scholarly journals Identification of Burkholderia and Penicillium isolates from kauri (Agathis australis) soils that inhibit the mycelial growth of Phytophthora agathidicida

2021 ◽  
Vol 74 (1) ◽  
pp. 42-54
Author(s):  
Alexa-Kate Byers ◽  
Leo Condron ◽  
Maureen O'Callaghan ◽  
Nick Waipara ◽  
Amanda Black
Keyword(s):  
Mycelial Growth ◽  
Solid Phase ◽  
Gas Chromatography Mass Spectrometry ◽  
Bacterial Isolates ◽  
Microbial Competition ◽  
Volatile Organic ◽  
Dieback Disease ◽  
Highly Virulent ◽  
Microbial Isolates

Phytophthora agathidicida is a highly virulent pathogen of kauri (Agathis australis) and the causal agent of dieback disease in New Zealand’s kauri forests. This study aimed to identify microbial isolates isolated from kauri forest soils that inhibited the growth of P. agathidicida. Three different forms of in vitro bioassays were used to assess the inhibition of each isolate on the mycelial growth of P. agathidicida. Furthermore, head space (HS) solid-phase micro-extraction coupled with gas chromatography-mass spectrometry (SPME-GCMS) was performed to identify if the microbial isolates emitted volatile organic compounds (VOCs), which may be contributing to inhibition. This research identified several bacterial isolates belonging to the genus Burkholderia that inhibited the mycelial growth of P. agathidicida. Furthermore, several VOCs produced by these isolates were putatively identified, which may be responsible for the inhibition observed in the bioassays. Several isolates of Penicillium were identified that inhibit Phytophthora agathidicida, with the culture filtrate of one isolate being found to strongly inhibit P. agathidicida mycelial growth. These isolates of Burkholderia and Penicillium appear to exhibit multiple modes of antagonism against P. agathidicida, including microbial competition and the production of diffusible and volatile anti-microbial compounds. Although further research is needed to better define their mechanisms of inhibition, these findings have identified candidate microbial antagonists of P. agathidicida.

scholarly journals Bioactivity of volatile organic compounds by Aureobasidium species against gray mold of tomato and table grape

2020 ◽  
Vol 36 (11) ◽  
Author(s):  
A. Di Francesco ◽  
J. Zajc ◽  
N. Gunde-Cimerman ◽  
E. Aprea ◽  
F. Gasperi ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Mycelial Growth ◽  
Solid Phase ◽  
Table Grape ◽  
Conidial Suspension ◽  
Vitro Assay ◽  
Volatile Organic

Abstract Aureobasidium strains isolated from diverse unconventional environments belonging to the species A. pullulans, A. melanogenum, and A. subglaciale were evaluated for Volatile Organic Compounds (VOCs) production as a part of their modes of action against Botrytis cinerea of tomato and table grape. By in vitro assay, VOCs generated by the antagonists belonging to the species A. subglaciale showed the highest inhibition percentage of the pathogen mycelial growth (65.4%). In vivo tests were conducted with tomatoes and grapes artificially inoculated with B. cinerea conidial suspension, and exposed to VOCs emitted by the most efficient antagonists of each species (AP1, AM10, AS14) showing that VOCs of AP1 (A. pullulans) reduced the incidence by 67%, partially confirmed by the in vitro results. Conversely, on table grape, VOCs produced by all the strains did not control the fungal incidence but were only reducing the infection severity (< 44.4% by A. pullulans; < 30.5% by A. melanogenum, and A. subglaciale). Solid-phase microextraction (SPME) and subsequent gas chromatography coupled to mass spectrometry identified ethanol, 3-methyl-1-butanol, 2-methyl-1-propanol as the most produced VOCs. However, there were differences in the amounts of produced VOCs as well as in their repertoire. The EC50 values of VOCs for reduction of mycelial growth of B. cinerea uncovered 3-methyl-1-butanol as the most effective compound. The study demonstrated that the production and the efficacy of VOCs by Aureobasidium could be directly related to the specific species and pathosystem and uncovers new possibilities for searching more efficient VOCs producing strains in unconventional habitats other than plants.

scholarly journals In Vitro Antifungal Activity of Plant Extracts on Pathogenic Fungi of Blueberry (Vaccinium sp.)

