Improvement of thermostability and activity of pectate lyase in the presence of hydroxyapatite nanoparticles

Study of nano-hydroxyapatite tagged alkaline protease isolated from Himalayan sub-alpine Forest soil bacteria and role in recalcitrant feather waste degradation

Purified calcium serine metalloprotease from Stenotrophomonas maltophilia strain SMPB12 exhibits highest enzyme activity at pH 9 and temperature range between 15 °C-25 °C. Enzyme supplemented with 40 μM Ca-Hap-NP (NP-protease) showed maximum elevated activity of 17.29 μmole/min/ml (1.9-fold of original protease activity). The thermostability of the enzyme was maintained for 1 h at 60 °C over an alkaline pH range 7.5-10, as compared to the NP untreated enzyme whose activity was of 8.97 μmole/min/ml. A significant loss of activity with EDTA (1.05 μmole/min/ml, 11.75 %), PMSF (0.93 μmole/min/ml, 10.46 %) and Hg2+ (3.81 μmole/min/ml, 42.49 %) was also observed. Kinetics study of NP-protease showed maximum decreases in Km (28.11 %) from 0.28 mM (NP untreated enzyme) to 0.22 mM (NP-protease) along with maximum increase in Vmax (42.88 %) from 1.25 μmole/min/ml to 1.79 μmole/min/ml at varying temperatures. The enhanced activity of NP-protease was able to efficiently degrade recalcitrant solid wastes like feather to produce value-added products like amino acids and helps in declogging recalcitrant solid wastes. The nano-enabled protease may be utilized in a smaller amount for degrading in bulk recalcitrant solid proteinaceous waste at 15 °C temperature as declogging agents providing an eco-friendly efficient process.

Production, statistical optimization, and functional characterization of alkali stable pectate lyase of Paenibacillus lactis PKC5 for use in juice clarification

Pectate lyase is a hydrolytic enzyme used by diverse industries to clarify food. The enzyme occupies a 25% share of the total enzyme used in food industries, and their demand is increasing gradually. Most of the enzymes in the market belong to the fungal origin and take more time to produce with high viscosity in the fermentation medium, limiting its use. The bacteria belonging to the genus Bacillus have vast potential to produce diverse metabolites of industrial importance. The present experiment aimed to isolate pectate lyase-producing bacteria that can tolerate an alkaline environment at moderate temperatures. Bacillus subtilis PKC2, Bacillus licheniformis PKC4, Paenibacillus lactis PKC5, and Bacillus sonorensis ADCN produced pectate lyase. The Paenibacillus lactis PKC5 gave the highest protein at 48 h of incubation that was partially purified using 80% acetone and ammonium sulphate. Purification with 80% acetone resulted in a good enzyme yield with higher activity. SDS-PAGE revealed the presence of 44 kDa molecular weight of purified enzyme. The purified enzyme exhibits stability at diverse temperature and pH ranges, the maximum at 50 °C and 8.0 pH. The metal ions such as Mg2+, Zn2+, Fe2+, and Co2+ significantly positively affect enzyme activity, while increasing the metal ion concentration to 5 mM showed detrimental effects on the enzyme activity. The organic solvents such as methanol and chloroform at 25% final concentration improved the enzyme activity. On the other hand, detergent showed inhibitory effects at 0.05% and 1% concentration. Pectate lyase from Paenibacillus lactis PKC5 had Km and Vmax values as 8.90 mg/ml and 4.578 μmol/ml/min. The Plackett–Burman and CCD designs were used to identify the significant process parameters, and optimum concentrations were found to be pectin (5 gm%) and ammonium sulphate (0.3 gm%). During incubation with pectate lyase, the clarity percentage of the grape juice, apple juice, and orange juice was 60.37%, 59.36%, and 49.91%, respectively.

Enhanced catalytic activity of Bacillus aryabhattai P1 protease by modulation with nanoactivator

In the developing area of modern nanobiotechnology, the research is being focused on enhancement of catalytic performance in terms of efficiency and stability of enzymes to fulfill the industrial demand. In the context of this interdisciplinary era, we isolated and identified alkaline protease producer Bacillus aryabhattai P1 by polyphasic approach and then followed one variable at a time approach to optimize protease production from P1. The modified components of fermentation medium (g/L) were wheat bran 10, soybean flour 10, yeast extract 5, NaCl 10, KH₂PO₄ 1, K₂HPO₄ 1 and MgSO₄·7H₂O 0.2 (pH 9). The optimum alkaline protease production from P1 was recorded 75 ± 3 U/mg at 35 °C and pH 9 after 96 h of fermentation period. Molecular weight of partially purified P1 alkaline protease was 26 KDa as revealed by SDS-PAGE. Calcium based nanoceramic material was prepared by wet chemical precipitation method and doped in native P1 protease for catalytic activity enhancement. Catalytic activity of modified P1 protease was attained by nanoactivator mediated modulation was more by 5.58 fold at pH 10 and 30 °C temperature. The nanoceramic material named as nanoactivator, with grain size of 40–60 nm was suitable to redesign the active site of P1 protease. Such types of modified proteases can be used in different nanobiotechnological applications.

