Isolation of cellulolytic bacteria from the gastro-intestinal tract of Achatina fulica (Gastropoda: Pulmonata) and their evaluation for cellulose biodegradation Mudasir A. Dar a , Kiran D. Pawar b, * , Jyoti P. Jadhav b , Radhakrishna S. Pandit a a Department of Zoology, University of Pune, Ganeshkhind, Pune 411007, Maharashtra, India b Department of Biotechnology, Shivaji University, Vidyanagar, Kolhapur 416004, Maharashtra, India article info Article history: Received 17 July 2014 Received in revised form 24 November 2014 Accepted 24 November 2014 Available online Keywords: Achatina fulica Gastro-intestinal tract Bacteria CMC 16S rDNA Cellulases abstract Gastrointestinal tract of Giant African snail, Achatina fulica was investigated as a source for isolation of cellulose degrading bacteria. The cellulose degrading bacteria from different gastrointestinal tract re- gions such as esophagus, crop, stomach, intestine and rectum were enriched in carboxymethyl cellulose and identified. Thirty two cellulose degrading bacteria belonging to two major phyla namely Proteo- bacteria and Firmicutes were enriched, isolated and identified by 16S rDNA amplification and sequencing. Based on plate based assay, 18 of these isolates displayed cellulase activity and were iden- tified as the members of Bacillus, Achromobacter, Ochrobactrum and Klebsiella. Among the 18 isolates, 5 isolates with high activity were further studied for various enzyme activities such as endoglucanase, exoglucanase and xylanase on different lignocellulosic substrates. Isolate identified as Ochrobactrum sp. K38 exhibited the highest CMCase activity (501.75 IU/ml extract) after 14 days of incubation. The highest avicelase activity (3116.92 IU/ml extract) was shown by Bacillus subtilis Cf60 on Filter paper as substrate after 10 days of incubation whereas all other isolates showed a low xylanase activity on all tested substrates except filter paper. The present study demonstrates the utility of snail gut as a rich source for isolation of cellulose degrading bacteria that can have many industrial applications. © 2014 Elsevier Ltd. All rights reserved. Introduction Interest in bioenergy has been sharply increasing from the onset of 21st century due to the necessity of sustainable economies and clean environments (Lynd et al.,1991, 2008; Sun and Scharf, 2010). Moreover drawbacks of fossil fuels like global warming and non- renewability are motivating research into optimizing new sus- tainable sources of energy from biological origin (Stern, 2006; Vert es et al., 2006; Escobar et al., 2009). Currently, the second generation biofuels such as bioethanol, biodiesel, bio-hydrogen and methane etc., are increasingly been produced from lignocellulosic wastes (LCW) rather than from energy crops such as Jatropha, Switchgrass, hybrid Poplar and Willow. This is because of the foodefuel conflicts related to energy crops (Mtui, 2009). Furthermore, the idea of producing biofuels from bio-wastes comes naturally as a promising alternative solution for problems related to much-feared energy crisis, waste disposal management problems and will thus be helpful in the upliftment of the rural population. In nature, lignocellulosic (LC) biomass is degraded with the cooperation of many microorganisms, mainly including diverse fungal and bacterial genera producing a variety of cellulolytic and hemi-cellulolytic enzymes under aerobic and anaerobic conditions (Kumar et al., 2008). Over the years, cellulase-producing bacteria have been isolated from a wide variety of sources such as com- posting plants, decaying plant material from forestry or agricultural waste, the feces of ruminants, soils and organic matter (Lynd et al., 1991) and guts of animals etc. Herbivorous animals lack the capacity to degrade down ligno- cellulose themselves and instead rely upon the gut microbial community having this repertoire. The invasive Giant African Snail (GAS), Achatina fulica is one of such animals which specifically feed on lignocellulosic plant material. A. fulica is most destructive pest, ranked 2 nd among the 100 worst alien invasive species (Anon., 2013). Despite the economic and ecological importance of snails * Corresponding author. Tel.: þ91 (0) 2312609365; fax: þ91 (0) 2311691533. E-mail addresses: muddar7@gmail.com (M.A. Dar), kdp308965@yahoo.co.in, pawarkiran1912@gmail.com (K.D. Pawar), jpj_biochem@unishivaji.ac.in (J.P. Jadhav), rspandit@unipune.ac.in (R.S. Pandit). Contents lists available at ScienceDirect International Biodeterioration & Biodegradation journal homepage: www.elsevier.com/locate/ibiod http://dx.doi.org/10.1016/j.ibiod.2014.11.016 0964-8305/© 2014 Elsevier Ltd. All rights reserved. International Biodeterioration & Biodegradation 98 (2015) 73e80