Purification and characterization of halo-alkali-thermophilic protease from Halobacterium sp. strain HP25 isolated from raw salt, Lake Qarun, Fayoum, Egypt

Elbanna, Кhaled; Ibrahim, Ibrahim M.; Revol-Junelles, Anne-Marie

doi:10.1007/s00792-015-0752-3

Cited by 36 publications

(19 citation statements)

References 49 publications

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“…Conversely, halophilic enzymes work in extremely high salt concentrations, and considering that salt tends to greatly reduce water activity, these enzymes may also perform well in other low water activity environments, such as organic solvents or aqueous/organic mixtures [13]. Various halophilic enzymes have been reported to be active and stable in the presence of different organic solvents, e.g., proteases [46,47], dehydrogenases [48,49] and amylases [50,51].…”

Section: Discussionmentioning

confidence: 99%

Unique Features of a New Baeyer–Villiger Monooxygenase from a Halophilic Archaeon

et al. 2020

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Type I Baeyer–Villiger monooxygenases (BVMOs) are flavin-dependent monooxygenases that catalyze the oxidation of ketones to esters or lactones, a reaction otherwise performed in chemical processes by employing hazardous and toxic peracids. Even though various BVMOs are extensively studied for their promising role in industrial biotechnology, there is still a demand for enzymes that are able to retain activity at high saline concentrations. To this aim, and based on comparative in silico analyses, we cloned HtBVMO from the extremely halophilic archaeon Haloterrigena turkmenica DSM 5511. When expressed in standard mesophilic cell factories, proteins adapted to hypersaline environments often behave similarly to intrinsically disordered polypeptides. Nevertheless, we managed to express HtBVMO in Escherichia coli and could purify it as active enzyme. The enzyme was characterized in terms of its salt-dependent activity and resistance to some water–organic-solvent mixtures. Although HtBVMO does not seem suitable for industrial applications, it provides a peculiar example of an alkalophilic and halophilic BVMO characterized by an extremely negative charge. Insights into the behavior and structural properties of such salt-requiring may contribute to more efficient strategies for engineering the tuned stability and solubility of existing BVMOs.

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Section: Discussionmentioning

confidence: 99%

Unique Features of a New Baeyer–Villiger Monooxygenase from a Halophilic Archaeon

et al. 2020

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“…The purified enzyme was incubated with detergent solutions (OMO and Ariel) with final concentration of 1% at 40 °C for 60 minutes for determination of stabilisation of the halophilic enzyme [Elbanna at al. 2015].…”

Section: Halophilic Protease Stability In Commercial Detergentsmentioning

confidence: 99%

“…Different concentrations of casein substrate 0.2-1.0% was used to determine the KM and Vmax values of the pure enzyme by using Lineweaver-Burk plot [Elbanna at al. 2015].…”

Section: Determination Of Km and Vmax Of Halophilic Proteasementioning

confidence: 99%

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Isolation, Screening, Partial Purification and Characterization of Protease From Halophilic Bacteria Isolated From Indonesian Fermented Food

Fitriani¹,

Güven²

2018

ANADOLU UNIVERSITY JOURNAL OF SCIENCE AND TECHNOLOGY –C Life Sciences and Biotechnology

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The protease producing bacteria were screened from Indonesian traditional fermented food, tauco and terasi, and 4 halophilic protease producers were isolated. Among these isolates, halophilic bacterial isolate TANN 4 was recorded as the best protease producer. Extracellular protease from isolate TANN 4 was partially purified using ammonium sulfate precipitation. The protease was partially purified with final yield of 72.87 % and 25.41 fold purity. This moderate thermoactive and alkaliphilic protease showed a pH optimum of 8.0 and temperature optimum was 50 °C. The enzyme was also active at salt concentrations ranging from 1 to 15 % (w/v), with optimum activity at 1 % NaCl (w/v). Ethylenediaminetetraacetic acid (EDTA) completely inhibited the enzyme activity suggesting that it was a metalloprotease. Among metal ions, the Ca 2+ , K + and Mg 2+ ions enhanced the activity of enzyme. The KM and Vmax values exhibited by partially purified protease were 0.0649 mM and 216.45 U mg −1 using casein as substrate. The molecular weight was estimated to be 19.8 kDa on SDS PAGE. The enzyme was also fairly stable in Triton X-100, SDS, 1 % commercial detergents (OMO and Ariel) and 25 % methanol and it was capable of hydrolyzing casein, hemoglobin and bovine serum albumin (BSA). These characteristics make this halophilic bacterial extracellular metalloprotease seem to be potentially useful for biotechnological and industrial applications. Automated ribotyping analysis revealed that 3 isolates (TANN 4, TR 2 and TR 4) resembled Halobacillus trueperi that exhibited 71, 68 and 69 % similarity respectively, and isolate (TR 1) resembled Virgibacillus pantothenticus with 64 % similarity.

