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ADAM33 is a zinc-dependent metalloprotease of the ADAM family, which plays a vital biological role as an activator of Th2 cytokines and growth factors. Moreover, this protein is crucial for the normal development of the lung in the fetus two months after gestation leading to determining lung functions all over life. In this regard, mutations in ADAM33 have been linked with asthma risk factors. Consequently, identifying ADAM33 pathogenic nonsynonymous single-nucleotide polymorphisms (nsSNPs) can be very important in asthma treatment. In the present study, 1055 nsSNPs of human ADAM33 were analyzed using biocomputational software, 31 of which were found to be detrimental mutations. Precise structural and stability analysis revealed D219V, C669G, and C606S as the most destabilizing SNPs. Furthermore, MD simulations disclosed higher overall fluctuation and alteration in intramolecular interactions compared with the wild-type structure. Overall, the results suggest D219V, C669G, and C606S detrimental mutations as a starting point for further case-control studies on the ADAM33 protein as well as an essential source for future targeted mechanisms.

Menaquinone-7 (MK-7) offers significant health benefits; however, only the all-trans form is biologically active. MK-7 produced through fermentation can occur as all-trans and cis isomers, and the therapeutic value of the resulting MK-7 is exclusively determined by the quantity of the all-trans isomer. Therefore, this study aimed to investigate the effect of the media composition on the isomer profile obtained from fermentation and determine the optimum media combination to increase the concentration of the all-trans isomer and diminish the production of cis MK-7. For this purpose, design of experiments (DOE) was used to screen the most effective nutrients, and a central composite face-centred design (CCF) was employed to optimise the media components. The optimum media consisted of 1% (w/v) glucose, 2% (w/v) yeast extract, 2% (w/v) soy peptone, 2% (w/v) tryptone, and 0.1% (w/v) CaCl2. This composition resulted in an average all-trans and cis isomer concentration of 36.366 mg/L and 1.225 mg/L, respectively. In addition, the optimised media enabled an all-trans isomer concentration 12.2-fold greater and a cis isomer concentration 2.9-fold less than the unoptimised media. This study was the first to consider the development of an optimised fermentation media to enhance the production of the bioactive isomer of MK-7 and minimise the concentration of the inactive isomer. Furthermore, this media is commercially promising, as it will improve the process productivity and reduce the costs associated with the industrial fermentation of the vitamin.

Despite iron-based nanoparticles gaining huge attraction in various field of sciences and technology, their application rises ecological concerns due to lack of studies on their interaction with microbial cells populations and communities, such as biofilms. In this study, Chlorella vulgaris cells were employed as a model of aquatic microalgae to investigate the impacts of l-lysine-coated iron oxide nanoparticles (lys@IONPs) on microalgal growth and biofilm formation. In this regard, C. vulgaris cells were exposed to different concentrations of lys@IONPs and the growth of cells was evaluated by OD600 and biofilm formation was analyzed using crystal violet staining throughout 12 days. It was revealed that low concentration of nanoparticles (

Downstream processing is an expensive step for industrial production of recombinant proteins. Cell immobilization is known as one of the ideal solutions in regard to process intensification. In recent years, magnetic immobilization was introduced as a new technique for cell immobilization. This technique was successfully employed to harvest many bacterial and eukaryotic cells. But there are no data about the influence of magnetic immobilization on the eukaryotic inducted recombinant cells. In this study, impacts of magnetic immobilization on the growth and metabolic status of induced recombinant Pichia pastoris as a valuable eukaryotic model cells were investigated. Results based on colony-forming unit, OD600, and trypan blue assay indicated that magnetic immobilization had no adverse effect on the growth and viability of P. pastoris cells. Also, about 20-40% increase in metabolic activity was recorded in immobilized cells that were decorated with 0.5-2 mg/mL nanoparticles. Total protein and carbohydrate of the cells were also measured as main indicatives for cell function and no significant changes were observed in the immobilized cells. Current data show magnetic immobilization as a biocompatible technique for application in eukaryotic expression systems. Results can be considered for further developments in P. pastoris-based expression systems.

L-asparaginase from Escherichia coli is an important therapeutic agent in the treatment of childhood acute lymphoblastic leukemia. In this study, the secretory production of a recombinant form of L...

The main objective of this study was to evaluate the possibility of ethanol production through the immobilization of S. cerevisiae with L-lysine coated magnetite nanoparticles (MNPs), using sugar b...

