Purification and characterization of a novel extracellular halophilic and organic solvent-tolerant amylopullulanase from the haloarchaeon, Halorubrum sp. strain Ha25

Siroosi, Maryam; Amoozegar, Mohammad Ali; Khajeh, Khosro; Fazeli, Mostafa; Rezaei, Mehran Habibi

doi:10.1007/s00792-013-0589-6

Cited by 32 publications

(13 citation statements)

References 37 publications

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“…For example, an amylopullulanase from Halorubrum sp. strain Ha25 showed activity in the presence of CaCl 2 , even when NaCl was completely removed from the enzyme solution [201]. This shows that Ca 2+ could replace Na + with almost the same effect.…”

Section: High-salt Adaptation Of Haloenzymesmentioning

confidence: 65%

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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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Section: High-salt Adaptation Of Haloenzymesmentioning

confidence: 65%

“…This enzyme was active on pullulan and starch as substrates. The optimum temperature for both amylolytic and pullulytic activity was 50 C. This enzyme was active over a wide range of NaCl concentrations (0-4.5 M) and showed more stability in the presence of nonpolar organic solvents than polar solvents [230].…”

Section: Amylasesmentioning

confidence: 93%

Systematics of haloarchaea and biotechnological potential of their hydrolytic enzymes

et al. 2017

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“…To detect pullulanase activity, the strains were cultured in saline liquid medium containing (g/L) yeast extract 1, pullulan 5, and appropriate concentration of salts and incubated for 72 h. The pullulanase activity was detected by clearness of medium observed followed by adding 97 % ethanol, since pullulan and ethanol interaction results in forming a white precipitate of non degraded pullulan [13]. Figure S2 shows hydrolytic activity of some strains qualitatively, using complicated appropriate culture media.…”

Section: Determination Of Extracellular Pullulanase Activitymentioning

confidence: 99%

“…These microorganisms produce compounds of industrial interest, such as extracellular hydrolytic enzymes, that are stable and efficient under conditions leading to precipitation or denaturation of most other proteins [7][8][9][10][11][12][13].…”

Section: Introductionmentioning

confidence: 99%

Comparison of Bacterial Biodiversity and Enzyme Production in Three Hypersaline Lakes; Urmia, Howz-Soltan and Aran-Bidgol

et al. 2014

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This research is a comparative study on the diversity of halophilic bacteria with hydrolytic activities in three significant hypersaline lakes; Urmia in the northwest and Howz-Soltan and Aran-Bidgol in the central desert in Iran. Isolated strains from these saline lakes were found to be halotolerant, moderately and extremely halophilic bacteria. The bacteria in each saline lake were able to produce different hydrolytic enzymes including amylase, protease, lipase, DNase, inulinase, xylanase, carboxy methyl cellulase, pectinase and pullulanase. 188, 302, 91 halophilic strains were isolated from Urmia Lake, Howz-Soltan and Aran-Bidgol playa, respectively. The numbers of Grampositive strains were more than Gram-negatives, and among Gram-positive bacteria; spore-forming bacilli were most abundant. Due to the unique physico-chemical conditions of the lake environments, the hydrolytic activities of isolated strains were significantly different. For instance, isolated strains from Howz-Soltan playa did not produce pectinase, DNase, amylase, lipase and inulinase, while the isolates from Aran-Bidgol playa had a great ability to produce pectinase and DNase. The strains from Urmia Lake were also good producers of DNase but failed to show any chitinase activity. The diversity of halophilic bacteria from the mentioned three saline lakes was also determined using PCR-amplified 16S rRNA followed by phylogenetic analysis of the partial 16S rRNA sequences.

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“…For economic purposes, fermentation and material processing under a high-NaCl concentration can reduce the total cost by eliminating the sterilization process . Recent studies have described NaCl-tolerant cellulase (Shi et al 2013;Zhang et al 2012), xylanase (Hung et al 2011), mannanase (Zhou et al 2012), α-amylase (Qin et al 2014), amylopullulanase (Siroosi et al 2014), exo-inulinase (Zhou et al 2015a), β-agarase (Minegishi et al 2013), esterase (Wu et al 2013), and laccase (Molina-Guijarro et al 2009). Some of these NaCl-tolerant enzymes can be activated and/or stabilized by NaCl.…”

Section: Introductionmentioning

confidence: 97%

Characterization of a NaCl-tolerant β-N-acetylglucosaminidase from Sphingobacterium sp. HWLB1

et al. 2016

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β-N-Acetylglucosaminidases serve important biological functions and various industrial applications. A glycoside hydrolase family 3 β-N-acetylglucosaminidase gene was cloned from Sphingobacterium sp. HWLB1 and expressed in Escherichia coli BL21 (DE3). The purified recombinant enzyme (rNag3HWLB1) showed apparent optimal activity at pH 7.0 and 40 °C. In the presence of 0.5-20.0 % (w/v) NaCl, the activity and stability of rNag3HWLB1 were slightly affected or not affected. The enzyme could even retain 73.6 % activity when 30.0 % (w/v) NaCl was added to the reaction mixture. The half-life of the enzyme was approximately 10 min at 37 °C without the addition of NaCl. However, the enzyme was stable at 37 °C in the presence of 3.0 % (w/v) NaCl. A large negatively charged surface in the catalytic pocket of the enzyme was observed and might contribute to NaCl tolerance and thermostability improvement. The degree of synergy between a commercial endochitinase and rNag3HWLB1 on chitin enzymatic degradation ranged from 3.11 to 3.74. This study is the first to report the molecular and biochemical properties of a NaCl-tolerant β-N-acetylglucosaminidase.

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Purification and characterization of a novel extracellular halophilic and organic solvent-tolerant amylopullulanase from the haloarchaeon, Halorubrum sp. strain Ha25

Cited by 32 publications

References 37 publications

Systematics of haloarchaea and biotechnological potential of their hydrolytic enzymes

Systematics of haloarchaea and biotechnological potential of their hydrolytic enzymes

Comparison of Bacterial Biodiversity and Enzyme Production in Three Hypersaline Lakes; Urmia, Howz-Soltan and Aran-Bidgol

Characterization of a NaCl-tolerant β-N-acetylglucosaminidase from Sphingobacterium sp. HWLB1

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