No abstract

Three novel strains isolated from brewery environments are described. These strains were Gram-positive, facultatively anaerobic, heterofermentative rods that did not exhibit catalase activity. Phylogenetic analysis based on 16S rRNA gene sequence similarity showed that these strains belong to the genus Lactobacillus and are most closely related to Lactobacillus collinoides (approximately 99 % similarity). The novel strains could be differentiated from L. collinoides on the basis of DNA-DNA relatedness, differences in beer-spoilage ability and the inability to utilize D-fructose. These isolates represent a novel species, for which the name Lactobacillus paracollinoides sp. nov. is proposed. The type strain is LA2 T (=DSM 15502 T =JCM 11969 T ).

MPD1, a yeast gene the overexpression of which suppresses the inviability caused by the loss of protein disulfide isomerase (PDI) was isolated and characterized. The MPD1 gene product retained a single disulfide isomerase active site sequence (APWCGHCK), an N-terminal putative signal sequence, and a C-terminal endoplasmic reticulum (ER) retention signal, and was a novel member of the PDI family. The gene product, identified in yeast extract, contained core size carbohydrates. MPD1 was not essential for growth, but overexpression of the gene suppressed the maturation defect of carboxypeptidase Y caused by PDH deletion, indicative of the related function to PDI in the yeast ER.