An assessment on the role of endophytic microbes in the therapeutic potential of Fagonia indica

Abstract Background Natural products of animals, plants and microbes are potential source of important chemical compounds, with diverse applications including therapeutics. Endophytic bacteria that are especially associated with medicinal plants presents a reservoir of therapeutic compounds. Fagonia indica has been recently investigated by numerous researchers because of its striking therapeutic potential especially in cancer. It is also reported that endophytes play a vital role in the biosynthesis of various metabolites; therefore we believe that endophytes associated with F. indica are of crucial importance in this regard. The present study aims successful isolation, molecular identification of endophytic bacteria and their screening for bioactive metabolites quantification and in vitro pharmacological activities. Methods 16S rRNA gene sequencing was used for the identification of isolated endophytic bacteria. Methanolic extracts were evaluated for total phenolic contents (TPC), total flavonoids contents (TFC), DPPH free radical scavenging activity, reducing power and total anti-oxidant assays were performed. And also screened for antibacterial and antifungal activities by disc diffusion method and their MIC were calculated by broth dilution method using microplate reader. Further, standard protocols were followed for antileishmanial activity and protein kinase inhibition. Analysis and statistics were performed using SPSS, Table curve and Origin 8.5 for graphs. Results Bacterial strains belonging to various genera (Bacillus, Enterobacter, Pantoea, Erwinia and Stenotrophomonas) were isolated and identified. Total phenolic contents and total flavonoids contents varies among all the bacterial extracts respectively in which Bacillus subtilis showed high phenolic contents 243 µg/mg of gallic acid equivalents (GAE) and Stenotrophomonas maltophilia showed high flavonoids contents 15.9 µg/mg quercitin equivalents (QA), total antioxidant capacity (TAC) 37.6 µg/mg of extract, reducing power (RP) 206 µg/mg of extract and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging activity with 98.7 μg/mL IC50 value. Although all the extracts tested were active to inhibit growth of selected pathogenic microbes (bacteria and fungi), but significant antibacterial activity was observed against Klebsiella pneumonia and B. subtilis. An Enterobacter cloaca was active against Leishmania tropica with IC50 value of 1.4 µg/mg extracts. B. subtilis and Bacillus tequilensis correspondingly exhibit significant protein kinase inhibition of 47 ± 0.72 and 42 ± 1.21 mm bald zones, indicating anti-infective and antitumor potential. Conclusions Our findings revealed that crude extracts of selected endophytic bacteria from F. indica possess excellent biological activities indicating their potential as an important source of antibiotics (antifungal, antibacterial) compounds

Genome of Serratia nematodiphila MB307 offers unique insights into its diverse traits

A pigment producing Serratia specie was isolated from the rhizosphere of a heavy metal resistant Cannabis sativa plant, growing in effluent affected soil of Hattar Industrial Estate, Haripur, Pakistan. Here, we report the genome sequence of this bacterium, which was demarcated as Serratia nematodiphila using whole genome comparison based OrthoANI classification scheme. The bacterium exhibited diverse traits, including plant growth promotion, antimicrobial, bioremediation and pollutant tolerance capabilities, including metal tolerance, azo dye degradation and ibuprofen degradation etc. Plant growth promoting exoenzyme production as well as phosphate solubilisation properties were observed. Genes for phosphate solubilisation, siderophore production and chitin destruction were identified in addition to other industrially important enzymes like nitrilase and lipase. Secondary metabolite producing apparatus for high value chemicals in the whole genome was also analysed. Number of antibiotic resistance genes was then profiled in silico, through a match with Antibiotic resistant gene and CAR database. This is the first report of a Serratia nematodiphila genome from polluted environment. This could significantly contribute to understand pollution tolerance, antibiotic resistance, association with nematodes, bio-pesticide production, and role in plant growth promotion.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author