Safety and potency of BIV1-CovIran inactivated vaccine candidate for SARS-CoV-2: A preclinical study.

The development of effective and safe COVID-19 vaccines is a major move forward in our global effort to control the SARS-CoV-2 pandemic. The aims of this study were (1) to develop an inactivated whole-virus SARS-CoV-2 candidate vaccine named BIV1-CovIran and (2) to determine the safety and potency of BIV1-CovIran inactivated vaccine candidate against SARS-CoV-2. Infectious virus was isolated from nasopharyngeal swab specimen and propagated in Vero cells with clear cytopathic effects in a biosafety level-3 facility using the World Health Organization's laboratory biosafety guidance related to COVID-19. After characterisation of viral seed stocks, the virus working seed was scaled-up in Vero cells. After chemical inactivation and purification, it was formulated with alum adjuvant. Finally, different animal species were used to determine the toxicity and immunogenicity of the vaccine candidate. The study showed the safety profile in studied animals including guinea pig, rabbit, mice and monkeys. Immunisation at two different doses (3 or 5 µg per dose) elicited a high level of SARS-CoV-2 specific and neutralising antibodies in mice, rabbits and nonhuman primates. Rhesus macaques were immunised with the two-dose schedule of 5 or 3 µg of the BIV1-CovIran vaccine and showed highly efficient protection against 104 TCID50 of SARS-CoV-2 intratracheal challenge compared with the control group. These results highlight the BIV1-CovIran vaccine as a potential candidate to induce a strong and potent immune response that may be a promising and feasible vaccine to protect against SARS-CoV-2 infection.

Lovastatin production by Aspergillus terreus in membrane gradostat bioreactor with two-stage feeding strategy.

Lovastatin is a blood cholesterol-lowering agent and is produced as a secondary metabolite by Aspergillus terreus. Microbial production of this drug is carried out in solid-state or submerged culture, and due to difficulties of controlling the procedure parameters in solid-state method, the submerged method is conventional for industrial production. Although the submerged method is widely used, but this method damages the morphology of fungus due to shear stress caused by stirring. Since the morphology of fungus is a key factor in lovastatin production, using a bioreactor that causes the least damage to it, can improve the lovastatin production. In this paper, for the first time, it has been shown that the membrane gradostat bioreactor is suitable for lovastatin production, using A. terreus, due to providing suitable environmental conditions, therefore, it can be implemented as an alternative method for lovastatin production. Furthermore, it was found that implementing two-stage feeding, using different ratios of Carbon to Nitrogen in the culture medium, makes the lovastatin production to be 5 times more than one-stage feeding. Finally, it is shown that adding Zinc and Magnesium at the second stage further increases lovastatin production by 18%.

Influence of the construction of porous spargers on lovastatin production by Aspergillus terreus ATCC 20,542 in a laboratory bubble column.

In bubble column bioreactors, the hydrodynamic behavior like mixing time, bubble size and morphology of filamentous fungi are influenced by the construction of spargers. Sparger pore size is an important factor influencing formation of bubbles. In this study for the first time, a 5-L bubble column bioreactor with different porous spargers was used to investigate the effect of mean air bubble diameter (at 0.36, 0.18 and 0.09 cm) on fungal growth, broth viscosity, fungal pellet morphology and lovastatin production by the filamentous fungus Aspergillus terreus. All cultivations were carried out at air flow rate equal to 0.5 Lair L-1 min-1. The viscosity of the broth was influenced by both biomass concentration and size of the fungal pellets. The highest values of viscosity were observed at bubbles of 0.09 cm diameter after 192 h of cultivation. The largest fluffy pellets and the highest yield of lovastatin (443 mg/L) were obtained at air bubbles diameter of 0.18 cm. Lovastatin yield on biomass growth in this condition was, respectively, 1.7-fold and 3.5-fold higher than in the cultivations performed with air bubbles of 0.36 and 0.09 cm diameters. These laboratory scale experiment indicates that air bubble diameter has the impact on lovastatin production and A. terreus culture conditions.

Comparison of morphology, protein concentration, and size distribution of bone marrow and Wharton's jelly-derived mesenchymal stem cells exosomes isolated by ultracentrifugation and polymer-based precipitation techniques.

