Functionalized graphene oxide-zinc oxide hybrid material and its deployment for adsorptive removal of levofloxacin from aqueous media.

This work reports on the synthesis of aspartic acid-functionalized graphene oxide-zinc oxide, as a functional porous material, and its potential to mitigate levofloxacin (LFXN). The adsorbent was characterized by various techniques, including ultraviolet-visible (UV-Vis), Fourier transform infrared (FT-IR) spectroscopy, powder X-ray diffraction (PXRD), and scanning electron microscopy (SEM). The average crystallite size of the prepared composite was about 17.30 nm. Batch adsorption studies were carried out to elucidate the adsorption process for LFXN. Different parameters, including contact time, LFXN initial concentration, adsorbent concentration, pH, temperature, and ionic strength were studied. The mechanism and kinetics were studied by fitting the data to Freundlich and Langmuir isotherms, pseudo-first-order and pseudo-second-order kinetic models, respectively. The isotherm data was better fitted to Langmuir isotherm (R2 = 0.999) as compared to the Freundlich model. The maximum adsorption capacity obtained at equilibrium was 73.15 mg/g. For kinetic studies, Pseudo first order was better fitted with R2 = 0.87797, confirming the physisorption process. Thermodynamics parameters revealed that the process was exothermic and spontaneous at low temperatures. The adsorption mechanism was studied and the impregnation of LFXN in the adsorbent was confirmed by FTIR studies. This research proved that the designed GO/Asp-ZnO was a novel and promising adsorbent for the removal of LFXN with an efficiency of 95.12% at 30 mg/L LFXN by 0.6 g/L adsorbent in 24 h at pH = 7 and T = 25 °C.

Exopolysaccharides production from marine Bacillus strains and their antioxidant and bio-flocculant capacities.

Microbial exopolysaccharides (EPS) have gained high scientific concern due to their exceptional physicochemical features and high industrial applicability. Owing to their biotechnological importance, the present study was designed to screen and isolate the EPS-producing Bacillus strains based on their growth potential on specific media and colony morphologies. The bacterial isolates Bacillus subtilis Bs1-01, Bacillus licheniformis Bl1-02, and Bacillus brevis Bb1-04 showed excellent EPS production due to their shortened lag phase and abundant biomass production. Shake-flask fermentation valued the maximum production yield of 50.19 ± 1.14 g/L by Bl1-02 after 72 h incubation (about 3.40 times higher than that of Bacillus thuringiensis Bt1-05). The basic component analysis revealed the improved amount of total carbohydrate, reducing sugar ends, and protein contents by Bl1-02 strain. Structural characteristics and functional groups of the EPS characterized by Fourier transform infrared spectroscopy demonstrated that all EPS were in close agreement to each other due to the presence of similar chemical bonds and functional groups. EPS from Bl1-02 strain showed stronger and more stable bio-emulsifying and hygroscopicity activities (12.23%). The crude EPS exhibited potent antioxidant properties which were examined against reducing potential (H2O2 scavenging) and total antioxidant tests. Among bio-flocculation activities of EPS at different concentrations, Bs1-01 strain produced EPS at a concentration of 60 mg/mL was observed to show the maximum value of 79.20%. In conclusion, the EPS from marine Bacillus strains showed excellent functional properties suggesting potential industrial applications that demand separate investigations.

Exploring Marine as a Rich Source of Bioactive Peptides: Challenges and Opportunities from Marine Pharmacology.

