Alanine racemase single deletion and trans complementation

The present invention relates to bacillus host cells belonging to the species Bacillus licheniformis or Bacillus pumilus, wherein the chromosome alr gene is inactivated. The present invention relates to a bacterial host cell comprising a plasmid comprising at least one autonomously replicating sequence, a first polynucleotide encoding at least one polypeptide of interest wherein the first polynucleotide is operably linked to a promoter, and a second polynucleotide encoding an alanine racemase that is not native to the host cell wherein the second polynucleotide is operably linked to the promoter. Wherein the second polynucleotide is operably linked to a promoter. The invention also relates to a method for producing at least one polypeptide of interest based on culturing a bacterial host cell of the invention. 本发明涉及属于物种地衣芽孢杆菌或短小芽孢杆菌的芽孢杆菌宿主细胞，其中染色体alr基因失活。所述细菌宿主细胞包含括质粒，所述质粒包含至少一种自主复制序列，编码至少一种感兴趣的多肽的第一多核苷酸，其中所述第一多核苷酸可操作连接启动子，和编码非宿主细胞天然的丙氨酸消旋酶的第二多核苷酸，其中所述第二多核苷酸可操作连接启动子。本发明还涉及基于培养本发明的细菌宿主细胞生产至少一种感兴趣的多肽的方法。