7/24/2019 Lysine Production From Methanol

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Lysine Production From MethanolMethylotrophs, microorganisms that use reduced onecarboncompounds, are diverse and ubiquitous. Even though many methylotrophs have beendescribed,only a few are gram positive. The industrial advantages of using methanol as a substrate forlargescale

production of fermentation products have been outlinedby other groups. Methanol is relatively inepensive, prices are relatively stable, productioneceeds demand, and it is easily stored and transported. !n addition,methanol is available in pure form, it is highly soluble in water, methanol solutions are noteplosive, and residual methanol can be easily removed fromproducts after fermentation is completed. Bacillus species have been used etensively inindustrial fermentation processes, but little information has beenpublished on the isolation of Bacillus species capable of rapid growth on methanol attemperatures above "# o$.The nutritionally important amino acid Llysineis a member of the aspartate family of amino acids and is primarily used in supplements foranimal feeds made

from grains that contain only limited quantities of Llysine.Poultry, swine, and other livestoc% are unable to synthesi&e Llysineand therefore must have thisamino acid supplied as part of their diet. $urrently, Llysineis being manufactured by either direct fermentation, or en&ymatic conversion of'Laaminoecaprolactam.Fermentations that use strains of Corynebacterium glutamicum or Brevibacteriumlactofermentum with molasses or starch hydrolysate asfeedstoc%s have become the ma(or method of Llysineproduction.$E)Tech has eperience with a pro(ect involving the isolation, characteri&ation, growth andLlysineproduction from, a grampositive

endosporeformingmethylotroph that grew rapidly on methanol at *# o$. The organism discovered waseventually named Bacillus methanolicus. Mutants of this newly discoveredmethylotroph that were homoserine auotrophs and +-aminoethylcysteine/E$ resistant, were found capable of secreting significant amounts of the aminoacid Llysine.Figures 0 1below show much of the run data generated during fermentations using homoserineauotrophic and amino acid analogresistantmutants of Bacillus methanolicus.