Glycoprotein (G) gene nucleotide sequences of four Korean isolates of infectious hematopoietic necrosis virus (IHNV) were analyzed to evaluate their genetic relatedness to worldwide isolates. All Korean isolates were closely related to Japanese isolates of genogroup JRt rather than to those of North American and European genogroups. It is believed that Korean IHNV has been most likely introduced from Japan to Korea by the movement of contaminated fish eggs. Among the Korean isolates, phylogenetically distinct virus types were obtained from sites north and south of a large mountain range, suggesting the possibility of more than one introduction of virus from Japan

In order to study the possibility of utilizing aromatic materials for the preservation of milk, the antibacterial effects of various aromatic materials against Pseudomonas fluorescens inoculated in milk were investigated. The effects of aromatic materials were generated using the "vapor contact method" and bacterial growth was measured by the menadione-catalyzed luminol chemiluminescence method. Wasabi (Wasabi japonica) and mustard (Brassica nigra L.) were found to be more effective than garlic (Allium sativum L.), ginger (Zingiber officinale Roscoe), sansho (Zanthoxylum piperitum) and peppermint (Mentha piperita). In addition to these materials, four types of commercially available food preservation sheets were tested for antibacterial activity. Sheets containing mustard extracts showed stronger antibacterial activities. Eucalyptus extract-treated sheets showed a moderate effect. PRACTICAL APPLICATIONSThe vapor contact method was advantageous when compared with the direct contact method, as the flavor of the milk was affected little by the aromatic substances. This study suggests that aromatic materials can be used to preserve milk in areas where milk quality is low or sanitary conditions are 3 Corresponding