The feasibility of using nitrite-accelerated photodegradation as a pretreatment for waste cellulose before converting the cellulose to protein was investigated. The substrates used were cotton linters paper and purified wood cellulose. The method employed was to irradiate the dry paper or a slurry of the cellulose in an aqueous solution with ultraviolet light, from lamps. The indicated cellulose materials were irradiated for selected time intervals, and the average degree of polymerization (and hence, the degree of degradation) was determined from their intrinsic viscosities in cadoxene solutions. Although some of the photochemical pretreatments showed beneficial effects in accelerating bacterial protein production, the quantum efficiencies did not appear to be sufficiently high to be of practical value for treatment of cellulosic wastes. Significant benefits, however, could possibly be obtained by less costly chemical treatments. (Author)