Pyrazines Bacillus subtilis

Another unusual rearrangement is performed by Bacillus subtilis during the catabolism of sepiapterin (237), in converting the whole side-chain with subsequent oxidation of the pyrazine ring into 6-(l-carboxyethoxy)pterin (238 equation 75). 

Scheme 23.22 Some nitrogen-containing flavour compounds produced by microorganisms, a Methylanthranilate formation from N-methyl methylanthranilate 1 Trametes sp., Polyporus sp. b Different pyrazines produced with microorganisms in optimised media 2 mutant strain from Pseudomonas perolens ATCC 10757 3 Bacillus subtilis, Brevibacterium linens 4 mutant strain of Corynebacterium glutamicum...

The most abundant pyrazine identified in cocoa butters was tetramethylpyrazine, which existed at an extremely high concentration in the unroasted cocoa butter but only a moderate level in the roasted cocoa butter. Tetramethylpyrazine accounted for over 90% of the pyrazine content of the unroasted cocoa butter. Besides thermal generation, tetramethylpyrzine could be formed in cocoa beans through biosynthetic reactions. Kosuge and Kamiya (38) identified tetramethylpyrazine as a metabolic product of a strain of Bacillus subtilis. Several species of this organism were identified in a fermenting mass of cocoa beans by Ostovar (39). 

Bacillus subtilis Corynebacterium glutamicum Tetramethyl pyrazine Nutty... 

Kosuge Takuo. and Kamiya H. (1962) Discovery of a pyrazine in a natural product tetramethylpyrazine from cultures of a strain of Bacillus subtilis. Nature (London) 193, 776. 

Pyrazines are generally associated with nonenzymatic browning. However, pyrazines have also been found as a result of microbial action. Bacillus subtilis was the first organism found to produce a pyrazine (tetramethyl pyrazine [105]). Since that time, several pyrazines (2-acetyl, dimethyl, 2-methoxy-3-ethyl, 2,5 or 2,6-diethyl-3-methyl, trimethyl, tetramethyl, and trimethyl pyrazine) have been identified in aged cheese [16,106-109]. While some of these pyrazines may be formed via the Maillard reaction during aging of the cheese, it is likely that they were formed via microbial action. 

Pyrazines occur naturally, although not in appreciable quantities. Fusel oil contains 2,5-dimethyl-, 2,5-diethyl-, trimethyl-, and tetra-methylpyrazine. The last compound has been isolated from cultures of Bacillus natto and B. subtilis and from fermented soybeans.4-6 Emimycin (pyrazine-2-one-4-oxide), a powerful antibiotic, has been obtained from Streptomyces No. 2020-1.7,8... 

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