Altered plasma metabolites and inflammatory networks in HIV-1 infected patients with different immunological responses after long-term antiretroviral therapy.

Background: Chronic metabolic changes relevant to human immunodeficiency virus type 1 (HIV-1) infection and in response to antiretroviral therapy (ART) remain undetermined. Moreover, links between metabolic dysfunction caused by HIV and immunological inflammation in long-term treated individuals have been poorly studied. Methods: Untargeted metabolomics and inflammatory cytokine levels were assessed in 47 HIV-infected individuals including 22 immunological responders (IRs) and 25 non-responders (INRs) before and after ART. The IRs and INRs were matched by age, gender, baseline viral load, and baseline CD4+T cell counts. Another 25 age-matched uninfected healthy individuals were also included as controls. Results: Among the 770 plasma compounds detected in the current study, significant changes were identified in lipids, nucleotides, and biogenic amino acids between HIV-infected patients and healthy controls. Principal Component Analysis (PCA) and the Random Forest (RF) model suggested that levels of selected metabolites could differentiate HIV-infected patients clearly from healthy controls. However, the metabolite profiles identified in our patients were similar, and only three metabolites, maltotetraose, N, N-dimethyl-5-aminovalerate, and decadienedioic acid (C10:2-DC), were different between IRs and INRs following long-term ART. The pathway enrichment analysis results revealed that disturbances in pyrimidine metabolism, sphingolipid metabolism, and purine metabolism after HIV infection and these changes did not recover to normal levels in healthy controls even with suppressive ART. Correlation analysis of the metabolism-immune network indicated that interleukin (IL)-10, D-dimer, vascular cell adhesion molecule-1 (VCAM-1), intercellular cell adhesion molecule-1 (ICAM-1), and TNF-RII were positively correlated with most of the significantly changed lipid and amino acid metabolites but negatively correlated with metabolites in nucleotide metabolism. Conclusions: Significant changes in many metabolites were observed in HIV-infected individuals before and after ART regardless of their immunological recovery status. The disturbed metabolic profiles of lipids and nucleotides in HIV infection did not recover to normal levels even after long-term ART. These changes are correlated with modified cytokines and biomarkers of chronic non-AIDS events, warranting tryout of interventions other than ART.

Genome Analysis of Carbaryl-Degrading Strain Pseudomonas putida XWY-1.

Carbaryl was a widely used pesticide in the agriculture industry. The toxicity against non-target organisms and the environmental pollution it caused became the focus of public concern. However, the microbial mechanism of carbaryl degradation was not fully investigated. In the study, we reported the complete genome of the carbaryl-degrading Pseudomonas putida strain XWY-1, which consists of a chromosome (5.9 Mbp) and a plasmid (0.4 Mbp). The carbaryl degradation genes are located on the plasmid. The study on the genome will facilitate to further elucidate the carbaryl degradation and advance the potential biotechnological applications of P. putida strain XWY-1.

An Amidase Gene, ipaH, Is Responsible for the Initial Step in the Iprodione Degradation Pathway of Paenarthrobacter sp. Strain YJN-5.

