Marine microbes as a valuable resource for brand new industrial biocatalysts

Chitin Deacetylase from Bacillus aryabhattai TCI-16: Heterologous Expression, Characterization, and Deacetylation Performance

Chitin deacetylase (CDA) removes the acetyl group from the chitin molecule to generate chitosan in a uniform, high-quality deacetylation pattern. Herein, BaCDA was a novel CDA discovered from our previously isolated Bacillus aryabhattai strain TCI-16, which was excavated from mangrove soil. The gene BaCDA was cloned and overexpressed in Escherichia coli BL21 (DE3) to facilitate its subsequent purification. The purified recombinant protein BaCDA was obtained at a concentration of about 1.2 mg/mL after Ni2+ affinity chromatography. The molecular weight of BaCDA was around 28 kDa according to the sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis. In addition, BaCDA exhibited a significant deacetylation effect on colloidal chitin, and the deacetylation degree was measured from the initial 25.69 to 69.23% by Fourier transform infrared (FT-IR) spectroscopy. Scanning electron microscopy (SEM) observation showed that the surface of colloidal chitin after enzymatic digestion was rough, the crystal fibers disappeared, and the chitin structure was loose and porous with grooves. The results of electrospray ionization mass spectrometry (ESI-MS) showed that BaCDA had full-deacetylation activity against (GlcNAc)4. Molecular docking revealed that BaCDA had an open active pocket capable of binding to the GlcNAc unit. This study not only provides a novel enzymatic resource for the green and efficient application of chitin but also helps to deepen the understanding of the catalytic mechanism of CDA.

Biocatalytic Conversion of Carrageenans for the Production of 3,6-Anhydro-D-galactose

Marine biomass stands out as a sustainable resource for generating value-added chemicals. In particular, anhydrosugars derived from carrageenans exhibit a variety of biological functions, rendering them highly promising for utilization and cascading in food, cosmetic, and biotechnological applications. However, the limitation of available sulfatases to break down the complex sulfation patterns of carrageenans poses a significant limitation for the sustainable production of valuable bioproducts from red algae. In this study, we screened several carrageenolytic polysaccharide utilization loci for novel sulfatase activities to assist the efficient conversion of a variety of sulfated galactans into the target product 3,6-anhydro-D-galactose. Inspired by the carrageenolytic pathways in marine heterotrophic bacteria, we systematically combined these novel sulfatases with other carrageenolytic enzymes, facilitating the development of the first enzymatic one-pot biotransformation of ι- and κ-carrageenan to 3,6-anhdyro-D-galactose. We further showed the applicability of this enzymatic bioconversion to a broad series of hybrid carrageenans, rendering this process a promising and sustainable approach for the production of value-added biomolecules from red-algal feedstocks.

Marine-Derived Fungi as a Valuable Resource for Amylases Activity Screening

Marine microbial enzymes including amylases are important in different industrial production due to their properties and applications. This study was focused on the screening of marine-derived fungi for amylase activities. First, we isolated a number of fungi from the sediments of the South China Sea. By the method of dish screening (in vitro), we subsequently obtained a series of amylase-producing fungal strains. The cell-lysate activities of amylases produced by marine fungi toward starch hydrolysis were achieved with the dinitrosalyicylic acid (DNS) method. In addition, the effect of pH and temperature on amylase activities, including thermal and pH stability were discussed. Results showed that out of the 57 isolates with amylase-producing activities, fungi Aspergillus flavus 9261 was found to produce amylase with the best activity of 10.7482 U/mg (wet mycelia). The amylase of Aspergillus flavus 9261 exhibited remarkable thermostability and pH stability with no activity loss after incubation at 50 °C and pH 5.0 for 1 h, respectively. The results provide advances in discovering enzymes from marine-derived fungi and their biotechnology relevance.