Background: Viral respiratory infections could result in perturbation of the gut microbiota due to a probable cross-talk between lungs and gut microbiota. This can affect pulmonary health and the gastrointestinal system. Objective: This review aimed to discuss the impact of probiotics/prebiotics and supplements on the prevention and treatment of respiratory infections, especially emerging pathogens. Methods: The data were searched in PubMed, Scopus, Google Scholar, Google Patents, and The Lens-Patent using keywords of probiotics and viral respiratory infections in the title, abstract, and keywords. Result: Probiotics consumption could decrease the susceptibility to viral respiratory infections, such as COVID-19 and simultaneously enhance vaccine efficiency in infectious disease prevention through the immune system enhancement. Probiotics improve the gut microbiota and the immune system via regulating the innate system response and production of anti-inflammatory cytokines. Moreover, treatment with probiotics contributes to intestinal homeostasis restitution under antibiotic pressure and decreasing the risk of secondary infections due to viral respiratory infections. Probiotics present varied performances in different conditions; thus, promoting their efficacy through combining with supplements (prebiotics, postbiotics, nutraceuticals, berberine, curcumin, lactoferrin, minerals, and vitamins) is important. Several supplements reported to enhance the probiotics’ efficacy and their mechanisms as well as probiotics- related patents are summarized in this review. Using nanotechnology and microencapsulation techniques can also improve probiotics’ efficiency. Conclusion: Given the global challenge of COVID-19, probiotic/prebiotic and following nutritional guidelines should be regarded seriously. Additionally, their role as an adjuvant in vaccination for immune response augmentation needs attention.

Effective engineering undergraduate programs should be well-structured to respond to the needs of students and prepare them for the workforce or further studies. Undoubtedly, the teaching and learning process should be student-centred to promote problem-solving skills and facilitate the generation of new knowledge by students. A capstone research project is one of the practices that aim to enable students to successfully move into either employment or graduate studies. In this study, a survey containing different categories was prepared to assess the usefulness of a capstone research project in achieving various outcomes, including personal, learning, and research perceptions, as well as other aspects such as supervision, career aspirations, safety matters, and hands-on experience . The survey was sent out to honours students who were carrying out an engineering capstone research project. The results suggested that an undergraduate research program can be an efficient tool in the teaching and learning process. Interestingly, the results showed that undergraduate research was unable to prompt students to choose their future career pathway or encourage them to pursue postgraduate studies. Defining projects that reflect the industry's needs with focusing on the society’s demands could present a possible solution to this issue.

Various studies were performed to fabricate self-assembling nanoobjects out of noble metals, but a few efforts were made for engineering iron-based nanorods toward sell-assembling blocks. In this regard β-FeOOH nanorods were fabricated in various sizes to achieve iron-based rod nanoblocks with self-assembling potential. Hydrolysis of ferric ions in various concentrations was successfully developed as a novel approach to control the growth of β-FeOOH crystals and tuning the length of rods in the nano range, below 100 nm. It was found that the concentration of ferric ion has no effect on the widths of nanorods, but the length was affected. By increasing the concentration of ferric ions, an increase in the length of nanorods and an increase of aspect ratio occurred. All sizes of the resulting FeOOH nanorods exhibited mesoporous feature, but interestingly the hysteresis loops were different due to different pore patterns. In fact, pores on the larger particles were more uniform in size and shape. Nanorods of small length did not make suitable interactions toward ordered phase formation, but rods with the mean length of about 90 nm or longer, at a certain concentration, were able to form nematic phases. The large (∼+40 mV) zeta-potential of nanorods prevents formation of dense arrays, and just bundle-like structures were observed. These findings highlight the importance of size, surface charge, and concentration of nanoobjects in the formation of 3D structures. The developed technique in the fabrication of β-FeOOH nanorods provides pure structures that are free from any size-controlling agent. These pure structures are suitable for further functionalization or coating. Self-assembling nanoobjects is a developing field in nanotechnology, and therefore studies can help our understanding over the assembling process.

