Optimization of different growth parameters for maximum production of bioactive crude metabolites by Aspergillus fumigatus.

Aspergillus fumigatus is a green echinulate with greenish phialides and 2.5-3 mm conidia. The diverse biological functions of A. fumigatus secondary metabolites make them interesting. The ethyl acetate extract of A. fumigatus was tested for antibacterial activity. Culture media, temperature, incubation and pH were optimized for A. fumigatus growth. Continuous 150rpm agitation incubated the fungus at 28°C for 10 days. Potato Dextrose Broth at 28°C in shaking incubator at pH 04 produced the most biomass and secondary metabolites. Metabolite antibacterial activity was tested. Salmonella flexneri had the greatest zone of inhibition at 100µl (25.66mm) while Staphylococcus aureus had the least (16.33mm). At 75µg/mL, S. flexneri showed 23.66mm activity and S. typhi 14.66mm. At 50µg/mL, S. flexneri was 21.33mm and S. typhi 12.33mmMBC was 0.01µg/µl and MIC50 varied. At 100µg/mL, the metabolites showed antifungal efficacy against Penicillium chrysogenum (26.33mm) but not A. flavus (21.33mm). A. oryzae was significantly inhibited at 75µg/mL (26.33mm) and 50µg/mL (20.33mm). 1000µl demonstrated 100% phytotoxicity, 100µl 60% and 10µl 50%. Bactrocera cucurbitae, Sitotroga cerealella and Callosobruchus maculatus were killed at 150, 100 and 75µl. Metabolites and antibiotics synergized well. Metabolites have alkanes, esters and ethers in their infrared spectra.

Pan-Genome Analysis of Oral Bacterial Pathogens to Predict a Potential Novel Multi-Epitopes Vaccine Candidate.

Porphyromonas gingivalis is a Gram-negative anaerobic bacterium, mainly present in the oral cavity and causes periodontal infections. Currently, no licensed vaccine is available against P. gingivalis and other oral bacterial pathogens. To develop a vaccine against P. gingivalis, herein, we applied a bacterial pan-genome analysis (BPGA) on the bacterial genomes that retrieved a total number of 4908 core proteins, which were further utilized for the identification of good vaccine candidates. After several vaccine candidacy analyses, three proteins, namely lytic transglycosylase domain-containing protein, FKBP-type peptidyl-propyl cis-trans isomerase and superoxide dismutase, were shortlisted for epitopes prediction. In the epitopes prediction phase, different types of B and T-cell epitopes were predicted and only those with an antigenic, immunogenic, non-allergenic, and non-toxic profile were selected. Moreover, all the predicted epitopes were joined with each other to make a multi-epitopes vaccine construct, which was linked further to the cholera toxin B-subunit to enhance the antigenicity of the vaccine. For downward analysis, a three dimensional structure of the designed vaccine was modeled. The modeled structure was checked for binding potency with major histocompatibility complex I (MHC-I), major histocompatibility complex II (MHC-II), and Toll-like receptor 4 (TLR-4) immune cell receptors which revealed that the designed vaccine performed proper binding with respect to immune cell receptors. Additionally, the binding efficacy of the vaccine was validated through a molecular dynamic simulation that interpreted strong intermolecular vaccine-receptor binding and confirmed the exposed situation of vaccine epitopes to the host immune system. In conclusion, the study suggested that the model vaccine construct has the potency to generate protective host immune responses and that it might be a good vaccine candidate for experimental in vivo and in vitro studies.