Termites are important ecosystem engineers and play key roles in modulating microbial communities within and outside their mounds. Microbial diversity within termite mounds is generally lower than surrounding soils, due to termite-associated antimicrobial compounds and active sanitary behaviours. Microbial symbionts of termites can also influence the microbial landscape, by inhibiting or out-competing other microbes.
View Article and Find Full Text PDFCharacterizing ancient clades of fungal symbionts is necessary for understanding the evolutionary process underlying symbiosis development. In this study, we investigated a distinct subgeneric taxon of Xylaria (Xylariaceae), named Pseudoxylaria, whose members have solely been isolated from the fungus garden of farming termites. Pseudoxylaria are inconspicuously present in active fungus gardens of termite colonies and only emerge in the form of vegetative stromata, when the fungus comb is no longer attended ("sit and wait" strategy).
View Article and Find Full Text PDFIn this study, we analyzed if Actinomadura sp. RB99 produces siderophores that that could be responsible for the antimicrobial activity observed in co-cultivation studies. Dereplication of high-resolution tandem mass spectrometry (HRMS/MS) and global natural product social molecular networking platform (GNPS) analysis of fungus-bacterium co-cultures resulted in the identification of five madurastatin derivatives (A1, A2, E1, F, and G1), of which were four new derivatives.
View Article and Find Full Text PDFKings and queens of eusocial termites can live for decades, while queens sustain a nearly maximal fertility. To investigate the molecular mechanisms underlying their long lifespan, we carried out transcriptomics, lipidomics and metabolomics in Macrotermes natalensis on sterile short-lived workers, long-lived kings and five stages spanning twenty years of adult queen maturation. Reproductives share gene expression differences from workers in agreement with a reduction of several aging-related processes, involving upregulation of DNA damage repair and mitochondrial functions.
View Article and Find Full Text PDFThe diverse bacterial communities in and around plants provide important benefits, such as protection against pathogens and cycling of essential minerals through decomposition of moribund plant biomass. Biodiverse fynbos landscapes generally have limited deadwood habitats due to the absence of large trees and frequent fire. In this study, we determined the effect of a fire disturbance on the bacterial communities in a fynbos landscape dominated by the shrub Protea repens using 16S ribosomal RNA amplicon sequencing.
View Article and Find Full Text PDFThe Ophiostomatales (Ascomycota) accommodates more than 300 species characterized by similar morphological adaptations to arthropod dispersal. Most species in this order are wood-inhabiting fungi associated with bark or ambrosia beetles. However, a smaller group of species occur in other niches such as in soil and infructescences.
View Article and Find Full Text PDFThe ancestor of termites relied on gut symbionts for degradation of plant material, an association that persists in all termite families. However, the single-lineage Macrotermitinae has additionally acquired a fungal symbiont that complements digestion of food outside the termite gut. Phylogenetic analysis has shown that fungi grown by these termites form a clade-the genus Termitomyces-but the events leading toward domestication remain unclear.
View Article and Find Full Text PDFMorphotype switches frequently occur in Actinobacteria and are often associated with disparate natural product production. Here, we report on differences in the secondary metabolomes of two morphotypes of a species, including the discovery of a novel antimicrobial glycosylated macrolide, which we named termidomycin A. While exhibiting an unusual 46-member polyene backbone, termidomycin A (1) shares structural features with the clinically important antifungal agents amphotericin B and nystatin A1.
View Article and Find Full Text PDFMacrotermitine termites have domesticated fungi in the genus as their primary food source using predigested plant biomass. To access the full nutritional value of lignin-enriched plant biomass, the termite-fungus symbiosis requires the depolymerization of this complex phenolic polymer. While most previous work suggests that lignocellulose degradation is accomplished predominantly by the fungal cultivar, our current understanding of the underlying biomolecular mechanisms remains rudimentary.
View Article and Find Full Text PDFSexually reproducing organisms face a strong selective pressure to find a mate and ensure reproduction. An important criterion during mate-selection is to avoid closely related individuals and subsequent potential fitness costs of resulting inbred offspring. Inbreeding avoidance can be active through kin recognition during mate choice, or passive through differential male and female-biased sex ratios, which effectively prevents sib-mating.
View Article and Find Full Text PDFSeveral species in the complex have emerged as important pests of woody plants globally, particularly in habitats where they are invasive aliens. These beetles live in obligate symbioses with fungi in the genus . In this study, we identified spp.