Cytotoxicity in freshwater fishes induced by industrial effluents and dyes is a global issue. Trypan blue dye has many applications in different sectors, including laboratories and industries. This study determines to detect the cytotoxic effects of trypan blue dye in vivo. The objective of this study was to estimate the sub-lethal effects of azodye in fish. Cirrhinus mrigala, a freshwater fish, was exposed to three different grading concentrations of dye 5 mg/L, 10 mg/L, and 20 mg/L in a glass aquarium. Significant (p 0.05) decrease in the weight of fish was observed as 0.728 ± 0.14 g and 2.232 ± 0.24 g, respectively, in the trial groups exposed to 10 and 20 mg/L of dye in a week. After exposure to trypan blue dye, fishes were dissected to remove liver and kidney tissues. Histopathological assessments determined hepatotoxicity and nephrotoxicity induced by trypan blue through the paraffin wax method. This dye induces mild alterations in the liver such as congestion, hemolysis, dilated sinusoids, ruptured hepatocytes, vacuolization, edema of hepatocytes, necrosis, degeneration, aggregation, and inflammation. This dye not only alters liver tissue, also induces an acute level of tissue alterations in the kidneys, such as degeneration of epithelial cells of renal tubules, shrinkage of the glomerulus, congestion, reduced lumen, degeneration of glomerulus, absence of space of bowmen, glomerulonephritis, necrosis in hematopoietic interstitial tissues and glomerulus, reduced lumen, vacuolar degeneration of renal tubules, increased per tubular space. The current study concludes that trypan blue dye released even in small amounts is found to be associated with a high incidence of cytotoxicity. Such tissue alterations in this species could be used as biomarkers for azo dyes.

Background: Broth microdilution is the only available microscale endpoint technique used to evaluate the antimicrobial potency of nanostructures. In the case of unstable nanostructures or at high concentrations of nanostructures, this technique is not applicable due to aggregation and sedimentation issues. Most nanostructures can absorb visible light, and this optical feature can interfere with the OD600 measurement that is commonly employed for the evaluation of microbial cells growth. The demand for high-tech plate readers is another limitation of the broth microdilution procedure. Agar microdilution can be a promising novel procedure to overcome all these technical difficulties. Objective: In the current experiment, the agar microdilution procedure was developed and introduced to be employed for the evaluation of antimicrobial potency of colloidally unstable nanostructures even at extremely high concentrations. Methods: Thymus daenensis herbal nanoparticles (HrbNPs) were fabricated through a top-down approach and were tested against methicillin-resistant Staphylococcus aureus (MRSA). Also, the particles were fortified with povidone-iodine and peracetic acid as potent antimicrobial compounds to achieve the enhanced antimicrobial activity. Results: Viscose molten agar media prevented the particles from sedimentation during 96-well plate preparation. By agar solidification, the nanoparticles were immobilized in the media, and no aggregation or sedimentation could occur. After incubation, the bacterial growth was recognizable in the well as a thin creamy layer. The MIC of HrbNPs against MRSA was found to be 20 mg/ml. Fortification with povidone- iodine had no impact on the antimicrobial potency of HrbNPs. However, fortification of HrbNPs with peracetic acid resulted in a four-fold increase in the antimicrobial potency of nanoparticles, and MIC was reduced to 5 mg/mL. Conclusions: Results indicated that agar microdilution can be a promising procedure for the antimicrobial susceptibility test of nanostructures at extremely high concentrations. Also, colloidally unstable nanostructures can be tested via this procedure without any concern for possible aggregation and sedimentation. On the other hand, it was found that fortification with antimicrobial compounds can be an effective approach to increasing the antimicrobial potency of HrbNPs against superbugs.

Background: Colour and turbidity (appearance), odour and flavour, taste, and texture are the main parameters affecting consumer’s perception of juice quality. Anthocyanins, as natural antioxidant and water-soluble pigment, exist in red fruit juices which are extremely unstable and more susceptible to degradation. These mainly include anthocyanins, pigments, proteins, and vitamins that are thermally sensitive. Objective: The present study focuses on the treatment of three different fruit juices namely red grape, pomegranate, and sour cherry using different preservative methods and evaluation of their organoleptic properties. Methods: Four preservative methods including pasteurization (90°C for 30 sec), mild heat treatment (60°C for 4, 8 and 12 min), sonication (25°C) and thermosonication (90°C) using amplitude levels of 24.4, 42.7 and 61 μm for 4, 8 and 12 min, have been used for the treatment of the three selected fruit juices. Results: Obtained results indicate that untreated grape juice had maximum L* value (29.83) and the pasteurized grape juice had a minimum L* value (25.77). Furthermore, while a* values of untreated grape, pomegranate, and sour cherry juices were 39.7, 42.03 and 38.13, respectively, these pasteurized juices had minimum a* values of 35.3, 38.47 and 36.97, respectively. In addition, results revealed that sonication and mild heating had minimum effects on colour and appearance, odour and flavour of all three studied juices. Furthermore, significant positive (p˂0.05) effects of thermosonication were observed for the cloudiness parameter of the studied juices. Maximum acceptability scores were achieved by mild heat-treated grape juice at 60°C for 8 min (8.33), thermosonicated pomegranate juice at 60°C and amplitude of 24.4 μm for 4 min (7.33) and sonicated sour cherry juice at 25°C and amplitude of 24.4 μm for 4 min (9.33). Conclusion: Different preservative methods with optimum processing conditions were successfully utilized to minimize the changes in the sensorial and physicochemical properties of the treated juices.

