ABSTRACT
A Gram-staining-negative, yellow-pigmented strain, designated SYP-B804T, was isolated from the rhizosphere of Panax notoginseng. The strain was rod-shaped with a single polar flagellum. The optimum temperature and pH required for growth of the strain were 28-32 °C and pH 7-8, respectively. 16S rRNA gene sequence analysis indicated that strain SYP-B804T showed highest 16S rRNA gene sequence similarity with Luteimonas mephitis DSM 12574T (98.0 %). However, the DNA-DNA relatedness value between them (38.1 ± 0.6 %) was less than the threshold value for the delineation of genomic species. Ubiquinone-8 (Q-8) was the predominant quinone. The major fatty acids were iso-C15 : 0 and iso-C17 : 1ω9c. The major polar lipids of the strain were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The G+C content of the genomic DNA was 71 %. On the basis of phenotypic, chemotaxonomic and molecular characteristics, strain SYP-B804T merits recognition as a representative of a novel species of the genus Luteimonas, for which the name Luteimonas notoginsengisoli sp. nov. is proposed, with SYP-B804T ( = KCTC 42211T = JCM 30329T) as the type strain.
ABSTRACT
A novel approach, ultrasound-assisted dispersive liquid-liquid microextraction combined with liquid chromatography-mass spectrometry (UA-DLLME with LC-MS) is demonstrated to be quite useful for the determination of trace amounts of organoarsenic compounds in edible oil. The organoarsenic compounds studied include dimethylarsinic acid (DMA), monomethylarsonic acid (MMA) and 3-nitro-4-hydroxyphenyl arsenic acid (Roxarsone). Orthogonal array experimental design (OAD) was utilized to investigate the parameter space of conditions for UA-DLLME. The optimum conditions were found to be 4 min of ultrasonic extraction using 1.25 mL of mixed solvent with 50 µL of buffer solution. Under these optimal conditions, the linear range was from 10 ng g(-1) to 500 ng g(-1) for DMA and Roxarsone, from 25 ng g(-1) to 500 ng g(-1) for MMA. Limits of detection of DMA, MMA and Roxarsone were 1.0 ng g(-1), 3.0 ng g(-1) and 5.8 ng g(-1), respectively. The precisions and recoveries also were investigated by spiking 3-level concentrations in edible oil. The recoveries obtained were over 89.9% with relative standard deviation (RSD) of 9.6%. The new approach was utilized to successfully detect trace amounts of organoarsenic compounds in various edible oil samples.
