Purpose The study aims to search for potent cellulase producer from the gut of Gryllotalpa africana as well as to characterize and determine the effect of the purified enzyme on the cellulosic waste materials. Methods The potent cellulolytic strain was identified through morphological, biochemical, physiological, and molecular characterization like 16S rRNA and fatty acid methyl ester profile. After the optimization of cellulase production, the enzyme was purified through DEAE-Sepharose column chromatographic separation. The molecular weight of the purified enzyme was determined by SDS-PAGE analysis. The purified enzyme was characterized in terms of its activity and its effect on cotton fiber, and sawdust was also studied. Result The selected potent strain GAC 16.2 was identified as Acinetobacter junii that was capable to produce enhanced cellulase (112.38 ± 0.87 U/ml) at standardized optimum fermentation conditions. The molecular weight of the purified enzyme was determined as 55 kDa. The utmost activity of the purified enzyme was detected pH 7.0, temperature 50 °C, and in the presence of metal ions like Mg2+ and Mn2+. The substantive degradation of cotton fiber and sawdust has been observed in a reasonably short period. Conclusion Purified cellulase from the selected isolate A. junii GAC16.2, a gut isolate of G. africana, has the potentiality to degrade cellulosic substances. This property can make the isolate a potent candidature for industrial application, as well as an effective biotechnological tool for environmental monitoring through cellulosic waste management.