Pichia pastoris expression system was introduced with post-translation process similar to higher eukaryotes. Preliminary studies were performed toward process intensification and magnetic immobilization of this system. In this experiment, effects of magnetic immobilization on the structure of recombinant protein were evaluated. P. pastoris cell which express human serum albumin (HSA) was used as a model. The cells were immobilized with various concentrations of APTES coated magnetite nanoparticles. HSA production was done over 5 days induction and structure of the product was analyzed by UV-vis, fluorescence, and ATR-FTIR spectroscopy. Second derivative deconvolution method was used to analyze the secondary structure of HSA. P. pastoris cell that were immobilized with 0.5 and 1 mg/mL of nanoparticles were produced HSA with intact structure. But immobilization with 2 mg/mL of nanoparticles resulted in some modifications in the secondary structures (i.e., α-helixes and β-turns) of produced HSA. Based on these data, immobilization of P. pastoris cells with 0.5 or 1 mg/mL of nanoparticles is completely efficient for cell harvesting and has any effect on the structure of recombinant product. These findings revealed that decoration of microbial cells with high concentrations of nanoparticles has some impacts on the structure of secretory proteins.

Simulation based learning has emerged as a new tool that potentially could replace and amplify the real-world experience in a fully interactive way. This learning technique can play a key role in the classroom setting to provide engineering students with the required knowledge and skills. In order to evaluate the possibility of using virtual bioprocess engineering laboratory as a tool in learning to mitigate practical dilemmas in chemical engineering curriculum, a virtual bioprocess engineering laboratory has been designed and developed at the University of Waikato. The virtual laboratory was made available to the third-year chemical engineering students enrolled in the biotechnology course. Participants were asked to attend both the physical and virtual laboratories and complete a range of questionnaires. It was found that by conducting the virtual bioprocess engineering laboratory, students gained a deeper understanding about fermentation principles, laboratory safety rules, experiment design and analysis of data. Based on the results, virtual reality bioprocess engineering laboratory can also provide a safe, affordable and timely experience to gain the required bioprocess engineering proficiency and skills. More than 90 % of students found the virtual lab to be an essential tool to undertake hands-on experiments effectively.

Due to the negative environmental impact of cement production, partial replacement of cement with by-products and wastes has been drawn much attention. However, the reduction in binder fraction can...

Vitamin menaquinone-7 (MK-7) supplementation improves bone health and reduces the incidence of osteoporosis. Despite the recent developments in MK-7 fermentation using Bacillus subtilis natto, low fermentation yields, as well as complicated downstream processing steps, are still the main reasons for the expensive final product. To overcome these issues, developing a fermented dairy-based product rich in MK-7 by avoiding costly downstream steps and optimising the fermentation operating conditions to enhance the MK-7 concentration would be an alternative approach. The present study, therefore, aims to evaluate the role of agitation and aeration as the key operating conditions on MK-7 production by Bacillus subtilis natto using a milk media. The agitation and aeration rates of 525 RPM and 5 VVM were found to be the optimum levels leading to the production of 3.54 mg/L of MK-7. Further, the sensory evaluation was performed to compare the sensory properties of the freeze-dried fermented samples with non-fermented milk samples. The results illustrated that the fermented samples had a significant saltiness with intense aroma resulting in the less acceptability of them by the panellists.

