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17β-estradiol (E2) is a natural endocrine disruptor that is frequently detected in surface and groundwater sources, thereby threatening ecosystems and human health. The newly isolated E2-degrading strain Sphingomonas colocasiae C3-2 can degrade E2 through both the 4,5-seco pathway and the 9,10-seco pathway; the former is the primary pathway supporting the growth of this strain and the latter is a branching pathway. The novel gene cluster ean was found to be responsible for E2 degradation through the 4,5-seco pathway, where E2 is converted to estrone (E1) by EanA, which belongs to the short-chain dehydrogenases/reductases (SDR) superfamily. A three-component oxygenase system (including the P450 monooxygenase EanB1, the small iron-sulfur protein ferredoxin EanB2, and the ferredoxin reductase EanB3) was responsible for hydroxylating E1 to 4-hydroxyestrone (4-OH-E1). The enzymatic assay showed that the proportion of the three components is critical for its function. The dioxygenase EanC catalyzes ring A cleavage of 4-OH-E1, and the oxidoreductase EanD is responsible for the decarboxylation of the ring A-cleavage product of 4-OH-E1. EanR, a TetR family transcriptional regulator, acts as a transcriptional repressor of the ean cluster. The ean cluster was also found in other reported E2-degrading sphingomonads. In addition, the novel two-component monooxygenase EanE1E2 can open ring B of 4-OH-E1 via the 9,10-seco pathway, but its encoding genes are not located within the ean cluster. These results refine research on genes involved in E2 degradation and enrich the understanding of the cleavages of ring A and ring B of E2. [ABSTRACT FROM AUTHOR]

Industrial microbes have become the core of biological manufacturing, which utilized as the cell factory for production of plenty of chemicals, fuels and medicine. However, the challenge that the extreme stress conditions exist in production is unavoidable for cell factory. Consequently, to enhance robustness of the chassis cell lays the foundation for development of bio-manufacturing. Currently, the researches on cell tolerance covered various aspects, involving reshaping regulatory network, cell membrane modification and other stress response. In fact, the strategies employed to improve cell robustness could be summarized into two directions, irrational engineering and rational engineering. In this review, the metabolic engineering technologies on enhancement of microbe tolerance to industrial conditions are summarized. Meanwhile, the novel thoughts emerged with the development of biological instruments and synthetic biology are discussed. [ABSTRACT FROM AUTHOR]

To disclose the impacts of element diffusion on bond breakage of cemented carbide cutter, this paper establishes a rational microscale model of cemented carbide and 2.25Cr1Mo0.25V, in the light of the working conditions in the cutting process. Drawing on the molecular dynamics (MD) theory, the MD simulation was carried out to set up the deterioration layer model of cemented carbide cutter. Then, the author computed the bonding energy and interaction parameters between WC and other elements (e.g. Co, Fe, Cr, Mo and V). The results show that element diffusion will happen between cemented carbide and 2.25Cr1Mo0.25V in the temperature range of the bond failure; In the temperature range of the bond failure, the WC can form a stable alloy with proper concentrations of Co and other elements in the 2.25Cr1Mo0.25V; Fe is the leading influencing factor on the bonding ability of WC particles in the cemented carbide deterioration layer. [ABSTRACT FROM AUTHOR]

The worldwide use of the carbamate insecticide carbofuran has caused considerable concern about its environmental fate. Degradation of carbofuran by Sphingobium sp. strain CFD-1 is initiated via the hydrolysis of its ester bond by carbamate hydrolase CehA to form carbofuran phenol. In this study, another carbofuran-degrading strain, Sphingobium sp. CFD-2, was isolated. Subsequently, a cfd gene cluster responsible for the catabolism of carbofuran phenol was predicted by comparing the genomes of strains CFD-1, CFD-2, and Novosphingobium sp. strain KN65.2. The key genes verified to be involved in the catabolism of carbofuran phenol within the cfd cluster include the hydroxylase gene cfdC, epoxide hydrolase gene cfdF, and ring cleavage dioxygenase gene cfdE and are responsible for the successive conversion of carbofuran phenol, resulting in complete ring cleavage. These carbofuran-catabolic genes (cehA and the cfd cluster) are distributed on two plasmids in strain CFD-1 and are highly conserved among the carbofuran-degrading sphingomonad strains. The mobile genetic element IS6100 flanks cehA and the cfd gene cluster, indicating the importance of horizontal gene transfer in the formation of carbofuran degradation gene clusters. The elucidation of the molecular mechanism of carbofuran catabolism provides insights into the evolutionary scenario of the conserved carbofuran catabolic pathway. IMPORTANCE Owing 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. In this study, the cfd gene cluster, responsible for the catabolism of carbofuran phenol, was predicted by comparing sphingomonad genomes. The function of key enzymatic genes in this gene cluster was identified. Furthermore, the carbamate hydrolase gene cehA and the cfd gene cluster are highly conserved in different carbofuran-degrading strains. Additionally, the horizontal gene transfer elements flanking the cfd gene cluster were investigated. These findings help elucidate the molecular mechanism of microbial carbofuran degradation and enhance our understanding of the evolutionary mechanism of the carbofuran catabolic pathway. [ABSTRACT FROM AUTHOR]