Marine enzymes: Classification and application in various industries

Oceans are regarded as a plentiful and sustainable source of biological compounds. Enzymes are a group of marine biomaterials that have recently drawn more attention because they are produced in harsh environmental conditions such as high salinity, extensive pH, a wide temperature range, and high pressure. Hence, marine-derived enzymes are capable of exhibiting remarkable properties due to their unique composition. In this review, we overviewed and discussed characteristics of marine enzymes as well as the sources of marine enzymes, ranging from primitive organisms to vertebrates, and presented the importance, advantages, and challenges of using marine enzymes with a summary of their applications in a variety of industries. Current biotechnological advancements need the study of novel marine enzymes that could be applied in a variety of ways. Resources of marine enzyme can benefit greatly for biotechnological applications duo to their biocompatible, ecofriendly and high effectiveness. It is beneficial to use the unique characteristics offered by marine enzymes to either develop new processes and products or improve existing ones. As a result, marine-derived enzymes have promising potential and are an excellent candidate for a variety of biotechnology applications and a future rise in the use of marine enzymes is to be anticipated.

Marine Cellulases and their Biotechnological Significance from Industrial Perspectives

Marine microorganisms represent virtually unlimited sources of novel biological compounds and can survive extreme conditions. Cellulases, a group of enzymes that are able to degrade cellulosic materials, are in high demand in various industrial and biotechnological applications, such as in the medical and pharmaceutical industries, food, fuel, agriculture, and single-cell protein, and as probiotics in aquaculture. The cellulosic biopolymer is a renewable resource and is a linearly arranged polysaccharide of glucose, with repeating units of disaccharide connected via β-1,4-glycosidic bonds, which are broken down by cellulase. A great deal of biodiversity resides in the ocean, and marine systems produce a wide range of distinct, new bioactive compounds that remain available but dormant for many years. The marine environment is filled with biomass from known and unknown vertebrates and invertebrate microorganisms, with much potential for use in medicine and biotechnology. Hence, complex polysaccharides derived from marine sources are a rich resource of microorganisms equipped with enzymes for polysaccharides degradation. Marine cellulases' extracts from the isolates are tested for their functional role in degrading seaweed and modifying wastes to low molecular fragments. They purify and renew environments by eliminating possible feedstocks of pollution. This review aims to examine the various types of marine cellulase producers and assess the ability of these microorganisms to produce these enzymes and their subsequent biotechnological applications.

Isolation and Molecular Identification of Xylanase-Producing Bacteria from Ulva flexuosa of the Persian Gulf

The marine ecosystem is one of the richest sources of biologically active compounds, such as enzymes, among which seaweed is one of the most diverse marine species and has a rich diversity of bacteria that produce different enzymes. Among these, the bacteria-derived xylanase enzyme has many applications in the fruit juice, paper, and baking industries; so, to consider the economic value of the xylanase enzyme and the isolation and identification of xylanase-producing bacteria is of particular importance. In this study, specimens of the alga Ulva flexuosa species were collected from the coasts of Bandar Abbas and Qeshm Island. The bacteria coexisting with the algae were isolated using a nutrient agar medium. The bacteria producing the xylanase enzyme were then screened by a specific solid culture medium containing xylan, and the activity of the xylanase enzyme isolated from the bacteria was measured using a xylan substrate. The bacteria with the highest enzymatic activity were selected and identified by 16S rRNA gene sequence analysis, and the culture medium conditions for the enzyme production by the selected bacterial strains were optimized. Among the bacterial community, two strains with the highest xylanase activity, which belonged to the genera Bacillus and Shewanella, were identified as Bacillus subtilis strain HR05 and Shewanella algae strain HR06, respectively. The two selected bacteria were registered in the NCBI gene database. The results demonstrated that the two selected strains had different optimal growing conditions in terms of pH and temperature, as well as the sources of carbon and nitrogen for enzyme production. It seems that the xylanase enzyme isolated from the bacterial strains HR05 and HR06, which coexist with alga Ulva flexousa, could be potential candidates for biotechnology and various industries, such as pulp production, paper, and food manufacture, due to their high activity and optimal alkaline pH.

Production and Functionalities of Specialized Metabolites from Different Organic Sources

Medicinal plants are rich sources of specialized metabolites that are of great importance to plants, animals, and humans. The usefulness of active biological compounds cuts across different fields, such as agriculture, forestry, food processing and packaging, biofuels, biocatalysts, and environmental remediation. In recent years, research has shifted toward the use of microbes, especially endophytes (bacteria, fungi, and viruses), and the combination of these organisms with other alternatives to optimize the production and regulation of these compounds. This review reinforces the production of specialized metabolites, especially by plants and microorganisms, and the effectiveness of microorganisms in increasing the production/concentration of these compounds in plants. The study also highlights the functions of these compounds in plants and their applications in various fields. New research areas that should be explored to produce and regulate these compounds, especially in plants and microbes, have been identified. Methods involving molecular studies are yet to be fully explored, and next-generation sequencing possesses an interesting and reliable approach.

