Signal peptide, l-glutamic acid thereof synthesized using konjac flour and high-value application thereof

Provided is a codon-optimized β- mannase signal peptide (MSP), and a nucleotide sequence thereof is shown as SEQ ID NO:1, and a genetically engineered bacteria comprising the signal peptide and the β- mannase, and a method for manufacturing the L-glutamic acid or γ-amino-butyric acid by fermenting the genetically engineered bacteria with the konjac flour as a primary carbon source.