不同基质条件下透性处理对脱硫弧菌硫酸盐还原活性的影响

Effect of Permeabilization on Sulfate Reduction Activity of Desulfovibrio vulgaris Hildenborough Cells in the Presence of Different Electron Donors

乙醇透性处理1株普通脱硫弧菌Desulfovibrio vulgaris Hildenborough(DvH)强化硫酸盐生物还原活性,研究不同基质条件下透性处理程度对其硫酸盐还原活性影响.当以H2为电子供体时,10%乙醇处理的DvH硫酸盐还原活性最强,其次为15%;当乙醇浓度>15%时,DvH硫酸盐还原活性显著降低.当以乳酸为电子供体时,最佳乙醇浓度为20%,其次为15%和10%,乙醇浓度达到25%时,DvH仍保持一定的还原活性.不同供体条件下DvH对透性处理程度的响应不同,是因为H2与乳酸在细胞内发生氧化的位置不同,从而胞内电子传递途径不同.确保供体与受体之间电子传递链的完整性是合理确定透性处理程度及透性技术应用的关键.

The Desulfovibrio vulgaris Hildenborough（DvH） cells permeabilized with ethanol were used as biocatalysts to enhance hydrogenotrophic sulfate conversion.The effect of permeabilization extent of DvH cells on sulfate reduction was studied in the presence of different electron donors.When hydrogen was used as an electron donor,the highest level of sulfate reduction activity attained in cells treated with 10% ethanol（V/V）,followed by 15%-ethanol treated cells.Furthermore,sulfate reduction activity markedly decreased when the ethanol concentration exceeded 15%.However,when lactate was used as the electron donor,the optimum ethanol concentration of the permeabilizing reagent was 20%,followed by 15% and 10%.Even when ethanol concentration reached 25%,DvH cells remained their partial activity with lactate.In a word,sulfate reduction activity of DvH cells responded differently in the presence of different donors.This was because the oxidation process of H2 and lactate occurred at different positions in DvH cells,and consequently intracellular electron transport pathway differed.To ensure the integrity of the electron transport chain between the donor and the accepter was a key factor for determining the permeabilization extent and for the application of cell permeabilization technology.