[Dioxin Pollution and Occupational Inhalation Exposure of PCDD/Fs in Municipal Solid Waste Incinerator].

To assess the pollution levels, characteristics, and the pollution sources and occupational inhalation exposure of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)in the workshops,ambient air samples in different types of incinerators of two municipal solid waste incinerators(MSWI) were collected and analyzed. The results showed that ① The I-TEQ concentration ranged from 0.034-2.152 pg·m-3in the two waste incineration plants, and the most sites' I-TEQ exceeded the ambient air quality standard. Besides, the I-TEQ concentration behind the incineration plant was higher than others. ② The dioxins in incineration plant were dominated by OCDD and 1,2,3,4,6,7,8-HpCDD. For MSWI A, the flue gas and the fly ash had major effect on PCDD/Fs, while the dioxins pollution in MSWI B was only affected by the fly ash. ③ Occupational inhalation exposure of PCDD/Fs was 0.01-1.10 pg·(kg·d)-1 in incineration plant, some occupational inhalation exposure values exceeded the evaluation standard, and the areas behind the incinerators were evaluated to have a high exposure risk.

Syntrophic Interactions Within a Butane-Oxidizing Bacterial Consortium Isolated from Puguang Gas Field in China.

Butane oxidation by the hydrocarbon degradation bacteria has long been described, but little is known about the microbial interaction in this process. To investigate this interaction, the efficiency of butane oxidation was estimated in monocultures and co-cultures of six strains of butane-oxidizing bacteria (BOB) and a butanol-oxidizing strain. Results showed that the butane degradation velocity was at least 26 times higher in the co-culture of the seven strains (228.50 nmol h(-1)) than in the six individual monocultures (8.71 nmol h(-1)). Gas chromatographic analysis of metabolites in the cultures revealed the accumulation of butanol in the monocultures of BOB strains but not in the co-culture with the butanol-oxidizing strain. These results evidenced a novel syntrophic association between BOB and butanol-oxidizing bacteria in the butane oxidation. The BOB strains oxidized butane into butanol, but this activity was inhibited by the accumulated butanol in monocultures, whereas the removal of butanol by the butanol-oxidizing strain in co-culture could eliminate the suppression and improve the butane degradation efficiency. In the co-culture, both BOB and butanol-oxidizing bacteria could grow and the time needed for butane complete removal was shortened from more than 192 h to less than 4 h. The unsuppressed effect of the co-culture was also consistent with the results of reverse transcription quantitative real-time PCR (RT-qPCR) of bmoX gene because increased expression of this gene was detected during the syntrophic growth compared with that in monoculture, pointing to the upregulation of bmoX in the syntrophic interaction.

Cloacibacterium rupense sp. nov., isolated from freshwater lake sediment.

A Gram-negative, yellow-pigmented bacterium, designated strain R2A-16(T), was isolated from sediment of Rupa Lake in Nepal and analysed using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain R2A-16(T) is affiliated to the genus Cloacibacterium of the family Flavobacteriaceae; 16S rRNA gene sequence similarity between strain R2A-16(T) and Cloacibacterium normanense CCUG 46293(T) was 98.07 %. The isolate contained iso-C(15 : 0) (35.6 %) as the major fatty acid and menaquinone MK-6 as the predominant respiratory quinone. The G+C content of the genomic DNA was 33.3 mol%. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain R2A-16(T) represents a novel species of the genus Cloacibacterium, for which the name Cloacibacterium rupense sp. nov. is proposed; the type strain is R2A-16(T) (=CGMCC 1.7656(T) =NBRC 104931(T)).

Flavobacterium cauense sp. nov., isolated from sediment of a eutrophic lake.

A Gram-negative, rod-shaped, yellow-pigmented bacterium, designated strain R2A-7(T), was isolated from sediment of the eutrophic Taihu Lake in Jiangsu Province, China. The isolate was subjected to a taxonomic study using a polyphasic approach. Phylogenetic analysis based on the 16S rRNA gene sequences placed strain R2A-7(T) within the genus Flavobacterium in the family Flavobacteriaceae. The highest sequence similarity was found with Flavobacterium saliperosum (98.3 %), followed by other Flavobacterium species with similarities <96.0 %. The major fatty acids (>5 %) were 15 : 0 iso, 17 : 1 iso omega9c, 17 : 0 iso 3-OH, 15 : 1 iso G and 15 : 0 iso 3-OH. The G+C content of the genomic DNA of strain R2A-7(T) was 37.7 mol%. The DNA-DNA relatedness value with F. saliperosum CGMCC 1.3801(T) was 40.6 %. Molecular and phenotypic data suggest that strain R2A-7(T) represents a novel species within the genus Flavobacterium, for which the name Flavobacterium cauense is proposed. The type strain is R2A-7(T) (=CGMCC 1.7270(T)=NBRC 104929(T)).