Enrichment and Identification of Cellulolytic Bacteria from the Gastrointestinal Tract of Giant African Snail, Achatina fulica

Abstract

The cellulolytic bacterial community structure in gastrointestinal (GI) tract of Achatina fulica was studied using culture-independent and -dependent methods by enrichment in carboxymethyl cellulose (CMC). Culture-dependent method indicated that GI tract of snail was dominated by Enterobacteriaceae members. When tested for cellulase activities, all isolates obtained by culture-dependent method showed both or either of CMCase or avicelase activity. Isolate identified as Citrobacter freundii showed highest CMCase and medium avicelase activity. Sequencing of clones from the 16S rRNA gene clone library identified ten operational taxonomic units (OTUs), which were affiliated to Enterobacteriaceae of phylum Gammaproteobacteria. Of these ten OTUs, eight OTUs closely matched with Enterobacter and Klebsiella genera. The most abundant OTU allied to Klebsiella oxytoca accounted for 70 % of the total sequences. The members of Klebsiella and Enterobacter were observed by both methods indicating their dominance among the cellulolytic bacterial community in the GI tract of the snail.

Compositional and predicted functional analysis of the gut microbiota of Radix auricularia (Linnaeus) via high-throughput Illumina sequencing

“…Huang, Sheng & Zhang (2012) reported that 70% of the isolated cellulolytic bacteria from the gut of Holotrichia parallela larvae were Proteobacteria, and some of the cellulolytic bacteria belonged to Actinobacteria, Firmicutes, and Bacteroidetes, which is similar to the findings of our study. The genera Klebsiella and Enterobacter were found in the A. fulica gut at a dominant position among the cellulolytic bacterial community; however, they were not found in our study (Pawar et al, 2015). Paracoccus , may not only be important cellulolytic bacteria as described above, but also have been found to be a potential bacteria for bioremediation of PAHs-contaminated soils (Teng et al, 2010).…”

“…Gut bacterial communities play an important role in the digestion of cell walls and plant lignocelluloses because of the presence of glycoside hydrolases (Morrison et al, 2009). Many bacteria found in our study, such as Paracoccus , Pseudomonas , Aeromonas , Stenotrophomonas , Citrobacter , Bacillus , Micrococcus , Devosia , Shinella , and Rhizobium , have previously been identified as cellulolytic species, associated with carboxymethyl cellulase (CMCase) activity or avicelase activity (Huang, Sheng & Zhang, 2012; Saha et al, 2006; Pawar et al, 2015). Paracoccus , Pseudomonas , and Aeromonas were predominant bacteria in R. auricularia , indicating that they might be important for the cellulose degradation process.…”

“…Beyond their own digestive enzymes, snails also utilize vast amounts of additional enzymes, secreted by bacterial activity within their gut, which assists in the digestion of up to 60–80% of the consumed plant fiber (Charrier et al, 2006). Cellulase secreted by snail gut bacteria is also used for industrial processes, including the production of biofuels from plant feedstocks (Cardoso et al, 2012a; Pinheiro et al, 2015; Pawar et al, 2015). Their use is more economic and eco-friendly than the use of acid hydrolysis and thermochemical methods (Hamelinck, Van Hooijdonk & Faaij, 2005).…”

The Gut-Associated <i>Klebsiella</i> Sp. of the Apple Snail Produces Multiple Polysaccharide Degrading Enzymes

“…Similarly Klebsiella sp. observed in GI tract of giant snails degraded only CMC 19 . However, Bacillus sp.…”

Screening Cellulolytic Bacteria from the Digestive Tract Snail (Achatina fulica) and Test the Ability of Cellulase Activity

“…Terrestial gastropods like snail, feed primarily on vascular plants. This snail also participates, with other soils invertebrates, in the decomposition of leaf litter (Pawar et al, 2015). Part gut / digestive snail further blended and reconstituted in sterile distilled water to make serial dilutions.…”