Sendango is a traditional delicacy this is made from fermented ground sweet potato and is produced exclusively in Tsushima, Nagasaki, Japan. Unexpectedly for a sweet potato product, a noodle prepared from sendango, rokube, has a unique texture somewhat similar to that of konnyaku. The fungi or other microbes that cause mold to from during sendago fermentation are considered likely to be involved in creating the specific texture of rokube, but this is yet to be determined. Here, we tracked culturable microbes occurring during the process of sendango formation over a 4-year period. Overall, the predominant microbes were Mucor sp., Penicillium spp., Candida sp., Bacillus sp. and Paenibacillus sp. Because previous studies have demonstrated that the unique texture of rokube is attributable to the partial degradation of starch and fiber, microorganisms with amylolytic or pectolytic activity, or both, were identified. Among the fungi and bacteria isolated, some strains of Penicillium spp. and Mucor sp. were capable of this degradation and were thus likely contributors to the fermentation.

Sendango is a traditional delicacy this is made by fermentation of sweet potato and is produced exclusively in Tsushima, Nagasaki, Japan. A noodle-type derivative of sendango, rokube, has a unique texture somewhat similar to that of konnyaku. A previous study has demonstrated that partial degradation of starch and fiber and especially a reduction in pectin levels is associated with this specific texture. In our preceding report we isolated Mucor sp. and Penicillium spp. with amylolytic and pectolytic activity. These organisms were present during the manufacturing process, regardless of the manufacturing farmer or the year, but it is not known whether they actually contribute to degradation within the sweet potato. Here, we attempted to reproduce sendango by fermentation with selected strains of Mucor sp. and Penicillium spp. Upon propagation of either Penicillium echinulatum 38-1 or Penicillium expansum 13-3 on sweet potato we observed partial degradation of starch and pectin. In addition, texture profiling showed that the simulated rokube made from the fermented sweet potato mix had physical properties similar to those of the original rokube form Tsushima. These results suggest that the unique texture of rokube is attributable to the action of specific strains of P. echinulatum and P. expansum.

This review highlights the major milestones in the growth of the Japan Society for Microbial Systematics (JSMS) over the past 33 years from its birth at Ubako Onsen in Hakone in October 1980 to its 33rd Annual Meeting at Takayama Green Hotel in Takayama in November 2013. The history of JSMS was divided into four ages based on the name changes of the Society: “The Group Meeting of Chemotaxonomy of Microorganisms” Age (1980-1984), “The Society for Microbial Chemotaxonomy” Age (1985-1994), “The Society for Microbial Taxonomy” Age (1995-2002), and “The Japan Society for Microbial Systematics” Age (2003-2013). With changes in the dynamics of science and the development of related methodologies, the core of discussions at the respective meetings changed from microbial chemotaxonomy in the 1980s to microbial molecular taxonomy/systematics in the 1990s and 2000s. In recent meetings, the theme “How to put the genome information to practical use in microbial systematics,” which reflects the Genomics Era, was repeatedly discussed. During the past 33 years, the following were held: special lectures (34 talks, with 12 invited speakers from overseas; keynote lecture (1 talk); symposia (5 themes, 27 talks); mini-symposia (2 themes, 5 talks); theme-oriented discussions (16 themes, 26 talks); workshops (3 themes, 7 talks); oral presentations (278 talks; of these, all talks were presented in English at the 2nd meeting in 1981, 3rd meeting in 1983, 8th meeting in 1988, and 20th meeting in 2000), and poster presentations (76 titles). Furthermore, 5 talks (with 3 invited speakers from overseas) at Symposium S-1“ Current advances in the species concept problems of microorganisms ―definitions, methodologies and practical applications” in the 10th International Conference on Culture Collections (ICCC-10) in Tsukuba on October 11, 2004, are included in JSMS’s contributions. The aims and goals, including the raison d’etre, of JSMS, have been mentioned and briefly discussed in this review. In addition, the author’s opinions or impressions regarding the past 33 years of the Society, including a few future perspectives, have been presented.

