Table 2.

Design strategies to maintain coexistence in engineered microbial consortia

Design strategy	Coexistence mechanisms	Examples
Resource partitioning	Reducing competition for resources	E. coli-E. coli coculture producing lactate from both glucose and xylose (Eiteman et al. 2009)
Chemical symbiosis	Engineering commensalism via non-metabolite molecules	Acetaldehyde-mediated coexistence of E. coli- mammalian cell consortium (Weber et al. 2007)
	Engineering metabolic syntrophy	Pairing auxotrophic E. coli strains that cross-fed amino acids (Pande et al. 2014)
	Engineering mutualism via non-metabolite molecules	Cooperative, nisin-mediated survival of a Lactococcus lactis-L. lactis consortium (Kong et al. 2018)
Horizontal gene transfer	Promoting specialization	HGT-induced specialization of Vibrionaceae populations into pioneers, harvesters, and scavengers (Hehemann etal. 2016)
Higher-order interactions	Modulating interaction strength between members	Complex interdependences within a methanogenic community created by amino acid auxotrophies (Embree et al. 2015)
Spatial organization	Modulating interaction strength between members	Spatial organization modulates the strength of cross-feeding between two members of a syntrophic consortium (Kim et al. 2008; Song et al. 2009)
	Conferring beneficial/cooperative traits	P. aeruginosa surrounding and shielding S. aureus from β-lactam antibiotics in a core-shell structure (Connell et al. 2013)