β-mannanases from a range of organisms have been reported (Table 4). The great
majority of alkaliphiles from which alkaline active mannanases have been reported
belong to the genus Bacillus. These includes Bacillus agaradhaerens [116], Bacillus
clausii [103], Bacillus circulans [109, 110], and several other unidentified Bacillus
strains [104, 117–119].
Characterization studies of Bacillus mannanases revealed that most of these
enzymes are optimally active around acidic to neutral pH [114]. However, as
shown in Table 4, some mannanases from alkaliphilic and alkali-tolerant Bacillus
strains exhibit optimal activity in the alkaline range (pH 8.5–12.5). Moreover,
similar to alkaline active xylanases (Table 2), the majority of the alkaline active
Table 4 Alkaline active mannanases
Organism
Optimum
pH
Activity
range
Optimum
temperature
(
C)
Molecular
weight (kDa) References
Bacillus JAMB-750
10
5–10.5
55
130
Takeda et al.
[100]
Bacillus JAMB-602
9
6.5–10
65
50
Takeda et al.
[101]
B. halodurans
PPKS-2
11
5–13
70
22
Vijayalaxmi
et al. [102]
B. clausii S10
9.5
6–11.5
75
34
Zhou et al.
[103]
Bacillus sp. N16-5
(ManA)
9.5
5–11
70
55
Ma et al.
[104]
B. nealsonii PN-11
8.8
7.2–9.2
65
50
Chauhan
et al. [105]
Streptomyces
sp. CS428
12.5
3–13.5
60
35
Pradeep et al.
[106]
Bacillus sp. M1
9
6–10
60
58
Akino et al.
[107]
Bacillus sp. M2
9
6–10
60
59
Akino et al.
[107]
Bacillus sp. M3
8.5
5–10
65
42
Akino et al.
[107]
B. subtilis subsp.
inaquosorum CSB31
12.5
4–13
60
47
Regmi et al.
[63]
B. cereus N1
10
–
50
63
El-Sharouny
et al. [108]
B. circulans
CGMCC1554
7.6
6–9
60
32
Yang et al.
[109]
B. circulans
CGMCC1416
7.6
5–10
58
31
Li et al. [110]
Bacillus sp. 22
8.8
7–9.2
70
38
Kumar et al.
[111]
Bacillus sp. JB-99
10
5–11
65
–
Virupakshi
et al. [112]
262
G. Mamo