A practical optical trap for manipulating and isolating bacteria from complex microbial communities.

A wide variety of naturally occurring bacteria cannot be isolated by classical microbiological methods, hindering study of microbial communities. To partially remove this limitation, a method using optical trapping was developed. It allows for one-step isolation of bacteria from a complex community to a pure culture. The method transfers a single bacterium to sterile culture medium using a non-destructive laser beam. The ease with which a previously unculturable cell was cultured by trapping suggests that competition may limit growth in some natural communities of bacteria.