This review highlights the underexplored potential and promises of marine bioactive peptides (MBPs) with unique structural, physicochemical, and biological activities to fight against the current and future human pathologies. A particular focus is given to the marine environment as a significant source to obtain or extract high-value MBPs from touched/untouched sources. For instance, marine microorganisms, including microalgae, bacteria, fungi, and marine polysaccharides, are considered prolific sources of amino acids at large, and peptides/polypeptides in particular, with fundamental structural sequence and functional entities of a carboxyl group, amine, hydrogen, and a variety of R groups. Thus, MBPs with tunable features, both structural and functional entities, along with bioactive traits of clinical and therapeutic value, are of ultimate interest to reinforce biomedical settings in the 21st century. On the other front, as the largest biome globally, the marine biome is the so-called "epitome of untouched or underexploited natural resources" and a considerable source with significant potentialities. Therefore, considering their biological and biomedical importance, researchers around the globe are redirecting and/or regaining their interests in valorizing the marine biome-based MBPs. This review focuses on the widespread bioactivities of MBPs, FDA-approved MBPs in the market, sustainable development goals (SDGs), and legislation to valorize marine biome to underlying the impact role of bioactive elements with the related pathways. Finally, a detailed overview of current challenges, conclusions, and future perspectives is also given to satisfy the stimulating demands of the pharmaceutical sector of the modern world.

Multi-point enzyme immobilization, surface chemistry, and novel platforms: a paradigm shift in biocatalyst design.

Engineering enzymes with improved catalytic properties in non-natural environments have been concerned with their diverse industrial and biotechnological applications. Immobilization represents a promising but straightforward route, and immobilized biocatalysts often display higher activities and stabilities compared to free enzymes. Owing to their unique physicochemical characteristics, including the high-specific surface area, exceptional chemical, electrical, and mechanical properties, efficient enzyme loading, and multivalent functionalization, nano-based materials are postulated as suitable carriers for biomolecules or enzyme immobilization. Enzymes immobilized on nanomaterial-based supports are more robust, stable, and recoverable than their pristine counterparts, and are even used for continuous catalytic processes. Furthermore, the unique intrinsic properties of nanomaterials, particularly nanoparticles, also confer the immobilized enzymes to be used for their broader applications. Herein, an effort has been made to present novel potentialities of multi-point enzyme immobilization in the current biotechnological sector. Various nano-based platforms for enzyme/biomolecule immobilization are discussed in the second part of the review. In summary, recent developments in the use of nanomaterials as new carriers to construct robust nano-biocatalytic systems are reviewed, and future trends are pointed out in this article.

Optimization of process variables for enhanced production of extracellular lipase by Pleurotus ostreatus IBL-02 in solid-state fermentation.

In the present study, Pleurotus ostreatus IBL-02, a white rot basidiomycete was exploited for lipase production in solid-state fermentation (SSF). Different agro-industrial wastes such as canola-oilseed cake, cotton-oilseed cake, linseed-oil cake, sesame-oilseed cake, rice bran and wheat bran were screened for fermentative production of the lipolytic enzyme. The enzyme profile of P. ostreatus showed the highest activity of lipase on canola oil seed cake as a substrate under SSF conditions. Various physiological factors such as incubation time, humidity level, culture pH, incubation temperature and supplementation of carbon and nitrogen sources were optimized to induce the lipase synthesis capability of P. ostreatus at an optimal level. Optimum lipase activity (3256 U/gram dry substrate) was measured in the solid fermentation medium using moisture level, 50.0%; pH, 4.0; temperature, 30°C and olive oil, 2.0% after 72 h of incubation period with glucose and urea as carbon and nitrogen supplements, respectively. Glucose supplementation significantly stimulated the lipase production, while nitrogen addition did not exert any significant effect on lipase yield. Overall, under optimized bioprocess conditions, the enzyme activity was improved up to 1.6 folds with respect to the original enzyme activities. The current findings indicate that culture conditions have great influence on the lipase production potential of P. ostreatus for commercial purpose.

Enhanced production of streptokinase from Streptococcus agalactiae EBL-31 by response surface methodology.

