Higashi Chikushi Junior College

Kitakyusyu, Japan

Higashi Chikushi Junior College

Kitakyusyu, Japan

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Konishi M.,Japan Agency for Marine - Earth Science and Technology | Nagahama T.,Japan Agency for Marine - Earth Science and Technology | Nagahama T.,Higashi Chikushi Junior College | Fukuoka T.,Japan Advanced Institute of Science and Technology | And 4 more authors.
Journal of Bioscience and Bioengineering | Year: 2011

We improved the culture conditions for a biosurfactant producing yeast, Pseudozyma hubeiensis SY62. We found that yeast extract greatly stimulates MEL production. Furthermore, we demonstrated a highly efficient production of MELs in the improved medium by fed-batch cultivation. The final concentration of MELs reached 129 ± 8.2 g/l for one week. © 2011 The Society for Biotechnology, Japan.


Mochida K.,Kyoto University | Mochida K.,University of Ryukyus | Kitada M.,Nagasaki University | Ikeda K.,Higashi Chikushi Junior College | And 3 more authors.
Journal of Chemical Ecology | Year: 2013

Most animals advertise their unprofitability to potential predators via conspicuous signals. Whether the strength of this aposematic signal indicates the quality and quantity of chemical defenses in animals is controversial. Here, we investigated the relationship between the conspicuousness of an aposematic signal and toxicity, which likely depends, at least in part, on dietary sources, in the newt Cynops pyrrhogaster. Our results indicate that the magnitude of the aposematic signal was not correlated with the amount of tetrodotoxin (TTX) and 6-epi TTX of wild individuals among populations. Using atoxic newts, reared from eggs, we compared the ability to accumulate TTX from diets between mainland and island populations. Newts of a mainland population that exhibited a less conspicuous signal accumulated more TTX than did equivalent newts of an insular population that displayed a more conspicuous signal; this was unrelated to variation in the toxicity of wild individuals of these two populations. We also found toxicity of wild newts changed over approximately one generation (10 years) in both populations. These results indirectly suggest that environmental variance, such as fluctuations in TTX resources in nature, may obscure differences in the ability of wild newts to accumulate TTX, and that this variation may be responsible for a lack of correlation between the strength of a newt's signal and its toxicity in the wild. These results imply that toxicity of wild individuals likely is a phenotypic trait largely dependent on environmental conditions. © 2013 Springer Science+Business Media New York.


Nagahama T.,Higashi Chikushi Junior College | Nagano Y.,Higashi Chikushi Junior College
Progress in molecular and subcellular biology | Year: 2012

The importance of fungi found in deep-sea extreme environments is becoming increasingly recognized. In this chapter, current scientific findings on the fungal diversity in several deep-sea environments by conventional culture and culture-independent methods are reviewed and discussed, primarily focused on culture-independent approaches. Fungal species detected by conventional culture methods mostly belonged to Ascomycota and Basidiomycota phyla. Culture-independent approaches have revealed the presence of highly novel fungal phylotypes, including new taxonomic groups placed in deep branches within the phylum Chytridiomycota and unknown ancient fungal groups. Future attempts to culture these unknown fungal groups may provide key insights into the early evolution of fungi and their ecological and physiological significance in deep-sea environments.


Nagahama T.,Higashi Chikushi Junior College | Nagahama T.,Japan Agency for Marine - Earth Science and Technology | Takahashi E.,Japan Agency for Marine - Earth Science and Technology | Nagano Y.,Japan Agency for Marine - Earth Science and Technology | And 3 more authors.
Environmental Microbiology | Year: 2011

