. 2022 Nov 18;23(22):14308. doi: 10.3390/ijms232214308

Table 1.

Enzyme activity, GOS production, and influence of metal ions on specific enzyme activity (SEA) of selected microbial β-galactosidases.

Species, Strain	Type of Enzyme ¹	Lactose (g/L)	GOS (g/L)	GOS (%) ²	SEA ³ (U/mg)	Metal Ions ⁴	Ref.
L. bulgaricus 43	Crude	200	70.91 (DP3)	34 (DP3)	2011 (O)	$↑$ Mn²⁺, Mg²⁺, Ca²⁺ $↓$ Zn²⁺, Cu²⁺	This study
L. bulgaricus CRL450	Cell-free extract	300	n/a	41.3	2.06 (O)	n/a	[36]
L. bulgaricus DSM 20081	Purified, non-His-tag	205	102	50	317 (O) 123 (L)	$↑$ Na⁺, K⁺ $↓$ Mg²⁺, Ca²⁺	[27]
L. bulgaricus wch9901	Crude	n/a	n/a	n/a	6.2 (O)	n/a	[35]
L. acidophilus R22	Purified natural	205	n/a	38.5	361 (O) 28.8 (L)	$↑$ Mg²⁺ $↓$ Mn²⁺, Cu²⁺, Zn²⁺	[37]
Lim. fermentum K4	Purified	200-400	n/a	37	184 (O) 41 (L)	$↑$ Na⁺, K⁺, Mg²⁺	[38]
L. helveticus DSM 20075	Purified	205	n/a	n/a	476 (O) 11.1 (L)	$↑$ K⁺, Na⁺ $↓$ Mn²⁺, Mg²⁺, Ca²⁺, Zn²⁺	[39]
L. leichmannii 313	Purified	n/a	n/a	n/a	31.28 (O)	$↑$ Na⁺ $↓$ Ca²⁺, Mn²⁺	[35]
Bifidobacterium breve DSM 20213	Purified (2 enzymes)	200	n/a	33-44	489 (O) 59 (L)	n/a	[23]
Bif. longum Bif. pseudocatenulatum	Purified (2 enzymes)	n/a	n/a	n/a	2200 (O) 0.58 (O)	$↑$ Zn²⁺, Na⁺, Ca²⁺, Mn²⁺ $↓$ Al³⁺	[40]
B. circulans	commercial	400	198	41	n/a	n/a	[34]
Pyrococcus woesei	Purified	n/a	n/a	n/a	5400 (O)	n/a	[41]
Aspergillus oryzae	commercial	400	107	26.8	n/a	n/a	[42]

¹ All recombinant and His-tagged unless otherwise noted; ² Percentage of total sugars; ³ SEA, specific enzyme activity (U/mg protein); substrates: O = ONPG; L = lactose; ⁴ Activators/inhibitors of SEA; $↑$ , activation; $↓$ , inhibition; 1U = μmol/min.