Table 1.

Transporter applications in microbial cell factories.

Transporter	Species	Compound	Function	Reference
Substrates
Gal2p	S. cerevisiae	Xylose	Improved the transport rate and accelerated utilization of xylose.	[40]
AraT	S. cerevisiae	L-arabinose	Transported L-arabinose with high specificity and high affinity.	[36]
XylE	P. putida	Xylose	Broadened metabolic capacity towards new substrates.	[43]
GatA	S. cerevisiae	D-galacturonic acid	Achieved coutilization of D-galUA and D-glucose.	[44]
Lac12	S. cerevisiae	Lactose	Increased uptake of the lactose.	[66–68]
Intermediate metabolites
ShiA	E. coli	3-Dehydroshikimate	Enhanced reuptake of intermediate metabolite from extracellular to cytoplasm.	[45]
FadL	E. coli	Palmitate	Achieved reuptake of excreted intermediate metabolite.	[69]
Δpxa1	S. cerevisiae	Fatty acyl-CoA	Increased production of fatty acyl-CoA in the cytoplasm.	[46]
NtJAT1, NtMATE2	S. cerevisiae	Tropine	Alleviated vacuolar intermediate metabolite transport limitations.	[47]
Target products
AcrE, MdtE, MdtC	E. coli	Medium-chain fatty acid	Increased extracellular MCFA concentration by 59.7%, 43.2%, and 83.1%.	[55]
FATP1	S. cerevisiae	Fatty alcohol	Enabled an increased cell fitness for fatty alcohol production.	[56]
FATP1	S. cerevisiae	1-Alkenes	Improved the extracellular and total 1-alkene production.	[57]
MacA, TolC, MacB	E. coli	6-Deoxyerythronolide B	Increased the 6dEB titers.	[60]
Orf14, Orf3	Burkholderia	Epothilones	Raised the ratio of extracellular to intracellular accumulation from 9.3 : 1 to 13.7 : 1.	[62]
TolC, AcrB	E. coli	amorphadiene	Increased yield by 46%.	[59]
AcrA, TolC AcrB,	E. coli	Kaurene	Increased yield by 82%.	[59]
Snq2p	S. cerevisiae	β-Carotene	Improved β-carotene secretion level by 4.04-fold.	[64]
AcrAB	E. coli	Limonene	Reduced limonene toxicity.	[70]
Bfr1	S. cerevisiae	Caffeine	Enhanced cellular resistance to caffeine.	[34]
AbPUP1, AbLP1	S. cerevisiae	Littorine and hyoscyamine	Exported vacuolar littorine and hyoscyamine to the yeast cytosol.	[37]
AtDTX1	E. coli	Reticuline	Achieved the secretion of high levels of reticuline.	[65]
MttA	A. niger	cis-aconitic acid	Secreted 9.8 g/L aconitic acid after 240 h of cultivation.	[71]
Spmae$\ast$	S. cerevisiae	L-malic acid	Increased the accumulation.	[50]
AtABCG29	S. cerevisiae	Coumaryl alcohol	Increased cellular tolerance to p-coumaryl alcohol.	[72]
PtPTP	Phaeodactylum tricornutum	Pyruvate	Enhanced biomass, lipid contents, and growth.	[73]
DCT1	A. niger	Malic acid	Improved malic acid production by 36.8%.	[74]
MTT	Y. lipolytica	Itaconic acid	Enhanced itaconic acid titer by 10.5-folds.	[75]
RibM	B. subtilis	Riboflavin and roseoflavin	Increased the production of riboflavin and roseoflavin.	[76]
PP_1271	P. putida	Propionic acid	Improved cellular tolerance to PA.	[48]
YbjE	Synechococcus sp	Lysine	Generated a large pool of lysine in the extracellular media.	[77]
Qdr3	S. cerevisiae	Muconic acid	Increased cellular tolerance to glutaric, adipic, muconic, and glutaconic acid.	[78]
CexA	A. niger	Citric acid	Enhanced the secretion of citric acid.	[79]
M2	E. coli	Proton	Increased acid tolerance.	[80]
SerE	C. glutamicum	L-serine	Increased L-serine efflux.	[51]
Tpo2p	S. cerevisiae	cis,cis-muconic acid, protocatechuic acid	Improved the production of target compound.	[39]