Crack propagation is one of the issues associating with dental composites which can significantly affect their performance. Current solutions for preventing and stopping the cracks include maximizing the filler to matrix ratio as well as fiber reinforcing of composites which are not always reliable. The precipitation of calcium carbonate (CaCO3) minerals by the generally recognized as safe (GRAS) bacteria can be seen as a novel approach to address this shortcoming. In the present study, the effect of microbially induced calcium carbonate precipitation (MICP) on filling dental composites' cracks and cavities was studied. In this first step, the capability of different GRAS bacteria to induce CaCO3 precipitation was investigated. In the next step, the capability of potent bacteria to initiate MCIP in solid matrix was evaluated. For this purpose, the CaCO3-bacteria along with necessary nutrients were introduced into different dental composites in two ways, namely, powder and paste form. The light-cured composites were analyzed using optical microscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDS) to identify and characterize the precipitated CaCO3 crystals. It was shown that the incorporation of powder healing compound in two composites resulted in precipitation of CaCO3, while no crystals were formed when a paste form of healing compound was mixed with composites. The results evidently show that MICP can be a feasible alternative to current inefficient approaches to address microcracking issues in dental composites.

Cell immobilization on the magnetic nanoparticles (MNPs) and magnetic harvesting is a novel approach for microalgal cells separation. To date, the effect of these nanoparticles on microalgal cells was only studied over a short period of time. More studies are hence needed for a better understanding of the magnetic harvesting proposes or environmental concerns relating to long-term exposure to nanoparticles. In this study, the impact of various concentrations of MNPs on the microalgal cells growth and their metabolic status was investigated over 12 days. More than 60% reduction in mitochondrial activity and pigments (chlorophyll a, chlorophyll b, and carotenoids) content occurred during the first 6 days of exposure to ≥50 µg/mL nanoparticles. However, more than 50% growth inhibitory effect was seen at concentrations higher than 400 µg/mL. Exposure to MNPs gradually induced cellular adaptation and after about 6 days of exposure to stress generating concentrations (˂400 µg/mL) of IONs, microalgae could overcome the imposed damages. This work provides a better understanding regarding the environmental impact of MNPs and appropriate concentrations of these particles for future algal cells magnetic immobilization and harvesting., Graphical Abstract

Menaquinone-7 (MK-7) is a type of vitamin K. MK-7 is produced via bacterial fermentation, and in order to reach the desired product purity, several downstream processing steps, including extraction, drying, ultrasonication, must be carried out. These processes, however, need to be carried out in such fashion to ensure the least amount of vitamin K lost and maximum recovery into the end-product. Therefore, in this study, drying, storage at 4 and −20 °C, and ultrasonication steps were evaluated under different conditions. Static liquid fermentations were conducted in McCartney bottles to explore the maximum MK-7 secretion potentials in different glycerol and glucose-based media compositions that were optimized in our previous studies. Maximum 32.5±0.4 mg l−1 and 14.6±0.4 mg l−1 concentrations were achieved in glycerol and glucose-based media, respectively. Concentrations of MK-7 produced under same fermentation conditions in 30 ml McCartney amber bottles with 3 ml of media in them and in 75 ml culture tubes with 20 ml media were compared. Also, ultrasonication, drying, and storage conditions were investigated to ensure the least amount of vitamin K is lost. Results showed that drying under forced air flow was the fastest, thus, demonstrated a better preservation of the vitamin, and should replace vacuum drying. Ultrasonication for 15 min seems to be safe and sufficient for phase transition for analysis. Also, storage at refrigerated temperatures seems to preserve MK-7 at least for one week. Furthermore, fermentations in McCartney bottles indicated how MK-7 concentrations are distributed in different zones of the static liquid broth. Culture tube results provided the conclusion as of how the metabolism of MK-7 changes in static fermentation when the scale-up process begins from McCartney bottle to culture tubes. Results in general showed a clearer road map to ensuring better quality and preservation of the valuable end-product, and illuminated more the path to further scaling up of the fermentation process for commercial production of MK-7.

