Aquaculture by-product: a source of proteolytic enzymes for detergent additives

AbstractIntestine proteases of Nile tilapia (Oreochromis niloticus) were partially purified by heat treatment (purification factor of 3.5, enzyme activity remained almost constant) to reach the maximum activity and stability within an alkaline pH range of 7.2–11.0. The optimum temperature and stability over a 120 min period were found to be at 55°C and at 35–45°C, respectively. The proteases’ activity was not affected by a 1 vol. % saponin surfactant, inactivated by 0.01 g mL−1 sodium dodecylsulphate after 120 min, and it remained stable for 30 min in a 5 vol. % and 10 vol. % hydrogen peroxide solutions. The proteases were slightly activated by Ca2+, Mg2+, and K+ and the substrate most effectively hydrolysed was casein (40.0 U mg−1). A 24 full factorial design used to evaluated the influence of independent variables showed that the enzyme extract, detergent concentration and the incubation time had a significant influence on the enzymatic activity. The best conditions to be used concerning detergent additive were found with 0.3 mg mL−1 of protein and 3.0 mg mL−1 of detergent for 30 min in the presence of Astrus® detergent.

Download Full-text

An initial characterization of the proteolytic enzymes secreted by the adult stage of the human hookworm Necator americanus

Parasitology ◽

10.1017/s0031182000065276 ◽

1995 ◽

Vol 110 (5) ◽

pp. 555-563 ◽

Cited By ~ 28

Author(s):

A. Brown ◽

J. M. Burleigh ◽

E. E. Billett ◽

D. I. Pritchard

Keyword(s):

Serine Proteases ◽

Metal Ion ◽

Proteolytic Enzymes ◽

Maximum Activity ◽

Biologically Relevant ◽

Necator Americanus ◽

Recent Developments ◽

Proteolytic Activities ◽

Secretory Products ◽

Ph Range

SUMMARYThe proteolytic activities present in adult Necator americanus excretory–secretory products have been assessed using biologically relevant, naturally occurring substrates (haemoglobin and fibrinogen) and a number of synthetic fluorogenic and chromogenic substrates. One broad peak of activity was observed against haemoglobin in the pH range 5 to 7, with maximum activity at pH 6·6, while fibrinogenolytic activity was shown to be greater at pH 3·5. Inhibition studies against haemoglobin, fibrinogen and synthetic substrates using a battery of appropriate protease inhibitors indicated the presence of a mixture of aspartyl, cysteinyl and serine proteases. Metal ion (Ca2+, Zn2+ and Fe2+) stimulation was demonstrated, with stimulation by Zn2+ being the most marked. These results are discussed in the context of recent developments in the field of parasite proteolytic enzymes, where they have been suggested as targets for immuno- and chemotherapy.

Download Full-text

Actividad enzimática de proteasas de Cyprinus carpio (Cypriniformes: Cyprinidae) extraídas de una laguna contaminada en México

Revista de Biología Tropical ◽

10.15517/rbt.v65i2.24486 ◽

2017 ◽

Vol 65 (2) ◽

Cited By ~ 1

Author(s):

Arisaí Hernández-Sámano ◽

Xochitl Guzmán-García ◽

Raquel García-Barrientos ◽

Isabel Guerrero-Legarreta

Keyword(s):

