▎ 摘　　要

NOVELTY - Short single-stranded deoxyribonucleic acid (ssDNA) aptamer, is new. The ssDNA aptamer comprises fully defined sequence of 80 base pairs (SEQ ID NO: 1) as given in the specification. USE - The ssDNA aptamer is useful for specifically identifying Weissella viridescens and detecting Weissella viridescens (claimed). ADVANTAGE - The ssDNA aptamer has potential application prospects in the accurate, rapid and sensitive detection of Weissella viridescens . DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for: (I) test kit for Weissella viridescens comprising ssDNA aptamer; (II) test paper for Weissella viridescens detection comprising ssDNA aptamer; (III) composition for detecting Weissella viridescens comprising ssDNA aptamer; (IV) fluorescent biosensor for detecting Weissella viridescens comprising a ssDNA aptamer, a fluorescent group and a fluorescence quencher; (V) a method for screening for ssDNA aptamers that specifically recognizeWeissella viridescens comprising constructing a random library and a primer pair with the nucleotide sequence shown in SEQ ID NO. 6-7, using Weissella viridescens as a positive screening strain, Lactobacillus plantarum, Lactobacillus brevis, Leuconostoc mesenteroides, Pediococcus pentosaceus and Staphylococcus aureus are counter-selected strains, which exclude sequences with lower specificity, eliminating non-specific binding sequences through bovine serum albumin and tRNA, screening to obtain ssDNA library, sequencing the ssDNA library obtained by screening, selecting sequences with stable structure and low free energy, and then screening for sequences with high affinity and high specificity for Weissella viridescens to obtain the ssDNA aptamer that specifically recognizes Weissella viridescens , where the random library conforms to the structural features comprises fully defined sequence of 40 base pairs (SEQ ID NO: no defined) as given in the specification, where N represents any of bases A, T, C, and G, and N40 represents a random fragment with a length of 40 bases.