Downstream processing is an expensive step for industrial production of recombinant proteins. Cell immobilization is known as one of the ideal solutions in regard to process intensification. In recent years, magnetic immobilization was introduced as a new technique for cell immobilization. This technique was successfully employed to harvest many bacterial and eukaryotic cells. But there are no data about the influence of magnetic immobilization on the eukaryotic inducted recombinant cells. In this study, impacts of magnetic immobilization on the growth and metabolic status of induced recombinant Pichia pastoris as a valuable eukaryotic model cells were investigated. Results based on colony-forming unit, OD600, and trypan blue assay indicated that magnetic immobilization had no adverse effect on the growth and viability of P. pastoris cells. Also, about 20-40% increase in metabolic activity was recorded in immobilized cells that were decorated with 0.5-2 mg/mL nanoparticles. Total protein and carbohydrate of the cells were also measured as main indicatives for cell function and no significant changes were observed in the immobilized cells. Current data show magnetic immobilization as a biocompatible technique for application in eukaryotic expression systems. Results can be considered for further developments in P. pastoris-based expression systems.

Iron oxide nanoparticles were employed to fabricate a soft tissue scaffold with enhanced physicochemical and biological characteristics. Growth promotion effect of L-lysine coated magnetite (Lys@Fe3O4) nanoparticles on the liver cell lines was proved previously. So, in the current experiment these nanoparticles were employed to fabricate a soft tissue scaffold with growth promoting effect on the liver cells. Lys@Fe3O4 nanoparticles were synthesized via co-precipitation reaction. Resulted particles were ~7 nm in diameter and various concentrations (3, 5, and 10 wt%) of these nanoparticles were used to fabricate nanocomposite PCL fibers. Electrospinning technique was employed and physicochemical characteristics of the resulted nanofibers were evaluated. Electron micrographs and EDX-mapping analysis showed that nanoparticles were well dispersed in the PCL fibers and no bead structure were formed. As expected, incorporation of Lys@Fe3O4 to the PCL nanofibers resulted in a reduction in hydrophobicity of the scaffold. Nanocomposite scaffolds were shown increased tensile strength with increasing concentration of employed nanoparticles. In contrast to PCL scaffold, nearly 150% increase in the cell viability was observed after 3-days exposure to the nanocomposite scaffolds. This study indicates that incorporation of magnetite nanoparticles in the PCL fibers make them more prone to cell attachment. However, incorporated nanoparticles can provide the attached cells with valuable iron element and consequently promote the cells growth rate. Based on the results, magnetite enriched PCL nanofibers could be introduced as a scaffold to enhance the biological performance for liver tissue engineering purposes.

The possibility of employing FeOOH nano-ellipsoids as a novel shape nano-based iron supplement was investigated. Ferrous sulfate and nano-ellipsoids were daily administered by gavage at low and high dosages. After 1 month of treatment, the hematologic parameters along with serum and organs’ iron contents were measured. Liver enzymes, total serum bilirubin, and LDH level were assayed to evaluate any possible toxicity. More investigation was also performed by organ index calculation and also pathologic studies. It was found that nano-ellipsoids are an effective iron supplement to improve iron-related blood parameters. Interestingly, low-dose nano-ellipsoids were even more effective than high-dose ferrous sulfate. Nano-ellipsoids had no considerable impact on the liver enzymes and serum bilirubin. Meanwhile, high-dose ferrous sulfate significantly increases liver enzyme activity. The increased serum LDH was also the only concern in the groups that were treated with high-dose ferrous sulfate and nano-ellipsoids. Pathologic evaluations revealed some signs of liver inflammation after supplementation with high dose nano-ellipsoids and also ferrous sulfate. Overall, these data indicate FeOOH nano-ellipsoids as a novel shape iron supplement to be employed at low dosage but with greater beneficial effects than high-dose ferrous sulfate.

Probiotic bacteria mainly Lactic Acid Bacteria (LAB) demonstrate to equilibrate the intestinal microflora. Strains of the Bacillus species have been extensively used as probiotics for human beings, animal feed as well as plant promoting bacteria. Attempts were made to characterize and assess the safety of Bacillus strains for their putative virulence factors. The present study includes screening the isolates by hemolysis on blood agar, DNase, lecithinase and cytotoxic activity as well as detection of toxins in the culture medium. PCR technique was used to detect genes encoding enterotoxin T (bceT), cytotoxin K (CytK), enterotoxin FM (EntFM), non-hemolytic enterotoxin (NheA, NheB), haemolysin BL (HblA, HblC, HblD) and emetic toxin (ces). Among seven Bacillus isolates, only isolates B. cereus sp. M14, B. subtilis sp. M12 and B. methylotrophicus sp. M8 showed weak hemolysis on blood agar. DNase and lecithinase activity were not observed for all isolates. However, isolates B. subtilis sp. M12 and B. cereus sp. M14 indicated low cytotoxic effects on HepG2 cell line. Using two commercial immunoassay kits, no enterotoxin was detected for all isolates. Nhe and Hbl genes were detected in isolates B. methylotrophicus sp. M8 and B. cereus sp. M14, respectively. In contrast, none of the Bacillus isolates harbored bceT, entFM and ces genes in their chromosomes. Taking together, among the evaluated Bacillus isolates, strains B. pumilus sp. M17 and B. pumilus sp. S10 found to be the most promising candidates to fulfill the safety assessments of putative virulence factors suitable for human consumption.

