Recombinant production and characterization of a novel esterase from a hypersaline lake, Acıgöl, by metagenomic approach

AbstractXylanases are widely used enzymes in the food, textile, and paper industries. Most efficient xylanases have been identified from lignocellulose-degrading microbiota, such as the microbiota of the cow rumen and the termite hindgut. Xylanase genes from efficient pulp and paper wastewater treatment (PPWT) microbiota have been previously recovered by metagenomics, assigning most of the xylanase genes to the GH10 family. In this study, a total of 40 GH10 family xylanase genes derived from a certain PPWT microbiota were cloned and expressed in Escherichia coli BL21 (DE3). Among these xylanase genes, 14 showed xylanase activity on beechwood substrate. Two of these, PW-xyl9 and PW-xyl37, showed high activities, and were purified to evaluate their xylanase properties. Values of optimal pH and temperature for PW-xyl9 were pH 7 and 60 ℃, respectively, while those for PW-xyl37 were pH 7 and 55 ℃, respectively; their specific xylanase activities under optimal conditions were 470.1 U/mg protein and 113.7 U/mg protein, respectively. Furthermore, the Km values of PW-xyl9 and PW-xyl37 were determined as 8.02 and 18.8 g/L, respectively. The characterization of these two xylanases paves the way for potential application in future pulp and paper production and other industries, indicating that PPWT microbiota has been an undiscovered reservoir of efficient lignocellulase genes. This study demonstrates that a metagenomic approach has the potential to screen efficient xylanases of uncultured microorganisms from lignocellulose-degrading microbiota. In a similar way, other efficient lignocellulase genes might be identified from PPWT treatment microbiota in the future.

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Recombinant Production and Characterization of an Extracellular Subtilisin-Like Serine Protease from Acinetobacter baumannii of Fermented Food Origin

The Protein Journal ◽

10.1007/s10930-021-09986-5 ◽

2021 ◽

Author(s):

Nur Syafiqah Muhammed ◽

Nurulfarhana Hussin ◽

Aik Siang Lim ◽

Mohd Anuar Jonet ◽

Shaza Eva Mohamad ◽

...

Keyword(s):

Acinetobacter Baumannii ◽

Serine Protease ◽

Fermented Food ◽

Recombinant Production

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Molecular and isotopic characterization of lipids in cultured halophilic microorganisms from the Dead Sea and comparison with the sediment record of this hypersaline lake

Organic Geochemistry ◽

10.1016/j.orggeochem.2005.05.002 ◽

2005 ◽

Vol 36 (9) ◽

pp. 1242-1251 ◽

Cited By ~ 18

Author(s):

Thorsten Stiehl ◽

Jürgen Rullkötter ◽

Arie Nissenbaum

Keyword(s):

Dead Sea ◽

Hypersaline Lake ◽

Sediment Record ◽

Halophilic Microorganisms ◽

Isotopic Characterization ◽

The Dead

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Optimization of Saccharomyces cerevisiae α-galactosidase production and application in the degradation of raffinose family oligosaccharides

Microbial Cell Factories ◽

10.1186/s12934-019-1222-x ◽

2019 ◽

Vol 18 (1) ◽

Cited By ~ 2

Author(s):

María-Efigenia Álvarez-Cao ◽

María-Esperanza Cerdán ◽

María-Isabel González-Siso ◽

Manuel Becerra

Keyword(s):

Saccharomyces Cerevisiae ◽

Food Industry ◽

Culture Conditions ◽

Raffinose Family Oligosaccharides ◽

Recombinant Production ◽

Gene Coding ◽

Productive Process ◽

Hydrolysis Of ◽

Degree Of Purification

Abstract Background α-Galactosidases are enzymes that act on galactosides present in many vegetables, mainly legumes and cereals, have growing importance with respect to our diet. For this reason, the use of their catalytic activity is of great interest in numerous biotechnological applications, especially those in the food industry directed to the degradation of oligosaccharides derived from raffinose. The aim of this work has been to optimize the recombinant production and further characterization of α-galactosidase of Saccharomyces cerevisiae. Results The MEL1 gene coding for the α-galactosidase of S. cerevisiae (ScAGal) was cloned and expressed in the S. cerevisiae strain BJ3505. Different constructions were designed to obtain the degree of purification necessary for enzymatic characterization and to improve the productive process of the enzyme. ScAGal has greater specificity for the synthetic substrate p-nitrophenyl-α-d-galactopyranoside than for natural substrates, followed by the natural glycosides, melibiose, raffinose and stachyose; it only acts on locust bean gum after prior treatment with β-mannosidase. Furthermore, this enzyme strongly resists proteases, and shows remarkable activation in their presence. Hydrolysis of galactose bonds linked to terminal non-reducing mannose residues of synthetic galactomannan-oligosaccharides confirms that ScAGal belongs to the first group of α-galactosidases, according to substrate specificity. Optimization of culture conditions by the statistical model of Response Surface helped to improve the productivity by up to tenfold when the concentration of the carbon source and the aeration of the culture medium was increased, and up to 20 times to extend the cultivation time to 216 h. Conclusions ScAGal characteristics and improvement in productivity that have been achieved contribute in making ScAGal a good candidate for application in the elimination of raffinose family oligosaccharides found in many products of the food industry.

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