The sake yeast YHR032W/ERC1 allele contributes to the regulation of the tetrahydrofolate content in the folate synthetic pathway in sake yeast strains.

To elucidate the mechanism underlying tetrahydrofolate (THF) accumulation in sake yeast strains compared with that in laboratory yeast strains, we performed a quantitative trait locus (QTL) analysis. The results revealed that the sake yeast ERC1 allele contributes to an increase in the ratio of THF to the total folate content in sake yeast.

Breeding of a cordycepin-resistant and adenosine kinase-deficient sake yeast strain that accumulates high levels of S-adenosylmethionine.

Adenosine kinase (ADO1)-deficient mutants can be obtained from cordycepin-resistant strains, and the disruption of ADO1 causes S-adenosylmethionine (SAM) accumulation. To breed a high-SAM-accumulating yeast strain without genetic manipulation for industrial purposes, we bred a cordycepin-resistant strain using sake yeast kyokai No. 9 as the parent strain with a mutation in adenosine kinase (ADO1) and acquired high-SAM-accumulating strain. In the bred strain (NY9-10), a single mutation (T258I) was present in the ADO1, and this mutation site is an ATP binding site and is highly conserved during evolution. Moreover, it was suggested that high accumulation of SAM and cordycepin resistance in NY9-10 was due to functional deficiency of ADO1 by this mutation. This strain is not a genetically-modified organism and can be employed for use in the food and medicine industry such as mass production and sake making.

Pneumatosis cystoides intestinalis induced by the α-glucosidase inhibitor miglitol.

Pneumatosis cystoides intestinalis (PCI) is a rare condition in which pneumocysts develop in the submucosa or subserosa of the colon. We report herein a case of PCI induced by the alpha-glucosidase inhibitor (alphaGI) miglitol. There have been 9 recorded cases of PCI induced by other alphaGIs, but this is the first report of miglitol causing PCI. The PCI lesions in our case were smaller than those induced by voglibose or acarbose. The possibility of PCI should be considered in diabetic patients on alphaGI therapy who complain of gastrointestinal symptoms, and the gastrointestinal tract should be thoroughly investigated in these patients.

Novel angiotensin-converting enzyme (ACE) inhibitory peptides derived from boneless chicken leg meat.

Four peptides that inhibit angiotensin-converting enzyme (ACE) were separated from the hydorlysate of boneless chicken leg meat digested with artificial gastric juice (pepsin). Two peptides were identified as the peptides encrypted in myosin heavy chain. The peptide P1 (MNVKHWPWMK) corresponds to the amino acid sequence from amino acids 825 to 834 of myosin heavy chain, and the peptide P4 (VTVNPYKWLP) corresponds to the amino acid sequence from amino acids 125 to 135 of myosin heavy chain. They are novel ACE inhibitory peptides derived from chicken, and IC(50) values of P1 and P4 were determined as 228 and 5.5 microM, respectively. Although these values were much larger than 0.022 microM for captopril, a typical synthetic ACE inhibitor, they are comparable to IC(50) values reported for various ACE inhibitory peptides derived from foods. Because the peptide P4 has a relatively low IC(50) value, it is a good starting substance for designing food supplements for hypertensive patients.