Levan is an industrially important, functional biopolymer with considerable applications in the food and pharmaceutical fields owing to its safety and biocompatibility. Here, levan-type exopolysaccharide produced by Pantoea agglomerans ZMR7 was purified by cold ethanol precipitation and characterized using TLC, FTIR, 1 H, and 13 C NMR spectroscopy. The maximum production of levan (28.4 g/l) was achieved when sucrose and ammonium chloride were used as carbon and nitrogen sources, respectively, at 35°C and an initial pH of 8.0. Some biomedical applications of levan like antitumor, antiparasitic, and antioxidant activities were investigated in vitro. The results revealed the ability of levan at different concentrations to decrease the viability of rhabdomyosarcoma and breast cancer cells compared with untreated cancer cells. Levan appeared also to have high antiparasitic activity against the promastigote of Leishmania tropica. Furthermore, levan had strong DPPH radical scavenging (antioxidant) activity. These findings suggest that levan produced by P. agglomerans ZMR7 can serve as a natural biopolymer candidate for the pharmaceutical and medical fields.

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Infection caused by Pseudomonas aeruginosa is one of the major problems in hospitalized patients which are related to the high mortality. The DNA gyrase B, gyrB reading gene sequence method provides a fast and efficient system for bacterial identification and diagnosis, taxonomic analysis and monitoring of bacteria in the natural environment. Evolution analysis was performed using gene nucleotide sequences for gyrB and 16S rRNA genes. PCR amplifiers were used for the genes under study and their genetic sequences were read. The evolutionary tree was drawn based on the genetic sequences of the classification of P. aeruginosa, compared to the analysis of the 16S rRNA genes, gyrB sequences showed a greater evolutionary deviation of bacteria and may be useful for distinguishing between closely related species. Sequence analysis of 16S rRNA is accurate for identifying unknown bacteria to the genus level. However, the variable gyrB sequence analysis can identify unknown bacteria to the species level. Together with the 16S rRNA analysis, gyrB sequence analysis is considered a useful tool to build the evolutionary relationships of bacteria, especially for the classification of converging bacterial species and controlling the invasive Patho Micobial infection treatment in the hospital.