An insecticidal protein gene, vip3A, was cloned from Bacillus thuringiensis strainWB50. The nucleotide sequenceof 2,460 bp (GenBank acc. No. AY295778) showed 99% homology with the known vip3A genes. Using specificprimers for vip3A gene, PCR was performed to demonstrate that the gene was not located on the bacterial chromosomeand this was confirmed by Southern blotting using an internal fragment (486 bp) from vip3A gene as aprobe. The gene was carried on a plasmid of 31.8 kb.

Aims: To isolate and characterize the novel Bacillus thuringiensis strains frombryophytes collected from Wuyi Mountain, Fujian Province of China, andidentify new B. thuringiensis strains and toxins active against mosquitoes.Methods and Results: Twelve novel B. thuringiensis strains were isolated from76 bryophyte samples. According to the results of this preliminary screening,LLB6 was the most toxic to Aedes albopictus. Then phase-contrast as well asscanning electron microscopy, bioassays, cloning, sequencing and expressionwere performed to characterize the novel isolate LLB6 and its new genecry2Ac5.Conclusions: Bacillus thuringiensis occurred naturally on bryophytes. LLB6 isolatedfrom Physcomitrium japonicum was toxic to A. albopictus. A new cry2Ac5gene of LLB6 was detected, cloned and expressed successfully. Bioassays onA. albopictus showed that the expressed Cry2Ac5 was also toxic to the thirdinstar larvae.Significance and Impact of the Study: This is the first report of B. thuringiensisstrains isolated from bryophytes. It represents a specific source of new B. thuringiensisstrains and is of great importance for the knowledge of the ecologyof B. thuringiensis. Novel LLB6 harboring the new gene cry2Ac5 and itsexpressed Cry2Ac5 protein revealed activity against A. albopictus and became anew member of B. thuringiensis toxins.