This disclosure relates to a modified version of cyanovirin-N protein and a transformed Lactobacillus bacterium that is capable of recombinantly expressing this modified protein. Further disclosed are polynucleotide sequence encoding the modified cyanovirin-N protein, expression cassette that allows the expression of the modified protein, and method of make and use of the modified protein as well as the transformed Lactobacillus bacterium. In addition, this disclosure describes two novel promoters originated from L. jensenii, which are capable of directing a high level of gene expression in Lactobacillus bacteria. Also described are an expression cassette comprising one of the novel promoters, a genetically modified Lactobacillus bacterium containing the expression cassette, a method for recombinant gene expression in Lactobacillus bacteria using the novel promoters, and a method for delivery of proteins with desired biological activity to a mucosal surface in a human.