Streptokinase (SK) is a fibrinolytic protein used for the treatment of cardiovascular disorders. In the present study, enhanced production of SK was achieved by determining the optimum fermentation conditions for the maximum growth of Streptococcus agalactiae EBL-31 using response surface methodology (RSM). Four process variables (pH, temperature, incubation time and inoculum size) with five levels were evaluated in 30 experimental runs. Central composite rotatable design (CCRD) was employed to predict the effect of independent variables on SK activity. The statistical evaluation by ANOVA showed that the model was fit as the effect of single factors, quadratic effects and most of the interactions among variables. The value ofR2 (0.9988) indicated the satisfactory interaction between the experimental and predicted responses. Furthermore, the model F value (902.67) and coefficient of variation (1.92) clearly showed that the model is significant (p =>0.0001). The functional activity of SK was determined by spectrophotometric analysis and maximum SK production was obtained at pH-7.0, temperature- 37.5oC, an incubation time of 36 hours and 2.5 mL inoculum size. Hence it was concluded that the optimization of culture conditions through RSM increases the production of SK by 2.01-fold. Production of SK by fermentation is an economical choice to be used for the treatment of cardiovascular diseases.

Optimization of pH, temperature and CaCl2 concentrations for Ricotta cheese production from Buffalo cheese whey using Response Surface Methodology.

The recovery of milk constituents from cheese whey is affected by various processing conditions followed during production of Ricotta cheese. The objective of the present investigation was to optimize the temperature (60-90 °C), pH (3-7) and CaCl2 concentration (2·0-6·0 mm) for maximum yield/recovery of milk constituents. The research work was carried out in two phases. In 1st phase, the influence of these processing conditions was evaluated through 20 experiments formulated by central composite design (CCD) keeping the yield as response factor. The results obtained from these experiments were used to optimize processing conditions for maximum yield using response surface methodology (RSM). The three best combinations of processing conditions (90 °C, pH 7, CaCl2 6 mm), (100 °C, pH 5, CaCl2 4 mm) and (75 °C, pH 8·4, CaCl2 4 mm) were exploited in the next phase for Ricotta cheese production from a mixture of Buffalo cheese whey and skim milk (9 : 1) to determine the influence of optimized conditions on the cheese composition. Ricotta cheeses were analyzed for various physicochemical (moisture, fat, protein, lactose, total solids, pH and acidity indicated) parameters during storage of 60 d at 4 ± 2 °C after every 15 d interval. Ricotta cheese prepared at 90 °C, pH 7 and CaCl2 6 mm exhibited the highest cheese yield, proteins and total solids, while high fat content was recorded for cheese processed at 100 °C, pH 5 and 4 mm CaCl2 concentration. A significant storage-related increase in acidity and NPN was recorded for all cheese samples.

Statistical Correlation between Ligninolytic Enzymes Secretion and Remazol Brilliant Yellow-3GL Dye Degradation Potential of Trametes versicolor IBL-04.

Trametes versicolor IBL-04 was used for biodegradation of Remazol Brilliant Yellow 3-GL (RBY3-GL) reactive textile dye in Kirk's basal salts medium. During the initial screening study, the maximum decolorization (93.5%) of RBY3-GL was achieved in 7 days' shaking incubation period at pH 4 and 30 °C. Different physical and nutritional factors were statistically optimized to enhance the efficiency of T. versicolor IBL-04 for maximum decolorization. Under optimal conditions T. versicolor IBL-04 completely decolorized (100%) the RBY3-GL in 2 days of incubation with negligible adsorption on fungal mycelia. Laccase was the major enzyme (938.3 U/mL) secreted by T. versicolor IBL-04 along with comparatively lower activities of MnP. In this article and for the first time, a statistical correlation has been successfully investigated between the ligninolytic enzymes from an indigenously isolated white rot fungi, T. versicolor IBL-04, and the degradation of RBY3-GL.

Kinetic characterization, thermo-stability and Reactive Red 195A dye detoxifying properties of manganese peroxidase-coupled gelatin hydrogel.

