Table 1.

Summary of the most widely used recombinant expression strains from E. coli and Bacillus species outlining their advantages and disadvantages.

	General Advantages	Disadvantages	References
Most common E. coli strains	Rapid expression, high yield, ease of culture and gene modification, cost effective.	Post translational modification not possible. Inclusion body formation	[41,45,46]
BL21, B21-Codonplus (RIL), BL21(DE3), BL21(DE3)pLys S/E, BL21 Star, C41(DE3), C43(DE3), Codon plus (RP), Lemon21(DE3), M15, Origami, Rosetta, SG13009, Shuffle Derivatives of K-12, AD494 and HMS174.
Most common Bacillus species
Bacillus brevis, Bacillus megaterium and Bacillus subtilis.	Preferred for homologous expression of some enzymes (e.g., proteases and amylases), Strong secretion, no involvement of intracellular inclusion bodies and ease of manipulation.	Contains proteases, which may hydrolyse recombinant proteins.	[42,47,48,49,50]