Phenazines are an important class of secondary metabolites and are primarily named for their heterocyclic phenazine cores, including phenazine-1-carboxylic acid (PCA) and its derivatives, such as phenazine-1-carboxamide (PCN) and pyocyanin (PYO). Although several genes involved in the degradation of PCA and PYO have been reported so far, the genetic foundations of PCN degradation remain unknown. In this study, a PCN-degrading bacterial strain, Sphingomonas histidinilytica DS-9, was isolated. The gene pcnH, encoding a novel amidase responsible for the initial step of PCN degradation, was cloned by genome comparison and subsequent experimental validation. PcnH catalyzed the hydrolysis of the amide bond of PCN to produce PCA, which shared low identity (only 26 to 33%) with reported amidases. The Km and kcat values of PcnH for PCN were 33.22 6 5.70 mM and 18.71 6 0.52 s21, respectively. PcnH has an Asp-Lys-Cys motif, which is conserved among amidases of the isochorismate hydrolase-like (IHL) superfamily. The replacement of Asp37, Lys128, and Cys163 with alanine in PcnH led to the complete loss of enzymatic activity. Furthermore, the genes pcaA1A2A3A4 and pcnD were found to encode PCA 1,2-dioxygenase and 1,2-dihydroxyphenazine (2OHPC) dioxygenase, which were responsible for the subsequent degradation steps of PCN. The PCN-degradative genes were highly conserved in some bacteria of the genus Sphingomonas, with slight variations in the sequence identities. [ABSTRACT FROM AUTHOR]

Previously, a LysR family transcriptional regulator, McbG, that activates the mcbBCDEF gene cluster involved in the upstream pathway (from carbaryl to salicylate) of carbaryl degradation in Pseudomonas sp. strain XWY-1 was identified by us (Z. Ke, Y. Zhou, W. Jiang, M. Zhang, et al., Appl Environ Microbiol 87:e02970-20, 2021, https://doi.org/10.1128/AEM.02970-20). In this study, we identified McbH and McbN, which activate the mcbIJKLM cluster (responsible for the midstream pathway, from salicylate to gentisate) and the mcbOPQ cluster (responsible for the downstream pathway, from gentisate to pyruvate and fumarate), respectively. They both belong to the LysR family of transcriptional regulators. Gene disruption and complementation study reveal that McbH is essential for transcription of the mcbIJKLM cluster in response to salicylate and McbN is indispensable for the transcription of the mcbOPQ cluster in response to gentisate. The results of electrophoretic mobility shift assay (EMSA) and DNase I footprinting showed that McbH binds to the 52-bp motif in the mcbIJKLM promoter area and McbN binds to the 58-bp motif in the mcbOPQ promoter area. The key sequence of McbH binding to the mcbIJKLM promoter is a 13-bp motif that conforms to the typical characteristics of the LysR family. However, the 12-bp motif that is different from the typical characteristics of the LysR family regulator binding site sequence is identified as the key sequence for McbN to bind to the mcbOPQ promoter. This study revealed the regulatory mechanisms for the midstream and downstream pathways of carbaryl degradation in strain XWY-1 and further our knowledge of (and the size of) the LysR transcription regulator family. [ABSTRACT FROM AUTHOR]

Aquatic animals are an important source of food for humans, yet little is known about their potential to transfer zoonotic viruses. Multiple recent cases of SARS-CoV-2 from cold-chain aquatic food and environmental samples has evoked worldwide concerns, and even though these cases pale in comparison to poultry and livestock. To investigate the potential threat of food from aquatic animals, we map their transcriptomes to the genomes of human respiratory- and intestine-related viruses. Analyses only find an influenza virus sequence in a salmon (Salmo salar) skin transcriptome. BLAST and phylogenetic analyses identify this sequence as influenza A, and this likely owes to contamination from a worker. Thus, when prepared properly, aquatic animals can provide great nutritional benefits to humans while posing minimal health risks. [ABSTRACT FROM AUTHOR]

In a previous study, the novel gene cluster cehGHI was found to be involved in salicylate degradation through the CoA-mediated pathway in Rhizobium sp. strain X9 (Mol Microbiol 116:783-793, 2021). In this study, an IclR family transcriptional regulator CehR4 was identified. In contrast to other regulators involved in salicylate degradation, cehR4 forms one operon with the gentisyl-CoA thioesterase gene cehI, while cehG and cehH (encoding salicylyl-CoA ligase and salicylyl-CoA hydroxylase, respectively) form another operon. cehGH and cehIR4 are divergently transcribed, and their promoters overlap. The results of the electrophoretic mobility shift assay and DNase I footprinting showed that CehR4 binds to the 42-bp motif between genes cehH and cehI, thus regulating transcription of cehGH and cehIR4. The repeat sequences IR1 (5'-TTTATATAAA-3') and IR2 (5'-AATATAGAAA-3') in the motif are key sites for CehR4 binding. The arrangement of cehGH and cehIR4 and the conserved binding motif of CehR4 were also found in other bacterial genera. The results disclose the regulatory mechanism of salicylate degradation through the CoA pathway and expand knowledge about the systems controlled by IclR family transcriptional regulators. [ABSTRACT FROM AUTHOR]

