Constructing and Screening Beta-Glucanase Activityof Metagenomic cDNA Expression Library ofDigestive Gland of Achatina fulica

Digestive juice of Achatinafulica shows hydrolase activities which are useful as an antibiofilm. Insidethe digestive system of snail many microorganisms live together as a normal flora.In this study, a metagenomicbased-activity technique was carried out to construct the metagenomic expression library of digestive gland ofAchatinafulica. The metagenomic library was screened for the recombinant harbouring genes encoding beta-glucanase again the specific substrate of laminarin.The metagenomic cloning was carried out by using λTriplEx2 as vector and E.coli XL1-Blue as host. The longer than 0.5 cDNAs ligated to vector and the total ligation solution were 1000 μL.Circularization of each recombinant phage inserted the target sequence were conducted in E.coli BM25.8, to become recombinant phagemids. Recombinant phagemids screening were carried out by using restriction method to analyse the DNA insert.We produced 2.8x108 plaques and 1.1x1010 library amplification titer. Seventeen hallo plaques from 100 μL of the ligation solution positive screening with laminarin substrate.Eight recombinant phagemids were randomly picked and analysed using restriction method showing different fragment. A high quantity cDNA library from digestive gland Achatinafulica was successfully constructed.