Production of Bacterial Proteins from Cellulosic Materials

An aerobic mesophilic Pseudomonas sp. isolated from activated sludge degraded different cellulosic materials to varying-degrees. The degradability was mostly influenced by the lignin content and the crystalline nature of the substrate. Filter paper and cotton fibres, containing little lignin, were degraded maximally. Lignin-rich Pinus and Larix needles were digested to a lesser extent. There was a difference between natural substrates and substrates that had undergone industrial treatment. At maximal protein production, the isolate converted 11–40% (w/w) of cellulosic substrates into proteins. Alkali treatment of the substrates had only little effect. Cellulose contained in pig-waste was also degraded by the isolate. At first there was a period of protein production, but after long incubation, the efficiency of conversion of cellulose to protein decreased.