Biochemical and Molecular Characterizations of a Novel pH- and Temperature-Stable Pectate Lyase from Bacillus amyloliquefaciens S6 for Industrial Application

In this paper, we report cloning of a pectate lyase gene from Bacillus amyloliquefaciens S6 (pelS6), and biochemical characterization of the recombinant pectate lyase. PelS6 was found to be identical with B. subtilis 168 pel enzyme with 100% amino acid sequence homology. Although these two are genetically very close, they are distinctly different in physiology. pelS6 gene encodes a 421-aa protein with a molecular mass of 65,75 kDa. Enzyme activity increased from 12.8 ± 0.3 to 49.6 ± 0.4 units/mg after cloning. The relative enzyme activity of the recPel S6 ranged from 80% to 100% at pH between 4 and 14. It was quite stable at different temperature values ranging from 15 to 90 °C. The recPEL S6 showed a maximal activity at pH 10 and at 60 °C. 0.5 mM of CaCl₂ is the most effective metal ion on the recPEL S6 as demonstrated by its increased relative activity with 473%. recPEL S6 remained stable at - 20 °C for 18 months. In addition recPEL S6 increased juice clarity. This study introduces a novel bacterial pectate lyase enzyme with its characteristic capability of being highly thermostable, thermotolerant, and active over a wide range of pH, meaning that it can work at both acidic and alkaline environments, which are the most preferred properties in the industry.

Inner-View of Nanomaterial Incited Protein Conformational Changes: Insights into Designable Interaction

Nanoparticle bioreactivity critically depends upon interaction between proteins and nanomaterials (NM). The formation of the "protein corona" (PC) is the effect of such nanoprotein interactions. PC has a wide usage in pharmaceuticals, drug delivery, medicine, and industrial biotechnology. Therefore, a detailed in-vitro, in-vivo, and in-silico understanding of nanoprotein interaction is fundamental and has a genuine contemporary appeal. NM surfaces can modify the protein conformation during interaction, or NMs themselves can lead to self-aggregations. Both phenomena can change the whole downstream bioreactivity of the concerned nanosystem. The main aim of this review is to understand the mechanistic view of NM-protein interaction and recapitulate the underlying physical chemistry behind the formation of such complicated macromolecular assemblies, to provide a critical overview of the different models describing NM induced structural and functional modification of proteins. The review also attempts to point out the current limitation in understanding the field and highlights the future scopes, involving a plausible proposition of how artificial intelligence could be aided to explore such systems for the prediction and directed design of the desired NM-protein interactions.

Engineering fungal morphology for enhanced production of hydrolytic enzymes by Aspergillus oryzae SBS50 using microparticles

Effect of microparticles and silver nanoparticles was studied on the production of hydrolytic enzymes by a potent phytase-producing mould, Aspergillus oryzae SBS50. Addition of microparticles, viz. talc powder and aluminum oxide enhanced phytase production from 2894 to 3903 and 2847 to 4204 U/L, cellulase from 2529 to 4931 and 2455 to 3444 U/L, xylanase from 9067 to 9642 and 9994 to 14,783 U/L, amylase from 5880 to 11,000 and 6130 to 13,145 U/L, respectively. Fungal morphology was also engineered by the use of microparticles. Fungal pellet size was significantly reduced (~ 90%) by the addition of microparticles. Fermentation time was reduced from 4 to 3 days after the addition of microparticles, thus increasing the productivity of the enzymes significantly. These results confirmed the importance of microparticles in engineering fungal morphology for enhanced production of hydrolytic enzymes.

