During the studies of two projects of the Institute for Fermentation, Osaka (IFO) and Japan Agency for Medical Research and Development (AMED), we isolated a large number of bacteria from the human feces and proposed 13 novel species until now. Among the novel species, there are butyrate-producing and succinate-utilizing bacteria, such as Lawsonibacter asaccharolyticus and Dialister hominis. In our studies, only strains that formed colonies on agar plate media were isolated. Recently, new isolation methods that do not rely on agar media have been developed. To understand microbe-microbe interactions, we investigated the growth behavior of co-cultured Bacteroides thetaiotaomicron and succinate-utilizing bacteria, such as Phascolarctobacterium faecium and D. hominis. Co-existence with succinate-producing bacteria, such as Bacteroides, is essential for succinate-utilizing bacteria to inhabit the human gut and produce propionate. In this review, new insights into the isolation of novel microorganisms from the human gut are discussed.

The great contribution of the late Prof. Kazuo Komagata to the taxonomy of coryneform bacteria is introduced. Coryneform bacteria have been defined as irregular nonsporing Gram-positive rods. Coryneform bacteria are widely distributed in, for example, animal pathogens, plant pathogens and soil habitat, and their taxonomy was in confusion. In 1958, glutamic acid-producing bacteria were found and developed for industrial amino acid production. The taxonomic position attracted attention because of a patent dispute. Prof. Komagata collected a wide variety of coryneform bacteria and studied the taxonomy using a polyphasic approach including newly introduced chemotaxonomy as well as morphological and physiological/biochemical tests and successfully classified them at the genus level. Since then, the chemotaxonomic approach, involving for example the peptidoglycan structure, menaquinone, and the cell wall acyl type, has played an important role in the progress of the taxonomy of coryneform bacteria. More recently, phylogenetic taxonomy based on 16S rRNA sequences has been used to construct the higher taxa and support the usefulness of chemotaxonomy as regards phenotypic characteristics. Harmonization of this work with that of microbiologists by sharing microbial resources to enrich the information obtained using culture collection is important for the future progress of microbial taxonomy.

Japanese forests are facing serious threats linked to climate change. These threats include tree decline and mortality due to various tree pathogenic fungi, such as Grosmannia aoshimae, Dryadomyces quercivorus, Phytophthora cinnamomi and Fomitoporia spp. This review discusses their impact on Japanese forests in the context of climate change. Two species of ophiostomataceous fungi (G. aoshimae and D. quercivorus) are closely associated with the bark beetle, Polygraphus proximus, and the ambrosia beetle, Platypus quercivorus, respectively. Climate change has contributed to the abundance and/or widespread distribution of these beetles, and has resulted in the mass mortalities of Abies maresii and Quercus spp. in Japan. Phytophthora cinnamomi is well-known as a serious tree pathogen. However, it had been thought to have only a limited impact on tree species in Japan. Recently, this pathogen has been found in more northern areas of Japan and is expected to become a more serious problem. The distribution of Fomitoporia torreyae and F. punctata is determined by their respective optimum growth temperatures, and climate change will affect the distribution of these two fungal species. This suggests that tree decline and mass mortality will become more frequent. The function and mechanism of the associated pathogens and other microbes in forests should be elucidated in order to adapt to climate change and minimize their undesirable effects. In this situation, the role of culture collections and related organizations will become more important than ever.

To prepare a cellular polyamine distribution catalogue of the three algal phyla Glaucophyta, Rhodophyta and Chlorophyta in Archaeplastida, we analyzed 2 strains (2 species) of glaucophytes, 14 strains (10 species) of red algae and 27 strains (22 species) chlorophyte green algae. The acid-extracted polyamines from the algae were analyzed by HPLC and HPGC-MS. Putrescine and spermidine were the polyamines of Cyanophora and Glaucophyra of Glaucophyta. In the unicellular acidothermophilic Rhodophyta, Cyanidium, Cyanidioschyzon and Cyanidiococcus contained putrescine, spermidine and spermie, and norspermidine, homospermidine and thermospermine were added in Galdieria. Multicellular marine Asparagopsis contained homospermidine and aminopropylhomospermidine. Caldopentamine and thermopentamine were distributed in multicellular freshwater Hildenbrandia. In the Chlorophyta, putrescine and spermidine were the major polyamines in Carolibrandtia, Picochlorum, achlorophylus Prototheca and phototrophic/heterotrophic Auxenochlorella. Norspermidine was added to endosynbiotic Protodesmus. Coccomyxa and photobiontic Asterochloris contained putrescine, norspermidine, spermidine, homospermidine and spermine. Grecesiella and bacteriovory-potent Pyramimonas and Pterosperma contained putrescine, norspermidine and spermidine. Snow alga Chloromonas contained diaminopropane, putrescine, norspermidine and spermidine. Gymnomonas contained putrescine alone.