scholarly journals Characterization of the Proteolytic Activity of a Halophilic Aspergillus reticulatus Strain SK1-1 Isolated from a Solar Saltern

2021 ◽  
Vol 10 (1) ◽  
pp. 29
Author(s):  
Dawoon Chung ◽  
Woon-Jong Yu ◽  
Ji-Yeon Lim ◽  
Nam-Seon Kang ◽  
Yong-Min Kwon ◽  
...  
Keyword(s):  
Proteolytic Activity ◽  
Food Processing ◽  
Waste Treatment ◽  
Maximum Activity ◽  
Hypersaline Environments ◽  
Alkaline Serine Protease ◽  
Saline Environment ◽  
The Republic ◽  
Halophilic Fungi

Salterns are hypersaline environments that are inhabited by diverse halophilic microorganisms, including fungi. In this study, we isolated a fungal strain SK1-1 from a saltern in the Republic of Korea, which was identified as Asperillus reticulatus. This is the first reported saline-environment-derived A. reticulatus that belongs to the Aspergillus penicillioides clade and encompasses xerophilic fungi. SK1-1 was halophilic, obligately requiring NaCl for growth, with a maximum radial growth of 6%–9% (w/v) NaCl. To facilitate the biotechnological application of halophilic fungi, we screened the SK1-1 strain for proteolytic activity. Proteases have widespread applications in food processing, detergents, textiles, and waste treatment, and halophilic proteases can enable protein degradation in high salt environments. We assessed the proteolytic activity of the extracellular crude enzyme of SK1-1 using azocasein as a substrate. The crude protease exhibited maximum activity at 40–50 °C, pH 9.5–10.5, and in the absence of NaCl. It was also able to retain up to 69% of its maximum activity until 7% NaCl. Protease inhibitor assays showed complete inhibition of the proteolytic activity of crude enzymes by Pefabloc® SC. Our data suggest that the halophilic A. reticulatus strain SK1-1 produces an extracellular alkaline serine protease.

Isolation, purification and characterization of chymosin from riverine buffalo (Bubalos bubalis)

2003 ◽  
Vol 70 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Ashok K Mohanty ◽  
Utpal K Mukhopadhyay ◽  
Jai K Kaushik ◽  
Sunita Grover ◽  
Virender K Batish
Keyword(s):  
Amino Acid ◽  
Proteolytic Activity ◽  
Gel Filtration ◽  
Maximum Activity ◽  
Amino Acid Sequences ◽  
Milk Clotting ◽  
Sds Page ◽  
Terminal Amino ◽  
The Stability

Chymosin, an aspartyl proteinase, is used for curdling of milk and manufacture of cheese. We report the purification and the physicochemical properties of chymosin isolated from the abomasal tissue of buffalo calves. The enzyme preparation extracted from buffalo abomasal tissues could be purified 29–fold using anion exchange and gel filtration chromatography. The molecular weight of the purified enzyme was 35·6 kDa on SDS-PAGE. Partial N-terminal amino acid sequence of the first eight amino acid sequences of buffalo chymosin was identical to the first eight amino acid sequences of cattle chymosin. Buffalo chymosin exhibited a skewed bell-shaped stability profile as a function of temperature with maximum activity near 55 °C. Milk clotting activity decreased gradually as pH increased. The enzyme became completely inactive, however, above pH 7·0. The ratio of milk clotting to proteolytic activity was 3·03. When compared with cattle chymosin, there were subtle differences in the stability and relative proteolytic activity of buffalo chymosin.

scholarly journals Functional and Molecular Characterization of the Halomicrobium sp. IBSBa Inulosucrase

2021 ◽  
Vol 9 (4) ◽  
pp. 749
Author(s):  
Gülbahar Abaramak ◽  
Jaime Ricardo Porras-Domínguez ◽  
Henry Christopher Janse van Rensburg ◽  
Eveline Lescrinier ◽  
Ebru Toksoy Öner ◽  
...  
Keyword(s):  
Molecular Characterization ◽  
Phylogenetic Analyses ◽  
Halophilic Archaea ◽  
Maximum Activity ◽  
Physiological Relevance ◽  
Health Related ◽  
Specific Alternative ◽  
Binding Groove ◽  
Native Host