Improved production of reducing sugars from rice straw using crude cellulase activated with Fe₃O₄/alginate nanocomposite

Effect of Fe3O4 nanoparticles (NPs) and Fe3O4/Alginate nanocomposites (NCs) have been investigated on production and thermostability of crude cellulase enzyme system obtained by newly isolated thermotolerant Aspergillus fumigatus AA001. Fe3O4 NPs and Fe3O4/Alginate NCs have been synthesized by co-precipitation method and characterized through various techniques. In presence of Fe3O4 NPs and Fe3O4/Alginate NCs, filter paper activity of crude cellulase was increased about 35% and 40%, respectively in 72 h as compared to control. Fe3O4/Alginate NCs treated crude enzyme was thermally stable up to 8h at 70°C and retained 56% of its relative activity whereas; control samples could retain only 19%. Further, the hydrolysis of 1.0% alkali treated rice straw using Fe3O4/Alginate NCs treated cellulase gave much higher sugar productivity than control at optimal condition. These findings may be utilized in the area of biofuels and biowaste management.

Enhanced functionality and stabilization of a cold active laccase using nanotechnology based activation-immobilization

A simple nanotechnology based immobilization technique for imparting psychrostability and enhanced activity to a psychrophilic laccase has been described here. Laccase from a psychrophile was supplemented with Copper oxide nanoparticles (NP) corresponding to copper (NP-laccase), the cationic activator of this enzyme and entrapped in single walled nanotube (SWNT). The activity and stability of laccase was enhanced both at temperatures as low as 4°C and as high as 80°C in presence of NP and SWNT. The enzyme could be released and re-trapped (in SWNT) multiple times while retaining significant activity. Laccase, immobilized in SWNT, retained its activity after repeated freezing and thawing. This unique capability of SWNT to activate and stabilize cold active enzymes at temperatures much lower or higher than their optimal range may be utilized for processes that require bio-conversion at low temperatures while allowing for shifts to higher temperature if so required.

Enhancement of thermal and pH stability of an alkaline metalloprotease by nano-hydroxyapatite and its potential applications

Protease stabilization using nanotechnology.

Effect of nickel-cobaltite nanoparticles on production and thermostability of cellulases from newly isolated thermotolerant Aspergillus fumigatus NS (class: Eurotiomycetes)

In the present study, effect of nickel-cobaltite (NiCo2O4) nanoparticles (NPs) was investigated on production and thermostability of the cellulase enzyme system using newly isolated thermotolerant Aspergillus fumigatus NS belonging to the class Euratiomycetes. The NiCo2O4 NPs were synthesized via hydrothermal method assisted by post-annealing treatment and characterized through X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. In the absence of NPs in the growth medium, filter paper cellulase (FP) activity of 18 IU/gds was achieved after 96 h, whereas 40 % higher FP activity in 72 h was observed with the addition of 1 mM concentration of NPs in the growth medium. Maximum production of endoglucanase (211 IU/gds), β-glucosidase (301 IU/gds), and xylanase (803 IU/gds) was achieved after 72 h without NPs (control), while in the presence of 1 mM concentration of NPs, endoglucanase, β-glucosidase, and xylanase activity increased by about 49, 53, and 19.8 %, respectively, after 48 h of incubation, against control, indicating a substantial increase in cellulase productivity with the addition of NiCo2O4 NPs in the growth medium. Crude enzyme was thermally stable for 7 h at 80 °C in presence of NPs, as against 4 h at the same temperature for control samples. Significant increase in the activity and improved thermal stability of cellulases in the presence of the NiCo2O4 NPs holds potential for use of NiCo2O4 NPs during enzyme production as well as hydrolysis. From the standpoint of biofuel production, these results hold enormous significance.

Improved production of reducing sugars from rice husk and rice straw using bacterial cellulase and xylanase activated with hydroxyapatite nanoparticles

Purified bacterial cellulase and xylanase were activated in the presence of calcium hydroxyapatite nanoparticles (NP) with concomitant increase in thermostability about 35% increment in production of d-xylose and reducing sugars from rice husk and rice straw was obtained at 80°C by the sequential treatment of xylanase and cellulase enzymes in the presence of NP compared to the untreated enzyme sets. Our findings suggested that if the rice husk and the rice straw samples were pre-treated with xylanase prior to treatment with cellulase, the percentage increase of reducing sugar per 100g of substrate (starting material) was enhanced by about 29% and 41%, respectively. These findings can be utilized for the extraction of reducing sugars from cellulose and xylan containing waste material. The purely enzymatic extraction procedure can be substituted for the harsh and bio-adverse chemical methods.

