Significant enhancement of hPrx1 chaperone activity through lysine acetylation.

The reversible acetylation of proteins plays a key role in regulating biological processes, including chromatin remodeling, progression of the cell cycle, and actin nucleation. Human peroxiredoxin 1(hPrx1), one of the most abundant proteins in the cytoplasm, has been shown to be acetylated in human liver-carcinoma tissues. However, little is known about what function(s) the acetylation serves for hPrx1. Herein, using the method of genetic code expansion, we incorporated N(ε)-acetyllysine (AcK) site-specifically into hPrx1. Our data showed that acetylation the K(27) residue promotes oligomerization of hPrx1 at low concentrations. In addition, K(27)-acetylated hPrx1(hPrx1-AcK27) exhibited greatly enhanced chaperone activity (e.g. protecting the protein malate dehydrogenase (MDH) from thermally induced aggregation and assisting the refolding of denatured citrate synthase (CS)). These findings suggest that the site-specific acetylation of hPrx1 may change its biological role in response to environmental changes.

Successful bioremediation of an aged and heavily contaminated soil using a microbial/plant combination strategy.

Bioremediation of an aged and heavily contaminated soil was performed using microbial remediation, phytoremediation, and microbial/phytoremediation. The removal efficiency of polycyclic aromatic hydrocarbons (PAHs) was in the order microbial/phytoremediation>microbial remediation≈phytoremediation>control. The removal percentage of microbial/phytoremediation (69.6%) was twice that of control. Kocuria sp. P10 significantly enhanced PAH removal (P<0.05) and ryegrass growth (P<0.01). Dehydrogenase activity increased steadily and was negatively correlated with total PAH content. Successional changes in soil microbial communities were also detected by pyrosequencing. The results indicated that biodiversity of the soil bacterial community gradually increased with time and was slightly lower in control, as indicated by operational taxonomic unit (OTU) numbers and Shannon-Wiener indices. Proportions of Betaproteobacteria and Gammaproteobacteria were consistently high in all groups. Actinobacteridae were initially predominant (>37.8%) but rapidly decreased to <4%. The proportions of Acidobacteria increased greatly and this increase was positively correlated with PAH removal. These findings indicate a healthy ecological progression and a role of Acidobacteria as an indicator of the process. This study provides new insights into the dynamics of community structure during bioremediation process and a possible basis for ecological assessment for bioremediation on a large scale.

Parapedobacter pyrenivorans sp. nov., isolated from a pyrene-degrading microbial enrichment, and emended description of the genus Parapedobacter.

A novel pyrene-degrading, Gram-negative bacterium, designated strain P-4(T), was isolated from a polycyclic aromatic hydrocarbon-degrading enrichment of polluted soils from a coking chemical plant. Cells of strain P-4(T) were non-motile rods. Strain P-4(T) grew at 15-45 °C (optimum, 37 °C), pH 6.0-10.0 (optimum, pH 8.5) and 0-4 % (w/v) NaCl. Analysis of the 16S rRNA gene sequence showed that strain P-4(T) was related phylogenetically to members of the genus Parapedobacter, with sequence similarity of 93.7-95.1 %. The cellular fatty acids of strain P-4(T) were iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), iso-C17 : 0 3-OH, summed feature 9 (iso-C17 : 1ω9c and/or 10-methyl C16 : 0), anteiso-C15 : 0, iso-C15 : 0 3-OH, C16 : 0, iso-C15 : 1 G, C16 : 0 3-OH and C17 : 0 2-OH. Cells contained menaquinone 7 as the major quinone. The polyamine of strain P-4(T) was homospermidine, and the main polar lipids were phosphatidylethanolamine and a sphingolipid. The G+C content of the DNA was 45.4 mol%. Strain P-4(T) showed a range of phenotypic characteristics that differentiated it from previously recognized Parapedobacter species, particularly its ability to use pyrene as a sole carbon source for growth and its alkaline optimal pH for growth (pH 8.5). On the basis of these results, it is concluded that strain P-4(T) represents a novel species of the genus Parapedobacter, for which the name Parapedobacter pyrenivorans (type strain P-4(T) = NBRC 109113(T) = CGMCC 1.12195(T)) is proposed. An emended description of the genus Parapedobacter is also provided.

Dokdonella immobilis sp. nov., isolated from a batch reactor for the treatment of triphenylmethane dye effluent.