Proteolytic Activity ◽

Cyprinus Carpio ◽

Proteolytic Enzymes ◽

Polyacrylamide Gel Electrophoresis ◽

Waste Water Treatment ◽

Sodium Dodecyl ◽

Maximum Activity ◽

Protease Production ◽

Human Consumption ◽

Alkaline Ph

Common carp (Cyprinus carpio) is an aquatic organism of commercial value able to survive in polluted environments; carps contain proteolytic enzymes of physiological importance and potential industrial application. The objective of this work was partially purify and study the proteolytic activity at different pH of carp proteases living in a polluted environment. Three carps were captured in different zones of Zumpango polluted lagoon (Mexico) at 1 m of maximum deep. Protease crude extracts were obtained from dorsal muscle by aqueous extraction and fractionated by 20 %, 50 %, 80 %-saturated (NH4)2SO4. Fractions extracted with 50 % and 80 %-saturated (NH4)2SO4 were selected for their high proteolytic activity and concentrated by ultrafiltration through 100 kDa molecular weight cutoff membranes and analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The crude proteolytic extract had significantly higher activity (19.7 - 20.3 U / mg) at pH 2, 5, and 7 (P < 0.001). Fractions obtained with 20 %, 50 % and 80 % - saturated (NH4)2SO4 showed peak activity at pH 5 (2.8 U / mg) and pH 6 (2.2 U / mg); pH 6 (4.3 U / mg) and pH 3 - 4 (3.6 - 3.7 U / mg); pH 3 (10.8 U / mg) and pH 10 (10.6 U / mg); respectively. Subfractions of < 100 kDa, obtained with 50 % and 80 %-saturated (NH4)2SO4, had peak proteolytic activity at alkaline pH. A < 100 kDa fraction, obtained with 80 %-saturated (NH4)2SO4, had the highest proteolytic activity (37.3 - 43.7 U / mg) at pH 8 - 10, purification factor of 3 and 19.1 % recovery. Thirteen proteins between 9.8 to 104.8 kDa were identified in the crude extract. Peak protein concentration was observed for 31 - 33 and 39 - 41 kDa, suggesting the possibility predominance of serine- and aspartyl- proteases, respectively. We suggest this protease with maximum activity at alkaline pH is related to the adaptation of C. carpio to polluted waters with high pH. Although unsuitable for human consumption, these organisms can be a source of protease production aimed to several uses as in the industry and waste water treatment among others.

Download Full-text

Some properties of the extracellular proteolytic enzymes of the milk-spoiling organismPseudomonas aeruginosaATCC 10145

Journal of Dairy Research ◽

10.1017/s0022029900019142 ◽

1968 ◽

Vol 35 (3) ◽

pp. 395-398 ◽

Cited By ~ 13

Author(s):

H. S. Juffs ◽

H. W. Doelle

Keyword(s):

Pseudomonas Aeruginosa ◽

Proteolytic Activity ◽

Culture Supernatant ◽

Proteolytic Enzymes ◽

Maximum Activity ◽

Ph Range

SummaryThe proteolytic enzymes present in the culture supernatant ofPseudomonas aeruginosaATCC 10145 were active in the pH range 5·5–9·0 with a maximum activity at pH 7·3. Heating for 15 sec at 72°C resulted in a 36% loss of proteolytic activity whereas heating for 30 min at 63°C resulted, in a 6% loss. Boiling for 2 min completely inactivated the proteolytic enzymes. At 2°C the proteolytic enzymes were stable for at least a month and casein was readily hydrolysed at this temperature.

Download Full-text

Comparative Two-Dimensional Gel Electrophoresis of Trypanosoma cruzi Mammalian-Stage Forms in an Alkaline pH Range

Protein and Peptide Letters ◽

10.2174/0929866522666150915122120 ◽

2015 ◽

Vol 22 (12) ◽

pp. 1066-1075 ◽

Cited By ~ 2

Author(s):

Adriana Magalhães ◽

Rayner Queiroz ◽

Izabela Bastos ◽

Jaime Santana ◽

Marcelo Sousa ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Gel Electrophoresis ◽

Two Dimensional ◽

Alkaline Ph ◽

Two Dimensional Gel Electrophoresis ◽

Ph Range

Download Full-text

Application of 32 Full Factorial Design and Desirability Function for Optimizing The Manufacturing Process for Directly Compressible Multi-Functional Co-Processed Excipient

Current Drug Delivery ◽

10.2174/1567201817666200508094743 ◽

2020 ◽

Vol 17 (6) ◽

pp. 523-539

Author(s):

Jalpa Patel ◽

Dhaval Mori

Keyword(s):

Factorial Design ◽

Spray Drying ◽

Desirability Function ◽

Full Factorial Design ◽

Angle Of Repose ◽

P Value ◽

Independent Variables ◽

Full Factorial ◽

32 Full Factorial Design ◽

Response Variables

Background: Developing a new excipient and obtaining its market approval is an expensive, time-consuming and complex process. Compared to that, the co-processing of already approved excipients has emerged as a more attractive option for bringing better characteristic excipients to the market. The application of the Design of Experiments (DoE) approach for developing co-processed excipient can make the entire process cost-effective and rapid. Objective: The aim of the present investigation was to demonstrate the applicability of the DoE approach, especially 32 full factorial design, to develop a multi-functional co-processed excipient for the direct compression of model drug - cefixime trihydrate using spray drying technique. Methods: The preliminary studies proved the significant effect of atomization pressure (X1) and polymer ratio (microcrystalline cellulose: mannitol - X2) on critical product characteristics, so they were selected as independent variables. The angle of repose, Carr’s index, Hausner’s ratio, tensile strength and Kuno’s constant were selected as response variables. Result: The statistical analysis proved a significant effect of both independent variables on all response variables with a significant p-value < 0.05. The desirability function available in Design Expert 11® software was used to prepare and select the optimized batch. The prepared co-processed excipient had better compressibility than individual excipients and their physical mixture and was able to accommodate more than 40 percent drug without compromising the flow property and compressibility. Conclusion: The present investigation successfully proved the applicability of 32 full factorial design as an effective tool for optimizing the spray drying process to prepare a multi-functional co-processed excipient.