Degumming of ramie fiber and the production of reducing sugars from waste peels using nanoparticle supplemented pectate lyase

Banana, citrus and potato peels were subjected to treatment with hydroxyapatite nanoparticle (NP) supplemented purified pectate lyase (NP-PL), isolated from Bacillus megaterium AK2 to produce reducing sugar (RS). At both 50 and 90°C production of RS by NP-PL was almost twofold greater than that by untreated pectate lyase (PL) from each of the three peels. The optimal production of RS from banana and citrus peels were after 24 and 6h of incubation while it was 24 and 4h for potato peels at 50 and 90°C, respectively, on NP-PL treatment. NP-PL could degum raw, decorticated ramie fibers as well as enhance fiber tenacity and fineness. The weight loss of the fibers were 24% and 31% better (compared to PL treatment) after 24 and 48 h of processing. These findings have potential implications for the bio-ethanol, bio-fuel and textile industries.

Nanotechnology enabled enhancement of enzyme activity and thermostability: study on impaired pectate lyase from attenuated Macrophomina phaseolina in presence of hydroxyapatite nanoparticle

In this paper we show that hydroxyapatite nanoparticles (NP) can not only act as a chaperon (by imparting thermostability) but can serve as a synthetic enhancer of activity of an isolated extracellular pectate lyase (APL) with low native state activity. The purified enzyme (an attenuated strain of Macrophomina phaseolina) showed feeble activity at 50°C and pH 5.6. However, on addition of 10.5 µg/ml of hydroxyapatite nanoparticles (NP), APL activity increased 27.7 fold with a 51 fold increase in half-life at a temperature of 90°C as compared to untreated APL. The chaperon like activity of NP was evident from entropy–enthalpy compensation profile of APL. The upper critical temperature for such compensation was elevated from 50°C to 90°C in presence of NP. This dual role of NP in enhancing activity and conferring thermostability to a functionally impaired enzyme is reported for the first time.

Thermostability, pH stability and dye degrading activity of a bacterial laccase are enhanced in the presence of Cu2O nanoparticles

The present study relates to a nanotechnology enabled method in which purified laccase from Escherichia coli AKL2 was supplemented with 100 μM copper oxide nanoparticles (Cu(2)O) (NP-laccase). The activity, half life and stability of NP-laccase were enhanced by 4, 42 and 36-fold respectively at high temperature (80 °C) and also over a wide range of pH (4-12) than laccase (in the presence of 0.18 mM CuSO(4)). Thermodynamic analysis of the nanoparticle-induced enzyme stability revealed an enhanced entropy-enthalpy compensation at 80 °C, which reflected the maintenance of its native structure. This was further supported by CD studies. The enhanced activity and thermostability of NP-laccase can be utilized for efficient decolorisation of dyes (both phenolic and azo).

Functionalized magnetic mesoporous silica nanoparticles: fabrication, laccase adsorption performance and direct laccase capture from Trametes versicolor fermentation broth

A simple and highly efficient protocol using magnetic mesoporous silica nanoparticles (MMSNPs) with metal affinity ligands was developed to directly capture laccase from Trametes versicolor fermentation broth. The Cu(2+)-chelated magnetic mesoporous silica nanoparticles (MMSNPs-Cu(2+)) with pore sizes ranging from 3.6 to 27.1 nm exhibited size selectivity on laccase capture from the fermentation broth, and the MMSNPs-Cu(2+) with an average pore size of 14.5 nm provided 60.6-fold purification of laccase and 114.6% recovery yield of enzyme activity. Both size selectivity of the MMSNPs and affinity of the chelated metal ion resulted in high laccase capture efficiency from the fermentation broth. The most efficient MMSNPs-Cu(2+) demonstrated no significant loss in laccase capture effectiveness following 10 reuse cycles. This simple and efficient strategy has the potential to be used for the robust and inexpensive preparation of purified laccase at the industrial scale.

Hydroxylapatite nanoparticles: fabrication methods and medical applications

Hydroxylapatite (or hydroxyapatite, HAp) exhibits excellent biocompatibility with various kinds of cells and tissues, making it an ideal candidate for tissue engineering, orthopedic and dental applications. Nanosized materials offer improved performances compared with conventional materials due to their large surface-to-volume ratios. This review summarizes existing knowledge and recent progress in fabrication methods of nanosized (or nanostructured) HAp particles, as well as their recent applications in medical and dental fields. In section 1, we provide a brief overview of HAp and nanoparticles. In section 2, fabrication methods of HAp nanoparticles are described based on the particle formation mechanisms. Recent applications of HAp nanoparticles are summarized in section 3. The future perspectives in this active research area are given in section 4.