Fructans are fructose-based (poly)saccharides with inulin and levan being the best-known ones. Thanks to their health-related benefits, inulin-type fructans have been under the focus of scientific and industrial communities, though mostly represented by plant-based inulins, and rarely by microbial ones. Recently, it was discovered that some extremely halophilic Archaea are also able to synthesize fructans. Here, we describe the first in-depth functional and molecular characterization of an Archaeal inulosucrase from Halomicrobium sp. IBSBa (HmcIsc). The HmcIsc enzyme was recombinantly expressed and purified in Escherichia coli and shown to synthesize inulin as proven by nuclear magnetic resonance (NMR) analysis. In accordance with the halophilic lifestyle of its native host, the enzyme showed maximum activity at very high NaCl concentrations (3.5 M), with specific adaptations for that purpose. Phylogenetic analyses suggested that Archaeal inulosucrases have been acquired from halophilic bacilli through horizontal gene transfer, with a HX(H/F)T motif evolving further into a HXHT motif, together with a unique D residue creating the onset of a specific alternative acceptor binding groove. This work uncovers a novel area in fructan research, highlighting unexplored aspects of life in hypersaline habitats, and raising questions about the general physiological relevance of inulosucrases and their products in nature.

scholarly journals Allergens from Edible Insects: Cross-reactivity and Effects of Processing

2021 ◽  
Vol 21 (5) ◽  
Author(s):  
Laura De Marchi ◽  
Andrea Wangorsch ◽  
Gianni Zoccatelli
Keyword(s):  
Food Processing ◽  
Cross Reactivity ◽  
Allergic Reactions ◽  
Edible Insects ◽  
Insect Allergy ◽  
Crucial Information ◽  
Inhalant Allergens ◽  
Minor Allergens

Abstract Purpose of Review The recent introduction of edible insects in Western countries has raised concerns about their safety in terms of allergenic reactions. The characterization of insect allergens, the sensitization and cross-reactivity mechanisms, and the effects of food processing represent crucial information for risk assessment. Recent Findings Allergic reactions to different insects and cross-reactivity with crustacean and inhalant allergens have been described, with the identification of new IgE-binding proteins besides well-known pan-allergens. Depending on the route of sensitization, different potential allergens seem to be involved. Food processing may affect the solubility and the immunoreactivity of insect allergens, with results depending on species and type of proteins. Chemical/enzymatic hydrolysis, in some cases, abolishes immunoreactivity. Summary More studies based on subjects with a confirmed insect allergy are necessary to identify major and minor allergens and the role of the route of sensitization. The effects of processing need to be further investigated to assess the risk associated with the ingestion of insect-containing food products.

scholarly journals Partial purification and biochemical characterization of a new highly acidic NYSO laccase from Alcaligenes faecalis

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Soad A. Abdelgalil ◽  
Ahmad R. Attia ◽  
Reyed M. Reyed ◽  
Nadia A. Soliman
Keyword(s):  
Enzyme Activity ◽  
Sodium Dodecyl ◽  
Alcaligenes Faecalis ◽  
Maximum Activity ◽  
Sodium Oxalate ◽  
Partial Purification ◽  
Bromophenol Blue ◽  
Bromocresol Purple ◽  
Laccase Enzyme

Abstract Background Due to the multitude industrial applications of ligninolytic enzymes, their demands are increasing. Partial purification and intensive characterization of contemporary highly acidic laccase enzyme produced by an Egyptian local isolate designated Alcaligenes faecalis NYSO were studied in the present investigation. Results Alcaligenes faecalis NYSO laccase has been partially purified and intensively biochemically characterized. It was noticed that 40–60% ammonium sulfate saturation showed maximum activity. A protein band with an apparent molecular mass of ~ 50 kDa related to NYSO laccase was identified through SDS-PAGE and zymography. The partially purified enzyme exhibited maximum activity at 55 °C and pH suboptimal (2.5–5.0). Remarkable activation for enzyme activity was recognized after 10-min exposure to temperatures (T) 50, 60, and 70 °C; time elongation caused inactivation, where ~ 50% of activity was lost after a 7-h exposure to 60 °C. Some metal ions Cu2+, Zn2+, Co2+, Ni2+, Mn2+, Cd2+, Cr2+, and Mg2+ caused strong stimulation for enzyme activity, but Fe2+ and Hg2+ reduced the activity. One millimolar of chelating agents [ethylenediamine tetraacetic acid (EDTA), sodium citrate, and sodium oxalate] caused strong activation for enzyme activity. Sodium dodecyl sulfate (SDS), cysteine-HCl, dithiothreitol (DTT), β-mercaptoethanol, thioglycolic acid, and sodium azide caused strong inhibition for NYSO laccase activity even at low concentration. One millimolar of urea, imidazole, kojic acid, phenylmethylsulfonyl fluoride (PMSF), H2O2, and Triton X-100 caused activation. The partially purified NYSO laccase had decolorization activity towards different dyes such as congo red, crystal violet, methylene blue, fast green, basic fuchsin, bromophenol blue, malachite green, bromocresol purple eriochrome black T, and Coomassie Brilliant Blue R-250 with various degree of degradation. Also, it had a vast range of substrate specificity including lignin, but with high affinity towards p-anisidine. Conclusion The promising properties of the newly studied laccase enzyme from Alcaligenes faecalis NYSO strain would support several industries such as textile, food, and paper and open the possibility for commercial use in water treatment. It will also open the door to new applications due to its ligninolytic properties in the near future.

