Strain YZ-1 was isolated from activated sludge and identified as Ochrobactrum anthropi. This strain was capable of degrading pyrethroids pesticides, suggesting the presence of degrading enzymes. In the present study, a novel esterase gene pytZ was cloned from the genomic library of YZ-1 successfully. The pytZ contained an open reading frame of 606bp encoding a pyrethroid-hydrolyzing carboxylesterase. Deduced amino acid sequence showed moderate identities (39-59%) with most homologous carboxylesterase, except a putative carboxylesterase from O. anthropi ATCC 49188 with the highest identity of 85%. Phylogenetic analysis revealed that PytZ belonged to esterase VI family. The gene pytZ showed no any sequence similarity with reported pyrethroid-hydrolyzing genes and was a new pyrethroid-degrading gene. PytZ was expressed in Escherichia coli BL21 (DE3) and purified using Ni-NTA Fast Start. PytZ was able to degrade various pyrethroids. The optimal temperature and pH were 35°C and 7.5. This enzyme was very stable over a wide range of temperature and pH. No cofactors were required for enzyme activity. Broad substrate specificity, high enzyme activity, and the favorable stability make the PytZ a potential candidate for the detoxification of pyrethroid residues in biotechnological application.

One bacterial strain, YC-RL2, isolated from petroleum-contaminated soil, could utilize environmental hormone Di(2-Ethylhexyl) phthalate (DEHP) as a sole carbon source for growth. Strain YC-RL2 was identified as Gordonia alkanivorans by 16S rRNA gene analysis and Biolog tests. The effects of environmental factors which might affect the degrading process were optimized at 30 °C and pH 8.0. Strain YC-RL2 showed superior halotolerance and could tolerate up to 0-5% NaCl in trace element medium supplemented with DEHP, although the DEHP degradation rates slowed as NaCl concentration increased. It also showed an outstanding performance in a wide range of pH (6.0-11.0). Meanwhile, strain YC-RL2 was able to withstand high concentrations of DEHP (from 100 to 800 mg/L), and the degradation rates were all above 94%. The DEHP intermediates were detected by HPLC-MS, and the degradation pathway was deduced tentatively. DEHP was transformed into phthalic acid (PA) via mono (2-ethylhexyl) phthalate (MEHP), and PA was further utilized for growth via benzoic acid (BA). The enzyme expected to catalyze the hydrolysis of MEHP to PA was identified from strain YC-RL2. Further investigation found that the enzyme could catalyze the transformation of a wide range of monoalkyl phthalates to PA. This study is the first report about species G. alkanivorans which could degrade several kinds of phthalic acid esters (PAEs), and indicates its application potential for bioremediation of PAE-polluted sites.

The bosonic analogs of topological insulators have been proposed in numerous theoretical works, but their experimental realization is still very rare, especially for spin systems. Recently, two-dimensional (2D) honeycomb van der Waals ferromagnets have emerged as a new platform for topological spin excitations. Here, via a comprehensive inelastic neutron scattering study and theoretical analysis of the spin-wave excitations, we report the realization of topological magnon insulators in CrXTe 3 (X = Si, Ge) compounds. The nontrivial nature and intrinsic tunability of the gap opening at the magnon band-crossing Dirac points are confirmed, while the emergence of the corresponding in-gap topological edge states is demonstrated theoretically. The realization of topological magnon insulators with intrinsic gap-unability in this class of remarkable 2D materials will undoubtedly lead to new and fascinating technological applications in the domain of magnonics and topological spintronics.

Kurthia huakuii sp. nov., isolated from biogas slurry, and emended description of the genus Kurthia T were Gram-stain-positive, motile, non-sporeforming and short-rod-shaped. The optimal temperature and pH for growth were 30 6C and 7.0, respectively. The strain did not require NaCl for growth but tolerated up to 70 g NaCl l "1 . The major fatty acids of strain LAM0618 T were iso-C 15 : 0 , anteiso-C 15 : 0 , iso-C 14 : 0 , C 16 : 0 and C 18 : 0 .The predominant menaquinones of strain LAM0618 T were menaquinone 7 (MK-7) and menaquinone 6 (MK-6). The genus Kurthia belongs to the family Planococcaceae of the phylum Firmicutes, and was created by Trevisan (1885) in honour of H. Kurth who published the description of the first species, Bacterium zopfii, which was isolated from the intestinal contents of chickens (Kurth, 1883). The genus name Kurthia came into general use only after the publication of the seventh edition of Bergey's Manual of Determinative Bacteriology (Breed et al., 1957). At the time of writing, the genus Kurthia comprised three recognized species (http://www.bacterio.net/ijk/kurthia.html) namely Kurthia zopfii, Kurthia gibsonii (Shaw & Keddie, 1983) and Kurthia sibirica (Belikova et al., 1986). In year 2012, a novel strain, 'Kurthia massiliensis' DSM 24639 was isolated and described (Roux et al., 2012). While studying the bacterial diversity of biogas slurry from the large-scale anaerobic digester in Hebei Province in China, a Kurthia-like strain, designated LAM0618 T , was isolated. Based on its phenotypic and genotypic properties, the new isolate was considered to represent a novel species of the genus Kurthia. Strain LAM0618T was isolated in 2012 from biogas slurry samples collected from the large-scale anaerobic digester of Modern Farming Corporation (41 u 529 N 115 u 489 E) located in Hebei Province in China. The strain grew well on nutrient agar (BD/Difco 212000, Sparks, MD, USA) plates at 30 u C. Morphological and physiological characteristics of cells from an exponentially growing culture were investigated by using a light microscope (Nikon 80i) and a transmission electron microscope (Hitachi 7500). The physiologically optimal growth conditions for strain LAM0618T were tested in nutrient broth medium. All tests were conducted independently in duplicate. The strain was cultured at temperatures of 4, 10, 15, 20, 25, 30, 35, 40, 45, 50 and 55 u C; pH 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5 and 10; and NaCl concentrations of 0, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 8, 10, 12 and 14 %. TheThe GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain LAM0618T is KC904244.