Microbial diversity and community structure in deep-sea sediments of South Indian Ocean

Microbial communities composed of bacteria, archaea and fungi play a pivotal role in driving the biogeochemical cycles in the marine ecosystem. Despite the vastness of the South Indian Ocean, only a few studies reported the simultaneous analysis of bacterial, archaeal and fungal diversity therein, particularly archaeal and fungal communities in deep-sea environments received less attention previously. In this study, microbial diversity, community composition and dynamics in microbial community structure in eight deep-sea sediment samples collected from different sites at varying depths of the South Indian Ocean were explored using Next-Generation Sequencing. In total, 21 bacterial phyla representing 541 OTUs were identified from the eight samples, where phylum Proteobacteria was found as the most abundant bacterial phylum in five out of eight samples. Firmicutes and Chloroflexi were the dominant phyla in the rest of the three samples. In the case of archaea, uncultured species belonging to the phyla Thaumarchaeota and Euryarchaeota were the abundant taxa in all the samples. Similarly, Ascomycota and Basidiomycota were the most abundant fungal phyla present therein. In all the eight samples studied here, about 10-58% and 19-26% OTUs in archaeal and fungal communities were mapped to unclassified taxa respectively, suggesting the lack of representation in databases. Co-occurrence network analysis further revealed that bacterial communities tend to be more dynamic than archaeal and fungal communities. This study provides interesting insights into the microbial diversity, community composition and dynamics in microbial community structure in the deep-sea sediments of the South Indian Ocean.

Emerging trends in environmental and industrial applications of marine carbonic anhydrase: a review

Biocatalytic conversion of greenhouse gases such as carbon dioxide into commercial products is one of the promising key approaches to solve the problem of climate change. Microbial enzymes, including carbonic anhydrase, NAD-dependent formate dehydrogenase, ribulose bisphosphate carboxylase, and methane monooxygenase, have been exploited to convert atmospheric gases into industrial products. Carbonic anhydrases are Zn²⁺-dependent metalloenzymes that catalyze the reversible conversion of CO₂ into bicarbonate. They are widespread in bacteria, algae, plants, and higher organisms. In higher organisms, they regulate the physiological pH and contribute to CO₂ transport in the blood. In plants, algae, and photosynthetic bacteria carbonic anhydrases are involved in photosynthesis. Converting CO₂ into bicarbonate by carbonic anhydrases can solidify gaseous CO2, thereby reducing global warming due to the burning of fossil fuels. This review discusses the three-dimensional structures of carbonic anhydrases, their physiological role in marine life, their catalytic mechanism, the types of inhibitors, and their medicine and industry applications.

Isolation and identification of marine microbial products

Background

The ocean is one of the world’s most important sources of bioactive chemicals in the marine environment. Microbiologists, ecologists, agronomists, taxonomists, and evolutionary biologists have been increasingly interested in marine microbial natural products (MMNPs) in recent decades.

Main body

Diverse marine bacteria appear to get the ability to manufacture an astounding diversity of MMNPs with a wide range of biological actions, including anti-tumor, antimicrobial, and anti-cardiovascular agents according to numerous studies.

Short conclusions

Innovative isolation and culture methodologies, tactics for identifying novel MMNPs via routine screens, metagenomics, genomics, combinatorial biosynthesis, and synthetic biology are all discussed in this review. There is also a discussion of potential issues and future directions for studying MMNPs.

Free Radicals and Actinobacteria as a Misexplored Goldmine of Antioxidant Compounds

Free radicals are highly reactive unstable molecules, which can be synthesized in different ways, considered harmful and threatening to humans; these chemical species have free traffic throughout the human body, interacting with biological molecules and human body organ tissues. The interaction between free radicals and biological molecules is the main factor for disease development or pre-existing disease symptoms aggravation. Antioxidants are chemical compounds able to donate electric charge to stabilize molecules such as free radicals. Recent studies have proved the benefits of antioxidants intake in health improvement. In this way, the search for natural sources of antioxidants has become an ascending trend. In this field, the microbial sources are considered poorly explored compared to the numerous amount of other compounds obtained from them, especially from Actinobacteria. The searched literature about Actinobacteria highlights an important capacity of producing natural antioxidants; however, there is a lack of in vivo studies of these isolated compounds. In this review, we gathered information that supports our point of view that Actinobacteria is a truly renewable and superficially explored source of natural antioxidants. Furthermore, our purpose is also to point this limitation and stimulate more researches in this area.

