 3 and 5 days maximum. In addition, its expression efficiency by media and cell line was investigated. The result showed that High-Five cells and Grace’s insect media for Sf21 were the best conditions for the expression of the glycoprotein E2.