粘细菌Corallococcus sp. strain EGB及其培养发酵液的安全性评估

【目的】研究粘细菌Corallococcus sp. strain EGB及其细胞培养发酵液的毒理安全性,为菌株EGB作为新型生防微生物菌剂的开发和环境施用安全性提供一定的科学基础。【方法】通过Ames试验、小鼠骨髓嗜多染红细胞微核试验和小鼠睾丸染色体畸变试验测定粘细菌EGB菌体及其细胞培养发酵液的遗传毒性;通过经口灌胃的方式测定粘细菌EGB菌体及其细胞培养发酵液对ICR小鼠的急性毒性和28d亚急性毒性。【结果】Ames试验、微核试验和精母细胞染色体畸变试验结果表明,与对照组相比,EGB菌体及其细胞培养发酵液无基因突变能力,对ICR小鼠无明显的遗传毒性。EGB菌体及其细胞培养发酵液对ICR小鼠的急性经口半致死剂量(LD50)>10g/kg BW (body weight);连续灌胃28 d后,处理组ICR小鼠的体重变化、采食饮水、血液生化指标、血常规、主要脏器指数和主要器官病理切片与对照组相比无显著差异(P<0.05)。【结论】粘细菌EGB菌体及其细胞培养发酵液的毒理安全性属于无毒类别,粘细菌的生物安全性使其在工农业领域的植物病害控制和生物转化等方面具有潜在的应用价值。

Toxicological evaluation of Corallococcus sp. strain EGB and its ferments

[Objective] We evaluated the safety of Corallococcus sp. strain EGB to provide a scientific basis for the development of novel biocontrol agent and its safe application to the environment.[Methods] The genotoxicity of the cells and fermentation products of strain EGB were investigated by Ames test, polychromatic erythrocyte micronucleus test, and testis spermatocyte chromosome aberration assay in mice. Intragastric administration was employed to study the acute toxicity and 28-d subchronic toxicity.[Results] The results of Ames test, polychromatic erythrocyte micronucleus test, and testis spermatocyte chromosome aberration assay in mice revealed that the cells and fermentation products of strain EGB exhibited no genotoxic potential within the testing system. The LD₅₀ values of the cells and fermentation products of strain EGB were greater than 10 g/kg BW in ICR mice. In the 28 days subchronic toxicity test, the body weight, food and water consumption, blood biochemical indexes, blood routine parameters, organ weights, and histopathology of treatment groups showed no difference compared with those of the control group (P<0.05).[Conclusion] Strain EGB and its ferments could be classified as no toxicity and are safe for practical application in the plant disease control and bioconversion.