In present study, Taguchiʼs design of experiment L₉ orthogonal array was created using Qualitek-4 software with four most critical factors namely, K₂HPO₄, MgSO₄, CaCl₂ and culture pH. Production of a new intracellular antifungal protein in submerged fermentation was optimized with yield of 0.98±0.1 mg/gram dry cell weight mycelia from Aspergillus giganteus MTCC 8408. The average molecular mass of the purified protein was figured as 5.122 kDa using Electro Spray Ionization-Mass Spectrometry. Scanning electron microscopy was used to correlate the effect of selected factors on fungal cell morphology and its metabolite production. In vitro antifungal susceptibility assay was profiled against Aspergillus niger and minimum inhibitory concentrations were in the range 0.3±0.06 µg/ml. The stronger influencing factors on afp production and mycelial biomass were noted with CaCl₂ and K₂HPO₄ respectively. The validation experiments using optimized conditions confirmed an improvement in afp by 3.86 times with mycelial biomass by 1.52 times, compared to the basal medium. The present statistical optimization study revealed an opportunity to promote economical design at the industrial level for future scale up of effective antifungal agent against systemic aspergillosis as well as possible post harvest loss.

　Recent studies have shown that the genome of Legionella pneumophila is characterized by many foreign genes from a variety of eukaryotes. The eukaryotic like proteins are known to play a role in its multiplication within host cells; however, their evolutionary genetics of L. pneumophila in environments is unknown. In this study, we examined the nonsynonymous/synonymous substitution rate of eukaryotic like domain encoding genes among L. pneumophila strains. In silico analysis revealed that the nonsynonymous/synonymous substitution rate in F-box domain gene (lpp0233) was higher than those in other eukaryotic like domain and protein encoding genes and housekeeping genes. The F-box domain gene sequences in L. pneumophila strains isolated from a natural hot spring were more diversified than those of previously known strains, owing to preferential positive selection.

　Exact evaluation of the performance of surgical masks and biohazard protective clothing materials against pathogens is important because it can provide helpful information that healthcare workers can use to select suitable materials to reduce infection risk. Currently, to evaluate the protective performance of nonwoven fabrics used in surgical masks against viral aerosols, a non-standardized test method using phi-X174 phage aerosols is widely performed because actual respiratory viruses pose an infection risk during testing and the phage is a safe virus to humans. This method of using a phage is simply modified from a standard method for evaluation of filter performance against bacterial aerosols using Staphylococcus aureus, which is larger than virus particles. However, it is necessary to perform such evaluations based on the size of the actual pathogen particles. Thus, we developed a new method that can be performed safely using inactivated viral particles and can quantitate the influenza virus in aerosols by antigen-capture ELISA (Shimasaki et al., 2016a) . In this study, we used three different microbial aerosols of phi-X174 phage, influenza virus, and S. aureus and tested the filter efficiency by capturing microbial aerosols for two medical nonwoven fabrics. We compared the filter efficiency against each airborne microbe to analyze the dependency of filter efficiency on the microbial particle size. Our results showed that against the three types of spherical microbe particles, the filter efficiencies against influenza virus particles were the lowest and those against phi-X174 phages were the highest for both types of nonwoven fabrics. The experimental results mostly corresponded with theoretical calculations. We conclude that the filter efficiency test using the phi-X174 phage aerosol may overestimate the protective performance of nonwoven fabrics with filter structure compared to that against real pathogens such as the influenza virus.

　Dandruff and underarm malodor are caused by microorganisms. Personal hygiene products that contain various types of antimicrobial agents are available and are used for the prevention and alleviation of these conditions. However, their effects are not significant and often do not last long. Working toward a solution, hair was treated with thioglycolic acid, a reducing agent, and then with [2-(acryloyloxy)ethyl] trimethylammonium chloride to covalently bond and immobilize quaternary ammonium chloride (QAC) to hair shafts. Fourier transform infrared analysis confirmed the bonding of QAC. Time-kill assays were performed to evaluate the antimicrobial activities against two yeast strains responsible for dandruff, two bacterial strains responsible for underarm malodor, and two typical bacterial skin microflora strains. The time- kill assays revealed the antimicrobial effects of QAC against all tested microorganisms. Washing with detergents decreased the antimicrobial effects compared to hair not washed with detergent. This method could potentially replace personal hygiene products, such as shampoos and antiperspirants, which act as antimicrobial agents in the prevention and alleviation of dandruff and underarm malodor.

　Group A streptococcus is a bacterium that resides in the throat and skin and causes respiratory infection and occasionally glomerulonephritis and rheumatic fever. Streptolysin O (SLO) produced by Streptococcus pyogenes (S. pyogenes) binds to the cell membrane, particularly to that of white and red blood cells, and is toxic to the cells and tissue. In this study, we evaluated the inhibitory activity of water-soluble polyphenols in olives (Olea europaea) against SLO-induced hemolysis. Hydroxytyrosol inhibited SLO-induced hemolytic activity, and the amount required for 50% inhibition of hemolysis was 1.30 µg. These findings suggest that the water-soluble polyphenols contained in olives have inhibitory activity against SLO-induced hemolysis.

　We investigated whether trimers of serine, threonine, tyrosine, and phenylalanine which may interact with water molecules and ice, show anti-ice nucleation activity. Only tyrosine trimer had high levels of anti-ice nucleation activity (10.10±0.74℃) at a final concentration of 0.2 mM. This was constant at an activity of 2.0℃ between the 0.01-0.1 mM concentrations, and rapidly increased at 0.1 mM or more. At the final concentration of 0.2 mM or more, the activity of the tyrosine trimer was almost constant (from 9.2℃ to 10.2℃). Although it is lower than the activity against silver iodide, the tyrosine trimer showed an effect on the activity of the ice nucleating bacteria. This is the first report that revealed that trimer of amino acid, especially tyrosine has the supercooling-facilitating activity.