Identification of a novel tailor-made chitinase from white shrimp Fenneropenaeus merguiensis

Fenneropenaeus merguiensis (commonly named banana shrimp) is one of the most important farmed crustacean worldwide species for the fisheries and aquaculture industry. Besides its nutritional value, it is a good source of chitinase, an enzyme with excellent biological and catalytic properties for many industrial applications. In the present study, a putative chitinase-encoding cDNA was synthesized from mRNA from F. merguiensis hepatopancreas tissue. Subsequently, the corresponding cDNA was cloned, sequenced and functionally expressed in Escherichia coli, and the recombinant F. merguiensis chitinase (rFmCHI) was purified by His-tag affinity chromatography. The bioinformatics analysis of aminoacid sequence of rFmCHI displayed a cannonical multidomain architecture in chitinases which belongs to glycoside hydrolase family 18 (GH18 chitinase). Biochemical characterization revealed rFmCHI as a monomeric enzyme of molecular weight 52 kDa with maximum activity at 40 °C and pH 6.0 Moreover, the recombinant enzyme is also stable up to 60 °C, and in the pH range 5.0-8.0. Steady-state kinetic studies for colloidal chitin revealed K_M, V_max and k_cat values of 78.18 μM, 0.07261 μM. min^-1 and 43.37 s^-1, respectively. Overall, our results aim to demonstrate the potential of rFmCHI as suitable catalyst for bioconversion of chitin waste.

Harnessing the sponge microbiome for industrial biocatalysts

Within the marine sphere, host-associated microbiomes are receiving growing attention as prolific sources of novel biocatalysts. Given the known biocatalytic potential of poriferan microbial inhabitants, this review focuses on enzymes from the sponge microbiome, with special attention on their relevant properties and the wide range of their potential biotechnological applications within various industries. Cultivable bacterial and filamentous fungal isolates account for the majority of the enzymatic sources. Hydrolases, mainly glycoside hydrolases and carboxylesterases, are the predominant reported group of enzymes, with varying degrees of tolerance to alkaline pH and growing salt concentrations being common. Prospective areas for the application of these microbial enzymes include biorefinery, detergent, food and effluent treatment industries. Finally, alternative strategies to identify novel biocatalysts from the sponge microbiome are addressed, with an emphasis on modern -omics-based approaches that are currently available in the enzyme research arena. By providing this current overview of the field, we hope to not only increase the appetite of researchers to instigate forthcoming studies but also to stress how basic and applied research can pave the way for new biocatalysts from these symbiotic microbial communities in a productive fashion. KEY POINTS: • The sponge microbiome is a burgeoning source of industrial biocatalysts. • Sponge microbial enzymes have useful habitat-related traits for several industries. • Strategies are provided for the future discovery of microbial enzymes from sponges.

Expression and Characterization of a GH16 Family β-Agarase Derived from the Marine Bacterium Microbulbifer sp. BN3 and Its Efficient Hydrolysis of Agar Using Raw Agar-Producing Red Seaweeds Gracilaria sjoestedtii and Gelidium amansii as Substrates

Agarases catalyze the hydrolysis of agarose to oligosaccharides which display an array of biological and physiological functions with important industrial applications in health-related fields. In this study, the gene encoding agarase (Aga-ms-R) was cloned from Microbulbifer sp. BN3 strain. Sequence alignment indicated that Aga-ms-R belongs to the GH16 family and contains one active domain and two carbohydrate binding module (CBM) domains. The mature Aga-ms-R was expressed successfully by employing the Brevibacillus system. Purified rAga-ms-R was obtained with a specific activity of 100.75 U/mg. rAga-ms-R showed optimal activity at 50 °C and pH 7.0, and the enzyme activity was stable at 50 °C and also over the pH range of 5.0–9.0. After exposure of rAga-ms-R to 70 °C for 30 min, only partial enzyme activity remained. Thin layer chromatographic analysis of the enzymatic hydrolysate of agar obtained using rAga-ms-R disclosed that the hydrolysate comprised, in a long intermediate-stage of the hydrolysis reaction, mainly neoagarotetraose (NA4) and neoagarohexaose (NA6) but ultimately, predominantly neoagarotetraose and trace amounts of neoagarobiose (NA2). Hydrolysates of the raw red seaweeds Gracilaria sjoestedtii and Gelidium amansii, produced by incubation with rAga-ms-R, were mainly composed of neoagarotetraose. The results demonstrate the high efficiency of rAga-ms-R in producing neoagaraoligosaccharide under low-cost conditions.