Exosomes which are tiny extracellular vesicles (30-150 nm), transport vital proteins and gene materials such as miRNA, mRNA, or DNA, whose role in cell communication and epithelia regulation is critical. Many techniques have been developed as a result of studying exosomes' biochemical and physicochemical properties, although there is still no standard method to isolate exosomes simply with high yield. Commercial kits have gained popularity for exosome extraction despite concerns about their effectiveness in scientific research. On the other hand, ultracentrifugation remains the gold standard isolation method. This study compares these two common exosome isolation methods to determine their impact on the quality and quantity of exosomes isolated from bone marrow (BM) and Wharton's jelly (WJ)-derived mesenchymal stem cells. Isolated exosomes from the two sources of the cell's conditioned medium by two methods (polymer kit and ultracentrifuge) were characterized using western blotting, scanning electron microscopy (SEM), dynamic light scattering (DLS), and the Bradford assay. Western blot analysis confirmed separation efficiency based on CD81 and CD63 markers, with the absence of calnexin serving as a negative control. The Morphology of exosomes studied by SEM image analysis revealed a similar round shape appearance and their sizes (30-150 nm) were the same in both isolation techniques. The DLS analysis of the sample results was consistent with the SEM ones, showing a similar size range and very low disparity. The exosome protein content concentration analysis revealed that exosomes isolated by the polymer-based kits contained higher protein concentration density and purity (p <0.001). In general, though the protein yield was higher when the polymer-based kits were used, there were no significant differences in morphology, or size between WJ-derived and BM-derived exosomes, regardless of the isolation method employed.

Omicron-specific and bivalent omicron-containing vaccine candidates elicit potent virus neutralisation in the animal model.

Omicron variant (B.1.1.529) is able to escape from naturally acquired and vaccine-induced immunity, which mandates updating the current COVID-19 vaccines. Here, we investigated and compared the neutralising antibody induction of the ancestral variant-based BIV1-CovIran vaccine, the Omicron variant-based BIV1-CovIran Plus vaccine, and the novel bivalent vaccine candidate, BBIV1-CovIran, against the Omicron and ancestral Wuhan variants on the rat model. After inactivating the viral particles, the viruses were purified and formulated. Bivalent vaccines were a composition of 2.5 µg (5 µg total) or 5 µg (10 µg total) doses of each ansectral-based and Omicron-based monovalent vaccine. Subsequently, the potency of the monovalent and bivalent vaccines was investigated using the virus neutralisation test (VNT). The group that received three doses of the Omicron-specific vaccine demonstrated neutralisation activity against the Omicron variant with a geometric mean titer of 337.8. However, three doses of the Wuhan variant-specific vaccine could neutralise the Omicron variant at a maximum of 1/32 serum dilution. The neutralisation activity of the Omicron-specific vaccine, when administered as the booster dose after two doses of the Wuhan variant-specific vaccine, was 100% against the Omicron variant and the Wuhan variant at 1/64 and 1/128 serum dilution, respectively. Three doses of 5 µg bivalent vaccine could effectively neutralise both variants at the minimum of 1/128 serum dilution. The 10 µg bivalent vaccine at three doses showed even higher neutralisation titers: the geometric mean of 388 (95% CI 242.2-621.7) against Omicron and 445.7 (95% CI 303.3-655.0) against Wuhan. It is shown that the candidate bivalent and Omicron-specific vaccines could elicit a potent immune response against both Wuhan-Hu-1 and Omicron BA.1 variants.

Evaluation of fig-milk dessert bioactive properties as a potential functional food.

