Which of the following/(s) can be used for the reduction of nitrate in waste water?

• A. Growth of Hypomicrobium in presence of added methanol
• B. <i>Micrococcus denitrificans</i>
• C. cells encapsulated in liquid membranes
• D. Both (a) and (b)
• E. <i>Nitrosomonas europaen</i>