Chunsang Hong

Phylogenetic analysis of atmospheric halotolerant bacterial communities at high altitude in an Asian dust (KOSA) arrival region, Suzu City.

The microbial communities transported by Asian desert dust (KOSA) events have attracted much attention as bioaerosols because the transported microorganisms are thought to influence the downwind ecosystems in Korea and Japan. However, the atmospheric microbial community has not been investigated at high altitude in the KOSA arrival area. In this study, to estimate the viability and diversity of atmospheric halotolerant bacteria, which are expected to resist to various environmental stresses as well as high salinities, bioaerosol samples were collected at 10 and 600 m above the ground within the KOSA arrival area, Suzu City, Japan, during KOSA events. During the sampling period, the particle numbers at 600 m were higher than those at 10 m, suggesting that large particles of aerosol fall from the high altitude of 600 m to the ground surface. The microorganisms in bioaerosol samples grew in media containing up to 15% NaCl concentrations demonstrating the viability of the halotolerant bacteria in bioaerosol samples. The PCR-DGGE analysis using 16S rDNA revealed that the bacterial species in NaCl-amended cultures were similar to the bacteria detected from the genomic DNA directly extracted from the bioaerosol samples. The 16S rDNA sequences of bacterial communities in bioaerosol samples were classified into 4 phylotypes belonging to the Bacilluscereus or Bacillussubtilis group. The bioaerosol samples collected at 600 m included 2 phylotypes belonging to B. subtilis, and one phylotype among all 4 phylotypes was identical between the samples at 10 and 600 m. In the atmosphere at 600 m, the halotolerant bacterial community was expected to remain viable, and the species composition was expected to include a few species of the genus Bacillus. During this investigation period, these atmospheric bacteria may have been vertically transported to the ground surface, where the long-range KOSA particle transport from China is frequently observed.

Immobilization of cross‐linked lipase aggregates onto magnetic beads for enzymatic degradation of polycaprolactone

Candida rugosa lipase was immobilized on amino‐functionalized magnetic supports via cross‐linked enzyme aggregates (CLEA) and used to enhance the enzymatic degradation of polycaprolactone (PCL). The maximum amounts of lipase immobilized on the magnetic beads using glutaraldehyde as a coupling agent were determined to be 33.7 mg/g of beads with an 81% recovery of activity after immobilization. Compared to the free enzyme, the immobilized lipase showed the optimum pH at 1 unit higher (pH 8.0) and also retained its enzymatic activity at higher temperatures. There was 62.9% retention of lipase activity after 30 consecutive reuses, indicating its stability and reusability in aqueous media. Moreover, the immobilized lipase maintained more than 80% of its initial activity during 30 days storage period, while the free lipase lost all under same condition. In addition, the immobilized lipase showed a more than 6‐fold increase in biodegradability over the free lipase when the immobilized lipase was used to degrade PCL in a batch system. Higher thermal and storage stability, as well as good durability after repeated use of the immobilized lipase CLEA, highlights its potential applicability as large scale continuous systems for the enzymatic degradation of PCL. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Mass Transport of Background Asian Dust Revealed by Balloon-Borne Measurement: Dust Particles Transported during Calm Periods by Westerly from Taklamakan Desert

The dust storm which is caused by low pressure activities in China and Mongolia has been investigated by many investigators, but very thin dust clouds, which can be frequently detected in every season (we call it background Asian dust here) by lidar in Japan, Korea, and China but not by satellite, have attracted very few investigators since detection of the cloud is not easy. It, however, has been suggested that the background Asian dust also plays an important role in the biogeochemical cycle of dust in east Asia and west Pacific regions through long range transport of dust particles by westerly winds, and information of outflow rate of background dust particles over the dust source areas is strongly desired since previous investigations were made mostly in the down wind regions (Iwasaka et al. 1988; Matsuki et al. 2002; Trochkine et al. 2002). According to the balloon-borne measurements made under the calm weather condition in 2001–2004 at Dunhuang (40°00′N, 94°30′E), China, mass flux of background Asian dust due to westerly wind was about 50 ton/km/day over the Taklamakan desert (about 4 to 6 km altitudes) and 1 Institute of Nature and Environmental Technology, Kanazawa University, Kanazawa, Japan 2 Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan 3 Institute of Atmospheric Physics, Chinese Academy of Science, Beijing, China 4 Faculty of Environmental and Symbiotic Sciences, Prefectural University of Kumamoto, Kumamoto, Japan 5 Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Science, Lanzhou, China a Now: Institute of Environmental and Industrial Medicine, Hanyang University, Seoul, Korea b Now: Laboratorire de Meteorologie Physique, Universite Blaise Pascal, Aubie re CEDEX, France c Now: Institute for Water and Environmental Problems, Siberian Branch of Russian Academy of Science, Barnaul, Russia 121 Y.J. Kim and U. Platt (eds.), Advanced Environmental Monitoring, 121–135.

Biodegradation of diisodecyl phthalate (DIDP) by Bacillus sp. SB-007.

In this study, diisodecyl phthalate (DIDP) was efficiently degraded by Bacillus sp. SB‐007. The optimal conditions for DIDP (100 mg l–1) degradation by Bacillus sp. SB‐007 in a mineral salts medium were found to be pH 7.0 at 30 °C, stirring at 200 rpm. The specific rate of DIDP degradation was found to be concentration dependent with a maximum of 4.87 mg DIDP l–1 h–1. DIDP was transformed rapidly by Bacillus sp. SB‐007 with the formation of monoisodecyl phthalate and phthalic acid, which subsequently degraded further. These results highlight the potential of this bacterium for removing DIDP contaminated waste in the environment. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Composition of halophilic bacteria survived in bioaerosol

Teruya Maki, Shinzi Susuki, Fumihisa Kobayashi, Makiko Kakikawa, Maromu Yamada, Tomomi Higashi, Chunsang Hong, Yutaka Tobo, Hiroshi Hasegawa, Kazumasa Ueda and Yasunobu Iwasaka 1 Graduate School of Natural Science and Technology, Kanazawa University, Kakuma, Kanazawa, 920-1192, Japan. 2 Institute of Nature and Environmental Technology, Kanazawa University, Kakuma, Kanazawa, 920-1192, Japan. 3 Faculty of Environmental and Symbiotic Science, Prefectural University of Kumamoto.3-1-100 Tsukide, Kumamoto 862-8502, Japan 4 Hygiene, Kanazawa University School of Medicine, 13-1 Takara-machi, Kanazawa 920-8640, Japan 5 Frontier Science Organization, Kanazawa University, Kakuma, Kanazawa, 920-1192, Japan.