Influence of medium composition and environmental conditions on production of (S)-adenosyl-L-methionine by wild strain of Pichia stipitis and mutant strain M12

(S)-adenozil-L-metionin, poznat kao SAMe, prisutan je u svim stanicama i igra bitnu ulogu u metabolizmu. Sudjeluje u više od sto različitih bioloških reakcija, prvenstveno kao donor metilne skupine. Nastaje od metionina i adenozin-trifosfata djelovanjem enzima metionin-adenoziltransferaze. Nedostatak SAMe u ljudskom organizmu uzrokuje poremećaje u funkcioniranju jetre, živčanog i imunološkog sustava. Komercijalno se proizvodi izolacijom iz kvaščevih stanica koje rastu na hranjivoj podlozi bogatoj L-metioninom. Mutanti dobiveni ultraljubičastim svjetlom i rezistentni na nistatin imaju promijenjen sastav sterola u staničnoj membrani, odnosno mogu nakupljati SAMe koji se ne iskoristi u biosintezi ergosterola. Cilj rada bio je proučiti utjecaj sastava podloge i uvjeta okoline na proizvodnju SAMe pomoću divljeg soja kvasca Pichia stipitis i mutiranog soja M12 pri aerobnom uzgoju u glukoznoj podlozi. Rezultati istraživanja pokazuju da je najveća količina SAMe proizvedena s mutiranim sojem M12 u 48-om satu uzgoja (44,88 mg g-1 s.tv.kvasca) s dodatkom 7,5 gL-1 D,L-metionina, pri temperaturi od 30oC i pH vrijednosti 5.(S)-adenosyl-L-methionine, also known as SAMe, is present in all cells and plays an essential role in metabolism. It participates in more than one hundred different biological reactions, primarily as a methyl group donor. SAMe is synthesized from methionine and adenosine triphosphate (ATP) by methionine adenosyltransferase. Deficiency of SAMe in humans can be manifested through various dysfunctions of liver, immunological and nervous system. SAMe is commercially produced by isolation from yeast cells grown in media with L-methionine. Mutants resistant to nystatin obtained by ultraviolet radiation, have altered sterol composition cellular membrane and can accumulate SAMe that is not utilized in ergosterol biosynthesis. The aim of this work was to determine the influence of medium composition and environmental conditions on the production of SAMe in the wild strain of Pichia stipitis and mutant strain M12 grown aerobicaly in glucose media. The maximal SAMe accumulation was achieved by M12 mutant strain in 48th hour of cultivation (44.88 mg g-1 dry cells) with the addition of 7.5g L-1 D,L-methionine, at temperature of 30° C and pH value 5