Aims: Isolation and characterization of nicotine‐degrading bacteria with advantages suitable for the treatment of nicotine‐contaminated water and soil and detection of their metabolites. Methods and Results: A novel nicotine‐degrading bacterial strain was isolated from tobacco field soil. Based on morphological and physiochemical properties and sequence of 16S rDNA, the isolate was identified as Pseudomonas sp., designated as CS3. The optimal culture conditions of strain CS3 for nicotine degradation were 30°C and pH 7·0. However, the strain showed broad pH adaptability with high nicotine‐degrading activity between pH 6·0 and 10·0. Strain CS3 could decompose nicotine nearly completely within 24 h in liquid culture (1000 mg L−1 nicotine) or within 72 h in soil (1000–2500 mg kg−1 nicotine) and could endure up to 4000 mg L−1 nicotine in liquid media and 5000 mg kg−1 nicotine in soil. Degradation tests in flask revealed that the strain had excellent stability and high degradation activity during the repetitive degradation processes. Additionally, three intermediates, 3‐(3,4‐dihydro‐2H‐pyrrol‐5‐yl) pyridine, 1‐methyl‐5‐(3‐pyridyl) pyrrolidine‐2‐ol and cotinine, were identified by GC/MS and NMR analyses. Conclusions: The isolate CS3 showed outstanding nicotine‐degrading characteristics such as high degradation efficiency, strong substrate endurance, broad pH adaptability, and stability and persistence in repetitive degradation processes and may serve as an excellent candidate for applications in the bioaugmentation process to treat nicotine‐contaminated water and soil. Also, detection of nicotine metabolites suggests that strain CS3 might decompose nicotine via a unique nicotine‐degradation pathway. Significance and Impact of the Study: The advantage of applying the isolated strain lies in broad pH adaptability and stability and persistence in repetitive use, the properties previously less focused in other nicotine‐degrading micro‐organisms. The strain might decompose nicotine via a nicotine‐degradation pathway different from those of other nicotine‐utilizing Pseudomonas bacteria reported earlier, another highlight in this study.
Genetic dissection kernel weight-related traits is of great significance for improving wheat yield potential. As one of the three major yield components of wheat, thousand kernel weight (TKW) was mainly affected by grain length (GL) and grain width (GW). To uncover the key loci for these traits, we carried out a quantitative trait loci (QTL) analysis of an F6 recombinant inbred lines (RILs) population derived from a cross of Henong 5290 (small grain) and 06Dn23 (big grain) with a 50 K single nucleotide polymorphism (SNP) array. A total of 17 stable and big effect QTL, including 5 for TKW, 8 for GL and 4 for GW, were detected on the chromosomes 1B, 2A, 2B, 2D, 4B, 5A, 6A and 6D, respectively. Among these, there were two co-located loci for three traits that were mapped on the chromosome 4BS and 6AL. The QTL on 6AL was the most stable locus and explained 15.4–24.8%, 4.1–8.8% and 15.7–24.4% of TKW, GW and GL variance, respectively. In addition, two more major QTL of GL were located on chromosome arm 2BL and 2DL, accounting for 9.7–17.8% and 13.6–19.8% of phenotypic variance, respectively. In this study, we found one novel co-located QTL associated with GL and TKW in 2DL, QGl.haaf-2DL.2/QTkw.haaf-2DL.2, which could explain 13.6–19.8% and 9.8–10.7% phenotypic variance, respectively. Genetic regions and linked markers of these stable QTL will help to further refine mapping of the corresponding loci and marker-assisted selection (MAS) breeding for wheat grain yield potential improvement.
Background: Several fetal cardiovascular structural defects may alter the hemodynamics of the cardiac chambers resulting in changes in chamber sizes. Quantitative measurements of the sizes of cardiac chambers can augment the diagnostic power of fetal echocardiography. Aims:Using a new left atrial volume tracking (LAVT) method, time-left atrial volume curves (TLAVCs) can be automatically obtained. The goal of this study was to examine whether this method can be used to evaluate left atrial volume (LAV) and provide reference values for LAV and indices of left atrial function in normal human fetuses.Methods: Two hundred and four normal human fetuses were enrolled. Using LAVT, the maximal left atrial volume (LAVmax) and minimal left atrial volume (LAVmin) were measured from TLAVCs. Left atrial ejection fraction (EF) was calculated. The maximal left atrial area (LAAmax) and minimal left atrial area (LAAmin) were measured using manual method tracing.Results: Between 21 and 40 weeks, mean LAVmax increased from 0.27 ml to 4.15 ml, and mean LAVmin increased from 0.13 ml to 2.26 ml, respectively, while the EF remained stable at around 0.43. From 21 to 40 weeks, mean LAAmax increased from 0.61 cm 2 to 2.64 cm 2 , and mean LAAmin increased from 0.34 cm 2 to 1.53 cm 2 .Conclusions: This study establishes reference values for fetal LAV during the second half of gestation. The LAVT method appears to be feasible in estimating fetal LAV and shows potential for assessing left atrial function.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.