A Gram-staining-negative, non-endospore-forming, non-flagellated, non-motile and rod-shaped bacterium, designated strain LM2-5(T), was isolated from activated sludge in a sequencing batch reactor used for the treatment of triphenylmethane dye effluent. The taxonomy of strain LM2-5(T) was studied by phenotypic, chemotaxonomic and phylogenetic methods. Strain LM2-5(T) was aerobic, heterotrophic and positive for oxidase but negative for catalase activity. It grew at 16-37 °C (optimum 25 °C) and at pH 5.0-8.5 (optimum between pH 6.5 and pH 7.0). NaCl was not obligatory for growth but was tolerated at concentrations up to 2.0 % (w/v) NaCl. The novel strain formed yellow colonies on trypticase soy agar. Cells of strain LM2-5(T) were rods that measured 0.3-0.5 µm in width and 3.0-5.0 µm in length. The predominant respiratory quinone was Q-8. The major fatty acids were iso-C15 : 0 and iso-C17 : 1ω9c. The genomic DNA G+C content was 66.7 mol%. In phylogenetic analyses based on 16S rRNA gene sequences, strain LM2-5(T) clustered with members of the genus Dokdonella and appeared most closely related to Dokdonella koreensis DS-123(T) (96.4 % sequence similarity), Dokdonella fugitiva A3(T) (96.1 %), Dokdonella soli KIS28-6(T) (95.7 %) and Dokdonella ginsengisoli Gsoil 191(T) (95.7 %). On the basis of the phenotypic, chemotaxonomic and phylogenetic data, strain LM2-5(T) was considered to represent a novel species of the genus Dokdonella, for which the name Dokdonella immobilis is proposed. The type strain is LM2-5(T) ( = CGMCC 1.7659(T)  = JCM 15763(T)).

Pilot scale ex-situ bioremediation of heavily PAHs-contaminated soil by indigenous microorganisms and bioaugmentation by a PAHs-degrading and bioemulsifier-producing strain.

This study aims at the remediation of heavily PAH-contaminated soil containing 375 mg of total PAHs per kilogram dry soil. Pilot scale bioremediation experiments were carried out by three approaches with contaminated soil from abandoned sites of Beijing Coking Plant using outdoor pot trials. The first approach was bioaugmentation with a bacterial strain which degrades PAH and produces bioemulsifier, the second approach comprised of biostimulation of indigenous microorganisms with supplementing nutrients and the last approach involved the combination of both biostimulation and bioaugmentation. An on-site land farming group was set as a control in which the total PAHs and 4-6 ring-PAHs were reduced by 23.4% and 10.1%, respectively after 175 days. Meanwhile, in the first approach group, the total PAHs and 4-6 ring-PAHs were reduced by 26.82% and 35.36%, respectively; in the second approach group both percentages were 33.9% and 11.0%, respectively; while in the third approach group, these pollutants were reduced by 43.9% and 55.0%, respectively. The results obtained suggested that biostimulation and bioaugmentation combined could significantly enhance the removal of PAHs in the contaminated soil.

[Protective effect of nicotinamide in a mouse Parkinson's disease model].

OBJECTIVE: To examine the protective effect of nicotinamide on 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP)-induced Parkinson's disease (PD) in mouse model and its mechanisms. METHODS: Parkinson's disease was induced by injection of MPTP in adult male C57BL/6 mice, nicotinamide (500 mg/kg,i.p.) was given prior to subacute (30 mg/kg/d × 5 d,i.p.) MPTP administration. Locomotor activities, striatal dopamine levels, lactate dehydrogenase (LDH) and NO synthase (NOS) activities of whole brains and striatum were analyzed at d5 after last MPTP injections. RESULTS: Pretreatment with nicotinamide significantly improved the locomotor activity in the open-field test (P<0.01), but not in the swimming test and grip & climbing test. Nicotinamide administration resulted in sparing striatal dopamine levels from MPTP-induced dopamine depletion. There was no significant difference in LDH and NOS activities in the whole brains among the groups; but the activities in the striatum were drastically elevated after MPTP treatment. Nicotinamide pretreatment markedly inhibited MPTP-induced LDH and NOS activities (P<0.01) and showed no significant difference compared to controls (P>0.05). CONCLUSION: Nicotinamide protects dopaminergic neurons against MPTP-induced neurodegeneration,which suggests that the neuroprotective effects be associated with the inhibition of cell injuries and NOS activities.

[Role of microglial activation induced by α-synuclein in pathogenesis of Parkinson's disease].

Parkinson's disease (PD), a progressive neurodegenerative disorder, is pathologically characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and the presence of deposits of aggregated α-synuclein in intracellular inclusions known as Lewy bodies (LB). A highly localized inflammatory response mediated by reactive microglia is prominent in PD brains, but the mechanisms underlying the microglial activation are poorly understood. Recently some lines of evidences have shown that monomeric, or aggregated α-synuclein can activate microglia, the toxic factors released from activated microglia may lead to the cell death of dopaminergic neurons. This review is to summarize the recent progress on the role of α-synuclein induced microglia activation on the PD pathogenesis and progression, and to discuss the possible mechanisms involved.

