Biology subjects

Van Den Heuvel, S.

Publications and source records attributed to Van Den Heuvel, S..

3 recordsLinked to original sources

bioRxiv2024

Temporal and spatial dynamics within the fungal microbiome of grape fermentation

Wine fermentation is a highly complex and competitive environment, imposing harsh selective pressures on fungal community ecology and diversity. The composition of fungal communities inhabiting the surface of grapes will directly impact fermentation progression, wine quality, and contribute to the distinctiveness between wines from different geographical regions. Despite this, the extent of microbial community diversity between geographies, termed microbial terroir, remains highly debated. We amassed a large survey of grape spontaneous ferments over six years, encompassing 3105 fungal microbiomes across 14 geographically separated grape-growing regions, and nine grape cultivars. Investigation into the biodiversity of these ferments identified that few high abundance genera form the core of the initial grape microbiome. In line with previous studies, various consistent taxa were linked to specific geographical locations and grape varieties. However, these taxa accounted for a small portion of the overall diversity in the dataset. Through unsupervised clustering, we identified three distinct community types in the grape fungal microbiome, each exhibiting variations in the abundance of key genera. Analysing ferments across temporal and spatial scales revealed significant differences in species richness and compositional heterogeneity between wineries and grape growing regions. However, microbial communities were transient between years in the same winery, regularly transitioning between the three broad community types. We then investigated microbial community composition throughout the fermentative process and observed that initial microbial community composition is predictive of the diversity during the early stages of fermentation, with Hanseniaspora uvarum detected as the main non-Saccharomyces species within this large cohort of samples. Our results help to formulate a clear understanding of the spatial and temporal characteristics of the grape juice fungal microbiome and suggest that these communities are mainly defined by the grape niche and in a minor way shaped by local environmental conditions.

microbiology↗

bioRxiv2023

Metagenomic ecosystem monitoring of soft scale and mealybug infestations in Australian vineyards

Soft scale insects and mealybugs are phloem feeding Hemipterans that are considered majors pests in agricultural and horticultural settings throughout the world. Viticulturally, scale are a major issue due to their ability to secrete honeydew, which facilitates the development of sooty mould and for their propensity as transmission vectors for several viral diseases of grapevine. To facilitate the rapid identification and quantification of vineyard-associated insects a metagenomic-based bioinformatic pipeline was developed for generalised ecosystem monitoring that automated the assembly and classification of insect mitochondrial genomes from shotgun sequencing data using the Barcode of Life Database API. Parthenolecanium corni (European fruit scale), which was thought to be absent from Australian grapevines, was identified as the dominant coccid species infesting all vines sampled, along with secondary infestation by Pseudococcus viburni (obscure mealybug) and Pseudo. longispinus (long-tailed mealybug). In addition, parisitoidism by Coccophagus scutellaris (Aphelinidae) wasps was also detected. The discovery of Parth. corni as a significant member of scale infestations in Australia has significant implications for the development of effective control strategies for this important group of pests.

ecology↗

bioRxiv2023

The genomic landscape of wild Saccharomyces cerevisiae is shaped by complex patterns of admixture, aneuploidy and recombination.

Cultural exchange of fermentation techniques has driven the spread of Saccharomyces cerevisiae across the globe, establishing wild populations in many countries. Despite this, most modern commercial fermentations are inoculated using monocultures, rather than relying on natural populations, potentially impacting wild population diversity. Here we investigate the genomic landscape of 411 wild S. cerevisiae isolated from spontaneous grape fermentations in Australia across multiple locations, years, and grape cultivars. Spontaneous fermentations contained highly recombined mosaic strains that commonly exhibited aneuploidy of chromosomes 1, 3, 6 and 9. Assigning wild genomic windows to putative ancestral origin revealed that few closely related commercial lineages have come to dominate the genetic landscape, contributing most of the genetic variation. Fine-scale phylogenetic analysis of loci not observed in strains of commercial wine origin identified widespread admixture with the Beer2 clade along with three independent admixture events from potentially endemic Oceanic lineages that last shared an ancestor with modern East Asian S. cerevisiae populations. Our results illustrate how commercial use of microbes can affect local microorganism genetic diversity and demonstrates the presence of non-domesticated, non-European derived lineages of S. cerevisiae in Australian ecological niches that are actively admixing.

genomics↗