View Article and Find Full Text PDFAmbrosia beetles are small wood inhabiting members of the Curculionidae that have evolved obligate symbioses with fungi. The fungal symbionts concentrate nutrients from within infested trees into a usable form for their beetle partners, which then utilize the fungi as their primary source of nutrition. Ambrosia beetle species associate with one or more primary symbiotic fungal species, but they also vector auxiliary symbionts, which may provide the beetle with developmental or ecological advantages.
View Article and Find Full Text PDF, one of the largest bacterial phyla, are ubiquitous in many of Earth's ecosystems and often act as defensive symbionts with animal hosts. Members of the phylum have repeatedly been isolated from basidiomycete-cultivating fungus-farming termites that maintain a monoculture fungus crop on macerated dead plant substrate. The proclivity for antimicrobial and enzyme production of make them likely contributors to plant decomposition and defense in the symbiosis.
View Article and Find Full Text PDFDuring studies to investigate the health of mangrove trees in South Africa, high numbers of Avicennia marina were found with leaf galls caused by unidentified adults and larvae of midges (Cecidomyiidae). Fungal fruiting structures were commonly observed on the abaxial areas of the galls. To determine the identity of the fungi associated with the gall midges, phylogenetic analyses using multigene sequence data were used.
View Article and Find Full Text PDFScientific communication is facilitated by a data-driven, scientifically sound taxonomy that considers the end-user's needs and established successful practice. In 2013, the community voiced near unanimous support for a concept of that represented a clade comprising all agriculturally and clinically important species, including the species complex (FSSC). Subsequently, this concept was challenged in 2015 by one research group who proposed dividing the genus into seven genera, including the FSSC described as members of the genus , with subsequent justification in 2018 based on claims that the 2013 concept of is polyphyletic.
View Article and Find Full Text PDFXylosandrus crassiusculus (Motchulsky) is a native Asian ambrosia beetle that has been accidentally introduced to many countries of the world, presumably through the international movement of nursery, timber, and wood products. The species is known in various tropical African countries but only as far south as Tanzania on the African continent. In this study, we report X.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
November 2020
Based on high-resolution tandem mass spectrometry (HR-MS) and global natural products social molecular networking (GNPS), we found that plant-derived daidzein and genistein derivatives are polyhalogenated by termite-associated species RB99. MS-guided purification from extracts of bacteria grown under optimized conditions led to the isolation of eight polychlorinated isoflavones, including six unreported derivatives, and seven novel polybrominated derivatives, two of which showed antimicrobial activity.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
October 2020
The taxonomic positions of two novel aerobic, Gram-positive actinobacteria, designated strains RB29 and RB68, were determined using a polyphasic approach. Based on 16S rRNA gene sequence analysis, the closest phylogenetic neighbours of RB29 were identified as DSM 102126 (99.2 % similarity) and DSM 43919 (98.
View Article and Find Full Text PDFInt J Syst Evol Microbiol
October 2020
The taxonomic positions of two novel aerobic, Gram-stain-positive Actinobacteria, designated RB20 and RB56, were determined using a polyphasic approach. Both were isolated from the fungus-farming termite . Results of 16S rRNA gene sequence analysis revealed that both strains are members of the genus with the closest phylogenetic neighbours JCM12860 (98.
View Article and Find Full Text PDFBark beetle galleries are complex ecosystems where many microbes and other arthropods co-exist with the beetles. Fungi isolated from these galleries are often referred to as 'beetle associates', but the nature of these associations are poorly understood. The possibility that many of these fungi might in fact be mite associates is often overlooked.
View Article and Find Full Text PDFDraft genome sequences of five species [including , , , and ], , and are presented. Species of are the causal agents of Eucalyptus leaf blight disease, threatening the growth and sustainability of plantations in China. is the causal agent of stem canker in native and exotic in South Africa.
View Article and Find Full Text PDFHerein, we report the targeted isolation and characterization of four linear nonribosomally synthesized tetrapeptides (pseudoxylaramide A-D) and two cyclic nonribosomal peptide synthetase-polyketide synthase-derived natural products (xylacremolide A and B) from the termite-associated stowaway fungus Pseudoxylaria sp. X187. The fungal strain was prioritized for further metabolic analysis based on its taxonomical position and morphological and bioassay data.
View Article and Find Full Text PDFGrowth from spores activated a biosynthetic gene cluster in sp. RB29, resulting in the identification of two novel groups of halogenated polyketide natural products, named maduralactomycins and actinospirols. The unique tetracyclic and spirocyclic structures were assigned based on a combination of NMR analysis, chemoinformatic calculations, X-ray crystallography, and C labeling studies.
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