Waste paper degradation by terrestrial slug: an alternative to manage waste using biological resource.

Paper waste constitutes a major part of municipal solid waste across the globe. Degradation of the paper wastes with the aid of the terrestrial slug Laevicaulis alte (Gastropoda: Veronicellidae) was assessed to deduce the biological degradation of waste paper and subsequent accessibility of cellulose from faecal matter. L. alte was fed three types of paper, i.e. cardboard, newsprint or newspaper, and tissue paper to observe their ability to decompose the waste papers. Among the paper types used in this study, L. alte consumed cardboard at the highest rate (126.31 ± 5.08 mg/individual, mean ± SE) but produced a higher amount of faecal matter when tissue paper was consumed as food (48.82 ± 3.42 mg/individual). The results of the Kruskal-Wallis test indicated significant variation in paper-specific consumption patterns and faecal matter produced by L. alte (K = 94.930, df = 2, p < 0.0001 and K = 103.102, df = 2, p < 0.0001, respectively). The scanning electron micrographs showed prominent grazing and scraping marks by L. alte and the breakdown and relaxation of the consumed paper fibres. The FTIR spectral analysis reflected differences in the degradation states of the three paper types. Apparently, the terrestrial slug L. alte consumed and facilitated the degradation of varied types of waste paper, thereby providing a feasible option to manage the waste and yield cellulose for use in further purposes.