Draft genome sequence of Parvularcula flava strain NH6-79 T, revealing its role as a cellulolytic enzymes producer

To date, the genus Parvularcula consists of 6 species and no potential application of this genus was reported. Current study presents the genome sequence of Parvularcula flava strain NH6-79 ^T and its cellulolytic enzyme analysis. The assembled draft genome of strain NH6-79 ^T consists of 9 contigs and 7 scaffolds with 3.68 Mbp in size and GC content of 59.87%. From a total of 3,465 genes predicted, 96 of them are annotated as glycoside hydrolases (GHs). Within these GHs, 20 encoded genes are related to cellulosic biomass degradation, including 12 endoglucanases (5 GH10, 4 GH5, and 3 GH51), 2 exoglucanases (GH9) and 6 β-glucosidases (GH3). In addition, highest relative enzyme activities (endoglucanase, exoglucanase, and β-glucosidase) were observed at 27th hour when the strain was cultured in the carboxymethyl cellulose/Avicel^®-containing medium for 45 h. The combination of genome analysis with experimental studies indicated the ability of strain NH6-79 ^T to produce extracellular endoglucanase, exoglucanase, and β-glucosidase. These findings suggest the potential of Parvularcula flava strain NH6-79 ^T in cellulose-containing biomass degradation and that the strain could be used in cellulosic biorefining process.

Reductive capabilities of different cyanobacterial strains towards acetophenone as a model substrate - Prospect of applications for chiral building blocks synthesis

Bioreductive capabilities of four morphologically different strains of cyanobacteria have been assessed in this work. Arthrospira maxima, Leptolyngbya foveolarum, Nodularia sphaerocarpa and Synechococcus bigranulatus were applied as catalysts for the reduction of acetophenone to the corresponding chiral phenylethyl alcohol. The process was modified regarding substrate concentration, duration of pre-cultivation period, duration of biotransformation, light regime and glucose addition to the culture media. Obtained results clearly showed that cyanobacteria were active towards acetophenone what resulted in the substrate reduction to (S)-1-phenylethanol with high enantiomeric excess. The reaction efficiency increased with the biotransformation time, but the higher concentration of substrate limited the process yield. Also, all tested strains performed reaction with the highest efficacy under continuous light regime. The most active strains - N. sphaerocarpa and S. bigranulatus carried out the conversion of 1 mM acetophenone with high efficiency of respectively 97.6% and 96.2% after 13 days of biotransformation. A. maxima reached 45.8% of conversion after 13 days of biotransformation whereas L. foveolarum did not exceed 20%. The enantiomeric excesses were respectively 98.8%- A. maxima, 91.7%- L. foveolarum, 72.6%- S. bigranulatus and N. sphaerocarpa 16.2%.

Marine chitinolytic enzymes, a biotechnological treasure hidden in the ocean?

Chitinolytic enzymes are capable to catalyze the chitin hydrolysis. Due to their biomedical and biotechnological applications, nowadays chitinolytic enzymes have attracted worldwide attention. Chitinolytic enzymes have provided numerous useful materials in many different industries, such as food, pharmaceutical, cosmetic, or biomedical industry. Marine enzymes are commonly employed in industry because they display better operational properties than animal, plant, or bacterial homologs. In this mini-review, we want to describe marine chitinolytic enzymes as versatile enzymes in different biotechnological fields. In this regard, interesting comments about their biological role, reaction mechanism, production, functional characterization, immobilization, and biotechnological application are shown in this work.

