Cloning and characterization of Enterobacter sakazakii pigment genes and in situ spectroscopic analysis of the pigment

Enterobacter sakazakii is considered an opportunistic foodborne pathogen that is characterized by formation of yellow-pigmented colonies. Because of the lack of basic knowledge about Enterobacter sakazakii genetics, the BAC approach and the heterologous expression of the pigment in Escherichia coli were used to elucidate the molecular structure of the genes responsible for pigment production in Enterobacter sakazakii strain ES5. Sequencing and annotation of a 33.025 bp fragment revealed seven ORFs that could be assigned to the carotenoid biosynthesis pathway. The gene cluster had the organization crtE-idi-XYIBZ, with the crtE-idi-XYIB genes putatively transcribed as an operon and the crtZ gene transcribed in the opposite orientation. The carotenogenic nature of the pigment of Enterobacter sakazakii wt was ascertained by in situ analysis using visible microspectroscopy and resonance Raman microspectroscop

Furan Fatty Acid Photooxidative Degradation Products in Dried Herbs and Vegetables

The influence of light exposure of dried herbs and vegetables on the formation of dimethyl furan fatty acid (DiMeFFA) photooxidative degradation products such as 2,3-butanedione, 2,3-octanedione, 3-methyl-2,4-nonanedione (MND), 3,4-dimethyl-5-pentyliden-2(5H)-furanone (bovolide) and 3,4-dimethyl-5pentyl-2(5H)-furanone (dihydrobovolide) was investigated. To our knowledge, the occurrence of these compounds in tarragon, dill, basil, chervil, chive, leek, savory and onion has hitherto not been reported. The flavour fraction was isolated by simultaneous distillation extraction and analysed by GC-MS. The flavour compounds were determined in relation to the exposure time as peak area ratio to an internal standard

Cloning and characterization of Enterobacter sakazakii pigment genes and in situ spectroscopic analysis of the pigment

ISSN:0378-1097ISSN:1574-6968ISSN:0168-6496ISSN:0920-8534ISSN:0168-644