The fig-milk dessert, a traditional and nutritionally rich treat infused with bioactive compounds, was subjected to a comprehensive analysis in this study. The novelty of this research lies in the investigation of the in vitro antioxidant, anticancer, and antimicrobial potential of the fig-milk dessert. This was accomplished through the utilization of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, Annexin/propidium iodide staining, microtiter plate-based assay and agar well diffusion, respectively, for the first time. Additionally, the study assessed the total phenols and flavonoid content of the extract using the Folin-Ciocalteu assay and the aluminum chloride method, respectively. The findings revealed that the cooking method exerted a significant influence on the bioactive properties and nutritional composition of the dessert. Among the samples analyzed, CM1, consisting of figs steamed for 2 min and milk heated to 70°C, exhibited remarkable characteristics. This sample demonstrated the highest peptide concentration (1290 mg/L), superior antioxidant and anticancer activities, and favorable sensory attributes. Specifically, CM1 induced apoptosis in 84% of AGS cells and inhibited 68% of free radicals in the DPPH assay. It is noteworthy that the fig-milk dessert did not exhibit any antibacterial properties. These discerning results carry substantial implications for the development of functional dairy products endowed with both nutritional and potential therapeutic properties.

The protection quest is a primary key to sharing the neutralizing antibody response to cover against all emerging VOCs based on BIV1-CovIran studies.

Over time, the antigenic evolution of emerging variants of SARS-CoV-2 has demanded the development of potential protective vaccines. Administration of additional doses of current vaccines based on the WT spike protein may boost immunity, but their effectiveness has dwindled for patients with more recent variants. Here, we studied the neutralization activity of post-WT strain-based vaccination and a structural simulation in-silico based on the interactions of the RBD-hACE2 as the key to initiating infection among the VOCs of SARS-CoV-2. Our data display shows that WT sera showed a markedly greater reduction in Delta and Omicron, suggesting that the Wuhan-based vaccines may be more susceptible to breakthrough and new VOCs. According to the MD simulation, mutations of Omicron result in a significant change in the variant charge distribution throughout the binding interface that consequently alters the critical interface electrostatic potential in comparison to other variants. This observation provides new insights into immunization policy and next-generation vaccine development.

Effect of light intensity and wavelength on nitrogen and phosphate removal from municipal wastewater by microalgae under semi-batch cultivation.

Domestic, agricultural and industrial water activities lead to organic and inorganic pollution of the environment. Biotreatment of municipal wastewater with the potential production of biomass is a valuable feature of microalgae. In this study we evaluated the effects of wavelength and light intensity on phosphate and ammonium removal on the one hand, and biomass and protein production on the other hand by Spirulina platensis in municipal wastewater treatment under semi batch cultivation. S. platensis was inoculated at 40% in artificial wastewater open pond system. Red, blue and purple light with 3800, 4800 and 5800 lux light intensity under 12 h light and 12 h darkness were investigated. Cultivation was conducted in semi-batch conditions; after four days cultivation, one third of the culture was replaced with fresh medium. The highest biomass and protein concentrations were observed under blue light at 5800 lux light intensity, 5.45 and 3 g/l respectively cumulatively; while the highest amount of phosphate and ammonium removal were about 145 and 218 mg/l under purple light at 5800 lux intensity, respectively. The amounts of biomass and protein produced, as well as phosphate and ammonium removed, are therefore impacted by wavelength, light intensity, results show that light intensity and wavelength can be customized to reach on the one hand the highest biomass and protein production, and on the other hand to maximize the removal of phosphorous and ammonium.

Assessment of BIV1-CovIran inactivated vaccine-elicited neutralizing antibody against the emerging SARS-CoV-2 variants of concern.

OBJECTIVES: The BIV1-CovIran vaccine is highly effective against COVID-19. The neutralizing potency of all SARS-CoV-2 vaccines seems to be decreased against variants of concern. We assessed the sensitivity of the Alpha (B.1.1.7), Beta (B.1.351), and Delta (B.1.617.2) variants to neutralizing antibodies (NAbs) present in sera from individuals who had received the BIV1-CovIran candidate vaccine compared with an original Wuhan-related strain. METHODS: The ability of vaccine serum to neutralize the variants was measured using the conventional virus neutralization test. The correlation of spike (S) protein antibody and anti-receptor binding domain with neutralizing activity was investigated. RESULTS: The current study demonstrated that 29 of 32 (90.6%; 95% CI: 75.0-98.0) of the vaccinees developed NAbs against a Wuhan-related strain. It is noteworthy that 28 (87.50%) and 24 of 32 (75%) of the recipients were able to produce NAbs against Alpha, Beta, and Delta variants, respectively. Serum virus-neutralizing titres for different SARS-CoV-2 strains were weakly correlated with anti-receptor binding domain antibodies (Spearman r = 36-42, p < 0.05), but not S-binding antibodies (p > 0.05). DISCUSSION: Although there was a reduction in neutralization titres against the Alpha, Beta, and Delta variants compared with the Wuhan strain, BIV1-CovIran still exhibited potent neutralizing activity against the SARS-CoV-2 variants of concern.

