Fig. 4From: Biological conversion of methane to putrescine using genome-scale model-guided metabolic engineering of a methanotrophic bacterium Methylomicrobium alcaliphilum 20Za Growth of wild-type and engineered strain M. alcaliphilum 20Z. b Putrescine accumulation of engineered strain M. alcaliphilum 20Z with spermidine synthase knockout and strain harboring pACE and pACO vector after 144 h of cultivation. The data are represented as the mean ± SD (n = 3)Back to article page