[Comparative study on determinations of BTEX in soils from industrial contaminated sites].

In order to ascertain BTEX measurements of soils from industrial contaminated sites, static headspace, purge-and-trap and solid phase microextraction (SPME) combined gas chromatography were selected to determine BTEX in the soils. This method of SPME could not be used to analyze BTEX isomers in soils from highly contaminated sites because the high concentration of organic contaminants eroded the SPME probe head. The recoveries for added standard ranged from 95.2% - 98.2% for static headspace-GC and 99.2% - 101.3% for purge-and-trap-GC. When the soil samples contained low concentrations of BTEX (< 60 mg/kg), the concentration determined by purge-and-trap-GC was 12.6% - 37.6% higher than the value from static headspace-GC. For soil samples containing high concentrations of BTEX, the static headspace-GC result was higher than that from purge-and-trap-GC. The correlation trend lines of individual BTEX isomers to total BTEX were similar for both static headspace-GC and purge-and-trap-GC results.

Identification and quantification of mycothiol in Actinobacteria by a novel enzymatic method.

Mycothiol (MSH) was reported to be the dominant low molecular weight thiol in members of the Actinobacteria. In this study, a simple, fast, and sensitive method for qualitative and quantitative determination of MSH molecules was developed based on maleylpyruvate isomerase (MPI) from Corynebacterium glutamicum. The principle of this method is that the activity of MPI from C. glutamicum was dependent on MSH molecules. It was found that this MPI activity displayed a linear response (R (2) = 0.9928) at MSH amounts ranging from 0.12 to 3.98 pmol in the defined assay system. This observation was applied to calculate the MSH levels, and the newly developed method was compared with thiol-specific fluorescent-labeling high-performance liquid chromatography method. Forty-eight genera of Actinobacteria were screened for MSH and 43 genera were reported for MSH occurrence, and the MSH levels in Actinobacteria were determined to be 0.01 to 9.69 µmol/g of residual dry cell weight.

[Identification of pyrene degrading strains and the degrading characteristics research].

Three bacterial strains J1, J2, J3 which could use pyrene as the sole carbon and energy sources were isolated from soils contaminated with polycyclic aromatic hydrocarbons (PAHs) by enrichment culture. The strains were identified as Pseudomonas aeruginosa, Flavobacterium mizutaii, Brevibacillus parabrevis according to the results of morphology, physiology and the phylogenetical analyses of 16S rDNA sequence. It was observed that the three strains could use pyrene at the concentrations of 50, 100, 200, 500, 1 000 mg/L and after 7 days culture the concentrations of microorganisms in the liquid medium were the highest. Under the treatment of 200 mg/L pyrene the degradation rate of pyrene by strain J1, J2, J3 was 53.04%, 65.03%, 51.02%. The three strains could grow and use pyrene at the culture medium pH 4 to pH 9 and the pH 7 was the best for the microbe growth and the degradation. Compare with the dichloromethane, N, N-dimethylformamide which could increase the solution of pyrene and enhance the degradation of pyrene was the better solvent in the pyrene degradation.

Dongia mobilis gen. nov., sp. nov., a new member of the family Rhodospirillaceae isolated from a sequencing batch reactor for treatment of malachite green effluent.

A Gram-negative, strictly aerobic and heterotrophic, non-spore-forming bacterial strain, designated LM22(T), was isolated from activated sludge of a sequencing batch reactor for the treatment of malachite green effluent. Cells of strain LM22(T) were slightly curved to straight rods (0.3-0.5×0.6-1.0µm) and motile by a single polar flagellum. Strain LM22(T) was negative for oxidase and catalase activities and phototrophic growth. An internal membrane system and bacteriochlorophyll a were absent. Growth occurred at 20-40°C (optimum 30-35°C) and pH6.0-10.0 (optimum pH7.0-7.5). Strain LM22(T) did not require NaCl for growth and tolerated up to 2.0 % NaCl (optimum 0.5 %). The major ubiquinone was Q-10. The major fatty acids (>10 % of the total) were C(18 : 1)ω7c (32.9 %), C(19 : 0) cyclo ω8c (18.7 %), C(16 : 0) (12.1 %) and C(16 : 0) 2-OH (10.5 %). Phylogenetic analysis of 16S rRNA gene sequences showed that Inquilinus limosus AU0476(T) was the closest relative (90.4 % 16S rRNA gene sequence similarity). The DNA G+C content was 65.6 mol%. On basis of phenotypic, chemotaxonomic and phylogenetic data, strain LM22(T) was considered to represent a novel genus and species of the family Rhodospirillaceae, for which the name Dongia mobilis gen. nov., sp. nov. is proposed. The type strain of Dongia mobilis is LM22(T) (=CGMCC 1.7660(T) =JCM 15798(T)).