Download Full-text

Comprehensive analysis of the isozyme composition of laccase derived from Japanese lacquer tree, Toxicodendron vernicifluum

Journal of Wood Science ◽

10.1186/s10086-021-01943-1 ◽

2021 ◽

Vol 67 (1) ◽

Author(s):

Mariko Takano ◽

Masaya Nakamura ◽

Masanobu Tabata

Keyword(s):

Isoelectric Focusing ◽

Laccase Activity ◽

Maximum Activity ◽

Acetone Powder ◽

Blue Color ◽

Buffer Solution ◽

Activity Staining ◽

Water Extracts ◽

Ph Range ◽

Toxicodendron Vernicifluum

AbstractWe performed an analysis using isoelectric focusing to comprehensively clarify the isozyme composition of laccase derived from Japanese lacquer tree, Toxicodendron vernicifluum. When water extracts of acetone powder obtained from lacquer were subjected to isoelectric focusing, five bands within pI 7.35–9.30 and nine bands within pI 3.50–5.25 were detected using Coomassie staining. Similarly, laccase activity staining using guaiacol showed five bands within pI 7.35–9.30 and three bands within pI 3.50–4.25. However, laccase activity staining using gallic acid showed remarkable staining within pI 3.50–5.85, whereas staining was very weak within pI 7.35–9.30. When the water extracts of acetone powder were fractionated into the fractions containing bands within pI 7.35–9.30 and pI 3.50–5.85 by SP-Sepharose column chromatography, the former had a blue color and the latter a yellow color. The laccase activity was measured for each of the fractions in buffer solution in the pH range of 2.5–8.0. When syringaldazine, guaiacol, and 2,6-dimethoxyphenol were used as substrates, the yellow fraction showed considerably higher activity than the blue fraction for pH 5.5–7.5. When 3-methylcatechol and 4-methylcatechol were used as substrates, the yellow fraction showed higher activity for pH 4.5–6.5, and the blue fraction showed higher activity for pH 7.0–8.0. When 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) was used as the substrate, both fractions showed maximum activity at optimum pH of 3.0–4.0. Conventionally, in research on blue laccase derived from lacquer, the non-blue fraction corresponding to the yellow fraction lower than pI 6 has been removed during the purification process and thus has not been analyzed. Our results indicated that yellow laccase was present in the non-blue components of lacquer and that it may play a role in urushiol polymerization with previously reported blue laccase.

Download Full-text

Pyridine–Adenine Dinucleotide Transhydrogenase Activity in Cells Cultured from Rat Hepatoma

Canadian Journal of Biochemistry ◽

10.1139/o72-062 ◽

1972 ◽

Vol 50 (5) ◽

pp. 447-456 ◽

Cited By ~ 1

Author(s):

C. De Luca ◽

R. P. Gioeli

Keyword(s):

Phosphate Buffer ◽

Pyridine Nucleotide ◽

Maximum Activity ◽

Ph Optimum ◽

Apparent Lack ◽

Minimal Deviation ◽

Ph Range ◽

Pyridine Nucleotide Transhydrogenase ◽

Rat Hepatoma ◽

Cells Cultured

Preparations from cells cultured from a minimal-deviation hepatoma in the rat exhibit pyridine nucleotide transhydrogenase (NAD(P)H: NAD(P) oxidoreductase, EC 1.6.1.1) activity. The pH optimum, its release by digitonin, and its apparent lack of dependence on steroids for activity tentatively classify it as a transhydrogenase of the type first described for animal tissue.Enzyme preparations from digitonin-treated homogenates were very unstable. The time necessary for the loss of one-half the activity was 16–18 h when the enzyme was stored at 5 °C; this was reduced to 4 h when storage was in polycarbonate tubes.The enzyme apparently transferred hydrogen directly and with equal ease from NADH to both the 3-acetyl-pyridine and thionicotinamide analogues of NAD. Half-saturation values for NAD and its acetylpyridine analogue were 0.99 × 10−5 M and 3.55 × 10−4 M, respectively. The enzyme exhibited its maximum activity in phosphate buffer at pH 5.8. It was inhibited by 50–60% over the pH range 7.0–8.5 in Tris buffer. This could be reversed by dithiothreitol; reversal was complete between pH 8.0 and 8.5.

