Table 1.

Examples of products that have been successfully produced using microbial communities.

Natural community
Undefined community
	Composition	Source	Product	Substrate	Ref
1	Mesophilic microbes	Rumen fluid, Swamp and compost material	Carboxylic acids	Municipal solid waste, Sewage sludge	[50]
2	Anaerobic microbes	Activated sludge	Biogas	Food waste, cattle manure	[51]
3	Yeasts and bacteria	Activated sludge	Biopolymers	Crude glycerol	[52]
4	Hydrogen-producing bacteria	Anaerobic digested sludge	Hydrogen	Glucose	[53]
5	Anaerobic bacteria and fungi	Cow Manure	Hydrogen	Cellulose	[46]
Defined community
	Predominant organisms	Source	Product	Substrate	Ref
1	Clostridia, Actinobaculum, Pseudomonas, Azotobacter and Bacillus	Marine sediment	Carboxylic acids	Sorghum	[54]
2	Bacteroidetes, Firmicutes, Proteobacteria, Methanoculleus and Methanomassiliicoccus	Pig manure	Biogas	Corn stover	[55]
3	Clostridium, Escherichia, Bacillus, Lysinibacillus, and Firmicutes	Compost soil	Isopropanol	Corncob	[38]
4	Clostridium, Pseudomonas, Desulfovibrio, Bacteroides, Petrimonas, Escherichia, Shigella and Alistipes	Goat or sheep faeces	Caproic acid	Ethanol and acetic acid	[56]
5	Proteobacteria, Bacteroidetes, Actinobacteria, Chloroflexi, and Verrucomicrobia and Firmicutes	Soil	Butyrate, Hexanoate, Octanoate	Acetate and ethanol	[57]

Artificial community
	Organism 1	Organism 2	Other microbes	Role in the community	Product	Substrate	Ref
1	Lactobacillus kefiranofaciens	Saccharomyces cerevisiae	NA	Lk – produces kefiran; Sc – lactic acid consumption thereby improving tolerance	Kefiran	MRS medium	[58]
2	Aspergillus fumigatus	Streptomyces peucetius	NA	Not clearly understood	N-Formyl Alkaloids	International Streptomyces Project Medium 2 (ISP2)	[43]
3	Bacillus cereus	Clostridium beijerinckii	NA	Bc – utilises starch; Cb – produces butanol	Butanol	Corn mash	[28]
4	Penicillium fuscum	Penicillium camembertii/ clavigerum	NA	Not clearly understood	Berkeleylactones, Antibiotic macrolides	Potato dextrose broth	[59]
5	Trichoderma reesei	Rhizopus delemar	NA	Tr – breakdown cellulose; Rd – produces fumaric acid	Fumaric acid	Corn stover	[44]
6	Trichoderma reesei	Rhizopus oryzae	NA	Tr – breakdown cellulose; Ro – produces lactic acid	Lactic acid	Microcrystalline cellulose	[44]
7	Ralstonia eutropha	Bacillus subtilis	NA	Re – produces PHA; Bs – sucrose utilisation	P(3HB-co-3HV) polymer	M9 minimal medium with sucrose	[19]
8	Clostridium beijerinckii	Saccharomyces cerevisiae	NA	Cb – produces butanol; Sc – produces amino acids for Cb and improves alcohol tolerance	Butanol	Glucose	[42]
9	Clostridium beijerinckii	Yokenella regensburgei	NA	Cb – produces hydrogen; Yr – produces lactate which boosts growth and hydrogen production by Cb	Hydrogen	Food waste	[60]
10	Schizophyllum commune	Bjerkandera adusta	Fomitopsis palustris	Sc – ethanol production; Ba – lignin degradation; Fp – cellulose degradation (all three microbes produces ethanol)	Ethanol	Japanese cedar wood chips	[61]
11	Bacteroides vulgatus	Desulfovibrio piger	Bifidobacterium longum, Eubacterium rectale, Roseburia intestinalis + 20 microbes	Not clearly understood	N-Formyl Alkaloids	DM38 medium	[45]

