Shinella oryzae sp. nov., a novel zearalenone-resistant bacterium isolated from rice paddy soil.

Abstract

A novel bacterium, designated Z-25T, was isolated from a rice paddy rhizosphere soil sample from Wuchang County, China. The Z-25T strain is gram-negative, rod-shaped, non-spore-forming, aerobic, motile by unipolar flagella and straw white in color. A phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain Z-25 belongs to the genus Shinella, and the closest members are Shinella zoogloeoides ATCC 19623T with 98.58% similarity, S. kummerowiae CCBAU 25,048T (98.03%) and S. granuli Ch06 T (97.37%). The average nucleotide identity and in silico DNA-DNA hybridization values between strain Z-25T and the closest members were less than 85.29% and 28.70%, respectively. The predominant fatty acids were the sums of features comprising C18:1 ω7c and/or C18:1 ω6c (34.62%), C18:1 ω7c -11-methyl (20.48%), and C19:0 cyclo ω8c (18.19%). The only respiratory quinone was ubiquinone-10, and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. Additionally, a genome analysis showed that Z-25T presented potential functional genes related to the degradation of zearalenone (ZEN). An HPLC analysis indicated that Z-25T could remove 74.13% of 10mg/L ZEN after 144h at 30°C. Therefore, based on phenotypic, chemotaxonomic, phylogenetic and genotypic analyses, strain Z-25T represents a novel species in the genus Shinella, for which the name Shinella oryzae sp. nov. is proposed. The type strain is Z-25T (= GDMCC 1.2424T = KCTC 82660T).