Biomedical subjects

Akihito Endo

Publications and source records attributed to Akihito Endo.

5 recordsLinked to original sources

PubMed2026

Fructophilic lactic acid bacteria as a window into multi-scale convergent evolution.

Fructophilic lactic acid bacteria (FLAB) are a group of lactic acid bacteria with unique growth characteristics, that is, poor growth on glucose. Their growth is enhanced in the presence of fructose or external electron acceptors. These organisms inhabit fructose-rich environments such as flowers, fruits, and pollinating insects, particularly honey bees. Apilactobacillus spp. and Fructobacillus spp. are representatives of FLAB, although they belong to phylogenetically distant clades. These organisms commonly possess markedly small genomes with a low number of coding DNA sequences. Furthermore, their genomes are characterized by a markedly reduced number of genes involved in carbohydrate transport and metabolism. Genome reduction in FLAB reflects convergent adaptation to fructose-rich environments rather than general genome streamlining. The two distinct FLAB genera, Fructobacillus and Apilactobacillus, independently lost more than 100 genes in statistically similar orders. In contrast, genes involved in carbohydrate and amino acid metabolism exhibited reversed orders of loss between the two genera. Furthermore, FLAB genomes lack an intact bifunctional alcohol/aldehyde dehydrogenase gene (adhE), which causes their poor growth on glucose. A comparative genomic study suggested the evolutionary process underlying adhE gene decay during adaptation to the fructose-rich environments, including pollinating insects. In conclusion, FLAB represent a unique example of habitat-driven convergent reductive evolution that can be investigated across multiple biological scales - from individual genes to whole genomes - in the diverse LAB group with a wide range of habitats, and partially share the fructophilic evolution with eukaryotic yeasts found in fructose-rich habitats.

Fructose↗

PubMed2006

Oenococcus kitaharae sp. nov., a non-acidophilic and non-malolactic-fermenting oenococcus isolated from a composting distilled shochu residue.

Six strains of lactic acid bacteria were isolated in Japan from a composting distilled shochu residue. The six isolates grew poorly on MRS agar and slowly in MRS broth. The 16S rRNA gene sequences did not show high levels of similarity to those of the recognized species of lactic acid bacteria, and formed a subcluster within the cluster comprising obligately heterofermentative lactic acid bacteria closely related to Oenococcus oeni. The levels of DNA-DNA relatedness revealed that the isolates belonged to the same taxon and were genetically separate from O. oeni. Furthermore, various phenotypic characteristics such as the optimum pH for growth, malolactic fermentation and resistance to 10 % ethanol revealed that the isolates are distinguishable from O. oeni. On the basis of their phylogenetic and phenotypic characteristics, the isolates represent a novel species, for which the name Oenococcus kitaharae sp. nov. is proposed. The type strain is NRIC 0645(T) (=JCM 13282(T)=DSM 17330(T)).

Alcoholic Beverages↗

PubMed2006

Lactobacillus durianis Leisner et al. 2002 is a later heterotypic synonym of Lactobacillus vaccinostercus Kozaki and Okada 1983.

The taxonomic status of the species Lactobacillus durianis and Lactobacillus vaccinostercus is briefly summarized and experimental evidence concerning their similarity is presented. Highly similar 16S rRNA gene sequences (99.8 % similarity over 1,523 bp), partial recA gene sequences (99.5 % similarity over 600 bp) and partial hsp60 gene sequences (99.1 % similarity over 924 bp) suggest that the two species are closely related. Moreover, a high DNA-DNA binding level (87 %) and similar genomic DNA G+C contents (41-44 mol% for both species) as well as similar biochemical characteristics support the evidence that they constitute a single species. Consequently, according to Rules 38 and 42 of the Bacteriological Code, the name Lactobacillus vaccinostercus, the oldest legitimate name, must be maintained and the name Lactobacillus durianis should be considered a later heterotypic synonym.

Bacterial Proteins↗

PubMed2005

Lactobacillus satsumensis sp. nov., isolated from mashes of shochu, a traditional Japanese distilled spirit made from fermented rice and other starchy materials.

Gram-positive, rod-shaped, motile lactic acid bacteria (strains NRIC 0603, NRIC 0604T, NRIC 0605 and NRIC 0606) were isolated from shochu mashes using an enrichment culture approach. These strains clustered in the Lactobacillus casei-Pediococcus group and were closely related to Lactobacillus nagelii and Lactobacillus mali on the basis of 16S rRNA gene sequence similarity. Levels of DNA-DNA relatedness revealed genotypic separation of the four isolates from the above two species. The isolates are therefore considered to represent a novel species, for which the name Lactobacillus satsumensis is proposed. The type strain is NRIC 0604T (=JCM 12392T=DSM 16230T).

Alcoholic Beverages↗

PubMed2005

Monitoring the lactic acid bacterial diversity during shochu fermentation by PCR-denaturing gradient gel electrophoresis.

The presence of lactic acid bacteria (LAB) during shochu fermentation was monitored by PCR-denaturing gradient gel electrophoresis (DGGE) and by bacteriological culturing. No LAB were detected from fermented mashes by PCR-DGGE using a universal bacterial PCR primer set. However, PCR-DGGE using a new primer specific for the 16S rDNA of Lactococcus, Streptococcus, Tetragenococcus, Enterococcus, and Vagococcus and two primers specific for the 16S rDNA of Lactobacillus, Pediococcus, Leuconostoc, and Weissella revealed that Enterococcus faecium, Lactobacillus casei, Lactobacillus fermentum, Lactobacillus nagelii, Lactobacillus plantarum, Lactococcus lactis, Leuconostoc citreum, Leuconostoc mesenteroides, and Weissella cibaria inhabited in shochu mashes. It was also found that the LAB community composition during shochu fermentation changed after the main ingredient and water were added during the fermentation process. Therefore, we confirmed that PCR-DGGE using all three primers specific for groups of LAB together was well suited to the study of the LAB diversity in shochu mashes. The results of DGGE profiles were similar to the results of bacteriological culturing. In conclusion, LAB are present during shochu fermentation but not dominant.

Bacteria, Aerobic↗