Draft Genome Sequences and Genomic Analysis for Pigment Production in Bacteria Isolated from Blue Discolored Soymilk and Tofu

Abstract

Cold-tolerant bacteria are known to contaminate and cause defects in refrigerated foods. Defects in food products can be observed as changes in appearance, texture, and/or flavor that detract from the product's intended look, feel, or taste. Two distinct organisms were cultured from blue pigmented soymilk and tofu that had been left opened and expired in a home refrigerator. The blue coloration was reproduced when isolates were cultured in fresh, sterile soymilk. These strains also produced a variety of colony color morphologies when cultured on different media types. We report two draft genome sequences of the potential causative agents of blue discoloration of soy foods, Pseudomonas carnis strains UCD_MED3 and UCD_MED7 as well as the 16S rRNA gene sequences of co-occurring strains isolated from the defective soy samples but that did not cause blue discoloration when cultured in fresh soymilk; Serratia liquefaciens strains UCD_MED2 and UCD_MED5.

Co-occurrence of VIM-positive non-aeruginosa Pseudomonasspp. andPseudomonas aeruginosain the hospital: A detailed molecular comparison ofblaVIM-2-containing plasmids from environmental and clinical isolates

“…P. carnis is a newly-described environmental species involved in the food spoilage of meat and soy products, but it has never before been reported to cause human infection or carry bla VIM (Lick et al ., 2020; De León et al ., 2021). P. oleovorans is considered an environmental isolate, and in only rare cases has caused infections in immunocompromised individuals (Faccone et al ., 2014; Gautam et al ., 2015).…”

Genome sequencing and multifaceted taxonomic analysis of novel strains of violacein-producing bacteria and non-violacein-producing close relatives

“…Growth phenotypes are of particular interest because they help better understand the selective forces that may have shaped the history of a particular organism and also because they provide insights into an organism's niche and how to work with it in the lab [60]. Many bacteria carry genes that are only expressed under certain circumstances, such as virulence factors regulated through quorum sensing and genes involved in pigment production being influenced by temperature variation [62,63]. Although it is doubtful that individual phenotypes or small collections of phenotypes can consistently and correctly represent evolutionary relationships [64], organisms are described in phenotypic terms, and the descriptions help define a taxonomic group that may also be recognized at the phylogenetic level [65].…”