Ligninolytic enzyme complexes are involved in lignin degradation. Among them laccases are outstanding because they use molecular oxygen as a co-substrate instead of hydrogen peroxide as used by peroxidases. Bacterial laccase of Bacillus genus was first reported in Claus and Filip (Microbiol Res 152:209-216, 1997), since then more bacterial laccases have been found. In this research, laccase-producing bacteria were screened from pulp and paper industry wastewater, bagass and sugarcane rhizosphere. Nutrient agar medium containing 0.5 mM of guaiacol was used. It was observed that the laccase-producing strains developed brown colour from which 16 strains of Bacillus were identified. One of the isolated strains was identified as Bacillus subtilis WPI based on the results of biochemical tests and 16S rDNA sequence analysis. This strain showed laccase-like activity towards the oxidizing substrates ABTS and guaiacol. In this study guaiacol was used as the substrate of laccase activity assay. For determination of laccase activity of this isolate guaiacol was used as a substrate of assay for the first time in this study. SDS-PAGE and Native-PAGE confirmed the presence of laccase.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has currently caused a significant pandemic among worldwide populations. The transmission speed and the high rate of mortality caused by the disease necessitate studies for the rapid designing and effective vaccine production. The purpose of this study is to predict and design a novel multi-epitope vaccine against the SARS-CoV-2 virus using bioinformatics approaches. Coronavirus envelope proteins, ORF7b, ORF8, ORF10, and NSP9 were selected as targets for epitope mapping using IEDB and BepiPred 2.0 Servers. Also, molecular docking studies were performed to determine the candidate vaccine's affinity to TLR3, TLR4, MHC I, and MHC II molecules. Thirteen epitopes were selected to construct the multi-epitope vaccine. We found that the constructed peptide has valuable antigenicity, stability, and appropriate half-life. The Ramachandran plot approved the quality of the predicted model after the refinement process. Molecular docking investigations revealed that antibody-mode in the Cluspro 2.0 server showed the lowest binding energy for MHCI, MHCII, TLR3, and TLR4. This study confirmed that the designed vaccine has a good antigenicity and stability and could be a proper vaccine candidate against the COVID-19 infectious disease though, in vitro and in vivo experiments are necessary to complete and confirm our results.

Background: Yersinia pestis and Francisella tularensis cause plague and tularemia, which are known as diseases of the newborn and elderly, respectively. Immunological and culture-based detection methods of these bacteria are time-consuming, costly, complicated and require advanced equipment. We aimed to design and synthesize a gene structure as positive control for molecular detection of these bacteria. Materials and Method: Conserved regions of each bacterium were determined. A fragment containing the fopA and caf1 genes (conserved genes of F. tularensis and Y. pestis, respectively) was artificially synthesized, cloned into the pUC57 vector (pUC-fopA-caf1), transformed into E. coli DH5α, and used in a multiplex PCR assay. The sensitivity of this assay was examined by serial dilution of the extracted plasmid, whereas the specificity was examined using genomes of Escherichia coli, Salmonella typhi, Enterobacter aerogenes, Vibrio cholerae as templates. Finally, PCR products were analyzed in agarose gel electrophoresis. Results: As expected, our analysis showed a clear dual band in the size range of 107 bp to 176 bp, confirming the presence of fopA and caf1 genes. Another 351 bp band was detected due to amplification being dependent on the forward primer of fopA and the reverse primer of caf1. Optimization of the PCR protocol reduced the amplification of this 351 bp band. The sensitivity of this assay was determined to be 36×10 −3 ng/µl and the selectivity test confirmed the specificity of this method is appropriate for the detection of target genes. Conclusion: This multiplex PCR method could be used in research laboratories for identification of these important pathogens.

Background: Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has currently caused a significant pandemic among worldwide populations. The high transmission and mortality rates of the disease necessitate studies for rapid designing and effective vaccine production. This study aims to predict and design a novel multi-epitope vaccine against the SARS-CoV-2 virus using bioinformatics approaches. Materials and Methods: Coronavirus envelope proteins, Open Reading Frame 7b (ORF7b), Open Reading Frame 8 (ORF8), Open Reading Frame 10 (ORF10), and Nonstructural protein 9 (Nsp9) were selected as targets for epitope mapping using Immune Epitope Data Bank (IEDB) and BepiPred 2.0 servers. Also, molecular docking studies were performed to determine the candidate vaccine’s affinity to Toll-Like Receptor (TLR3, TLR4) and Major Histocompatibility Complex (MHC I and MHC II) molecules. Thirteen epitopes were selected to construct the multi-epitope vaccine. Results: We found that the constructed peptide has valuable antigenicity, stability, and appropriate half-life. The Ramachandran and ERRAT plots approved the quality of the predicted model after the refinement process. Molecular docking investigations revealed that antibody-mode in the ClusPro 2.0 server showed the lowest binding energy for MHC I, MHC II, TLR3, and TLR4. Conclusion: The designed vaccine has a good antigenicity and stability and could be a proper vaccine candidate against the Coronavirus Disease 2019 (COVID-19) infectious disease though, in vitro and in vivo experiments are necessary to complete and confirm our results.

No abstract