An indigenous and industrially important manganese peroxidase (MnP) was isolated from solid-state bio-processing of wheat bran by white-rot fungal strain Ganoderma lucidum IBL-05 under pre-optimized growth conditions. Crude MnP extract was partially purified (2.34-fold) to apparent homogeneity by ammonium sulphate precipitation and dialysis. The homogeneous enzyme preparation was encapsulated on gelatin matrix using glutaraldehyde as a cross-linking agent. Optimal conditions for highest immobilization (82.5%) were: gelatin 20% (w/v), glutaraldehyde 0.25% (v/v) and 2 h activation time using 0.6 mg/mL of protein concentration. Gelatin-encapsulated MnP presented its maximum activity at pH 6.0 and 60 °C. Thermo-stability was considerably improved after immobilization. The optimally active MnP fraction was tested against MnSO4 as a substrate to calculate kinetic parameters. More than 90% decolorization of Sandal-fix Red C4BLN (Reactive Red 195A) dye was achieved with immobilized MnP in 5 h. It also preserved more than 50% of its original activity after the sixth reusability cycle. The water quality parameters (pH, chemical oxygen demand, total organic carbon) and cytotoxicity (brine shrimp and Daphnia magna) studies revealed the non-toxic nature of the bio-treated dye sample. A lower Km, higher Vmax, greater acidic and thermal-resistant up to 60 °C were the improved catalytic features of immobilized MnP suggesting its suitability for a variety of biotechnological applications.

Dye decolorization and detoxification potential of Ca-alginate beads immobilized manganese peroxidase.

BACKGROUND: In view of compliance with increasingly stringent environmental legislation, an eco-friendly treatment technology of industrial dyes and effluents is a major environmental challenge in the color industry. In present study, a promising and eco-friendly entrapment approach was adopted to immobilize purified manganese peroxidase (MnP) produced from an indigenous strain of Ganoderma lucidum IBL-05 on Ca-alginate beads. The immobilized MnP was subsequently used for enhanced decolorization and detoxification of textile reactive dyes). RESULTS: MnP isolated from solid-state culture of G. lucidum IBL-05, presented highest immobilization yield (83.9 %) using alginate beads prepared at optimized conditions of 4 % (w/v) sodium alginate, 2 % (w/v) Calcium chloride (CaCl2) and 0.5 mg/ml enzyme concentration. Immobilization of MnP enhanced optimum temperature but caused acidic shift in optimum pH of the enzyme. The immobilized MnP showed optimum activity at pH 4.0 and 60 °C as compared to pH 5.0 and 35 °C for free enzyme. The kinetic parameters K(m) and V(max) of MnP were significantly improved by immobilization. The enhanced catalytic potential of immobilized MnP led to 87.5 %, 82.1 %, 89.4 %, 95.7 % and 83 % decolorization of Sandal-fix Red C4BLN, Sandal-fix Turq Blue GWF, Sandal-fix Foron Blue E2BLN, Sandal-fix Black CKF and Sandal-fix Golden Yellow CRL dyes, respectively. The insolubilized MnP was reusable for 7 repeated cycles in dye color removal. Furthermore, immobilized MnP also caused a significant reduction in biochemical oxygen demand (BOD) (94.61-95.47 %), chemical oxygen demand (COD) (91.18-94.85 %), and total organic carbon (TOC) (89.58-95 %) of aqueous dye solutions. CONCLUSIONS: G. lucidum MnP was immobilized in Ca-alginate beads by entrapment method to improve its practical effectiveness. Ca-alginate bound MnP was catalytically more vigorous, thermo-stable, reusable and worked over wider ranges of pH and temperature as compared to its free counterpart. Results of cytotoxicity like hemolytic and brine shrimp lethality tests suggested that Ca-alginate immobilized MnP may effectively be used for detoxification of dyes and industrial effluents.

Decolorization applicability of sol-gel matrix immobilized manganese peroxidase produced from an indigenous white rot fungal strain Ganoderma lucidum.

