Screening and Characterization of Cold-Active β-Galactosidase Producing Psychrotrophic Enterobacter ludwigii from the Sediments of Arctic Fjord

Abstract

Low-temperature-tolerant microorganisms and their cold-active enzymes could be an innovative and invaluable tool in various industrial applications. In the present study, bacterial isolates from the sediment samples of Kongsfjord, Norwegian Arctic, were screened for β-galactosidase production. Among the isolates, KS25, KS85, KS60, and KS92 have shown good potential in β-galactosidase production at 20 °C. 16SrRNA gene sequence analysis revealed the relatedness of the isolates to Enterobacter ludwigii. The optimum growth temperature of the isolate was 25 °C. The isolate exhibited good growth and enzyme production at a temperature range of 15-35 °C, pH 5-10. The isolate preferred yeast extract and lactose for the maximum growth and enzyme production at conditions of pH 7.0, temperature of 25 °C, and agitation speed of 100 rpm. The growth and enzyme production was stimulated by Mn and Mg and strongly inhibited by Zn, Ni, and Cu. β-Galactosidases with high specific activity at low temperatures are very beneficial in food industry to compensate the nutritional problem associated with lactose intolerance. The isolate exhibited a remarkable capability to utilize clarified whey, an industrial pollutant, for good biomass and enzyme yield and hence could be well employed in whey bioremediation.

Recent Development of Extremophilic Bacteria and Their Application in Biorefinery

“…Cold-active endoglucanase (CelX) from psychrotrophic Pseudoalteromonas sp. DY3 and β-galactosidase enzyme produced by Enterobacter ludwigii are regarded as possible and economically attractive alternatives to hydrolyze lignocellulose at refrigerated temperatures (Zeng et al, 2006;Alikkunju et al, 2016;Alikunju et al, 2018). These psychrophilic endocellulases can also be used as detergents in laundry as well as to produce biofuels and chemicals (Yuan et al, 2018).…”

Enzymes from Marine Polar Regions and Their Biotechnological Applications

“…Among them, some are from Antarctic organisms, e.g., H. lacusprofundi , isolated from the hypersaline Deep Lake [71,196], Arthrobacter species from soil samples [197,198], and marine Pseudoalteromonas species [86,87,88,199]. Other enzymes were isolated from marine organisms from the Arctic region, including those from Enterobacter ludwigii [91] and Alkalilactibacillus ikkense [92]. A cold-active β-galactosidase from the Antarctic marine bacterium P. haloplanktis TAE 79 was applied to lactose hydrolysis at low temperatures during milk storage [88] and was proposed for the production of tagatose, a natural monosaccharide with low caloric value and glycemic index [200].…”

Cloning, Expression and Characterization of a Novel Cold-adapted β-galactosidase from the Deep-sea Bacterium Alteromonas sp. ML52

“…Most reported β-galactosidases are recombinant enzymes derived from heterologous expression than from a natural source. In recent years, the number of cold-adapted β-galactosidases were isolated from psychrophilic and psychrotrophic microorganisms obtained from isothermal cold environments such as polar [15,16,17], deep-sea [18] and high mountainous regions [19]. The main source of enzymes has been obtained from bacterial strains such as Arthrobacter psychrolactophilus strain F2 [20], Arthrobacter sp.…”