Synthetic community
	Organism 1	Organism 2	Role in the community	Significant mutations	Product	Substrate	Ref
1	Escherichia coli	Escherichia coli	Ec1 – produces p-coumaric acid; Ec2 – converts p-coumaric acid to caffeyl alcohol and coniferyl alcohol	E. coli ATCC 31884 with pheA and tyrA disrupted, cloning of various plasmids with genes that encode for p-coumaric acid production	p-coumaryl alcohol, caffeyl alcohol and coniferyl alcohol	Modified M9 (M9Y) medium	[62]
2	Synechococcus elongatus	Halomonas boliviensis	Se – photosynthetically fixes carbon and exports as sucrose; Hb – produces PHB	Se – cloning of cscB gene, a sucrose transporter	Polyhyroxy-butyrate	Carbon dioxide	[63]
3	Escherichia coli	Corynebacterium glutamicum	Ec – utilisation of starch; Cg – production of L-lysine	Ec – deletion of lysA to make it a lysine-auxotroph and cloning of EcLys1 (α-amylase) from S. griseus to utilise starch; Cg – multiple deletions (Δpta-ackA Δcat ΔaceAB ΔldhA ΔnanR) to get strain CgLys4 for better production of L-lysine	L-lysine, L-pipecolic acid, cadaverine	Starch and sucrose	[49]
4	Escherichia coli	Escherichia coli	Ec1 – converts p-coumaric acid into resveratrol; Ec2 – converts the resveratrol into polydatin and resveratroloside	Ec1 – E. coli BL21 (DE3) containing pAC-4CL-STS (Cm); Ec2 – E. coli BL21 (DE3)/Δpgi/Δzwf containing pET28a-hasC (Km) and pQE30-PaGT3 (Amp)	Resveratrol	M9 minimal medium with glucose	[48]
5	Escherichia coli	Saccharomyces cerevisiae	Ec – produces ethanol from xylose; Sc – produces ethanol from glucose	Ec – deletion of ptsG, pgi and zwf genes to construct glucose negative strain of E. coli strain SL100	Ethanol	Sugar cane bagasse	[64]
6	Pichia pastoris	Pichia pastoris	Pp1 – converts to dihydromonacolin L (DML); Pp2 – converts DML to monacolin and lovastatin	Pp1 – cloning of lovB, lovC, lovG, npgA genes; Pp2 – cloning of slovA, cpr genes	Monacolin and lovastatin	Methanol	[65]
7	Escherichia coli	Rhodopseudomonas palustris	Ec – produce organic acids; Rp – convert organic acids to hydrogen	Rp – deletion of nifA, amtB1, amtB2 genes for NH4+ excretion, deletion of hupS to prevent H2 oxidation and uppE to prevent biofilm formation	Hydrogen	M9-derived coculture (MDC) medium	[47]
8	Escherichia coli	Streptomyces venezuelae	Ec – produces phenylpropanoids like pterostilbene, naringenin, and apigenin; Sv – expresses a methyltransferase that catalyses mono-, di-, and tri-methylation of phenylpropanoids	Ec – cloning multiple genes responsible for phenylpropanoid synthesis (Os4CL, VvSTS, VvROMT, PeCHS, PcFNS and MtCHI); Sv – deletion of pikromycin polyketide synthase and cloning of a methyltransferase from Streptomyces avermitilis (SaOMT2)	O-methylated phenylpropanoids	LB medium and R2YE medium	[66]
9	Klebsiella pneumonia	Shewanella oneidensis	Kp – converts glucose and xylose into lactate; So – electron donor	Kp – deletion of adhE, pta genes and cloning of ldhD, lldP genes to improve lactate production; So – deletion of 1S1 and cloning of ribA, ribD, ribE and ribH genes to improve direct-contact extracellular electron transfer	Electricity	Corn stalk hydrolysate	[67]
10	Clostridium beijerinckii	Clostridium cellulovorans	Cb – produces butanol; Cc – breakdown lignocellulose	Cc – deletion of cell wall lyases genes (Clocel_0798 and Clocel_2169) and overexpression of agmatine deiminase genes (augA, encoded by Cbei_1922) from C. beijerinckii to improve pH tolerance, cloning of gene adhE1 from Clostridium acetobutylicum for butanol production	Butanol	Glucose	[68]