Streptomyces as a Prominent Resource of Future Anti-MRSA Drugs

Methicillin-resistant Staphylococcus aureus (MRSA) pose a significant health threat as they tend to cause severe infections in vulnerable populations and are difficult to treat due to a limited range of effective antibiotics and also their ability to form biofilm. These organisms were once limited to hospital acquired infections but are now widely present in the community and even in animals. Furthermore, these organisms are constantly evolving to develop resistance to more antibiotics. This results in a need for new clinically useful antibiotics and one potential source are the Streptomyces which have already been the source of several anti-MRSA drugs including vancomycin. There remain large numbers of Streptomyces potentially undiscovered in underexplored regions such as mangrove, deserts, marine, and freshwater environments as well as endophytes. Organisms from these regions also face significant challenges to survival which often result in the production of novel bioactive compounds, several of which have already shown promise in drug development. We review the various mechanisms of antibiotic resistance in MRSA and all the known compounds isolated from Streptomyces with anti-MRSA activity with a focus on those from underexplored regions. The isolation of the full array of compounds Streptomyces are potentially capable of producing in the laboratory has proven a challenge, we also review techniques that have been used to overcome this obstacle including genetic cluster analysis. Additionally, we review the in vivo work done thus far with promising compounds of Streptomyces origin as well as the animal models that could be used for this work.

Penaeus vannamei protease activating mechanism of sulfhydryl reducing compounds

For the very first time, protease enzyme from Penaeus vannamei was investigated for its activation with thiol reductant compounds. The mechanism by which sulfhydryl reductant compounds enhances the activity of P. vannamei protease still remains unclear. In this study, it was discovered that thiol-reactive compounds increase P. vannamei protease activity by a factor of about 4 with increasing V_max and decreasing Km parameters. Moreover, the reaction is an S_N2-type that does not require the initial binding of the thiol group of these compounds to the enzyme. Additionally, k₂ increased appreciably with increasing concentration of sulfhydryl reductant compounds. The linearity of this plot indicates that k₁ is unaffected by the addition of thiol compounds. Hence, the observed effect of thiol compounds on K_m seems to be due to an increase in k₂. These results suggest that the activation mechanism of P. vannamei protease almost certainly takes place by an S_N2 reaction mechanism.

Marine microbial L-asparaginase: Biochemistry, molecular approaches and applications in tumor therapy and in food industry

The marine environment is a rich source of biological and chemical diversity. It covers more than 70% of the Earth's surface and features a wide diversity of habitats, often displaying extreme conditions, where marine organisms thrive, offering a vast pool for microorganisms and enzymes. Given the dissimilarity between marine and terrestrial habitats, enzymes and microorganisms, either novel or with different and appealing features as compared to terrestrial counterparts, may be identified and isolated. L-asparaginase (E.C. 3.5.1.1), is among the relevant enzymes that can be obtained from marine sources. This amidohydrolase acts on L-asparagine and produce L-aspartate and ammonia, accordingly it has an acknowledged chemotherapeutic application, namely in acute lymphoblastic leukemia. Moreover, L-asparaginase is also of interest in the food industry as it prevents acrylamide formation. Terrestrial organisms have been largely tapped for L-asparaginases, but most failed to comply with criteria for practical applications, whereas marine sources have only been marginally screened. This work provides an overview on the relevant features of this enzyme and the framework for its application, with a clear emphasis on the use of L-asparaginase from marine sources. The review envisages to highlight the unique properties of marine L-asparaginases that could make them good candidates for medical applications and industries, especially in food safety.

Penaeus vannamei protease stabilizing process of ZnS nanoparticles

The protease enzyme purified from the Penaeus vannamei shrimp has unique properties, so improving the stability of this enzyme can improve their practical applications. In this study, ZnS nanoparticles, which have special properties for enzyme immobilization, were synthesized using a chemical precipitation method, and Penaeus vannamei protease was successfully immobilized on them. The size, structure, and morphology of the ZnS nanoparticles, and the immobilization of the protease were studied, using Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FT-IR) spectroscopy, UV-Vis spectroscopy and Dynamic Light Scattering (DLS) analysis. We show that the immobilized enzyme has improved functionality at high temperatures, extreme pH conditions (pH3 and 12), and during storage. Immobilization increased the optimum temperature range of the enzyme, but did not change the pH optimum, which remained at pH7. Immobilization of P. vannamei protease enzyme increased the K_m and decreased k_cat/K_m. These results indicate that P. vannamei protease immobilized on ZnS nanoparticles, has improved properties due to its high stability and unique properties, can be used for biotechnology applications.