[Objectives] The paper was to explore the influence of unmanned aerial vehicle (UAV) low volume spray technology on the control effect of viruliferous thrips and tomato spotted wilt virus (TSWV) under different pesticide concentrations, and to explore the effective control nodes and methods of thrips and TSWV. [Methods] According to the occurrence characteristics of thrips and TSWV, the field control effects of 4 pesticides on thrips and TSWV were tested by UAV with the thrips number and disease index as indicators, following the principle of regional and periodic control trials. [ Results] In the groups of UAV and artificial prevention and control, 4 agents were used alternatively, including 1% emamectin benzoate ME, 1.7% abamectin imidacloprid ME, 5% emamectin benzoate WDG, and 30% pyriproxyfen dinotefuran SL. There was no significant difference in the control effect of thrips and TSWV among treatment 1 (recommended dosage of UAV agent), treatment 2 (reduction of recommended dosage of UAV agent by 25%) and treatment4 (recommended dosage of artificial control agent), and the control effects on thrips were more than 83. 16% in the 3 treatments. The disease index of TSWV in the 3 treatments decreased from 8.64 ±1.37 in the blank control group to less than 3, which reached the prevention and control threshold. But treatment 3 (reduction of recommended dosage of UAV agent by 50%) did not reach the prevention and control threshold. The disease index of TSWV in the blank control area increased with the increase of the number of live nymphs of thrips, and there was a significant positive correlation, with good fitness. [ Conclusions] UAV has a significant impact on the control effect of thrips and TSWV under different pesticide concentrations. In the actual flight control application, it is recommended that the amount of the pesticides is about 3/4 and not less than 1/2 of that of the artificial application. The control area should be extended to 100 m of the ridge of the tobacco field, and UAV is used periodically to control thrips and TSWV for 5 times from pre-transplanting stage to pre-squaring stage of flue-cured tobacco. The control effect is significantly different from the traditional artificial application. [ABSTRACT FROM AUTHOR]

Chinese indigenous Mi gilts have clearer estrus expression than European Large White gilts, and sulfotransferase 1C1 (SULT1C1) gene was differentially expressed between them. To investigate the differential expression mechanism of porcine SULT1C1 gene, we cloned its promoter region and predicted its activity. Six deletion expression vectors (P1, P2, P3, P4, P5, and P6) for the promoter of SULT1C1 gene were constructed. Vector P3 (-1084/+261) had the highest expression activity, whereas vector P4 (-642/+261) showed a reduced in promoter activity, which suggests that the core promoter region of SULT1C1 gene is located between -1084 bp and -642 bp. Two single nucleotide polymorphisms (SNPs), c. – 994 G > A (rs345070974) and c. – 946 G > A (rs337902009) were found in Mi and Large White gilts between -1100 and -661 bp, and the expression vectors with four haplotypes (GG, AA, GA, and AG) of two SNPs were constructed. The relative luciferase activity of vector with haplotype GG was the greatest among four vectors. These indicate that c. – 994 G > A and c. – 946 G > A are key mutations for promoter activity of SULT1C1 gene. Porcine SULT1C1 promoter with -994 G allele and -946 G allele significantly improved the gene expression level. It could be involved in different estrus expression between Large White and Mi gilts. [ABSTRACT FROM AUTHOR]

Objective(s): Endometritis is the inflammation of the uterine lining that is associated with infertility. It affects milk production and reproductive performance and leads to huge economic losses in dairy cows. Dimethyl itaconate (DI), a promising chemical agent, has recently been proved to have multiple health-promoting effects. However, the effects of DI on endometritis remain to be unknown. Materials and Methods: In this study, we assessed the anti-inflammatory effects of DI on Lipopolysaccharide (LPS)-induced endometritis in mice. The endometritis was induced by LPS treatment for 24 hr, and DI was given 24 hr before induction of LPS. Results: As a result, DI administered mice significantly suffered less impairment of uterine tissue and less recruitment of inflammatory cells than LPS administered mice. In addition, DI markedly inhibited uterine myeloperoxidase (MPO) activity and pro-inflammatory cytokines of tumor necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) induced by LPS. Moreover, LPS-induced toll-like receptor 4/ nuclear factor-kappa B (TLR4/NF-κB) activation was suppressed by DI. In addition, the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase (HO-1) were upregulated by DI. Conclusion: These findings suggest that DI has anti-inflammatory functions in the LPS-induced mice and may be a therapeutic agent against endometritis. [ABSTRACT FROM AUTHOR]