BACKGROUND: An eco-friendly treatment of industrial effluents is a major environmental concern of the modern world in the face of stringent environmental legislations. By keeping in mind the extensive industrial applications of ligninolytic enzymes, this study was performed to purify, and immobilize the manganese peroxidase (MnP) produced from an indigenous strain of Ganoderma lucidum. The present study was also focused on investigating the capability of immobilized MnP for decolorization of dye containing textile effluents. RESULTS: A large magnitude of an indigenous MnP (882±13.3 U/mL) was obtained from white rot fungal strain G. lucidum in solid state bio-processing of wheat straw under optimized fermentation conditions (moisture, 50%; substrate, 5 g; pH, 5.5; temperature, 30°C; carbon source, 2% fructose; nitrogen source, 0.02% yeast extract; C: N ratio, 25:1; fungal spore suspension, 5 mL and fermentation time period, 4 days). After ammonium sulfate fractionation and Sephadex-G-100 gel filtration chromatography, MnP was 4.7-fold purified with specific activity of 892.9 U/mg. G. lucidum MnP was monomeric protein as evident by single band corresponding to 48 kDa on native and denaturing SDS-PAGE. The purified MnP (2 mg/mL) was immobilized using a sol-gel matrix of tetramethoxysilane (TMOS) and proplytrimethoxysilane (PTMS). The oxidation of MnSO4 for up to 10 uninterrupted cycles demonstrated the stability and reusability of the immobilized MnP. Shelf life profile revealed that enzyme may be stored for up to 60 days at 25°C without losing much of its activity. To explore the industrial applicability of MnP produced by G. lucidum, the immobilized MnP was tested against different textile effluents. After 4 h reaction time, the industrial effluents were decolorized to different extents (with a maximum of 99.2%). The maximally decolorized effluent was analyzed for formaldehyde and nitroamines and results showed that the toxicity parameters were below the permissible limits. CONCLUSIONS: In conclusion, G. lucidum MnP was immobilized by sol-gel matrix entrapment with an objective to enhance its practical efficiencies. The MnP was successfully entrapped into a sol- gel matrix of TMOS and PTMS with an overall immobilization efficiency of 93.7%. The sol- gel entrapped MnP seems to have prospective capabilities which can be useful for industrial purposes, especially for bioremediation of industrial effluents.

Degradation and mineralization of azo dye reactive blue 222 by sequential Photo-Fenton's oxidation followed by aerobic biological treatment using white rot fungi.

A two stage sequential Photo-Fenton's oxidation followed by aerobic biological treatment using two white rot fungi P. ostreatus IBL-02 (PO) and P. chrysosporium IBL-03 (PC) was performed to check decolorization and to enhance mineralization of azo dye Reactive Blue 222 (RB222). In the first stage, selected dye was subjected to Photo-Fenton's oxidation with decolorization percentage ≈90 % which was further increased to 96.88 % and 95.23 % after aerobic treatment using two white rot fungi P. ostreatus IBL-02 (PO) and P. chrysosporium IBL-03 (PC), respectively. Mineralization efficiency was accessed by measuring the water quality assurance parameters like COD, TOC, TSS and Phenolics estimation. Reduction in COD, TOC, TSS and Phenolics were found to be 95.34 %, 90.11 %, 90.84 % and 92.22 %, respectively in two stage sequential processes. The degradation products were characterized by UV-visible and FTIR spectral techniques and their toxicity was measured. The results provide evidence that both fungal strains were able to oxidize and mineralize the selected azo dye into non-toxic metabolites.

Characterization of purified and xerogel immobilized novel lignin peroxidase produced from Trametes versicolor IBL-04 using solid state medium of corncobs.

