Improved selective medium for isolating Cylindrocladium crotalariae microsclerotia from naturally infested soils

1977 ◽  
Vol 23 (6) ◽  
pp. 680-683 ◽  
Author(s):  
Gary J. Griffin
Keyword(s):  
Water Potential ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Compounds ◽  
Selective Medium ◽  
Ammonium Compounds ◽  
Soil Dilution

Reduced development of fusaria and other undesired fungi, and improved recognition of Cylindrocladium crotalariae colonies on soil-dilution plates were accomplished by supplementing a previously used medium (sucrose–TBZ medium) with three quaternary ammonium compounds, replacing peptone with tyrosine, and increasing the concentration of sucrose to yield a water potential of −10 bars. These changes eliminated the need to treat soil with NaClO to control undesired fungi. The new medium, designated sucrose–QT medium, allowed increased recovery of C. crotalariae microsclerotia from all 16 naturally infested soils tested.

Stress metabolism. IX. Effect of salt stress on trigonelline accumulation in tomato

2001 ◽  
Vol 81 (3) ◽  
pp. 487-498 ◽  
Author(s):  
Lada R. Rajasekaran ◽  
D. Aspinall ◽  
G. P. Jones ◽  
L. G. Paleg
Keyword(s):  
Salt Stress ◽  
Lycopersicon Esculentum ◽  
Water Potential ◽  
Quaternary Ammonium ◽  
Osmotic Potential ◽  
Water Status ◽  
Nacl Stress ◽  
Quaternary Ammonium Compounds ◽  
Sand Culture ◽  
Ammonium Compounds

The presence of quaternary ammonium compounds (QAC) and their accumulation in tomato (Lycopersicon esculentum Mill.) cv. Duke in response to different modes for causing NaCl stress were studied. Pre-germinated tomato seeds were grown in sand culture and 25-d-old seedlings were subjected to abrupt, progressive or prolonged salt stress using NaCl at various osmotic potentials. Plant water status was measured using psychrometry and quaternary ammonium compounds were visualized using thin-layer chromatography and then confirmed and quantified using nuclear magnetic resonance spectrometry. Leaf water potential and osmotic potential declined depending on the osmotic potential of the rooting medium and the mode of stress imposition. A greater decline in osmotic potential compared with the total water potential led to turgor maintenance in plants under progressive or prolonged NaCl stress. The QAC, trigonelline and choline were identified in tomato. Trigonelline, but not choline, accumulated rapidly in response to abrupt, progressive or prolonged NaCl stress. The threshold external water potential (ψext.) for trigonelline accumulation was –0.565 MPa. Trigonelline accumulation correlated with changes in ψL (r = –0.92***), ψS (r = –0.94***) and ψP (r = 0.85***). Trigonelline contributed only –0.035 MPa to the osmotic adjustment, suggesting that its role may also lie in areas other than osmoregulation. Key words: Bataines choline, growth, Lycopersicon esculentum, salt stress, trigonelline, water relations

Determination of quaternary ammonium compounds in food products by the method of ultra-performance liquid chromatography/high resolution mass-spectrometry

2020 ◽  
Vol 86 (8) ◽  
pp. 23-31
Author(s):  
V. G. Amelin ◽  
D. S. Bolshakov
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Quaternary Ammonium ◽  
High Resolution Mass Spectrometry ◽  
Food Products ◽  
Quaternary Ammonium Compounds ◽  
High Resolution Mass ◽  
Ammonium Compounds ◽  
Resolution Mass

The goal of the study is developing a methodology for determination of the residual amounts of quaternary ammonium compounds (QAC) in food products by UHPLC/high-resolution mass spectrometry after water-acetonitrile extraction of the determined components from the analyzed samples. The identification and determination of QAC was carried out on an «UltiMate 3000» ultra-high-performance liquid chromatograph (Thermo Scientific, USA) equipped with a «maXis 4G» high-resolution quadrupole-time-of-flight mass spectrometric detector and an ion spray «ionBooster» source (Bruker Daltonics, Germany). Samples of milk, cheese (upper cortical layer), dumplings, pork, chicken skin and ground beef were used as working samples. Optimal conditions are specified for chromatographic separation of the mixture of five QAC, two of them being a mixture of homologues with a linear structure (including isomeric forms). The identification of QAC is carried out by the retention time, exact mass of the ions, and coincidence of the mSigma isotopic distribution. The limits for QAC detection are 0.1 – 0.5 ng/ml, the determination limits are 1 ng/ml for aqueous standard solutions. The determinable content of QAC in food products ranges within 1 – 100 ng/g. The results of analysis revealed the residual amount of QAC present in all samples, which confirms data of numerous sources of information about active use of QAC-based disinfectants in the meat and dairy industry. The correctness of the obtained results is verified by introduction of the additives in food products at a level of 10 ng/g for each QAC. The relative standard deviation of the analysis results does not exceed 0.18. The duration of the analysis is 30 – 40 min.

scholarly journals From antimicrobial activity to mechanism of resistance: the multifaceted role of simple quaternary ammonium compounds in bacterial eradication

Tetrahedron ◽  
2016 ◽  
Vol 72 (25) ◽  
pp. 3559-3566 ◽  
Author(s):  
Kevin P.C. Minbiole ◽  
Megan C. Jennings ◽  
Laura E. Ator ◽  
Jacob W. Black ◽  
Melissa C. Grenier ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Quaternary Ammonium ◽  
Quaternary Ammonium Compounds ◽  
Bacterial Eradication ◽  
Mechanism Of Resistance ◽  
Ammonium Compounds
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