外源硫诱导下的Desulfovibrio desulfuricans sub sp.EPS特性及对Zn(Ⅱ)的吸附

The EPS characteristics of Desulfovibrio desulfuricans sub sp.and its adsorption performance for Zn(Ⅱ)under exogenous sulfur induction

研究了3种外源硫(Na_(2)SO_(4)、Na_(2)SO_(3)和Na_(2)S_(2)O_(3)·5H_(2)O)对Desulfovibrio desulfuricans sub sp.(D.desulfuricans sp.)的胞外聚合物(EPS)的胁迫/诱导作用.结果表明,在还原性硫源0.50g/L Na_(2)SO_(3)的条件下,EPS产量最高,为2104.39mg/g VSS,蛋白质含量为1888.52mg/g VSS,较胁迫/诱导前均提高了300%以上;其对Zn(Ⅱ)的吸附性能最好,为954.4mg/g EPS,提高了98.17%.三维荧光(3D-EEM)结果表明,胁迫/诱导后EPS中类酪氨酸均大量增加;傅里叶红外光谱(FTIR)结果表明,胁迫后-OH、C=O、C-O-C等官能团均大量增加,在Zn(Ⅱ)的吸附中发挥了重要作用;X光电子能谱(XPS)结果表明,在还原性硫源(Na_(2)SO_(3)和Na_(2)S_(2)O_(3)·5H_(2)O)胁迫/诱导后,EPS中C-O/C-N、C=N和某种含氧基团(X)大量增加,可能是吸附Zn(Ⅱ)的主要基团.

In this paper,the effect of exogenous sulfur(Na_(2)SO_(4),Na_(2)SO_(3),Na_(2)S_(2)O_(3)·5H_(2)O)stress/induction on extracellular polymeric substances(EPS)of Desulfovibrio desulfuricans sub sp.(D.desulfuricans sp.)was studied.The results showed that addition of 0.50g/L Na_(2)SO_(3)led to the highest EPS yield of 2104.39mg/g VSS(1888.52mg/g VSS of protein content),which was 300%higher than that without Na_(2)SO_(3)addition,and as a result,98.17%increase in Zn(Ⅱ)adsorption capacity(954.4mg/g EPS)achieved.Three-dimensional fluorescence(3D-EEM)spectral results showed that tyrosine-like substances in EPS were greatly increased after sulfur stress/induction;Fourier transform infrared spectroscopy(FTIR)results showed that significant increases in functional groups such as—OH,C=O,C—O—C EPS were mainly responsible for the enhance adsorption of Zn(Ⅱ);The results of X-ray photoelectron spectroscopy(XPS)results showed that the content of C—O/C—N,C=N and oxygen-containing functional group(X)in EPS increased after sulfur stress/induction(Na_(2)SO_(3)and Na_(2)S_(2)O_(3)·5H_(2)O).