Abstract: A gram-negative bacterial cell is described that is deficient in a chromosomal gene present in a wild-type such cell which gene shares at least 80% sequence identity with the native sequence of the yfcK gene and encodes an aminopeptidase. Alternatively, a gram-negative bacterial cell is deficient in a chromosomal gene present in a wild-type such cell which gene encodes an aminopeptidase that shares at least 80% sequence identity with the native sequence of aminopeptidase b2324. Either of these types of cells, when comprising a nucleic acid encoding a heterologous polypeptide, produces an N-terminal unclipped polypeptide when it is cultured and the polypeptide recovered, with virtually no N-terminal clipped polypeptide produced as an impurity. Conversely, a method is provided for cleaving an N-terminal amino acid from a polypeptide comprising contacting the polypeptide with an aminopeptidase sharing at least 80% sequence identity with the native sequence of aminopeptidase b2324.

Abstract: The invention provides a method for increasing product yield of a polypeptide of interest produced by recombinant host cells, where expression of the polypeptide by the recombinant host cells is regulated by an inducible system. More specifically, the method involves culturing the recombinant host cells under conditions of high metabolic and growth rate and then reducing the metabolic rate of the recombinant host cells at the time of induction of polypeptide expression. In particular, the invention provides a method of increasing product yield of an antibody, growth factor, or protease produced by a recombinant E. coli host cell regulated by an inducible system.

Abstract: The invention provides a method for increasing product yield of a polypeptide of interest produced by recombinant host cells, where expression of the polypeptide by the recombinant host cells is regulated by an inducible system. More specifically, the method involves culturing the recombinant host cells under conditions of high metabolic and growth rate and then reducing the metabolic rate of the recombinant host cells at the time of induction of polypeptide expression. In particular, the invention provides a method of increasing product yield of an antibody, growth factor, or protease produced by a recombinant E.