Menaquinone-7 (MK-7) is the most potent subtype of vitamin K with extraordinarily high half-life in the circulatory system. Therefore, MK-7 plays a critical role in promoting human wellbeing today. Studies on MK-7 every year show more and more magnificent benefits of it in preventing cardiovascular diseases and osteoporosis to battling cancer cells, Alzheimer's and Parkinson's diseases. Thus, it needs to be supplemented to daily diet for accumulative and long-term benefits. Chemical synthesis of MK-7 produces a significant cis-isomer form of it, which has no biological activity. Fortunately, due to its key role in electron transfer in bacteria, trans-MK-7 is biosynthesized by especially Gram-positive strains mainly Bacillus genus. Concordantly, MK-7 could be produced via solid or liquid state fermentation strategies. In either regime, when static fermentation is applied in the absence of agitation and aeration, operational issues arise such as heat and mass transfer inefficiencies. Thus, scaling up the process becomes a challenge. On the other hand, studies have indicated that biofilm and pellicle formation that occur in static fermentations are key characteristics for extracellular MK-7 secretion. Therefore, this review covers the most recent discoveries of the therapeutic properties of MK-7 and optimization attempts at increasing its biosynthesis in different media compositions and effective growth parameters as well as the cutting-edge use of biofilm reactors where B. subtilis cells have the infrastructures to form mature biofilm formations on plastic composite supports. Biofilm reactors therefore can provide robust extracellular MK-7 secretion while simultaneously enduring high agitation and aeration rates, which then address the scale-up and operational issues associated with static fermentation strategies.

Due to the limitations associated with real field trips (RFTs) and considering the advances in technology in the last decade, virtual field trips (VFTs) have been introduced to replace RFTs. In the present study, we investigated the essentiality and usefulness of VFTs on student’s learning as well as the acquisition of insight for designing an industrial scale plant. A combination of quantitative and qualitative methods was used to investigate the importance of different types of field trips in promoting student’s knowledge and perceptions. The results show that students rated RFTs higher as it enhanced their perceptions, provided an opportunity to communicate with experts in the field and witnessed how theoretical knowledge can be applied to practical knowledge. However, the lack of pre-information substantially decreased the effectiveness of RFT. The results of this study clearly demonstrate that VFT can be a powerful supplement to RFT as it provides the necessary pre-knowledge to students in a way that maximises learning during the RFT while concurrently providing opportunities to digitally revisit the plant after the RFT has ended.

Bringing two completely different properties into one nanostructure by using individual metals is a difficult goal to achieve. However, recently core-shell metallic nanostructures have introduced as a novel multifunctional nanomaterial with enhanced properties. Iron and silver based nanoparticles are among the most widely applicable nanomaterials in modern industries. Zero-valent iron nanostructures and silver nanoparticles are well known for their applications as catalyst and antimicrobial agent, respectively. In the present study, for the first time, we are reporting a successful fabrication of zero valent iron coated silver nanoparticles (ZVI@AgNPs) by using a green and one-pot synthesis approach. Aqueous leaf extract of Mediterranean cypress (Cupressus sempervirens) was used as a natural source of reducing and capping agent for reduction of both Ag+ and Fe3+ ions. Prepared nanostructures were characterised by a range of analytical techniques namely UV–vis spectroscopy, Transmission Electron Microscopy, X-Ray Diffraction, and Fourier Transform Infra-Red Spectroscopy. The prepared nanostructures were found to be an effective material for dye removal and were capable to remove 98.5% of the initial dye just after 4 h. Based on the results, zero valent iron coating enhanced the antimicrobial potential of AgNPs against Gram-positive bacteria (S. aureus), while showing no significant enhancement against Gram-negative bacteria (E. coli). ZVI@AgNPs, therefore, can be introduced as a novel nanostructure for application in aquatic filter materials to simultaneously reduce microbial and organic contaminants.

