Background and Aim:Microorganisms have been introduced as eco-friendly Nano factories for biosynthesis of nanoparticles in a clean and low-cost way. Usage of luminescent bacteria for production of ZnO nanoparticles have not been documented yet. Methods:Therefore in this study luminescent bacteria (Vibrio spp.) isolated from shrimp farm located in south east of Iran were used for in vitro biosynthesis of ZnO NPs. Luminescent Vibrio strains (VLA, VLB identified as Vibrio harvey using 16s rRNA gene analysis) were grown overnight on seawater-based complete (SWC) medium and then 5 mM ZnSO4.H2O solution was added into flaks containing minimal media of fourth dilution of above overnight bacterial suspension, heated on a water bath up to 80 ºC for 30 min. A white precipitation was appeared at the bottom of the flask as indication for nanoparticles formation. Then, flasks were incubated at 30 ºC in shaking condition of 120 rpm for 24 hours. The product was filtered and then dried in a vacuum oven at 70 ºC for 3 hours. Results:The initial formation of nanoparticles was studied by UV-vis spectroscopy in absorption peak at 360 nm. Further characterizations were applied using XRD, FTIR and DLS instruments. XRD pattern showed that ZnO nanoparticles were properly formed. Also the obtained FTIR spectra of ZnO NPs exhibited peak at 420 cm-1 (standard peaks for ZnO NPs are normally between 400–500 cm-1) and the size of particles was around 60 nm according to DLS analysis. Conclusion:Therefore we concluded that luminescent Vibrios are able to produce ZnO nanoparticles, fast and extracellular.

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