Iprodione [3-(3,5-dichlorophenyl) N-isopropyl-2,4-dioxoimidazolidine-1-carboxamide] is a highly effective broad-spectrum dicarboxamide fungicide. Several bacteria with iprodione-degrading capabilities have been reported; however, the enzymes and genes involved in this process have not been characterized. In this study, an iprodione-degrading strain, Paenarthrobacter sp. strain YJN-5, was isolated and characterized. Strain YJN-5 degraded iprodione through the typical pathway, with hydrolysis of its N-1 amide bond to N-(3,5-dichlorophenyl)-2,4-dioxoimidazolidine as the initial step. The ipaH gene, encoding a novel amidase responsible for this step, was cloned from strain YJN-5 by the shotgun method. IpaH shares the highest similarity (40%) with an indoleacetamide hydrolase (IAHH) from Bradyrhizobium diazoefficiens USDA 110. IpaH displayed maximal enzymatic activity at 35°C and pH 7.5, and it was not a metalloamidase. The kcat and Km of IpaH against iprodione were 22.42 s-1 and 7.33 µM, respectively, and the catalytic efficiency value (kcat/Km ) was 3.09 µM-1 s-1 IpaH has a Ser-Ser-Lys motif, which is conserved among members of the amidase signature family. The replacement of Lys82, Ser157, and Ser181 with alanine in IpaH led to the complete loss of enzymatic activity. Furthermore, strain YJN-5M lost the ability to degrade iprodione, suggesting that ipaH is the only gene responsible for the initial iprodione degradation step. The ipaH gene could also be amplified from another previously reported iprodione-degrading strain, Microbacterium sp. strain YJN-G. The sequence similarity between the two IpaHs at the amino acid level was 98%, indicating that conservation of IpaH exists in different strains.IMPORTANCE Iprodione is a widely used dicarboxamide fungicide, and its residue has been frequently detected in the environment. The U.S. Environmental Protection Agency has classified iprodione as moderately toxic to small animals and a probable carcinogen to humans. Bacterial degradation of iprodione has been widely investigated. Previous studies demonstrate that hydrolysis of its N-1 amide bond is the initial step in the typical bacterial degradation pathway of iprodione; however, enzymes or genes involved in iprodione degradation have yet to be reported. In this study, a novel ipaH gene encoding an amidase responsible for the initial degradation step of iprodione in Paenarthrobacter sp. strain YJN-5 was cloned. In addition, the characteristics and key amino acid sites of IpaH were investigated. These findings enhance our understanding of the microbial degradation mechanism of iprodione.

Optimization of fed-batch fermentation and direct spray drying in the preparation of microbial inoculant of acetochlor-degrading strain Sphingomonas sp. DC-6.

Microbial inoculant preparation is a prerequisite for its application in large-scale bioremediation. In the present study, Sphingomonas sp. DC-6, an efficient acetochlor-degrading strain, was used to investigate the process of preparing the inoculant. Optimization of submerged fermentation (SmF) by response surface methodology (RSM) resulted in a first 22% increase in biomass of liquid inoculant. Then, a biomass increase of 2.18 times with 14.58% shortened incubation period was further obtained in optimized medium using a 7.5-l bioreactor. However, less than 0.4% viable cells in liquid inoculant survived after 180-days storage. Thus, optimized spray drying conditions were subsequently employed for the production of high viability powder (2.11 × 1012 cfu g- 1 powder) without additive and its survival ratio (SR) after 180-days storage was still maintained at 90.5%. Both the 180-days stored powder and the original powder showed the same degradation performance, being able to completely degrade 200 mg l- 1 acetochlor within 48 h. This study demonstrated that strain DC-6 was suitable for industrial production of bacteria powder and provided a potential approach for the preparation of pesticide-degrading microbial inoculant.

Hydrolase CehA and Monooxygenase CfdC Are Responsible for Carbofuran Degradation in Sphingomonas sp. Strain CDS-1.

Carbofuran, a broad-spectrum systemic insecticide, has been extensively used for approximately 50 years. Diverse carbofuran-degrading bacteria have been described, among which sphingomonads have exhibited an extraordinary ability to catabolize carbofuran; other bacteria can only convert carbofuran to carbofuran phenol, while all carbofuran-degrading sphingomonads can degrade both carbofuran and carbofuran phenol. However, the genetic basis of carbofuran catabolism in sphingomonads has not been well elucidated. In this work, we sequenced the draft genome of Sphingomonas sp. strain CDS-1 that can transform both carbofuran and carbofuran phenol but fails to grow on them. On the basis of the hypothesis that the genes involved in carbofuran catabolism are highly conserved among carbofuran-degrading sphingomonads, two such genes, cehACDS-1 and cfdCCDS-1, were predicted from the 84 open reading frames (ORFs) that share ≥95% nucleic acid similarities between strain CDS-1 and another sphingomonad Novosphingobium sp. strain KN65.2 that is able to mineralize the benzene ring of carbofuran. The results of the gene knockout, genetic complementation, heterologous expression, and enzymatic experiments reveal that cehACDS-1 and cfdCCDS-1 are responsible for the conversion of carbofuran and carbofuran phenol, respectively, in strain CDS-1. CehACDS-1 hydrolyzes carbofuran to carbofuran phenol. CfdCCDS-1, a reduced flavin mononucleotide (FMNH2)- or reduced flavin adenine dinucleotide (FADH2)-dependent monooxygenase, hydroxylates carbofuran phenol at the benzene ring in the presence of NADH, FMN/FAD, and the reductase CfdX. It is worth noting that we found that carbaryl hydrolase CehAAC100, which was previously demonstrated to have no activity toward carbofuran, can actually convert carbofuran to carbofuran phenol, albeit with very low activity.IMPORTANCE Due to the extensive use of carbofuran over the past 50 years, bacteria have evolved catabolic pathways to mineralize this insecticide, which plays an important role in eliminating carbofuran residue in the environment. This study revealed the genetic determinants of carbofuran degradation in Sphingomonas sp. strain CDS-1. We speculate that the close homologues cehA and cfdC are highly conserved among other carbofuran-degrading sphingomonads and play the same roles as those described here. These findings deepen our understanding of the microbial degradation mechanism of carbofuran and lay a foundation for the better use of microbes to remediate carbofuran contamination.

