Influence of medium composition on (S)-adenosyl-L-methionine and ergosterol content in biomass of the wild yeast strain Pichia stipitis and mutant M12

(S)-adenozil-L-metionin (SAMe) biološki je aktivna molekula koja sudjeluje u brojnim biokemijskim reakcijama. Njezin manjak ili prekomjerna količina u organizmu mogu uzrokovati različita oboljenja. Budući da se SAMe koristi pri liječenju bolesti jetre, depresije i osteoartritisa, vrlo je važno pronaći učinkovitije načine proizvodnje te tvari. S ciljem proizvodnje SAMe, uzgajana je biomasa divljeg soja kvasca Pichia stipitis i mutiranog soja M12. Cilj ovog rada bio je istražiti utjecaj sastava hranjive podloge na stanični rast, te sadržaj SAMe i ergosterola u stanicama ispitivanih kvasaca. Oba su soja pokazala bolji rast i proizvodnju SAMe u hranjivoj podlozi u koju su dodane magnezijeve i kalijeve soli, u usporedbi s podlogom koja ne sadrži te soli. Također, mutirani soj uzgojen u hranjivoj podlozi s dodatkom soli proizveo je znatno više SAMe u usporedbi s divljim kvascem. Tako je mutirani soj proizveo 48,12 mg g-1 (SAMe / s. tv.), dok je s divljim sojem postignuto svega 26,05 mg g-1. Također je potvrđeno da je divlji soj P. stipitis tolerantniji prema etanolu u odnosu na mutant M12.(S)-adenosyl-L-methionine (SAMe) is an important bioactive molecule which participates in a number of biochemical reactions. Its absence or extortionate amount in organism can cause different diseases. Since this substance is used in treatment of liver diseases, depression and osteoarthritis, it's very important to find more efficient ways of SAMe production. In order to produce SAMe, wild yeast strain Pichia stipitis and mutant strain M12 were used. The aim of this work was to investigate the influence of medium composition on cell growth, ergosterol and SAMe content in yeasts cells. Both strains showed better growth and SAMe production in medium which contains magnesium and potassium salts, compared to medium which doesn’t contain these salts. Also, mutant strain growing on medium supplemented with salts produced much more SAMe compared to wild strain. 48,12 mg g-1 (SAMe / dry weight) was achieved with mutant strain, and only 26,05 mg g-1 with wild strain. It was also confirmed that wild strain P. stipitis has a better ethanol tolerance than mutant strain M12