Tellurite reducing bacterial strain was isolated from Zuari estuary, Goa India which could tolerate 5.5 mM potassium tellurite with a minimum inhibitory concentration of 6 mM. This strain was designated as GUSDZ9 and was identified as Shewanella baltica (accession number: MF350629) based on 16S rRNA gene sequencing and BLAST analysis. The Diethyl-dithiocarbamate based colorimetric analysis clearly demonstrated a complete reduction of 2 mM tellurite to elemental tellurium during the late stationary phase. Te Nanoparticles (TeNPs) biosynthesis which initiated at early log phase (i.e. 4 h) was evidently monitored through colour change and a peak due to surface plasmon resonance at 210 nm using UV–Vis spectroscopic analysis. X-ray crystallographic studies and transmission electron microscopy revealed unique nano-rods with a diameter ranging from 8 to 75 nm. Energy dispersive X-ray analysis further confirmed the presence of pure tellurium. The biogenic TeNPs at 10 and 5 µg/mL evidently demonstrated 90% degradation of methylene blue dye and anti-biofilm activity against potential Gram-positive and Gram-negative human pathogens respectively. The alkaline comet assay revealed time and dose-dependent genotoxicity at concentrations higher than 15 µg/mL of TeNPs. This study clearly demonstrated the potential of Shewanella baltica strain GUSDZ9 in bioremediation of toxic tellurite through bio-reduction into elemental tellurium and involvement of biogenic TeNPs in the photo-catalytic reduction of methylene blue and anti-biofilm activity. This is the first report of its kind on the synthesis of biogenic TeNPs from Shewanella baltica demonstrating photo-catalytic, anti-biofilm activity as well as genotoxicity.

从印度果阿的Zuari河口分离出减少亚碲酸盐的细菌菌株，该菌株可耐受5.5 mM的亚碲酸钾，最低抑制浓度为6 mM。该菌株被命名为GUSDZ9，并被鉴定为波罗的希瓦氏菌（Shewanella baltica）（登录号：MF350629）基于16S rRNA基因测序和BLAST分析。基于二乙基二硫代氨基甲酸酯的比色分析清楚地表明，在固定后期，完全将2 mM亚碲酸盐还原为元素碲。Te纳米粒子（TeNPs）的生物合成是在对数早期（即4 h）开始的，通过颜色变化和使用UV-Vis光谱分析在210 nm处的表面等离振子共振产生的峰进行了明显监测。X射线晶体学研究和透射电子显微镜显示直径为8至75 nm的独特纳米棒。能量色散X射线分析进一步证实了纯碲的存在。TeNPs的生物成因浓度分别为10和5 µg / mL，分别证明了90％的亚甲基蓝染料降解和对潜在革兰氏阳性和革兰氏阴性人类病原体的抗生物膜活性。碱性彗星试验揭示了浓度高于15 µg / mL的TeNPs时的时间和剂量依赖性的遗传毒性。这项研究清楚地表明了波氏希瓦氏菌菌株GUSDZ9通过生物还原成元素碲而对有毒亚碲酸盐进行生物修复，并利用生物源TeNP参与亚甲基蓝的光催化还原和抗生物膜活性。这是关于波罗的海希瓦氏菌（Shewanella baltica）合成生物型TeNPs的首次报道，证明其具有光催化，抗生物膜活性和遗传毒性。