Terrimonas soli sp. nov., isolated from farmland soil.

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 Terrimonassoli sp. nov. is proposed. The type strain is FL-8T (=CCTCC AB 2017059T=JCM 32095T).

Pedobacter agrisoli sp. nov., isolated from farmland soil.

A Gram-stain-negative, aerobic, non-motile, non-spore-forming and rod-shaped bacterium, designated YHM-9T, was isolated from soil in Yangquan, Shanxi Province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YHM-9T belonged to the genus Pedobacter and shared the highest similarity (97.4 %) to the type strain Pedobacter lignilitoris W-WS13T. Strain YHM-9T exhibited low DNA-DNA relatedness with P. lignilitoris W-WS13T (21.7±1.3 %). The DNA G+C content was 38.9 mol%. The major fatty acids were iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and iso-C17 : 0 3-OH. The respiratory quinone was MK-7, the major polyamine was sym-homospermidine and the major polar lipids were phosphatidylethanolamine. Based on the morphological, physiological, biochemical and chemotaxonomic characteristics, strain YHM-9T was recognized as a representative of a novel species within the genus Pedobacter, for which the name Pedobacteragrisoli sp. nov. is proposed. The type strain is YHM-9T (=JCM 32093T=CCTCC AB 2017125T).

Nocardioides agrisoli sp. nov., isolated from farmland soil.

A novel Gram-stain-positive bacterium, designated djl-8T, was isolated from farmland soil in Nanjing, Jiangsu province, PR China. Cells of strain djl-8T were aerobic, non-motile, non-spore-forming and rod-shaped. The organism grew at 25-37 °C, pH 5.5-8.0 and 0.5-4.0 % NaCl (w/v). The DNA G+C content was 69.3 mol%. The diagnostic diamino acid in the cell-wall peptidoglycan was LL-2, 6-diaminopimelic acid. The major fatty acids (>5 %) were iso-C16 : 0, anteiso-C17 : 0, iso-C15 : 0, 10-Me C17 : 0 and C17 : 1ω8c. The respiratory quinone was MK-8 (H4) and the major polar lipids were phosphatidylglycerol, phosphatidylinositol, diphosphatidylglycerol and unknown phospholipids. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain djl-8T is a member of the genus Nocardioides and shared the highest similarity with Nocardioides ginkgobilobae SYP-A7303T (97.1 %), followed by Nocardioides soli mbc-2T (96.9 %), Nocardioide spyridinolyticus OS4T (96.6 %) and Nocardioides maradonensis RP-B30T (96.6 %). Strain djl-8T exhibited low DNA-DNA relatedness with Nocardioides ginkgobilobae SYP-A7303T (26.9±2.1 %). On the basis of the morphological, physiological, biochemical and chemotaxonomic characteristics presented in this study, strain djl-8T represents a novel species of the genus Nocardioides, for which the name Nocardioides agrisoli sp. nov. is proposed. The type strain is djl-8T (=KCTC 39844T=CCTCC AB 2017058T).