Download Full-text

Large Vessel Nozzle Penetration Geometric Optimisation Study in 3D Incorporating Design of Experiments Techniques

Volume 2: Computer Technology and Bolted Joints ◽

10.1115/pvp2012-78076 ◽

2012 ◽

Author(s):

Adam Towse ◽

Michael Martin ◽

Adrian Allen ◽

Chris Andrews

Keyword(s):

Pressure Vessel ◽

Shell Thickness ◽

Element Model ◽

Structural Effects ◽

Independent Variables ◽

Trade Offs ◽

Large Pressure ◽

Full Factorial ◽

Structural Influence ◽

Geometric Optimisation

This paper describes the results of an optimisation study into the effects of changing geometrical variables local to the nozzle entry on a large pressure vessel. The purpose of the study was to quantify the effects of altering the geometry, and thereby provide trade-offs between key responses such as primary strength and shakedown performance. A 3D Finite Element model was built of a 90 degree sector of the pressure vessel which was sufficiently detailed to allow the thermal and structural effects of the vessel remote from the nozzle to be included. Specifically, this included the thermal and structural influence of the closure head and bolting assembly. The model was then parameterised for 5 independent variables, including the extent of the nozzle reinforcement, crotch corner fillet radius and nozzle thickness. The parameterised model was then subjected to a number of thermal and structural transient analyses during Level A operation, as well as a representative strength loadcase. A full factorial design study was undertaken, comprising of separate 243 analysis runs covering the 5 independent variables at 3 levels. A number of output metrics were monitored, and the effects on the output metrics resulting from changes to the inputs were quantified. Due to the full factorial nature of the experimental design, interactions between variables could also be investigated. The response for each output metric was then fitted to a response surface, which allows a polynomial (meta-model) of each metric to be calculated. These responses were input to a simple Excel chart which allows the designers to perform rapid what-if design scenarios, and see the resulting effects of their changes on the responses. This allows the trade-offs between responses, for example shakedown and strength trade-off for shell thickness, to be easily seen and quantified.

Download Full-text

Optimization of moist and oven-dried bacterial cellulose production for functional properties

10.21203/rs.3.rs-203952/v1 ◽

2021 ◽

Author(s):

Ioana Maria Bodea ◽

Florin Ioan Beteg ◽

Carmen Rodica Pop ◽

Adriana Paula David ◽

Mircea Cristian Dudescu ◽

...

Keyword(s):

Bacterial Cellulose ◽

Physical And Mechanical Properties ◽

Young Modulus ◽

Culture Conditions ◽

Independent Variables ◽

Optimization Study ◽

Full Factorial Experimental Design ◽

Experimental Values ◽

Inoculum Volume ◽

Full Factorial

Abstract Bacterial cellulose (BC) is a natural polymer with properties suitable for tissue engineering and possible applications in scaffold production. However, current procedures have limitations in obtaining BC pellicles with the desired structural, physical, and mechanical properties. Thus, this study analyzed the optimal culture conditions of BC membranes and 2 types of processing: draining and oven-drying. The aim was to obtain BC membranes with properties suitable for a wound dressing material. Two studies were carried out. In the preliminary study the medium (100 mL) was inoculated with varying volumes (1; 2; 3; 4; and 5 mL) and incubated statically for different periods (3; 6; 9; 12; and 18 days), using a full factorial experimental design. Thickness, uniformity, weight, and yield were evaluated. In the optimization study, a Box–Behnken design was used. Two independent variables were used: inoculum volume (X1: 1; 3; and 5 mL) and fermentation period (X2: 6; 12; and 18 d) to determine the target response variables: thickness, swelling ratio, drug release, fiber diameter, Tensile strength, and Young's Modulus for both dry and moist BC membranes. The mathematical modelling of the effect of the 2 independent variables was accomplished by response surface methodology (RSM). The obtained models were validated with new experimental values, and confirmed for all tested properties, except Young Modulus of oven-dried BC. Thus, the optimal properties in terms of a scaffold material of the moist BC were obtained with an inoculum volume of 5% (v/v) and 16 d of fermentation. While, for the oven-dried membranes a 4% (v/v) and 14 d of fermentation.

Download Full-text