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 852
Author(s):  
Abraham Hernández-Ceja ◽  
Pedro Damián Loeza-Lara ◽  
Francisco Javier Espinosa-García ◽  
Yolanda M. García-Rodríguez ◽  
José Roberto Medina-Medrano ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
Colletotrichum Gloeosporioides ◽  
Pathogenic Fungi ◽  
Gas Chromatography Mass Spectrometry ◽  
Antifungal Compounds ◽  
Northwestern Region ◽  
Dieback Disease ◽  
Hexanedioic Acid ◽  
In Vitro Antifungal Activity

Three pathogenic fungi of blueberry (Vaccinium spp.) responsible for dieback disease, identified as Pestalotiopsis clavispora, Colletotrichum gloeosporioides and Lasiodiplodia pseudotheobromae, were isolated in the northwestern region of the state of Michoacán, Mexico. The mycelial growth in vitro of these fungi was inhibited by extracts from Lantana hirta, Argemone ochroleuca and Adenophyllum porophyllum, medicinal plants collected in Sahuayo, Michoacán, Mexico. The extracts showed different degrees of inhibition; the most effective were: M5L extract from L. hirta and M6LFr extract from A. ochroleuca, both of which inhibited 100% of the mycelial growth of P. clavispora and C. gloeosporioides; and M4LS extract from A. porophyllum, which inhibited 100% of the mycelial growth of the three pathogens. The extracts were fractionated by thin layer and column chromatography, and the most active fractions were analyzed by gas chromatography-mass spectrometry. The major compounds identified in L. hirta extract were Phytol and α-Sitosterol. The compounds identified in A. ochroleuca were Toluene and Benzene, 1,3-bis(3-phenoxyphenoxy)-. In A. porophyllum, the compound identified was Hexanedioic acid, bis(2-ethylhexyl) ester. These results show the potential of L. hirta, A. ochroleuca and A. porophyllum as a source of antifungal compounds.

scholarly journals The Stool Volatile Metabolome of Pre-Term Babies

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3341
Author(s):  
Alessandra Frau ◽  
Lauren Lett ◽  
Rachael Slater ◽  
Gregory R. Young ◽  
Christopher J. Stewart ◽  
...  
Keyword(s):  
Early Life ◽  
Solid Phase ◽  
Mass Spectrometry Data ◽  
Gas Chromatography Mass Spectrometry ◽  
Mass Spectral ◽  
Branched Chain Fatty Acids ◽  
Volatile Organic ◽  
Stool Samples ◽  
Branched Chain ◽  
Mixed Modelling

The fecal metabolome in early life has seldom been studied. We investigated its evolution in pre-term babies during their first weeks of life. Multiple (n = 152) stool samples were studied from 51 babies, all <32 weeks gestation. Volatile organic compounds (VOCs) were analyzed by headspace solid phase microextraction gas chromatography mass spectrometry. Data were interpreted using Automated Mass Spectral Deconvolution System (AMDIS) with the National Institute of Standards and Technology (NIST) reference library. Statistical analysis was based on linear mixed modelling, the number of VOCs increased over time; a rise was mainly observed between day 5 and day 10. The shift at day 5 was associated with products of branched-chain fatty acids. Prior to this, the metabolome was dominated by aldehydes and acetic acid. Caesarean delivery showed a modest association with molecules of fungal origin. This study shows how the metabolome changes in early life in pre-term babies. The shift in the metabolome 5 days after delivery coincides with the establishment of enteral feeding and the transition from meconium to feces. Great diversity of metabolites was associated with being fed greater volumes of milk.

