Cognate foldase co-expression

A Gram-positive host cell comprising in its genome:

• 1) a nucleic acid construct;
• and/or
• 2) an expression vector comprising said nucleic acid construct;
• wherein the nucleic acid construct comprises:
• a) a first heterologous promoter operably linked to at least one polynucleotide encoding a foldase;
• and
• b) a second heterologous promotor operably linked to at least one polynucleotide encoding a polypeptide of interest;
• wherein the foldase has a sequence identity of at least 80% to SED ID NO:
• 3, and the polypeptide of interest is from Bacillus amyloliquefaciens,
• wherein the foldase has a sequence identity of at least 80% to SED ID NO:
• 9, and the polypeptide of interest is from Bacillus licheniformis,
• wherein the foldase has a sequence identity of at least 80% to SED ID NO:
• 15, and the polypeptide of interest is from Bacillus sp. NSP9.1,
• wherein the foldase has a sequence identity of at least 80% to SED ID NO:
• 21, and the polypeptide of interest is from Bacillus sonorensis L12, or
• wherein the foldase has a sequence identity of at least 80% to SED ID NO:
• 27, and the polypeptide of interest is from Bacillus subtilis;
• wherein the foldase is cognant to the polypeptide of interest;
• and
• wherein the host cell has improved yield of the polypeptide of interest and/or reduced secretion stress when compared to the same host cell having co-expression of the same heterologous polypeptide of interest with a non-cognate foldase.