BACKGROUND: Cost-effective production of industrially important enzymes is a key for their successful exploitation on industrial scale. Keeping in view the extensive industrial applications of lignin peroxidase (LiP), this study was performed to purify and characterize the LiP from an indigenous strain of Trametes versicolor IBL-04. Xerogel matrix enzyme immobilization technique was applied to improve the kinetic and thermo-stability characteristics of LiP to fulfil the requirements of the modern enzyme consumer sector of biotechnology. RESULTS: A novel LiP was isolated from an indigenous T. versicolor IBL-04 strain. T. versicolor IBL-04 was cultured in solid state fermentation (SSF) medium of corn cobs and maximum LiP activity of 592 ± 6 U/mL was recorded after five days of incubation under optimum culture conditions. The crude LiP was 3.3-fold purified with specific activity of 553 U/mg after passing through the DEAE-cellulose and Sephadex-G-100 chromatography columns. The purified LiP exhibited a relatively low molecular weight (30 kDa) homogenous single band on native and SDS-PAGE. The LiP was immobilized by entrapping in xerogel matrix of trimethoxysilane (TMOS) and proplytetramethoxysilane (PTMS) and maximum immobilization efficiency of 88.6% was achieved. The free and immobilized LiPs were characterized and the results showed that the free and immobilized LiPs had optimum pH 6 and 5 while optimum temperatures were 60°C and 80°C, respectively. Immobilization was found to enhance the activity and thermo-stability potential of LiP significantly and immobilized LiP remained stable over broad pH and temperature range as compare to free enzyme. Kinetic constants K(m) and V(max) were 70 and 56 µM and 588 and 417 U/mg for the free and immobilized LiPs, respectively. Activity of this novel extra thermo-stable LiP was stimulated to variable extents by Cu(2+), Mn(2+) and Fe(2+) whereas, Cystein, EDTA and Ag(+) showed inhibitory effects. CONCLUSIONS: The indigenously isolated white rot fungal strain T. versicolor IBL-04 showed tremendous potential for LiP synthesis in SSF of corncobs in high titters (592 U/mL) than other reported Trametes (Coriolus, Polyporus) species. The results obtained after dual phase characterization suggested xerogel matrix entrapment a promising tool for enzyme immobilization, hyper-activation and stabilization against high temperature and inactivating agents. The pH and temperature optima, extra thermo-stability features and kinetic characteristics of this novel LiP of T. versicolor IBL-04 make it a versatile enzyme for various industrial and biotechnological applications.

Spirothienoquinoline-based acceptor molecular systems for organic solar cell applications: DFT investigation.

In this research, eight three-dimensional benzothiadiazole and spirothienoquinoline-based donor molecules of the A-D-A-D-A configuration were formulated by introducing new acceptor groups (A1-A4) to the terminal sites of recently synthesized potent donor molecule (tBuSAF-Th-BT-Th-tBuSAF). Frontier molecular orbital analysis, reorganization energies, the density of states analysis, transition density matrix analysis, dipole moment, open-circuit voltage, and some photophysical properties were all assessed using CAMB3LYP/LanL2DZ. The optoelectronic properties of freshly proposed compounds were compared to the reference molecule (SQR). Due to the existence of robust electron-attracting acceptor moiety, SQM3 and SQM7 had the greatest maximum absorption of all other investigated molecules, with the values of 534 and 536 nm, respectively. The maximum dipole moment, narrow bandgap (3.81 eV and 3.66 eV), and HOMO energies (- 5.92 eV, 5.95 eV) are also found in SQM3 and SQM7, respectively. The SQM3 molecule also possesses the least reorganization energy for hole mobility (0.007237 eV) than all other considered molecules. The open-circuit voltage of all the molecules considered to be donors, was calculated with respect to PC61BM and it is estimated that except SQM7 and SQM3 all other newly developed molecules have improved open-circuit voltage. The findings show that most of the designed donor molecules can perform better experimentally and should be employed for practical implementations in the future.

Phanerochaete chrysosporium IBL-03 secretes high titers of manganese peroxidase during decolorization of Drimarine Blue K2RL textile dye.

