scholarly journals Identification, Characterization, and Evaluation of Nematophagous Fungal Species of Arthrobotrys and Tolypocladium for the Management of Meloidogyne incognita

2021 ◽  
Vol 12 ◽  
Author(s):  
Rami Kassam ◽  
Jyoti Yadav ◽  
Gautam Chawla ◽  
Aditi Kundu ◽  
Alkesh Hada ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Morphological Characteristics ◽  
Ultra Performance Liquid Chromatography ◽  
Fungal Species ◽  
Gas Chromatography Mass Spectrometry ◽  
Egg Mass ◽  
Multiplication Factor ◽  
Root Knot Nematode ◽  
Flight Mass Spectrometry

Root-knot nematodes belonging to the genus Meloidogyne are agriculturally important pests, and biocontrol strategies offer safer alternatives for their management. In the present study, two fungal species from Indian soils were identified as Arthrobotrys thaumasia and Tolypocladium cylindrosporum based on morphological characteristics and further confirmed using molecular markers. In vitro evaluation of A. thaumasia against M. incognita and Caenorhabditis elegans showed 82 and 73% parasitism, respectively, whereas T. cylindrosporum gave 65.2 and 57.7% parasitism, respectively. Similarly, culture filtrates of A. thaumasia caused 57.7 and 53.7% mortality of M. incognita and C. elegans, respectively, whereas T. cylindrosporum caused higher mortality of 87.3 and 64%, respectively. Besides, greenhouse evaluation of both fungi against M. incognita infecting tomato significantly reduced nematode disease burden reflecting parasitic success measured as the total number of galls, egg masses, eggs per egg mass, and derived nematode multiplication factor. Application of A. thaumasia and T. cylindrosporum reduced nematode multiplication factor by 80 and 95%, respectively, compared with control. General metabolite profiling of tested fungi using gas chromatography–mass spectrometry and ultra-performance liquid chromatography–quadrupole/time of flight mass spectrometry reported for the first time here showed presence of various volatile and non-volatile compounds with nematicidal activity, viz., trimethyl-heptadiene, methyl-hexadecanol, dodecadienal, decane, terpendole E, dodecane, acetamido-6-anthraquinone, and hexadecanol. Also, other compounds such as undecane, dibutyl-disulfide, octadecenal, paganin, talathermophilin, dactylarin, tolypyridone A, tolypyridone B, pyridoxatin, and destruxin were identified, reported in the literature to possess antibacterial, antifungal, and insecticidal properties. This is the first report of the occurrence of both fungi from India and pioneer demonstration of T. cylindrosporum for root-knot nematode management.

scholarly journals Effect of relative humidity on SOA formation from isoprene/NO photooxidation: role of particle-phase esterification under dry conditions

2011 ◽  
Vol 11 (2) ◽  
pp. 5407-5433 ◽  
Author(s):  
H. Zhang ◽  
J. D. Surratt ◽  
Y. H. Lin ◽  
J. Bapat ◽  
R. M. Kamens
Keyword(s):  
Mass Spectrometry ◽  
Relative Humidity ◽  
Chemical Characterization ◽  
Ultra Performance Liquid Chromatography ◽  
Gas Chromatography Mass Spectrometry ◽  
Particle Phase ◽  
Particle Volume ◽  
Flight Mass Spectrometry ◽  
Dry Conditions ◽  
Detailed Chemical

Abstract. The effect of relative humidity (RH) on secondary organic aerosol (SOA) formation from the photooxidation of isoprene under initially high-nitric oxide (NO) conditions was investigated in a dual outdoor smog chamber. Based upon particle volume concentration measurements and the detailed chemical characterization of isoprene SOA using gas chromatography/mass spectrometry (GC/MS) and ultra performance liquid chromatography/electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry (UPLC/ESI-HR-Q-TOFMS), enhanced SOA formation was observed under lower RH conditions (15–40%) compared to higher RH conditions (40–90%). 2-methylglyceric acid (2-MG) and its corresponding oligoesters, which have been previously shown to form from further oxidation of methacryloylperoxynitrate (MPAN), were enhanced in the particle-phase under lower RH conditions. In addition, an abundant unknown SOA tracer likely derived from the further oxidation of MPAN was detected and enhanced under lower RH conditions. In contrast, the 2-methyltetrols, which are known to form from the reactive uptake of isoprene epoxydiols (IEPOX) under low-NO conditions in the presence of acidified aerosol, did not substantially vary under different RH conditions; however, isoprene-derived organosulfates were found to be enhanced under high-RH conditions, indicating the likely importance of the aqueous aerosol phase in their formation. Based upon the detailed chemical characterization results, particle-phase organic esterification is proposed to explain the observed enhancements of isoprene SOA mass under lower RH conditions. This is one of only a few chamber studies that have examined the effect of RH on isoprene SOA formation. In comparison to our recent results obtained from aromatic SOA formation, the effect of RH on isoprene SOA formation is reversed. The results of this study highlight the importance of elucidating the key reactive intermediates that lead to SOA formation, especially since RH likely affects their ability in forming SOA. Furthermore, ignoring the effects of RH may significantly affect the accuracy of both regional and global SOA models.

