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Phthalate esters (PAEs), a class of toxic anthropogenic compounds, have been predominantly used as additives or plasticizers, and great concern and interests have been raised regarding its environmental behavior and degradation mechanism. In the present study, a bacterial consortium consisting of Microbacterium sp. PAE-1 and Pandoraea sp. PAE-2 was isolated by the enrichment method, which could degrade dibutyl phthalate (DBP) completely by biochemical cooperation. DBP was converted to phthalic acid (PA) via monobutyl phthalate (MBP) by two sequential hydrolysis steps in strain PAE-1, and then PA was further degraded by strain PAE-2. Strain PAE-1 could hydrolyze many dialkyl Phthalate esters (PAEs) including dimethyl, diethyl, dibutyl, dipentyl, benzyl butyl, dihexyl, di-(2-ethyhexyl) and their corresponding monoalkyl PAEs. Two esterase genes named dpeH and mpeH, located in the same transcription unit, were cloned from strain PAE-1 by the shotgun method and heterologously expressed in Escherichia. coli (DE3). The Km and kcat values of DpeH for DBP were 9.60 ± 0.97 μM and (2.72 ± 0.06) × 106 s−1, while those of MpeH for MBP were 18.61 ± 2.00 μM and (5.83 ± 1.00) × 105 s−1, respectively. DpeH could only hydrolyze dialkyl PAEs to the corresponding monoalkyl PAEs, which were then hydrolyzed to PA by MpeH. DpeH shares the highest similarity (53%) with an alpha/beta hydrolase from Microbacterium sp. MED-G48 and MpeH shows only 25% identity with a secreted lipase from Trichophyton benhamiae CBS 112371, indicating that DpeH and MpeH are two novel hydrolases against PAEs.

A Gram-staining-negative, aerobic, non-motile and rod-shaped bacterium that produced yellow viscous colonies, designated FL-8T, was isolated from farmland soil in Chuzhou, Anhui province, PR China. 16S rRNA gene sequence similarities between strain FL-8T and the type strains of species of the genus Terrimonas with validly published names ranged from 94.6 to 96.1 %. Strain FL-8T contained iso-C15 : 1 G, iso-C15 : 0 and iso-C17 : 0 3-OH as the predominant fatty acids. The predominant polar lipid of strain FL-8T was phosphatidylethanolamine. The sole respiratory quinone of strain FL-8T was MK-7 and the DNA G+C content was 44.8 mol%. On the basis of phenotypic, chemotaxonomic and phylogenetic data, strain FL-8T is considered to represent a novel species of the genus Terrimonas , for which the name Terrimonas soli sp. nov. is proposed. The type strain is FL-8T (=CCTCC AB 2017059T=JCM 32095T).

Administration of α-MSH to C57-BL/6J mice bearing B-16 melanoma induced striking increases in tyrosinase activity and melanogenesis of the tumor. Time course studies on the increases of tyrosinase activity and melanin content of the tumor produced by one injection of α-MSH indicated that the action of α-MSH on the melanogenesis of B-16 melanoma is mediated through an increase of tyrosinase activity. Subcellular fractionation of the tumor homogenates by differential centrifugation revealed that the pattern of distribution of tyrosinase activity among the subcellular fractions remained unchanged like that of the controls, when the animals were administered 0.5 mg α-MSH per mouse per day for 2, 4, 6, 9, 12 and 21 days. This observation is considered incompatible with the hypothesis that a de novo synthesis of the enzyme took place. No tyrosinase activator was detected in the tumor from α-MSH treated mice. Therefore, it is tentatively concluded that the increase of tyrosinase activity is brought about by the ...