The motile cells of chytrids were once believed to be relics from the time before the colonization of land by fungi. However, the majority of chytrids had not been found in marine but freshwater environments. We investigated fungal diversity by a fungal-specific PCR-based analysis of environmental DNA in deep-sea methane cold-seep sediments, identifying a total of 35 phylotypes, 12 of which were early diverging fungi (basal fungi, ex 'lower fungi'). The basal fungi occupied a major portion of fungal clones. These were phylogenetically placed into a deep-branching clade of fungi and the LKM11 clade that was a divergent group comprised of only environmental clones from aquatic environments. As suggested by Lara and colleagues, species of the endoparasitic genus Rozella, being recently considered of the earliest branching taxa of fungi, were nested within the LKM11 clade. In the remaining 23 phylotypes identified as the Dikarya, the majority of which were similar to those which appeared in previously deep-sea studies, but also highly novel lineages associated with Soil Clone Group I (SCGI), Entorrhiza sp. and the agaricomycetous fungi were recorded. The fungi of the Dikarya may play a role in the biodegradation of lignin and lignin-derived materials in deep-sea, because the characterized fungal species related to the frequent phylotypes within the Dikarya have been reported to possess an ability to degrade lignin. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.


Nagano Y.,Japan Agency for Marine - Earth Science and Technology | Nagahama T.,Japan Agency for Marine - Earth Science and Technology | Nagahama T.,Higashi Chikushi Junior College
Review of High Pressure Science and Technology/Koatsuryoku No Kagaku To Gijutsu | Year: 2010

Fungi are one of the most important components in ecosystems and they occupy a wide variety of environments by virtue of their highly versatile physiology function. Recently, the presence of fungi in one of the extreme environments, deep-sea, has started to be recognized. In this article, recent scientific findings through the investigation of fungal diversity in deep-sea sediments collected from several deep-sea environments, including water depths of 10,000 m and methane cold-seep sites were described. PCR-mediated analysis revealed the presence of diverse highly novel fungal phylotypes, including new taxonomic groups placed in deep branches within the phylum of Chytridiomycota with Rozella spp. as the closest related organisms, which may provide key insights into the early evolution of fungi.


Abdel-Wahab M.A.,Japan Agency for Marine - Earth Science and Technology | Abdel-Wahab M.A.,Sohag University | Nagahama T.,Japan Agency for Marine - Earth Science and Technology | Nagahama T.,Higashi Chikushi Junior College
Nova Hedwigia | Year: 2011

A new genus, Gesasha Abdel-Wahab & Nagahama, and three new species therein are described and illustrated from Gesashi mangroves, Okinawa, Japan. Molecular phylogenetic analyses of the partial SSU and LSU rDNA placed the three new species into a clade distantly related to morphologically similar fungi with a high statistical support in the Halosphaeriales, Sordariomycetidae, Sordariomycetes, Ascomycota. The new genus is characterized by hyaline to light-brown, immersed to erumpent coriaceous ascomata, persistent asci with a thickened apical pore with a cytoplasmic retraction below the ascus apex and uni or bi-celled, globose to widely ellipsoidal ascospores with or without ephemeral, amorphous polar to sub-polar appendages. © 2011 J. Cramer in Gebr.


Nagano Y.,Japan Agency for Marine - Earth Science and Technology | Nagahama T.,Japan Agency for Marine - Earth Science and Technology | Nagahama T.,Higashi Chikushi Junior College
Fungal Ecology | Year: 2012

The deep-sea is one of the most mysterious and unexplored extreme environments, holding great potential and interest for science. Despite extensive studies on deep-sea prokaryotes, the diversity of fungi, one of the most ecologically important groups of eukaryotic micro-organisms, remains largely unknown. However, the presence of fungi in these ecosystems is starting to be recognised. Many fungi have been isolated by culture-dependent methods from various deep-sea environments, with the majority showing similarity to terrestrial species. However, culture-independent methods have revealed many novel fungal phylotypes, including novel fungal lineages recently described as Cryptomycota, which are suspected to lack typical fungal chitin-rich cell walls. Although true fungal diversity and its role in deep-sea environments is still unclear, the intention of this review is to assess current knowledge of the diversity of fungi in these ecosystems and to suggest future direction for deep-sea fungal research. © 2012 Elsevier Ltd and The British Mycological Society.