scholarly journals In Vitro/In Vivo Metabolism of Ginsenoside Rg5 in Rat Using Ultra-Performance Liquid Chromatography/Quadrupole-Time-of-Flight Mass Spectrometry

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2113 ◽  
Author(s):  
Chao Hong ◽  
Ping Yang ◽  
Shuping Li ◽  
Yizhen Guo ◽  
Dan Wang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Time Of Flight ◽  
Ultra Performance Liquid Chromatography ◽  
In Vivo Metabolism ◽  
Rat Urine ◽  
Flight Mass Spectrometry ◽  
Ginsenoside Rg5

Background: Ginsenoside Rg5 has been proved to have a wide range of pharmacological activities. However, the in vitro and in vivo metabolism pathways of ginsenosides are still unclear, which impedes the understanding of their in vivo fate. In this paper, the possible metabolic process of Rg5 was studied and the metabolites are identified. Methods: Samples from rat liver microsomes (RLMs) in vitro and from rat urine, plasma and feces in vivo were collected for analysis after oral administration of Rg5. A rapid analysis technique using ultra-performance liquid chromatography (UPLC)/quadrupole-time-of-flight mass spectrometry (QTOF-MS) was applied for detecting metabolites of Rg5 both in vitro and in vivo. Results: A feasible metabolic pathway was proposed and described for ginsenoside Rg5. A total of 17 metabolic products were detected in biological samples, including the RLMs (four), rat urine (two), feces (13) and plasma (four). Fifteen of them have never been reported before. Oxidation, deglycosylation, deoxidation, glucuronidation, demethylation and dehydration were found to be the major metabolic reactions of Rg5. Conclusions: The present study utilized a reliable and quick analytical tool to explore the metabolism of Rg5 in rats and provided significant insights into the understanding of the metabolic pathways of Rg5 in vitro and in vivo. The results could be used to not only evaluate the efficacy and safety of Rg5, but also identify potential active drug candidates from the metabolites.

scholarly journals Effect of cultivation media and temperature on metabolite profiles of three nematicidal Bacillus species

Nematology ◽  
2021 ◽  
pp. 1-17
Author(s):  
Ilzé Horak ◽  
Peet J. Jansen van Rensburg ◽  
Sarina Claassens
Keyword(s):  
Mass Spectrometry ◽  
Luria Bertani ◽  
Gas Chromatography Mass Spectrometry ◽  
Bacillus Species ◽  
Root Knot Nematode ◽  
Cultivation Conditions ◽  
Flight Mass Spectrometry ◽  
Luria Bertani Broth ◽  
Antagonistic Microorganisms ◽  
Metabolite Profiles

Summary Globally, root-knot nematode (RKN) infestations cause great financial losses. Although agrochemicals are used to manage these pests, there is increased interest in using biocontrol agents based on natural antagonistic microorganisms, such as Bacillus. These nematicidal bacteria demonstrate antagonism towards RKN through different modes of action, including specialised metabolite production. The aim of this study was to compare metabolite profiles of nematicidal Bacillus species and assess the influence of cultivation conditions on these profiles. Two hyphenated metabolomics platforms, gas chromatography-mass spectrometry (GC-MS) and liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (LC-QTOF-MS), were employed to profile and compare metabolite features produced during the cultivation of three nematicidal Bacillus species (Bacillus firmus, B. cereus and B. soli) in complex Luria-Bertani broth (LB) and a simpler minimal broth (MB), at three different temperatures (25, 30 and 37°C). Cultivation in complex LB as opposed to simpler MB resulted in the production of more statistically significant metabolite features. Selected temperatures in this study did not have a significant influence on metabolite profiles. Moreover, media-specific influences outweighed temperature-specific influences on metabolite profiles. Results from this study are a valuable first step in establishing suitable cultivation conditions for the production of Bacillus metabolites of interest.

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