scholarly journals The Effect of Carnosol, Carnosic Acid and Rosmarinic Acid on the Oxidative Stability of Fat-Filled Milk Powders throughout Accelerated Oxidation Storage

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 762
Author(s):  
Katerina Tzima ◽  
Nigel P. Brunton ◽  
Noel A. McCarthy ◽  
Kieran N. Kilcawley ◽  
David T. Mannion ◽  
...  
Keyword(s):  
Rosmarinic Acid ◽  
Solid Phase ◽  
Thiobarbituric Acid ◽  
Butylated Hydroxytoluene ◽  
Carnosic Acid ◽  
Gas Chromatography Mass Spectrometry ◽  
Peroxide Values ◽  
Antioxidant Potency ◽  
Antioxidant Effects

The in vitro antioxidant effects of the most potent antioxidants of rosemary, namely carnosol, carnosic acid and rosmarinic acid (c: ca: ra) were assessed in fat-filled milk powders (FFMPs) under accelerated conditions (40 °C and relative humidity (RH) 23%) over 90 days. Lipid oxidation was assessed in FFMPs by measuring peroxide values (PVs), thiobarbituric acid reactive substances (TBARS) and aroma volatiles using headspace (HS) solid-phase microextraction (SPME) coupled to gas-chromatography-mass spectrometry (GC-MS). The antioxidant potency of c: ca: ra exhibited a concentration-related effect (308 ppm > 200 ppm > 77 ppm), with the highest concentration being the most effective at controlling the formation of TBARS and PVs. At a concentration of 308 ppm c: ca: ra were particularly effective (p < 0.05) in inhibiting all the evaluated oxidation indices (primary and secondary) compared to the control samples, but in some cases less effectively (p < 0.05) than butylated hydroxyanisole: butylated hydroxytoluene (BHA: BHT) (200 ppm).

Development of a Headspace-Solid Phase Micro Extraction Method for the Analysis of Volatile and Semi-Volatile Organic Compounds from Polyurethane Resins for Leather Finishing

2021 ◽  
Vol 116 (8) ◽  
Author(s):  
Antonia Flores ◽  
Silvia Sorolla ◽  
Concepció Casas ◽  
Rosa Cuadros ◽  
Anna Bacardit
Keyword(s):  
Gas Chromatography ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Solid Phase ◽  
Monomethyl Ether ◽  
Gas Chromatography Mass Spectrometry ◽  
Extraction Temperature ◽  
Solid Phase Micro Extraction ◽  
Volatile Organic ◽  
Leather Finishing

Volatile organic compounds (VOCs) and Semi-Volatile Organic Compounds (SVOCs) arise from the chemicals used in the various stages of the leather manufacturing process. An important aim of the tanning industry is to minimize or eliminate VOCs and SVOCs, without lowering the quality of leather.   This paper shows the development of a new headspace-solid phase micro extraction coupled with gas chromatography–mass spectrometry (HS-SPME/GC-MS) method for the identification of VOCs and SVOCs emitted by newly designed polymers for the leather finishing operation. These new polymers are polyurethane resins designed to reduce the VOC and SVOC concentration. This method enables a simple and fast determination of the qualitative and semi-quantitative content of VOCs and SVOCs in polyurethane-type finishing resins. The chemicals that are of concern in this paper are the following: Dipropylene glycol Monomethyl Ether (DPGME), DBE-3 (a mixture of dibasic esters) and Triethylamine (TEA). The test conditions that have been determined to carry out the HS-SPME assay are the following: incubation time (2 hours), extraction temperature and time (40°C; 5 minutes) and the desorption conditions (280°C, 50 seconds).  Ten samples of laboratory scale resins were tested by HS-SPME followed by gas chromatography (GC-MS). DPGME and DBE-3 (a mixture of dimethyl adipate, dimethyl glutarate and dimethyl succinate) have been identified effectively. The compounds are identified by a quantitative method using external calibration curves for the target compounds. The technique is not effective to determine the TEA compound, since the chromatograms shown poor resolution peaks for the standard. 

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