Nitrite and Formaldehyde Formation in Certain Algae.

I. Photochemical reduction of nitrate to nitrite within the algal cell For a number of years there has been disagreement on the question as to whether or not light plays an important part in the reduction of nitrate to nitrite by the green plant. Some investigators, including NIGHTINGALE (12, 13, 14), THOMAS (16), ECKERSON (7, 8, 9, 10), MUENSCHER (11), and ANDERSON (4), have presented evidence that some reduction may take place without light. In much of the work the presence of nitrate-reducing microorganisms was not ruled out. Moreover, in some of the experiments the reducing action was studied by testing for nitrite formed by adding nitrate to the expressed juice of plants. This procedure brings about contact between nitrates and other compounds that might not occur in the intact plant. A method which will detect the presence of, and an increase in, nitrite in a short period of time and without destroying the plant would give more conclusive evidence. It is believed that such a method was used in the work presented in this paper.