Investigating the Relationship between Company Competitiveness and Environmental Regulation in European Food Processing: Results of a Matched Firm Comparison

1998 ◽  
Vol 30 (9) ◽  
pp. 1585-1602 ◽  
Author(s):  
D M W N Hitchens ◽  
J E Birnie ◽  
A McGowan ◽  
U Triebswetter ◽  
A Cottica
Keyword(s):  
Environmental Regulation ◽  
Food Processing ◽  
Value Added ◽  
Effluent Treatment ◽  
Environmental Costs ◽  
The European Union ◽  
The Republic ◽  
The Cost ◽  
The Relationship ◽  
Regulation Costs

The authors use a method of matched-plant comparisons between food processing firms in Germany, Italy, Northern Ireland, and the Republic of Ireland to investigate the relationship between environmental regulation and company competitiveness across the European Union. Comparative competitiveness was indicated by measures of value-added per employee, physical productivity, export share, and employment growth. The cost of water supply (public or well), effluent treatment (in-plant treatment and/or sewerage system), and disposal of sludge and packaging were also compared. Total environmental costs in Germany, Italy, and Ireland were small: usually less than 1% of turnover. Compared with the Irish firms, German companies had relatively high environmental costs as well as productivity levels. There was, however, a lack of a clear relationship between company competitiveness and the size of regulation costs: in Ireland and Italy environmental costs were similar but German firms had much higher productivity; compared with German counterparts, Italian firms had lower environmental costs but higher productivity.

Characterization of the Low-Salinity Stress in Vibrio vulnificus

2008 ◽  
Vol 71 (2) ◽  
pp. 416-419 ◽  
Author(s):  
HIN-CHUNG WONG ◽  
SHU-HUI LIU
Keyword(s):  
Salinity Stress ◽  
Food Processing ◽  
Vibrio Vulnificus ◽  
Exponential Phase ◽  
Salinity Adaptation ◽  
Significant Protection ◽  
Low Salinity ◽  
Short Period ◽  
Nonculturable State

Vibrio vulnificus is a marine pathogenic bacterium commonly found in seawater or seafood. This organism encounters low-salinity stress in its natural environment and during food processing. This study was designed to investigate the response of V. vulnificus YJ03 to lethal low salinity (0.04% NaCl) and its adaptation to sublethal salinity (0.12% NaCl with 20 amino acids added). A short period in the nonculturable state was induced by lethal low-salinity stress followed by cell death after 30 min of stress. Addition of 1 mM glycine betaine or 0.5 mM sucrose reduced the damage. Low-salinity adaptation was achieved in the exponential-phase cells but not in the stationary-phase cells. Significant protection against lethal low-salinity stress was attained when the cells were adapted for as little as 1.5 min. The adapted cells were significantly protected against lethal low salinity and 2.4% sodium sorbate but sensitized to the challenge of heat (52°C) and acid (pH 3.2). Nonlethal lowsalinity treatment of seafood should be avoided to prevent stress adaptation of V. vulnificus.

scholarly journals Purification and characterization of acid phosphatase from a germinating black gram (Vigna mungo L.) seedling

2011 ◽  
Vol 63 (3) ◽  
pp. 747-756 ◽  
Author(s):  
A.K.M. Asaduzzaman ◽  
Habibur Rahman ◽  
Tanzima Yeasmin
Keyword(s):  
Acid Phosphatase ◽  
Gel Electrophoresis ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Inhibitory Effect ◽  
Maximum Activity ◽  
Exchange Chromatography ◽  
Black Gram ◽  
Km Value

