Prospecting the gut fluid of giant African land snail, Achatina fulica for cellulose degrading bacteria

Abstract The rapidly increasing human population poses a serious risk of fast depletion of natural resources like fossil fuels. Therefore, production of ecofriendly renewable alternatives like biofuels from waste materials has sparked more curiosity from the industrialists as well as academicians. Similarly, production of bioenergy from agricultural wastes is gaining interest worldwide. In view of the above objective, cellulose degrading bacterium G9-KDP isolated from the crop fluid of giant African land snail, Achatina fulica was identified as Bacillus tequilensis based on 16S rRNA gene sequencing. The B. tequilensis G9 produced cellulase with the highest activity of 956.9 IU/ml extract on 8th day of incubation when grown in BMS medium induced by sugarcane bagasse. The optimal temperature and pH of the organism were 60 °C and 6.6, respectively. It was observed that the activity of crude enzyme was affected to various extents by different metal ions. The activity was inhibited by Co2+ and Ca2+ at 5 mM concentrations but enhanced by K+ and Mn2+ ions. However, EDTA at 1% concentration increased the activity by 94% while SDS reduced it by 57% at the same concentration. Scanning electron microscopy of the filter paper used as substrate revealed significant structural modifications after the treatment with bacteria. The degradation of the various cellulosic compounds into simpler sugars by this isolate brands its potential applications in industrial biotechnology.