The life and times of yeasts in traditional food fermentations

Yeasts are eukaryotic microorganisms which have a long history in the biotechnology of food production, as they have been used since centuries in bread-making or in the production of alcoholic beverages such as wines or beers. Relative to this importance, a lot of research has been devoted to the study of yeasts involved in making these important products. The role of yeasts in other fermentations in association with other microorganisms - mainly lactic acid bacteria - has been relatively less studied, and often it is not clear if yeasts occurring in such fermentations are contaminants with no role in the fermentation, spoilage microorganisms or whether they actually serve a technological or functional purpose. Some knowledge is available for yeasts used as starter cultures in fermented raw sausages or in the production of acid curd cheeses. This review aimed to summarize the current knowledge on the taxonomy, the presence and potential functional or technological roles of yeasts in traditional fermented plant, dairy, fish and meat fermentations.

Virgibacillus phasianinus sp. nov., a halophilic bacterium isolated from faeces of a Swinhoe's pheasant, Lophura swinhoii

A rod-shaped, Gram-stain-positive, motile and aerobic bacterium, designated LM2416^T, was isolated from faeces of Lophuras winhoii living in Seoul Grand Park, Gyeonggi-do, Republic of Korea. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain LM2416^T belonged to the genus Virgibacillus, sharing high 16S rRNA gene sequence similarities to Virgibacillus necropolis LMG 19488^T (99.0 %), Virgibacillus carmonensis LMG 20964^T (98.4 %), Virgibacillus arcticus Hal 1^T (98.3 %) and Virgibacillus flavescens S1-20^T (97.9 %). The isolate grew at 10-30 °C, pH 6-7 and 0-20 % (w/v) NaCl. Optimal growth was observed at 30 °C, pH 6-7 and 10 % (w/v) NaCl. The major fatty acid was anteiso-C15 : 0. Polar lipids were composed of phosphatidylglycerol, diphosphatidylglycerol, three unknown phospholipids and two unknown aminophospholipids. The main menaquinone was MK-7. Strain LM2416^T had alanine, lysine, glutamic acid, glycine and aspartic acid as cell-wall amino acids and ribose as a cell-wall sugar. The whole genome sequences of strain LM2416^T and V. necropolis KCTC 3820^T were sequenced by PacBio RS II sequencing. The genome sequence-based G+C content of strain LM2416^T was 39.5 mol%. The orthologous average nucleotide identity value, showing genetic relatedness between strain LM2416^T and V. necropolis KCTC 3820^T, was 78.3 %. Based on the phylogenetic, biochemical, chemotaxonomic and genotypic data presented in this study, strain LM2416^T is considered to represent a novel species of the genus Virgibacillus, for which the name Virgibacillus phasianinus is proposed. The type strain is LM2416^T (=KCTC 33927^T=JCM 32144^T).