An acid phosphatase has been isolated and purified from an extract of a germinating black gram seedling. The method was accomplished by gel filtration of a germinating black gram seedling crude extract on sephadex G-75 followed by ion exchange chromatography on DEAE cellulose. The acid phosphatase gave a single band on SDS-polyacrylamide slab gel electrophoresis. The molecular weight of the acid phosphatase determined by SDS-polyacrylamide slab gel electrophoresis was estimated to be 25 kDa. The purified enzyme showed maximum activity at pH 5 and at temperature of 55?C. Mg2+, Zn2+ and EDTA had an inhibitory effect on the activity of the acid phosphatase. Black gram seedling acid phosphatase was activated by K+, Cu2+ and Ba2+. The Km value of the enzyme was found to be 0.49 mM for pNPP as substrate.

scholarly journals Purificación Parcial y Caracterización de Alfa Amilasa de granos germinados de Chenopodium quinoa (Quinua)

2018 ◽  
pp. 52-58
Keyword(s):  
Specific Activity ◽  
Chenopodium Quinoa ◽  
Maximum Activity ◽  
Alpha Amylase ◽  
Partial Purification ◽  
Chemical Hydrolysis ◽  
Germination Process ◽  
Sds Page ◽  
Global Population

Purificación Parcial y Caracterización de Alfa Amilasa de granos germinados de Chenopodium quinoa (Quinua) Partial Purification and Characterization of Alpha Amylase from germinated grains from Chenopopdium quinoa (Quinua) Melissa Bedón Gómez, Oscar Nolasco Cárdenas, Carlos Santa Cruz C. y Ana I. F. Gutiérrez Román Universidad Nacional Federico Villarreal, Facultad de Ciencias Naturales y Matemática, Laboratorio de Bioquímica y Biología Molecular, Jr. Río Chepén S/N, El Agustino. Telefax: 362 - 3388 DOI: https://doi.org/10.33017/RevECIPeru2013.0007/ Resumen Las alfa amilasas son las enzimas más estudiadas e importantes en el campo biotecnológico e industrial; ya que han reemplazado por completo la hidrólisis química del almidón. Estas enzimas son imprescindibles en la elaboración de productos alimenticios, combustibles, medicamentos y detergentes con la finalidad de optimizar procesos y conservar el medio ambiente. La α-amilasa puede ser purificada de diferentes organismos como plantas, animales, hongos y bacterias; actualmente un gran número de α-amilasas bacterianas en especial del género Bacillus están disponibles comercialmente y son las más utilizadas en las industrias. Sin embargo, la producción de éstas no satisfacen los requerimientos industriales en el mundo; ya que, la demanda de esta enzima se ha incrementado en los últimos dos años y el empleo de α-amilasas bacterianas ha provocado alergias afectando al 15% de la población a nivel mundial. . En este estudio, como fuente de α-amilasa se emplearon semillas de Chenopodium quinoa (quinua) var hualhuas blanca durante el proceso de germinación; esta enzima fue parcialmente purificada por precipitación con sulfato de amonio obteniendo una actividad específica final de 35.60U/mg y un grado de purificación de 5 veces. La purificación fue confirmada por SDS-PAGE, encontrando un peso molecular de 44kDa. La actividad enzimática se evaluó mediante el método de Miller mostrando máxima actividad a pH 7 y a temperatura de 37ºC. La linealización de Lineweaver-Burk nos dio un Km de 16mg/mL y Vmax de 100µM de maltosa/min. Por lo tanto, esta caracterización reúne los pre-requisitos necesarios para la aplicación en la industria. Descriptores: Chenopodium quinoa, alfa amilasa, germinación, purificación parcial. Abstract The alpha amylases are the enzymes most studied and important in biotechnology and industry; because they have completely replaced the starch’s chemical hydrolysis. These enzymes are essential in the food production, medicines and detergents in order to optimize processes and conserve the environment. The α-amylase can be isolated from different organisms such as plants, animals, fungi and bacteria, now a large number of bacterial α-amylases especially from genus Bacillus are commercially available and they are the most used in industry. However, the production of these do not meet industry requirements in the world, because the demand for this enzyme has increased in the last two years and the use of bacterial α-amilase has caused allergies affecting the 15% of the global population. In this study, as a source of α-amylase used the seeds from Chenopodium quinoa (quinoa). Var. white hualhuas during the germination process, this enzyme was partially purified by ammonium sulfate precipitation to obtain a final specific activity of 35.60U/mg, and a grade of purification of 5 times. The purification was confirmed by SDS-PAGE, where the molecular weight was 44kDa. The enzyme activity was evaluated by Miller method showing maximum activity at pH 7 and 37ºC. The Lineweaver-Burk linearization shows a Km of 16mg/mL and Vmax of 100μM the maltose / min. Therefore, these characterizations meet the prerequisites need for industry. Keywords: Chenopodium quinoa; alpha amylase; germination; partial purification

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