Flavobacterium caeni sp. nov., isolated from a sequencing batch reactor for the treatment of malachite green effluents.

A Gram-stain-negative, heterotrophic, aerobic, non-spore-forming and non-motile bacterial strain, designated LM5(T), was isolated from activated sludge from a sequencing batch reactor for the treatment of effluents contaminated by malachite green. The taxonomy of strain LM5(T) was studied by phenotypic and phylogenetic methods. Strain LM5(T) formed orange colonies on R2A and YP plates. Cells were rods, 0.4-0.6 microm in diameter and 0.8-1.2 microm in length. Growth occurred at 10-35 degrees C (optimum, 20-25 degrees C), at pH 5.5-9.5 (optimum, pH 6.5-7.5) and in the presence of 0-2 % (w/v) NaCl (optimum, 0.5 %). Oxidase and catalase activities were present. Flexirubin-type pigments were present, but extracellular glycans were absent. MK-6 was the major respiratory quinone. The major fatty acids were iso-C(15 : 0) (28.3 %) and iso-C(17 : 1)omega9c (13.8 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain LM5(T) was a member of the genus Flavobacterium with highest sequence similarity to Flavobacterium soli DS-6(T) (93.2 %) and Flavobacterium lindanitolerans IP-10(T) (92.9 %). Together with F. lindanitolerans IP-10(T), strain LM5(T) formed a distinct lineage in the phylogenetic tree. The DNA G+C content was 52+/-0.6 mol% (HPLC), which is significantly higher than that of other species of the genus Flavobacterium (30-41 mol%). Based on phylogenetic and phenotypic evidence, strain LM5(T) is considered to represent a novel species of the genus Flavobacterium, for which the name Flavobacterium caeni sp. nov. is proposed; the type strain is LM5(T) (=CGMCC 1.7031(T)=NBRC 104239(T)).

[Alpha-synuclein interacted proteins: the relevance with the pathogenesis of Parkinson's disease].

Parkinson's disease (PD) is characterized pathologically by the relatively preferential loss of dopaminergic neurons with resultant depletion of striatal dopamine and presence of Lewy bodies mainly composed by alpha-synuclein (alpha-SYN) in the remaining neurons in the substantia nigra. A lot of evidence suggests that the aggregation of alpha-SYN play an essential role in the pathogenesis of PD and formation of Lewy body. Increasing findings have implicated that some proteins, including parkin, synphilin-1,14-3-3, agrin and tau, interact with alpha-SYN and are involved in the abnormal aggregation of alpha-SYN.

[Proteomic analysis of cellular responses to low concentration of N-methyl-N'-nitro-N-nitrosoguanidine in human amnion FL cells].

OBJECTIVE: To investigate the protein profile after treatment of low concentration of N- methyl-N'-nitro-N-nitrosoguanidine (MNNG) in human FL cells. METHODS: After MNNG treatment, whole cellular proteins were separated using two-dimensional gel electrophoresis and visualized by silver staining; the digitized images were analyzed with 2D analysis software. The differentially expressed protein spots were identified by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). RESULT: More than 60 proteins showed significant changes in MNNG-treated cells compared to control cells (DMSO treatment). There were 18 protein spots detected only after MNNG treatment, while 13 protein spots were detected only in the control cells. Moreover, the levels of another 31 proteins were either increased or decreased in MNNG-treated FL cells. And some of the proteins were identified by MALDI-TOF-MS. CONCLUSION: There are significant alterations of protein profile after MNNG attack.

Specific detection and differentiation of two subspecies of Fusobacterium necrophorum by PCR.

The phylogenic relationships of two subspecies of Fusobacterium necrophorum were investigated by randomly amplified polymorphism DNA-polymerase chain reaction (RAPD-PCR). With each of the 12 random primers, the DNA fingerprints generated were subjected to cluster analysis for dendrograms. The analysis indicated that twelve strains were organized into two major clusters, and that all strains of each subspecies were confined to one cluster. Furthermore, two of the random primers examined each generated a unique band in F. n. necrophorum strains. We cloned these specific bands and determined the nucleotide sequences. A search for amino acid sequence homologies revealed that the two specific fragments had significant homology to the rpoB gene of Lactococcus lactis subsp. lactis and the hemagglutinin-related protein gene of Ralstonia solanacearum, respectively. New specific primers designed for the rpoB gene were able to amplify 900bp fragments from both subspecies. However, the specific primers designed for the hemagglutinin-related protein gene amplified only a 250bp fragment of the genome of the F. n. necrophorum strains, suggesting that this gene is unique to F. n. necrophorum. These results were further confirmed by dot blot hybridization. Finally, a one-step duplex PCR technique in a single tube for the rapid detection and differentiation of the F. necrophorum subspecies was developed.