Aquimarina penaei sp. nov., isolated from intestinal tract contents of Pacific white shrimp, Penaeus vannamei.

Abstract

A novel bacterial strain designated P3-1(T) was isolated from the intestinal tract contents of Pacific white shrimp (Penaeus vannamei) in Zhangpu, Fujian province, China. The isolate was found to be Gram-negative, long rod shaped, oxidase- and catalase- positive. Growth was observed at 1-7 % sea salt (w/v, optimum, 3 %), at pH 7.0-9.0 (optimum, pH 7.0) and at 10-37 °C (optimum, 28 °C). The isolate was capable of hydrolysing gelatin, casein, starch and DNA but unable to degrade Tween 20, 40, 80 and cellulose. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain P3-1(T) belongs to the genus Aquimarina, with highest sequence similarity to Aquimarina gracilis PSC32(T) (96.2 %), followed by Aquimarina intermedia KMM 6258(T) (96.1 %), Aquimarina spongiae A6(T) (95.9 %) and Aquimarina muelleri KMM 6020(T) (95.8 %). The principal cellular fatty acids were identified as iso-C15:0, iso-C17:0 3OH, C16:1 ω7c/ω6c, iso-C15:1 G, iso-C15:0 3OH, iso-C17:1 ω9c/C16:0 10-methyl and C16:0. The G+C content of the chromosomal DNA was determined to be 33.3 mol%. The respiratory quinone was determined to be MK-6 (100 %). The combined genotypic and phenotypic data show that strain P3-1(T) represents a novel species within the genus Aquimarina, for which the name Aquimarina penaei sp. nov. is proposed, with the type strain P3-1(T) (=MCCC 1A09871(T) = LMG 27943(T)).