Increased ethanol accumulation from glucose via reduction of ATP level in a recombinant strain of Saccharomyces cerevisiae overexpressing alkaline phosphatase
메타 데이터
바이오화학분류
바이오플라스틱
플라스틱
바이오정밀화학
용매
화학제품
연료
화장품용 기능성소재
계면활성제⁄증점제
의료용 화학소재
식품첨가제
논문
Increased ethanol accumulation from glucose via reduction of ATP level in a recombinant strain of Saccharomyces cerevisiae overexpressing alkaline phosphatase
학술지
BMC biotechnology
저자명
Semkiv, Marta V; Dmytruk, Kostyantyn V; Abbas, Charles A; Sibirny, Andriy A
초록
<P><B>Background</B></P><P>The production of ethyl alcohol by fermentation represents the largest scale application of <I>Saccharomyces cerevisiae</I> in industrial biotechnology. Increased worldwide demand for fuel bioethanol is anticipated over the next decade and will exceed 200 billion liters from further expansions. Our working hypothesis was that the drop in ATP level in <I>S. cerevisiae</I> cells during alcoholic fermentation should lead to an increase in ethanol production (yield and productivity) with a greater amount of the utilized glucose converted to ethanol. Our approach to achieve this goal is to decrease the intracellular ATP level via increasing the unspecific alkaline phosphatase activity.</P><P><B>Results</B></P><P>Intact and truncated versions of the <I>S. cerevisiae PHO8</I> gene coding for vacuolar or cytosolic forms of alkaline phosphatase were fused with the alcohol dehydrogenase gene (<I>ADH1</I>) promoter. The constructed expression cassettes used for transformation vectors also contained the dominant selective marker <I>kanMX4</I> and <I>S. cerevisiae</I> δ-sequence to facilitate multicopy integration to the genome. Laboratory and industrial ethanol producing strains BY4742 and AS400 overexpressing vacuolar form of alkaline phosphatase were characterized by a slightly lowered intracellular ATP level and biomass accumulation and by an increase in ethanol productivity (13% and 7%) when compared to the parental strains. The strains expressing truncated cytosolic form of alkaline phosphatase showed a prolonged lag-phase, reduced biomass accumulation and a strong defect in ethanol production.</P><P><B>Conclusion</B></P><P>Overexpression of vacuolar alkaline phosphatase leads to an increased ethanol yield in <I>S. cerevisiae</I>.</P>