A novel indigenous strain, Phanerochaete chrysosporium IBL-03, with high manganese peroxidase (MnP) activities was used for decolorization of a reactive textile dye, Drimarine Blue K2R, which is used extensively in textile units of Pakistan. The initial experiment was run for seven days with 0.01% (w/v) dye solution prepared in Kirk's basal nutrient medium. Samples were removed after every 24 h and the extent of dye decolorization was determined at lambda(max) of the dye. The study revealed that P. chrysosporium caused 65% decolorization of Drimarine Blue K2RL in seven days. By process optimization, 97% colour removal could be achieved in three days using 0.005% (w/v) Drimarine Blue K2RL solution at pH 4.0 and 30 degrees C in defined Kirk's medium with 0.9% (w/v) molasses and 0.2% (w/v) ammonium dihydrogen phosphate added as carbon and nitrogen sources, respectively. Manganese peroxidase was found to be the major enzyme (560 IU/mL) involved in dye decolorization of Drimarine Blue K2RL by P. chrysosporium. The dye adsorption studies showed that the dye initially adsorbed on fungal mats disappeared later on, possibly by the action of MnP secreted by the fungus in secondary metabolism.

Decolorization of dye-containing textile industry effluents using Ganoderma lucidum IBL-05 in still cultures.

A locally isolated white rot fungus Ganoderma lucidum IBL-05 was used for development of a bioremediation process for original textile industry effluents. Dye-containing effluents of different colors were collected from the Arzoo (maroon), Ayesha (yellow), Ittemad (green), Crescent (navy blue) and Magna (yellowish) textile industries of Faisalabad, Pakistan. G. lucidum IBL-05 was screened for its decolorization potential on all the effluents. Maximum decolorization (49.5 %) was observed in the case of the Arzoo textile industry (ART) effluent (lambda(max) = 515 nm) on the 10th day of incubation. Therefore, the ART effluent was selected for optimization of its decolorization process. Process optimization could improve color removal efficiency of the fungus to 95% within only 2 days, catalyzed by manganese peroxidase (1295 U/mL) as the main enzyme activity at pH 3 and 35 degrees C using 1% starch supplemented Kirk's basal medium. Nitrogen addition inhibited enzyme formation and effluent decolorization. The economics and effectiveness of the process can be improved by further process optimization.

Improved exopolysaccharide production from Bacillus licheniformis MS3: Optimization and structural/functional characterization.

Exopolysaccharides (EPS) are microbially-originated, complex biosynthetic polymers, mainly carbohydrates in nature. They have gained attention of modern researches due to their novel physicochemical characteristics. However, the development of cost-effective strategies to improve the EPS yield, remains a challenge. In this study, cost-effective EPS production was carried out from B. licheniformis in solid state fermentation of mango peels substrate with waste-to-value theme. Initially, B. licheniformis was exposed to ultraviolet (UV) radiations of short wavelength which significantly improved the EPS yield (from 3.4 to 4.6 g/L). The highest EPS producing mutant strain (B. licheniformis MS3) was further proceeded for yield optimization using RSM-CCD approach. Optimization improved the yield >3.2-folds (from 4.6 to 15.6 g/L). The optimally yielded fraction was characterized using HPLC, FT-IR and SEM analyses. HPLC revealed the hetero-polymeric nature of EPS containing mannose (20.60%), glucose (46.80%), and fructose (32.58%) subunits. FT-IR spectroscopy revealed the presence of hydroxyl and carboxyl functional groups, and glycosidic linkages among monosaccharides. SEM microstructure showed that EPS comprise smoother surface with less porosity. Studies on functional characteristics revealed the presence of hydrophilic moieties among EPS with moderate water (105.3%) and oil (86.3%) uptake capacity. The EPS exhibited excellent emulsifying properties showed good stability against all hydrocarbons/oils tested. In conclusion, the cost-effective EPS production with multifunctional properties, this study may be valuable for various biochemical and biotechnological sectors.

Bio-based active food packaging materials: Sustainable alternative to conventional petrochemical-based packaging materials.

