Photorhabdus sp. ETL Antimicrobial Properties and Characterization of Its Secondary Metabolites by Gas Chromatography–Mass Spectrometry

Abstract

Entomopathogenic nematodes (EPNs) are known to be highly pathogenic to insect pests, due to their associated symbiotic bacteria, which produce virulence factors, exo-enzymes and other harmful secondary metabolites to conquer, kill, and degrade their insect hosts. However, these properties are not fully characterized. This study reports on the antimicrobial activities of Photorhabdus sp. strain ETL, symbiotically associated to an insect pathogenic nematode, Heterorhabditis zealandica, against human pathogenic bacteria and toxigenic fungi, as well as the non-targeted profiling of its secondary metabolites (SMs) using gas chromatography coupled to high-resolution time-of-flight mass spectrometry. Fatty acids including 3-eicosene, (E)-; 5-eicosene, (E)-; eicosene; 9-octadecenamide; undecanoic acid with shown antimicrobial activities were detected. This provided more insight on the composition and bioactivities of SMs produced by the Photorhabdus sp.

Variability in metabolites produced by Talaromyces pinophilus SPJ22 cultured on different substrates

“…Furthermore, GC coupled to high-resolution time-of-flight mass spectrometry (HRTOF-MS) is one of the recent innovations and robust metabolomic technologies, with improved mass resolutions and data collection rates [ 24 , 25 ]. As shown in previous studies, GC-HRTOF-MS is a potent analytical technique that can effectively screen various metabolites in microorganisms with high sensitivity and excellent results [ 26 – 28 ].…”

Isolation and extraction of some compounds that act as antimicrobials from actinomycetes

“…coli O157 (ATCC93111) as model strains of gram-positive and gram-negative species. Lulamba et al (2021) mentioned that he extracted this compound, and he also indicated that this compound is pathogenic to a wide range of insects.…”

Endosymbiotic microbes from entomopathogenic nematode (EPNs) and their applications as biocontrol agents for agro-environmental sustainability

“…In EPNs infected insects, these endosymbionts defend the host cadaver from the invading microbiome by the secretion of a variety of compounds possessing antibiotic activities. These metabolites are also used as biocontrol negotiators for the management of viruses, fungi, nematodes, and insects (Lulamba et al 2021). The bioactive components produced by Xenorhabdus and Photorhabdus play an essential role in the biological transformation of host insects.…”