Analysis of the complete genome sequence of Paenibacillus sp. lzh-N1 reveals its antagonistic ability.

Background: Plant diseases caused by pathogenic fungi are devastating. However, commonly used fungicides are harmful to the environment, and some are becoming ineffective due to fungal resistance. Therefore, eco-friendly biological methods to control pathogenic fungi are urgently needed.

The inhibition effects of Cu and Ni alloying elements on corrosion of HSLA steel influenced by Halomonas titanicae.

Halomonas titanicae accelerated steel corrosion by dissimilatory Fe(III) reduction under anaerobic environments, and their adhesion was the key to achieving extracellular electron transfer between cells and Fe(III). This work investigated the inhibition effects of Cu and Ni alloying elements on corrosion of high strength low alloy (HSLA) steel affected by H. titanicae.

Exogenous autoinducer-2 inhibits biofilm development of Desulfovibrio sp. Huiquan2017.

Sulfate-reducing bacteria (SRB) are culprits for microbiologically influenced corrosion, and biofilms are believed to play essential roles in the corrosion induced by SRB. However, little is known about the regulation of SRB biofilms. Quorum sensing signal molecules acyl-homoserine lactones (AHLs) and autoinducer-2 (AI-2) regulate biofilm formation of many bacteria.

Oxygen Reduction Reaction Affected by Sulfate-Reducing Bacteria: Different Roles of Bacterial Cells and Metabolites.

Sulfate-reducing bacteria (SRB) were found to be capable of tolerating a certain amount of oxygen (O), but how they affect oxygen reduction reaction (ORR) has not been clear. The present work investigated the impact of SRB on ORR in 3.5 wt% sodium chloride solution with the cyclic voltammetry method.

D-Phenylalanine inhibits biofilm development of a marine microbe, Pseudoalteromonas sp. SC2014.

D-Amino acids have been reported to be able to inhibit biofilm formation or disperse existing biofilms of many microbes; in some cases this is due to growth inhibition as an unspecific effect. In this work, six different D-amino acids were tested for their inhibitory effects on biofilm development and bacterial growth of Pseudoalteromonas sp. SC2014, a marine microbe involved in microbiologically influenced corrosion (MIC).

Design and statistical optimization of an effervescent floating drug delivery system of theophylline using response surface methodology.

The aim of this research was to formulate effervescent floating drug delivery systems of theophylline using different release retarding polymers such as ethyl cellulose, Eudragit® L100, xanthan gum and polyethylene oxide (PEO) N12K. Sodium bicarbonate was used as a gas generating agent. Direct compression was used to formulate floating tablets and the tablets were evaluated for their physicochemical and dissolution characteristics.

Heterologous biosynthesis of costunolide in Escherichia coli and yield improvement.

Costunolide, the main bioactive compound of the medicinal plant, Radix Aucklandiae, is a sesquiterpene lactone (SL) and has a broad range of biological activities. It is also a precursor of many biologically-active SLs and is a branching point in the biosynthesis of SLs. Here we have reconstituted the costunolide biosynthetic pathway in Escherichia coli by co-expression of three genes (GAS, GAO, LsCOS) involved in costunolide biosynthesis and eight genes involved in converting acetyl-CoA into farnesyl diphosphate from mevalonate pathway.

Deletion of intragenic tandem repeats in unit C of FLO1 of Saccharomyces cerevisiae increases the conformational stability of flocculin under acidic and alkaline conditions.

Flocculation is an attractive property for Saccaromyces cerevisiae, which plays important roles in fermentation industry and environmental remediation. The process of flocculation is mediated by a family of cell surface flocculins. As one member of flocculins, Flo1 is characterized by four families of repeats (designated as repeat units A, B, C and D) in the central domain.

[Regulation of tandem repeats on the function of flocculation protein in Saccharomyces cerevisiae].

Objective: There are a large numbers of tandem repeats in FLO1, which are highly dynamic components in genome leading to the unstable flocculation profiles in Saccharomyces cerevisiae. The effects of repeated unite B or D deletion on the function of flocculation protein was studied to provide theory basis for constructing genetically stable flocculation gene with minimal size.