Abdel-Wahab M.A.,Japan Agency for Marine - Earth Science and Technology | Abdel-Wahab M.A.,Sohag University | Nagahama T.,Japan Agency for Marine - Earth Science and Technology | Nagahama T.,Higashi Chikushi Junior College
Mycological Progress | Year: 2012

A new Halosarpheia species, collected from driftwood from Hakkeijima beach, Yokohama, Japan, is described and illustrated and is compared with other species of the genus. The new fungus was growing together with its anamorph on a piece of decaying wood. SSU and LSU rDNA sequences for both morphs were 99% similar. Phylogenetic analyses of SSU and LSU rDNA sequences of the both morphs confirm their anamorph-teleomorph relationship and placed the new fungus in the Halosarpheia sensu stricto clade with high statistical support. Halosarpheia japonica is characterized by its polar appendage that is initially enclosed in a cellular sheath and dissolves in water, the appendage then swells to form a huge tree-like structure. The other three species currently included in Halosarpheia sensu stricto differ from H. japonica by having two polar appendages that uncoil in water to form long filaments. © 2010 German Mycological Society and Springer.


Kobayashi H.,Japan Agency for Marine - Earth Science and Technology | Hatada Y.,Japan Agency for Marine - Earth Science and Technology | Tsubouchi T.,Japan Agency for Marine - Earth Science and Technology | Nagahama T.,Japan Agency for Marine - Earth Science and Technology | And 2 more authors.
PLoS ONE | Year: 2012

The Challenger Deep in the Mariana Trench is the deepest point in the ocean (10,994 m). Certain deep-sea animals can withstand the extreme pressure at this great depth. The amphipod Hirondellea gigas is a resident of the Challenger Deep. Amphipods are common inhabitants at great depths and serve as scavengers. However, there is relatively little information available regarding the physiology of H. gigas or this organism's ecological interactions in the hadopelagic zone. To understand the feeding behavior of this scavenger in the deepest oligotrophic hadal zone, we analyzed the digestive enzymes in whole-body extracts. We describe the detection of amylase, cellulase, mannanase, xylanase, and α-glycosidase activities that are capable of digesting plant-derived polysaccharides. Our identification of glucose, maltose, and cellobiose in the H. gigas extracts indicated that these enzymes function under great pressure in situ. In fact, the glucose content of H. gigas averaged 0.4% (w/dry-w). The purified H. gigas cellulase (HGcel) converted cellulose to glucose and cellobiose at an exceptional molar ratio of 2:1 and efficiently produced glucose from dried wood, a natural cellulosic biomass, at 35°C. The enzyme activity increased under a high hydrostatic pressure of 100 MPa at 2°C, conditions equivalent to those found in the Challenger Deep. An analysis of the amino acid sequence of HGcel supported its classification as a family 31 glycosyl hydrolase. However, none of the enzymes of this family had previously been shown to possess cellulase activity. These results strongly suggested that H. gigas adapted to its extreme oligotrophic hadal oceanic environment by evolving digestive enzymes capable of digesting sunken wooden debris. © 2012 Kobayashi et al.


PubMed | Higashi Chikushi Junior College
Type: | Journal: Progress in molecular and subcellular biology | Year: 2012

The importance of fungi found in deep-sea extreme environments is becoming increasingly recognized. In this chapter, current scientific findings on the fungal diversity in several deep-sea environments by conventional culture and culture-independent methods are reviewed and discussed, primarily focused on culture-independent approaches. Fungal species detected by conventional culture methods mostly belonged to Ascomycota and Basidiomycota phyla. Culture-independent approaches have revealed the presence of highly novel fungal phylotypes, including new taxonomic groups placed in deep branches within the phylum Chytridiomycota and unknown ancient fungal groups. Future attempts to culture these unknown fungal groups may provide key insights into the early evolution of fungi and their ecological and physiological significance in deep-sea environments.

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