Effect of mixed culture of yeast and microalgae on acetyl-CoA carboxylase and Glycerol-3-phosphate acyltransferase expression.

In recent years, some studies have reported that co-culturing green algae and yeast improve lipid and biomass concentration. In this study, a co-culture of the oleaginous yeast Rhodotorula glutinis and the microalgae Chlorella vulgaris was consequently conducted with inoculation of microalga and yeast in growth and stationary phases, respectively. For the first time, the expression of two pivotal enzymes in fatty acids synthetic pathway, acetyl-CoA carboxylase and Glycerol-3-phosphate acyltransferase, was evaluated. To evaluate the synergistic impacts of the mixed culture on the enzymes expression, several co-culture models were designed, including the use of different ratio of microalgae to yeast or the use of residual cell-free medium of yeast; a positive impact on enzymes overexpression was shown in the case of the co-culture of the two microorganisms, and when the remaining cell-free medium of yeast was added to the microalgal culture. The results of in vitro co-culture demonstrated increased 6- and 5-fold of nervonic acid (C24:1) and behenic acid (C22:0) concentrations, respectively, in 2:1 microalgae to yeast co-culture as compared to the monoculture batches. Addition of yeast residual cell-free medium in the 2:1 ratio to the microalgal culture enhanced 9 and 6 times nervonic acid (C24:1) and behenic acid (C22:0) amounts, respectively.

Enzymatic hydrolysis of microalgae proteins using serine proteases: A study to characterize kinetic parameters.

Protein composition and molecular weight play an important role in the digestibility of microalgae proteins. In this study for the first time, proteinous materials of Dunaliella salina and Spirulina platensis were extracted and purified by fast protein liquid chromatography. Then, they are affected by trypsin and chymotrypsin as indicator intestinal enzymes. The results showed that the extracted protein from S. plantesis (ProS) was more rapidly hydrolysed than proteins from D. salina (ProD) because of their lower molecular weight and likely their greater flexibility and open structure. Also, the extent of hydrolysis by trypsin and chymotrypsin of ProS were higher and faster than ProD due to the more number of hydrolytic sites in ProS for both enzymes. The catalytic efficiency and kcat displayed that ProS were more suitable substrate than ProD for intestinal enzymes. The results exhibited that chymotrypsin can act better and faster than trypsin on peptide bonds of proteins.

Kinetic analysis and effect of culture medium and coating materials during free and immobilized cell cultures of Bifidobacterium animalis subsp. lactis Bb 12

Microencapsulation technique appears helpful for more protection of Bifidobacteria against acid inhibitory effect. The effect of medium composition and product inhibitory in free cell culture, as well as the effect of the coating materials in immobilized cells, on biomass growth, acid production and substrate utilization kinetics of Bifidobacterium animalis subsp. lactis Bb 12 in uncontrolled batch fermentation was examined. The Monod and the Luedeking and Piret equations with a product inhibition term involving toxic power terms improved model efficiency for both growth and production. The model showed that media and coating materials had an effect on toxic power terms. Cell immobilization had a positive impact on B. animalis culture. Kinetic analysis revealed the permeability of the coating material had a major impact on culture parameters; permeability increased in the following way: Gellan xanthan < Alginate chitosan < K-Carageenan-locust been, and hence growth parameters x m, maximum specific growth rate (h-1) (um) and monod constant (g lactose L-1) (K S) followed the same trend as well as the linking between growth and production. The link between the microbial environment and cell growth was highlighted by the model. It was shown that for an increasing protect effect of coating materials against environmental deleterious factors, namely a decrease of the permeability, transport limitation occurred, which was disadvantageous for cell formation.