Effect of nutritional conditions on extracellular protease production by the haloalkaliphilic archaeon Natrialba magadii

D’Alessandro, Celeste Paola; Castro, Rosana Esther de; Giménez, María Inés; Paggi, Roberto A.

doi:10.1111/j.1472-765x.2007.02122.x

Cited by 17 publications

(17 citation statements)

References 20 publications

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“…1). This finding supports our previous observations, which showed that carbon and nitrogen starvation did not induce protease accumulation, suggesting that de novo synthesis of Nep was required (D’Alessandro et al. 2007).…”

Section: Discussionsupporting

confidence: 93%

“…2000), suggesting that it was produced in response to nutrient scarcity, an increase in the population density or both. We have recently shown that accumulation of Nep activity is stimulated by nutrient limitation or slow growth rate, indicating that this protease is induced in response to a deficit in the energetic status of the cells and thus may serve a nutritional purpose (D’Alessandro et al. 2007).…”

Section: Introductionmentioning

confidence: 99%

“…2007). However, low‐density cultures starved for carbon and nitrogen sources did not produce detectable amounts of extracellular protease activity (D’Alessandro et al. 2007), which suggested the possibility that de novo synthesis of the protease was required and/or ‘factors’ present in stationary phase cultures may be needed for Nep formation.…”

Section: Introductionmentioning

confidence: 99%

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Growth phase-dependent biosynthesis of Nep, a halolysin-like protease secreted by the alkaliphilic haloarchaeon Natrialba magadii

Paggi¹,

Madrid²,

D’Alessandro³

et al. 2010

Letters in Applied Microbiology

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Aims: The alkaliphilic haloarchaeon Natrialba magadii secretes a halolysin‐like protease (Nep) that is active and stable in high salt and in organic solvents, which represents a potential resource for biocatalysis in low water activity conditions. In this study, the effect of the growth stage on Nep biosynthesis was examined. Methods and Results: Nep mRNA and extracellular protease activity were measured by RT‐PCR and azocaseinolytic activity determination, respectively. Increased abundance in Nep mRNA was observed in Nab. magadii cells with culture age, which correlated with accumulation of extracellular protease activity. Moreover, a ‘stationary phase behavior’ on synthesis of Nep was evidenced in low‐density cultures incubated with stationary phase medium. Conclusions: nep gene expression is up‐regulated during the transition to the stationary phase in response to ‘factors’ (metabolite and/or regulatory molecule) occurring in high‐density cultures of Nab. magadii. Although the identity of these molecules remains to be determined, preliminary evidence suggests that they are hydrophobic and stable in high salt and high pH values (3·5 mol l−1 NaCl, pH 10). Significance and impact of study: This study contributes to gain insight into the regulation of haloarchaeal protease biosynthesis, facilitating the large‐scale production of this extremozyme for basic studies or potential applications.

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Section: Discussionsupporting

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Growth phase-dependent biosynthesis of Nep, a halolysin-like protease secreted by the alkaliphilic haloarchaeon Natrialba magadii

Paggi¹,

Madrid²,

D’Alessandro³

et al. 2010

Letters in Applied Microbiology

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“…in enzyme production has been reported for some haloarchaeal proteases such as those produced by Nab. magadii [213], Halobacterium sp. Js1 [214], Halorubrum ezzemoulense ETR14 [215] and Halogeometricum sp.…”

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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“…Till date only few attempts have been made to study the effect of culture conditions on protease production by halophilic archaea (Vidyasagar et al. 2006; D’Alessandro et al. 2007).…”

Section: Introductionmentioning

confidence: 99%

Statistical optimization of medium components for extracellular protease production by an extreme haloarchaeon,Halobacteriumsp. SP1(1)

Akolkar

Bharambe

Trivedi

et al. 2009

Letters in Applied Microbiology

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Aims: Optimization of medium components for extracellular protease production by Halobacterium sp. SP1(1) using statistical approach. Methods and Results: The significant factors influencing the protease production as screened by Plackett–Burman method were identified as soybean flour and FeCl3. Response surface methodology such as central composite design was applied for further optimization studies. The concentrations of medium components for higher protease production as optimized using this approach were (g l−1): NaCl, 250; KCl, 2; MgSO4, 10; tri‐Na‐citrate, 1·5; soybean flour, 10 and FeCl3, 0·16. This statistical optimization approach led to production of 69·44 ± 0·811 U ml−1 of protease. Conclusions: Soybean flour and FeCl3 were identified as important factors controlling the production of extracellular protease by Halobacterium sp. SP1(1). The statistical approach was found to be very effective in optimizing the medium components in manageable number of experimental runs with overall 3·9‐fold increase in extracellular protease production. Significance and Impact of the Study: The present study is the first report on statistical optimization of medium components for production of haloarchaeal protease. The study also explored the possibility of using extracellular protease produced by Halobacterium sp. SP1(1) for various applications like antifouling coatings and fish sauce preparation using cheaper raw material.

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Effect of nutritional conditions on extracellular protease production by the haloalkaliphilic archaeon Natrialba magadii

Cited by 17 publications

References 20 publications

Growth phase-dependent biosynthesis of Nep, a halolysin-like protease secreted by the alkaliphilic haloarchaeon Natrialba magadii

Growth phase-dependent biosynthesis of Nep, a halolysin-like protease secreted by the alkaliphilic haloarchaeon Natrialba magadii

Systematics of haloarchaea and biotechnological potential of their hydrolytic enzymes

Statistical optimization of medium components for extracellular protease production by an extreme haloarchaeon,Halobacteriumsp. SP1(1)

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