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“…[204] and ethanol showed no inhibitory effect toward the protease activity isolated from Halobacterium sp. strain HP25 [208].…”

Section: Proteasesmentioning

confidence: 99%

Systematics of haloarchaea and biotechnological potential of their hydrolytic enzymes

et al. 2017

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Halophilic archaea, also referred to as haloarchaea, dominate hypersaline environments. To survive under such extreme conditions, haloarchaea and their enzymes have evolved to function optimally in environments with high salt concentrations and, sometimes, with extreme pH and temperatures. These features make haloarchaea attractive sources of a wide variety of biotechnological products, such as hydrolytic enzymes, with numerous potential applications in biotechnology. The unique trait of haloarchaeal enzymes, haloenzymes, to sustain activity under hypersaline conditions has extended the range of already-available biocatalysts and industrial processes in which high salt concentrations inhibit the activity of regular enzymes. In addition to their halostable properties, haloenzymes can also withstand other conditions such as extreme pH and temperature. In spite of these benefits, the industrial potential of these natural catalysts remains largely unexplored, with only a few characterized extracellular hydrolases. Because of the applied impact of haloarchaea and their specific ability to live in the presence of high salt concentrations, studies on their systematics have intensified in recent years, identifying many new genera and species. This review summarizes the current status of the haloarchaeal genera and species, and discusses the properties of haloenzymes and their potential industrial applications. SYSTEMATICS OF HALOPHILIC ARCHAEAHalophilic micro-organisms are found in the three domains of life, and are extremophiles living in hypersaline environments in the presence of salt (generally NaCl) as a specific requisite for their growth [1]. Hypersaline environments contain higher salt concentrations than seawater (3.5 % total dissolved salts) [2]. According to the optimum NaCl concentration for growth, micro-organisms fall into one of the following categories: extreme halophiles with optimum growth at 15-30 % (2.5-5.2 M) NaCl; moderate halophiles with optimum growth at 3-15 % (0.5-2.5 M) NaCl; slight halophiles with optimum growth at 1-3 % (0.2-0.5 M) NaCl; non-halophiles with optimum growth at less than 1 % (0.2 M) NaCl; and halotolerant micro-organisms which are non-halophiles showing the ability to tolerate high NaCl concentrations [3]. Halophiles can live in hypersaline environments because they are able to sustain osmotic balance. They use two main strategies to withstand the adverse consequences of water loss when exposed to high salt concentrations. The first strategy used by extremely halophilic archaea (haloarchaea) and halophilic anaerobic bacteria such as members of Halanaerobiales is known as the 'salt-in-cytoplasm' strategy, during which salts such as NaCl or KCl accumulate in the cytoplasm at concentrations similar to the extracellular ones [4,5]. Another mechanism to cope with high salt concentrations is the accumulation of organic molecules such as amino acids, sugars and polyols, known as compatible solutes or osmolytes. Compatible solutes are small and highly soluble molecules that can...

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Purification and characterization of halo-alkali-thermophilic protease from Halobacterium sp. strain HP25 isolated from raw salt, Lake Qarun, Fayoum, Egypt

Cited by 36 publications

References 49 publications

Unique Features of a New Baeyer–Villiger Monooxygenase from a Halophilic Archaeon

Unique Features of a New Baeyer–Villiger Monooxygenase from a Halophilic Archaeon

Isolation, Screening, Partial Purification and Characterization of Protease From Halophilic Bacteria Isolated From Indonesian Fermented Food

Systematics of haloarchaea and biotechnological potential of their hydrolytic enzymes

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