A plasmid-borne diacetyl (acetoin) reductase (butA) from Leuconostoc pseudomesenteroides CHCC2114 was sequenced and cloned. Nucleotide sequence analysis revealed an open reading frame encoding a protein of 257 amino acids which had high identity at the amino acid level to diacetyl (acetoin) reductases reported previously. Downstream of the butA gene of L. pseudomesenteroides, but coding in the ...

Two 2,3-butanediol dehydrogenases (enzymes 1 and 2; molecular weight of each, 170,000) have been partially purified from Lactococcus lactis subsp. lactis (Streptococcus diacetylactis) D10 and shown to have reductase activity with either diacetyl or acetoin as the substrate. However, the reductase activity with 10 mM diacetyl was far greater for both enzymes (7.0- and 4.7-fold for enzymes 1 and ...

Artificial butter flavoring and two important constituents, diacetyl and acetoin, were nominated by the United Food and Commercial Workers International Union for long-term testing via inhalation for respiratory and other toxicity and for cancer-causing properties. There is growing concern that workers in the microwave popcorn manufacturing industry may be at risk of developing the lung disease...

Diacetyl has been associated with the "buttermilk off-flavor" sometimes found in orange juice and in frozen concentrated orange juice. Bacteria of the Lactobacillus and Leuconostoc genera have been identified as causative agents of this type of spoilage (Hays, 1951; Hays and Riester, 1952; Murdock et al., 1952, 1953; and Hill et al., 1954). Growth rates of these spoilage organisms have been inv...

Artificial butter flavoring and two important constituents, diacetyl and acetoin, were nominated by the United Food and Commercial Workers International Union for long-term testing via inhalation for respiratory and other toxicity and for cancer-causing properties. There is growing concern that workers in the microwave popcorn manufacturing industry may be at risk of developing the lung disease...

ABSTRACT: Kefir is fermented milk that has a unique flavor because of acetaldehyde, diacetyl, acetoin and ethanol. The aim of this study was to evaluate flavor and aroma compounds present in kefir. Two types of starter (Christian Hansen and Sacco) and three levels of temperatures (30, 33 and 35oC) were used for the preparation of kefir samples. The samples were analyzed for acetaldehyde, diacet...

Using Caenorhabditis elegans as an animal model, the possible toxic effects of six insecticides (dinotefuran, thiamethoxam, thiacloprid, nitenpyram, acetamiprid, and sulfoxaflor) commonly used in agriculture on sensory perception were examined. The behaviors thermotaxis, avoidance copper ion, chemotaxis to NaCl, diacetyl measured investigate damage perceptions nematodes exposed examined range m...

Here we describe the design of 1,2-phenylenediamine capturing molecule and the synthesis steps necessary for its preparation. The designed 1,2-phenylenediamine derivative is able to capture diacetyl in solution, as shown by ESIMS, forming a chemical adduct, 1-4-quinoxaline. The methyl esters of diacetyl-adduct (DAA) and pentanedione-adduct (PDA) are incorporated to the lysines in BSA and the co...

A method was developed to screen and isolate mutagenized Lactococcus lactis subsp. lactis biovar diacetylactis strains accumulating (alpha)-acetolactate. This compound is accumulated by (alpha)-acetolactate decarboxylase-deficient strains and undergoes spontaneous degradation into diacetyl on agar plates. The diacetyl produced is detected by a colorimetric reaction yielding a red halo around th...