Table 5.

Physicochemical properties of selected pullulan-hydrolyzing enzymes from various microorganisms.

Organism	M r a (kDa)	pI	Optimal  pH	Optimal temperature (°C)	Reference
Type I pullulanase
Bacillus flavocaldarius KP 1228	55	n.d.b	7.0	75–80	[51]
Streptomyces sp. No. 27	n.d.	n.d.	4–7	55–60	[52]
Thermus caldophilus GK-24	65	6.1	5.5	75	[27]
Fervidobacterium pennavorans Ven 5	240	n.d.	6.0	85	[28]
Bacillus thermoleovorans US 105 (expressed in E. coli)	n.d.	n.d.	5.6–6.0	75	[30]
Type II pullulanase
Thermoanaerobacter strain B6A	450	4.5	5.0	75	[53]
Clostridium thermosulfurigenes EM 1	102	n.d.	5.5–6.0	60–65	[54]
Pyrococcus furiosus	110	n.d.	5.5	98	[55]
Thermococcus litoralis	119	n.d.	5.5	98	[55]
Desulfurococcus mucosus	n.d.	n.d.	5.0	100	[56]
Thermococcus celer	n.d.	n.d.	5.5	90	[56]
Thermococcus strain TY	n.d.	n.d.	6.5	100	[56]
Pyrococcus woesei	90	n.d.	6.0	100	[26]
Thermococcus hydrothermalis	110–128	n.d.	5.5	95	[14]
Desulfurococcus mucosus expressed in Bacillus subtilis	66	n.d.	5.0	85	[32]
Neopullulanases
Bacillus stearothermophilus expressed in B. subtilis	62	n.d.	6.0	60–65	[42]
Bacillus stearothermophilus TRS 40	62	n.d.	6.0	60–65	[42]
Bacteroides thetaiotaomicron 95-1	70	n.d.	6.5	37	[57]
Bacillus polymyxa CECT 155	n.d.	n.d.	6.0	50	[58]
Isopullulanases
Aspergillus niger ATCC 9642	69–71	n.d.	3.5	40	[36]
Bacillus sp. US 149	200	n.d.	5.0	60	[31]
Alkaline amylopullulanase
Bacillus sp. KSM-1876	120	5.2	10–10.5	50	[59]
Bacillus sp. KSM 1378	210	4.8	9.5	50	[41]
Pullulan hydrolase type III
Thermococcus aggregans expressed in E. coli	n.d.	n.d.	6.5	95	[37]

^aMolecular mass; ^bnot detected by the researchers.