In food industry, a growing concern is the use of suitable packaging material (i.e., biodegradable coatings and films) with enhanced thermal, mechanical and barrier characteristics to prevent from contamination and loss of foodstuff. Biobased polymer resources can be used for the development of biodegradable bioplastics. To achieve this goal, biopolymers should be economic, renewable and abundantly available. Bioplastic packaging materials based on renewable biomass could be used as sustainable alternative to petrochemically-originated plastic materials. This review summarizes the recent advancements in biopolymer-based coatings and films for active food packaging applications. Microbial polymers (PHA and PLA), wood-based polymers (cellulose, hemicellulose, starch & lignin), and protein-based polymers (gelatin, keratin, wheat gluten, soy protein and whey protein isolates) were among the materials most widely exploited for the development of smart packaging films. These biopolymers are able to synthesize coatings and films with good barrier properties against food borne pathogens and the transport of gases. Biobased reinforcements e.g., plant essential oils and natural additives to bioplastic films improve oxygen barrier, antibacterial and antifungal properties. To induce the desired functionality the simultaneous utilization of different synthetic and biobased polymers in the form of composites/blends is also an emerging area of research. Nanoscale reinforcements into bioplastic packaging have also been reported to improve packaging characteristics ultimately increasing food shelf life. The development of bioplastic/biocomposite and nanobiocomposites exhibits high potential to replace nonbiodegradable materials with characteristics comparable to fossil-based plastics, additionally, giving biodegradable and compostable characteristics. The idea of utilization of renewable biomass and the implications of biotechnology can firstly reduce the burden from fossil-resources, while secondly promoting biobased economy.

Multifunctional materials conjugated with near-infrared fluorescent organic molecules and their targeted cancer bioimaging potentialities.

Near-infrared fluorescent dyes based on small organic molecules are believed to have a great influence on cancer diagnosis at large and targeted cancer cell bioimaging, in particular. NIR dyes-based organic molecules have notable characteristics features, such as high tissue penetration and low tissue autofluorescence in the NIR spectral region. Cancer targeted bioimaging relies significantly on the synthesis of highly specific molecular probes with excellent stability. Recently, NIR dyes have emerged as unique fluorescent probes for cancer bioimaging. These current advancements have overcome many limitations of conventional NIR probes e.g., poor photostability and hydrophilicity, insufficient stability and low quantum yield. The further potential lies in NIR dyes or NIR dyes-coated nanocarriers conjugated with cancer-specific ligand (e.g., peptides, antibodies, proteins or other small molecules). Multifunctional NIR dyes have synthesized, which efficiently accumulate in cancer cells without requiring chemical conjugation and also these dyes have presented novel photophysical and pharmaceutical properties for in vivo imaging. This review highlights the recently developed NIR dyes with novel applications in cancer bioimaging. We believe that these novel fluorophores will enhance our understanding of cancer imaging and pave a new road in cancer diagnosis and treatment.

Engineering enzyme-coupled hybrid nanoflowers: The quest for optimum performance to meet biocatalytic challenges and opportunities.

The current industrial revolution signifies the high-value of biocatalysis engineering. Over the past decade, multiple micro- and nanostructured materials have been attempted for immobilization of enzymes to improve their catalytic properties. Conventional immobilization strategies result in improved stability, while insolubilized enzymes generally lost their activity compared to free counterparts. Recently, a new generation organic-inorganic hybrid nanoflowers with unique properties have received great attention as a novel and incentive immobilization approach owing to their simple fabrication, high biocatalytic efficiency, and enzyme stabilizing capability. The hybrid nanoflowers biocatalytic system implicates metal ions and biomolecules (enzymes). In contrast to free or conventionally immobilized enzymes, single enzyme or multi enzyme-incorporated flowers-like hybrid nanoconstructs demonstrated elevated catalytic activities and stabilities over a very broader range of experimental conditions, i.e., pHs, temperatures and salt concentration. This review discusses the recent developments in the fabrication strategies to diversifying nanoflowers, types, characteristics, and applications of organic-inorganic hybrid nanoflowers as a host platform to engineer different kinds of enzymes with requisite functionalities for biocatalysis applications in different sectors of the modern world. Based on experimental and theoretical literature data, the review is wrapped up with concluding remarks and an outlook in terms of upcoming challenges and prospects for their scale-up applications.