초록
<P><B>Abstract</B></P> <P>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, <I>Achatina fulica</I> was identified as <I>Bacillus tequilensis</I> based on 16S rRNA gene sequencing. The <I>B. tequilensis</I> G9 produced cellulase with the highest activity of 956.9 IU/ml extract on 8<SUP>th</SUP> 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 Co<SUP>2+</SUP> and Ca<SUP>2+</SUP> at 5 mM concentrations but enhanced by K<SUP>+</SUP> and Mn<SUP>2+</SUP> 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.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A <I>Bacillus tequilensis</I> G9 strain identified by 16S rRNA sequencing was isolated from gut fluid of <I>Achatina fulica.</I> </LI> <LI> SEM analysis revealed a significant degradation of the Filter paper by the <I>Bacillus tequilensis</I> G9. </LI> <LI> The isolate demonstrated the utility of agricultural wastes like grass straw, wheat husk etc, as sole source of energy. </LI> <LI> Isolate showed tolerance to a broad range of pH, temperature and chemicals facilitating effective fermentation process. </LI> <LI> The study validates the snail gut as a potential source for isolation of industrially important bacteria. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>