ABSTRACT
There exist a number of mercury-resistant bacterial in environment, Mer operon is involved in the resistant mechanism, MerRTPA of Mer operon encodes the proteins related to the regulation, transport and reduction of mercury ion, respectively. The toxic mercury ion is transported by MerTP from medium to cytoplasmic mercuric reductase, MerA, and deoxidized to non-toxic and volatile element mercury, Hg(0). Bacterial mercury-resistant system originated from ancient times, and evolved into the Mer operon with diversity by gene integration and insertion. Mercury-resistant bacteria highly specifically absorb mercury ion, and can be used in recovering the mercury-polluted environment as well as the genetic selective marker.
ABSTRACT
Fermentation condition optimization of P. decumbens Ju-A10 for production of CMCase using three kinds of plant cellulosic wastes as carbon sources was made using RSA method. The result was that CMCase was the highest when the level of carbon source was 9. 77 % , 8. 69 % and 9. 97% , and liquid volume was 64. 7 mL, 54. 2 mL, 40. 8 mL for carbon sources of millet straw, wheat straw and paper sludge, respectively. The value of CMCase was 29. 26IU/mL, 29. 14 IU/mL, 29. 81 IU/mL, respectively, in the above cases. The value of R2 is 0. 9117 , 0. 9246, 0. 8655 , respectively. It could be concluded that the fermentation models were quite reliable. The method can be applied in optimization of fungi fermentation medium.