The invention relates to the technical field of
biology, and provides a method for constructing a bacterial
mutant library and application thereof, and the method comprises the following steps: (1) based on a
mutation site of a
target protein, carrying out splitting treatment on coding
nucleic acid of the
target protein, and constructing a saturated
mutation site fragment for coding the
target protein; (2) constructing a first vector which contains an expression
signal marker and an SUMO-FutC
enzyme fragment and does not contain an IIS type
restriction enzyme digestion site; (3) connecting the saturated
mutation site fragment with a first vector to obtain a saturated mutation vector
library; and (4) transferring the vectors in the saturated mutation vector
library into
bacteria to obtain the bacterial
mutant library. The bacterial
mutant library can be combined with a microfluidic technology to screen key functional sites and corresponding strains of a target
protein, for example, a target strain with high yield of 2 '-fucosyllactose can be efficiently obtained, the yield of the target strain is 4.7-7.6 times that of a
wild strain, meanwhile, the time, instrument and
reagent cost is saved, and the operation requirement is low.