[Characterization of Reductive Dechlorination of Chlorinated Ethylenes by Anaerobic Consortium].

Tetrachloroethylene （PCE） and trichloroethylene （TCE） are typical volatile halogenated organic compounds in groundwater that pose serious threats to the ecological environment and human health. To obtain an anaerobic microbial consortium capable of efficiently dechlorinating PCE and TCE to a non-toxic end product and to explore its potential in treating contaminated groundwater， an anaerobic microbial consortium W-1 that completely dechlorinated PCE and TCE to ethylene was obtained by repeatedly feeding PCE or TCE into the contaminated groundwater collected from an industrial site. The dechlorination rates of PCE and TCE were （120.1 ±4.9） µmol·ï¼ˆL·d）-1 and （172.4 ±21.8） µmol·ï¼ˆL·d）-1 in W-1， respectively. 16S rRNA gene amplicon sequencing and quantitative PCR （qPCR） showed that the relative abundance of Dehalobacter increased from 1.9% to 57.1%， with the gene copy number increasing by 1.7×107 copies per 1 µmol Cl- released when 98.3 µmol of PCE was dechlorinated to cis-1，2-dichloroethylene （cis-1，2-DCE）. The relative abundance of Dehalococcoides increased from 1.1% to 53.8% when cis-1，2-DCE was reductively dechlorinated to ethylene. The growth yield of Dehalococcoides gene copy number increased by 1.7×108 copies per 1 µmol Cl- released for the complete reductive dechlorination of PCE to ethylene. The results indicated that Dehalobacter and Dehalococcoides cooperated to completely detoxify PCE. When TCE was used as the only electron acceptor， the relative abundance of Dehalococcoides increased from （29.1 ±2.4）% to （7.7 ±0.2）%， and gene copy number increased by （1.9 ±0.4）×108 copies per 1 µmol Cl- released， after dechlorinating 222.8 µmol of TCE to ethylene. The 16S rRNA gene sequence of Dehalococcoides LWT1， the main functional dehalogenating bacterium in enrichment culture W-1， was obtained using PCR and Sanger sequencing， and it showed 100% similarity with the 16S rRNA gene sequence of D. mccartyi strain 195. The anaerobic microbial consortium W-1 was also bioaugmented into the groundwater contaminated by TCE at a concentration of 418.7 µmol·L-1. The results showed that （69.2 ±9.8）% of TCE could be completely detoxified to ethylene within 28 days with a dechlorination rate of （10.3 ±1.5） µmol·ï¼ˆL·d）-1. This study can provide the microbial resource and theoretical guidance for the anaerobic microbial remediation in PCE or TCE-contaminated groundwater.

Rhizobium flavescens sp. nov., Isolated from a Chlorothalonil-Contaminated Soil.

A Gram-negative, facultative anaerobic, non-lagellated and rod-shaped bacterium FML-4T was isolated from a chlorothalonil-contaminated soil in Nanjing, China. Phylogenetic analyses of 16S rRNA genes revealed that the strain FML-4T shared the highest sequence similarity of 97.1% with Ciceribacter thiooxidans KCTC 52231T, followed by Rhizobium rosettiformans CCM 7583T (97.0%) and R. daejeonense KCTC 12121T (96.8%). Although the sequence similarities of the housekeeping genes thrC, rceA, glnII, and atpD between strain FML-4T and C. thiooxidans KCTC 52231T were 83.8%, 88.7%, 86.2%, and 92.0%, respectively, strain FML-4T formed a monophyletic clade in the cluster of Rhizobium species. Importantly, the feature gene of the genus Rhizobium, nifH gene (encoding the dinitrogenase reductase), was detected in strain FML-4T but not in C. thiooxidans KCTC 52231T. In addition, strain FML-4T contained the summed feature 8 (C18:1ω7c and/or C18:1ω6c), C19:0 cyclo ω8c and C16:0 as the major fatty acids. Genome sequencing of strain FML-4T revealed a genome size of 7.3 Mbp and a G+C content of 63.0 mol%. Based on the results obtained by phylogenetic and chemotaxonomic analyses, phenotypic characterization, average nucleotide identity (ANI, similarity 77.3-75.4%), and digital DNA-DNA hybridization (dDDH, similarity 24.5-22.3%), it was concluded that strain FML-4T represented a novel species of the genus Rhizobium, for which the name Rhizobium flavescens sp. nov. was proposed (type strain FML-4T = CCTCC AB 2019354T = KCTC 62839T).

[Clinicopathologic characteristics of basal cell carcinoma of the prostate: analysis of 5 cases and review of the literature].

OBJECTIVE: To investigate the histogenesis, clinicopathologic characteristics, pathologic diagnosis, differential diagnosis, treatment and prognosis of basal cell carcinoma of the Prostate (BCCP). METHODS: We conducted clinicopathologic analysis on the manifestations of 5 cases of BCCP by HE staining and immunohistochemistry and reviewed relevant literature. RESULTS: Microscopically, the tumor cells were small in volume with ovoid karyomegaly and mitosis, some arranged like a solid nest or with a cribriform appearance. The tumors displayed an invasive growth, with positive expressions of 34betaE12, P63 and Cytokeratin 14, and negative expressions of PSA and P504s. No recurrence and metastasis were found in these patients during over 12 months of follow-up after surgery. CONCLUSION: BCCP is a rare neoplasm different from prostate adenocarcinoma. Immunohistochemistry is indispensable in distinguishing this tumor from other types of prostatic carcinoma. Its biological behavior remains to be further studied. The best treatment option may be radical surgery combined with chemo-radiotherapy at the present time.

[Investigation on snails Achatina fulica and Pomacea canaliculata infected with Angiostrongylus cantonensis in Panyu region of Guangzhou City].

OBJECTIVE: To understand the natural infection status of Angiostrongylus cantonensis in snails Achatina fulica and Pomacea canaliculata from Panyu region of Guangzhou City. METHODS: The snails Achatina fulica and Pomacea canaliculata captured from the field were digested with the artificial stomach fluid. The third-stage larvae of A. cantonensis were examined and counted under a microscope. The collected third-stage larvae were used to infect SD rats. RESULTS: A total of 367 Achatina fulica and 357 Pomacea canaliculata were examined. The infection rate of A. cantonensis in Achatina fulica was 22.62%, with a mean intensity of 57.00 larvae per positive snail. The infection rate of A. cantonensis in Pomacea canaliculata was 3.08%, with a mean intensity of 1.64 larvae per positive snail. The infection rates of A. cantonensis in Achatina fulica from Dagang, Shiqi, Hualong, and Lanhe towns and Nansha District, were 13.33%, 15.00%, 20.93%, 73.68% and 8.41%, respectively. Those in Pomacea canaliculata were 5.88%, 2.88%, 1.89%, 0% and 3.96%, respectively. CONCLUSIONS: A. cantonensis infection exists in Achatina fulica and Pomacea canaliculata from Panyu region of Guangzhou City, and the infection in Achatina fulica is more serious than that in Pomacea canaliculata. The infection rates of the snails among five sites are different.

[Studies of flowering genes of plants].

Plant flower can be divided into two phases--from stem apex meristem tissue into flower meristem tissue and floral apparatus. The flower time genes control the flower development and the homologous genes control flower apparatus identify. This paper summarizes recent studies on plant flower and emphasizes on the first phase flower control genes, theirs interaction and function,characteristic of the homologous genes.