Table 3B. Summary of Microbially-Secreted Organic Acids to Mobilize Soil P.

microbe species			mobilized P
strain	organic acid species	exptl conditions	mg L–1	pH	ref
D 5/23 Pantoea agglomerans	succinate, hydroxyglutarate, adipate, lactate, ketogluconate	200 μg P mL–1 as Ca3(PO4)2, 28 °C 7 d	62.8	5.93	Deubel and Merbach175
PsIA12 Pseudomonas fluorescens	succinate, lactate, malate, ketogluconate, galacturonate, citrate		44.1	4.77
CC 322 Azospirillum sp.	gluconate, succinate, 2-ketoglutarate, ketogluconate		83.4	6.19
Mac 27 Azotobacter chroococcum	citrate, malate, fumarate, succinate, lactate		98.1	4.84
Msx 9 Azotobacter chroococcum	citrate, fumarate, malate, lactate, succinate		65.9	5.82
ER 3	fumarate, isocitrate, lactate, malonate		75.5	5.32
ER 10	lactate, gluconate, malonate, citrate		36.2	5.72
	citric	200 mg L–1 P as Ca3(PO4)2, 28 °C 7 d	236 mg g–1
	succinic		178
	lactic		126
	citric	2 g soil +100 mL 5 g L–1 carboxylic acid, pH 7, 24 h	250 mg kg–1
	oxalic		175
	gluconic		50
	succinic		25
A. calcoaceticus YC-5a	oxalic, malic, lactic, tartaric	5 g L–1 Ca3(PO4)2, 28 °C, 7 d	518 ± 17.3	3.92 ± 0.02	Ren et al.176
E. agglomerans KMC-7	oxalic, lactic, citric, succinic		435 ± 15.6	4.13 ± 0.01

microbe species
fungi	organic acid species	ref
Aspergillus flavus, A. candidus, A. niger, A. terreus, A. wentii, Fusarium oxysporum, Penicillium sp., Trichoderma isridae, Ttrichoderma sp.	lactic, maleic, malic, acetic, tartaric, citric, fumaric, gluconic	Akintokun et al.177
Penicillium oxalicum	malic, gluconic, oxalic	Shin et al.178
Aspergillus flavus, A. niger, P. canescens	oxalic, citric, gluconic, succinic	Maliha et al.179
Penicillium rugulosum	citric, gluconic	Reyes et al.180
A. niger	succinic	Vazquez et al.181
Penicicllium variabile	gluconic	Fenice et al.182
	oxalic, lactic, glycolic, citric, succinic, tartaric	Whitelaw183