Methods: We cloned the intact flocculation gene FLO1 from S.

DNA adduct measurements, cell proliferation and tumor mutation induction in relation to tumor formation in B6C3F1 mice fed coal tar or benzo[a]pyrene.

Coal tar is a complex mixture containing hundreds of compounds, at least 30 of which are polycyclic aromatic hydrocarbons, including the carcinogen benzo[a]pyrene (BaP). Although humans are exposed to complex mixtures on a daily basis, the synergistic or individual effects of components within a mixture on the carcinogenic process remain unclear. We have compared DNA adduct formation and cell proliferation in mice fed coal tar or BaP for 4 weeks with tumor formation in a 2 year chronic feeding study.

H- and K-ras mutational profiles in chemically induced liver tumors from B6C3F1 and CD-1 mice.

Liver tumors from mice treated with genotoxic carcinogens often possess mutations in ras protooncogenes, and these sequence alterations in ras frequently reflect the mutational specificity of the carcinogen. Previous studies suggest that the mouse model used for tumor induction may affect ras mutational patterns. In order to explore this possibility, H- and K-ras mutational profiles were established in liver tumors from male B6C3f1 and CD-1 mice administered benzo[a]pyrene (BaP), 6-nitrochrysene (6-NC), and 4-aminobiphenyl (4-ABP).

Relationships of DNA adduct formation, K-ras activating mutations and tumorigenic activities of 6-nitrochrysene and its metabolites in the lungs of CD-1 mice.

6-Nitrochrysene (6-NC), an environmental pollutant and a potent mouse lung carcinogen, is activated by two major metabolic pathways to yield DNA adducts derived from either trans-1,2-dihydro-1,2-dihydroxy-6-aminochrysene (1,2-DHD-6-AC) or N-hydroxy-6-aminochrysene (N-OH-6-AC). While the former pathway has been shown to be the major activation pathway leading to DNA adducts in mice treated with 6-NC, the potential contribution of the minor nitroreduction pathway to tumorigenicity in this system is not clear. To evaluate the roles of these activation pathways and the resulting DNA adducts in mouse lung tumorigenesis, we studied DNA adduct formation, the induction of tumors and tumor K-ras mutational spectra in the lungs of male CD-1 mice treated with 6-NC and its metabolites.

Trans-1,2-dihydro-1,2-dihydroxy-6-aminochrysene is metabolized to form a major adduct with deoxyguanosine and produces mutations in the hprt gene of Chinese hamster ovary cells at G:C basepairs.

6-Nitrochrysene can be activated to genotoxic derivatives by two major metabolic pathways: nitroreduction to N-hydroxy-6-aminochrysene, and a combination of ring-oxidation and nitroreduction that involves the intermediate formation of trans-1,2-dihydro-1,2-dihydroxy-6-aminochrysene (6-AC-1,2-dihydrodiol). The DNA adduct formed from this latter pathway was evaluated by reacting individual deoxynucleoside 5'-monophosphates with 6-AC-1,2-dihydrodiol in the presence of liver microsomal enzymes from 3-methylcholanthrene-pretreated rats. Binding was greatest to deoxyguanosine monophosphate and the major deoxyguanosine (dG) adduct co-chromatographed with the single major adduct formed from the microsome-catalyzed reaction of 6-AC-1,2-dihydrodiol with DNA.

32P-postlabelling in studies of arylamine and nitroaromatic hydrocarbon activation and mutagenesis.

Carcinogenic arylamines and nitroaromatic hydrocarbons are chemicals that present occupational health hazards and share pathways of metabolic activation. The 32P-postlabelled DNA adducts formed in Chinese hamster ovary (CHO) cells treated with metabolites from two pathways that are common to the activation of the nitroaromatic hydrocarbon 6-nitrochrysene (6-NC) and the arylamine 6-aminochrysene (6-AC) compared with the spectra of mutations induced at the CHO hprt locus by these were metabolites. 6-Nitrosochrysene (6-NOC), which is reduced by the cells to N-hydroxy-6-AC, formed adducts mainly with deoxyguanosine, but induced mutations primarily through base-pair substitution involving deoxyadenosine.