Background:Arginine deiminase (ADI), an arginine catabolizing enzyme, is considered as an anti-tumor agent for the treatment of arginine auxotrophic cancers. However, some obstacles limit its clinical applications.Objective:This review will summarize the clinical applications of ADI, from a brief history to its limitations, and will discuss the different ways to deal with the clinical limitations.Method:The structure analysis, cloning, expression, protein engineering and applications of arginine deiminase enzyme have been explained in this review.Conclusion:Recent patents on ADI are related to ADI engineering to increase its efficacy for clinical application. The intracellular delivery of ADI and combination therapy seem to be the future strategies in the treatment of arginine auxotrophic cancers. Applying ADIs with optimum features from different sources and or ADI engineering, are promising strategies to improve the clinical application of ADI.

Menaquinoe-7 (MK-7) is the most potent form of vitamin K with numerous benefits for human health such as reducing the risks of cardiovascular diseases and osteoporosis in addition to having antitumor characteristics. Therefore, MK-7 production via bacterial fermentation has been studied intensely in the last few decades. Recently, biofilm reactors were implemented to enhance production levels in our lab. The specific objective of this study was to mathematically model the findings in batch biofilm reactors and thus further deepen our understanding of the conditions governing fermentation to pave the path to scaling up the production to pilot scale fermenters. The modified logistic equation was used to correlate substrate consumption with fermentation time and to model the substrate consumption in the four batch fermentations. Results indicated that this modified logistic model fits well with the experimental data for substrate consumption. Therefore there was no need for the other more complex models. Furthermore, this successfully modified-logistic equation was inserted into the Luedeking-Piret model to estimate MK-7 production based on substrate consumption, because of the typical MK-7 profiles in batch fermentations. There is sufficient evidence in the literature that MK-7 biosynthesis follows a mixed-metabolite pattern in Bacillus subtilis natto. Similarly, the modified-Gompertz model was used also for the same purpose. Results indicated that the modified Luedeking-Piret model fits more accurately for MK-7 production (R2 = 0.971, 0.943, 0.970, and 0.959) compared to the modified-Gompertz (R2 = 0.914, 0.943, 0.949 and 0.860).

In the current study, the optimal reaction condition for fabrication of INPs by using pine tree (Pinus eldarica) leaf extract was developed. A fractional factorial design was utilized to screen the effective parameters in the green synthesis reaction, and central composite face design was employed to achieve the optimal reaction condition. Leaf extract and iron precursor concentrations were found to be the most effective parameters for the fabrication of INPs. Physicochemical characteristics of the obtained nanoparticles were evaluated by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffractometer (XRD), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA), and derivative thermo gravimetric (DTG). The prepared particles were found to be zero-valent iron nanoparticles without any iron oxide impurities. Nanoparticles were spherical in shape with diameters ranging from 8 nm to 34 nm with a mean particle size of 18 nm. The fabricated particles were amorphous with a low magnetization value of 33 memu/g.

Herbal nanoparticles (HNPs) were introduced as a novel generation of antimicrobial nanoparticles. But in the battle against superbugs we need nanostructures with boosted antimicrobial potency. So in the current experiment, for the first time a green approach was developed for the silver functionalization of HNPs which were fabricated from an antimicrobial herb Thymus vulgaris. Silver functionalized HNPs (AgHNPs) were found to be mesoporous and were further fortified with antimicrobial compounds. The resulted structures were re-tested against MRSA and P. aeruginosa as superbugs. It was found that silver functionalization can provide eight-fold increase in the antimicrobial potency of HNPs. Moreover, MIC was reduced from 20 mg/mL to 2.5 mg/mL. Another eight-fold reduction in the MIC (0.3 mg/mL) was achieved by fortification with antimicrobial compounds. So, the antimicrobial potency of HNPs was successfully increase approximately up to 64-folds. Obtained results illustrated that silver functionalization and fortification with antimicrobial compounds can be considered as effective approaches to achieve HNPs with boosted antimicrobial potency. These nanostructures have the potency to be loaded with other antimicrobial compound such as antibiotics toward synergistic effects of AgNPs and antibiotics. Resulted nanostructures can be employed in the formulation of powerful topical and surface disinfectants against superbugs. Also, these particles can be considered as a next generation of boosted antimicrobial nanostructures.