Actinobacteria are Gram-stain-positive bacteria with a variety of morphologies. They produce various secondary metabolites and are therefore treated as distinct from other bacteria. Until the early 1970s actinobacteria were classified mainly on the basis of their morphological features, but they are currently classified by a combination of their chemotaxonomic characteristics and phylogenetic relationships based on 16S rRNA gene sequences. However, this classification is problematic, because the phenotypic diversity of actinobacteria has led to excessive division of genera and species. Recent taxonomic studies using whole-genome sequences have resulted in more reliable phylogenetic relationships than those based on 16S rRNA gene sequences and should therefore facilitate the reclassification of known species. Furthermore, recent increases in the sophistication of analytical instruments are enabling more detailed chemotaxonomic characterization and could lead to the discovery of new taxonomic indicators. Therefore, more appropriate classification systems will likely be built through a combination of detailed chemotaxonomic characterization and phylogenetic analysis based on whole-genome sequences.

In 1872, bacteria were classified by Ferdinand J. Cohn, a botanist and microbiologist, for the first time in the world. This classification was based on morphology. Cohn’s concept was reasonable to a point, but it soon became unsuitable because bacteria have quite low levels of morphological variation. At the beginning of the 20th century, Sigurd Orla- Jensen, a biochemist, proposed a new taxonomic system grounded in physiology, and by half a century later modern bacterial taxonomy based on polyphasic comparison of morphological, physiological, and biochemical characteristics had been established. At the end of the 20th century, bacterial taxonomy entered a new epoch thanks to the great insight of the molecular evolutionist Carl R. Woese. The ribosomal RNA that he noticed turned out to be a molecule useful for revealing phylogenetic relationships, not only among all living organisms but also within bacteria. Use of this excellent evolutionary marker also allowed scientists other than bacterial taxonomists to study bacterial classification and identification, thus accelerating progress in bacterial taxonomy. Today, a new era is again about to begin in this intersection of bacteriology, as a result of rapid progress in the development of DNA sequencing technology and computer science.

The past 20 years have seen great progress in prokaryotic systematics. Application of genetic information such as 16S rDNA sequencing has been the greatest driving force behind these achievements. DNA–DNA hybridization is still considered a gold standard for species delineation, but phenotypic characterization (including characterization of cultural behavior characteristics) is still required for bacterial species description. In contrast, molecular approaches have brought great progress in microbial ecology. One of these advances is the analysis of microbial consortia without the need for culture. As a result, some taxonomic discordance has arisen between microbial taxonomy and microbial ecology. From this perspective, microbial ecologists have put forward suggestions for prokaryotic taxonomy. Furthermore, recent advances in sequencing technology have resulted in easy access to genomic information on microbes, even in the environment. The application of advanced bioinformatics techniques to genome sequencing now allows for a genotype-to-phenotype approach, which can reveal phenotypic information on microbes of interest without the need for culture. These amazing advances in molecular biology and informatics will provide a paradigm shift in prokaryotic taxonomy and the concept of species in the near future.

Aspergillus fumigatus is distributed worldwide in soil, air, foods, feeds, compost, and human habitats. Aspergillus fumigatus and its related species, including the genus Neosartorya, which is a teleomorph of Aspergillus, are the most important causative agents of aspergillosis. These species belong to Aspergillus section Fumigati. Conidiogenesis and conidial ornamentation are important morphological characters for distinguishing Aspergillus species. The teleomorph of Aspergillus has various ascospore ornamentations, and these are characteristic of species discrimination.

Rules for the systematic biology of Aspergillus were suggested in 2007, and since then the partial β-tubulin, calmodulin, actin, and RNA polymerase genes and the internal transcribed spacer (ITS) region have been used for the taxonomy of Aspergillus. The β-tubulin and calmodulin genes, in particular, have been well analyzed in Aspergillus and its related genera.

The correlations among molecular phylogenetics and phenotypic characters have been investigated well in Aspergillus. Molecular phylogenetics has become a useful tool for distinguishing species of Aspergillus and its related genera, and many new species have been discovered and described since 2007.

In section Fumigati, several species (especially A. udagawae and A. viridinutans) show within-species diversity of DNA sequences. Recently, several researchers have reevaluated A. viridinutans by using a mating test. As a result, A. viridinutans has been separated into seven species on the basis of conidial or ascospore morphology. Application of systematic biology has promoted variation in the modern taxonomy of Aspergillus.