Compositional Shifts of Bacterial Communities Associated With Pyropia yezoensis and Surrounding Seawater Co-occurring With Red Rot Disease

Abstract

Pyropia yezoensis is commercially the most important edible red alga in China, and red rot disease is viewed as one of the major constraints for its cultivation. Microbes within the oomycetic genus Pythium have been reported as the causative agents for this disease; however, little is known about the interactions between the disease and the epiphytic and planktonic bacterial communities. In the present study, bacterial communities associated with uninfected, locally infected, and seriously infected thalli collected from cultivation farms, and within seawater adjacent to the thalli, were investigated using in-depth 16S ribosomal RNA (rRNA) gene sequencing in conjunction with assessing multiple environmental factors. For both thalli and seawater, uninfected and infected communities were significantly different though alpha diversity was similar. Phylogenetic differences between epiphytic bacterial communities associated with P. yezoensis were mainly reflected by the relative changes in the dominant operational taxonomic units (OTUs) assigned as genus Flavirhabdus , genus Sulfitobacter , and family Rhodobacteraceae. The prevalent OTUs in seawater also differed in relative abundance across the communities and were affiliated with diverse taxa, including the phyla Actinobacteria, Verrucomicrobia, and Bacteroidetes, and the classes Alpha- and Gamma-proteobacteria. The differentiation of bacterial communities associated with P. yezoensis and seawater was primarily shaped by reactive silicate (RS) content and salinity, respectively. In particular, 14 potential indicators (two OTUs on P. yezoensis and twelve OTUs in seawater) were identified that significantly differentiated P. yezoensis health statuses and correlated with environmental changes. Overall, the present study provides insights into the alterations of bacterial communities associated with P. yezoensis and surrounding seawater co-occurring with red rot disease. Observed changes were closely associated with health status of algal host, and highlight the potential of using community differentiation to forecast disease occurrence.

Integration of spatio-temporal variations of surface metabolomes and epibacterial communities highlights the importance of copper stress as a major factor shaping host-microbiota interactions within a Mediterranean seaweed holobiont

“…Among this family, OTUs affiliated to Octadecabacter , Silicimonas , Loktanella , and Pseudoruegeria were found positively correlated to the seawater temperature. The Rhodobacteraceae family was already described at the surface of many macroalgae and several taxa within this family were recurrently associated to high temperature conditions [ 27 , 72 – 76 ]. Especially, in the case of D. pulchra , the temperature was associated to the development of several pathogens from the Roseobacter group, such as Nautella italica [ 20 , 74 ].…”

Health Functionality and Quality Control of Laver (Porphyra, Pyropia): Current Issues and Future Perspectives as an Edible Seaweed

“…Microbiome Diversity in the microbiota P. umbilicalis -Seasonal variation to the microbial community in laver -Identification of bacterial groups which are expected to contribute to the evolution and/or function of laver [155] P. yezoensis -Seasonal variation and the effects of the yellow spot disease outbreaks to the microbial community in the seawater of laver seedling pools -Identification of disease-associated bacteria [174] Analytical techniques P. umbilicalis -Microbial communities affected by the sampling position of laver and the stabilization techniques applied for the microbiome analysis [171] Influencing factor (Red rot disease) P. yezoensis -Alterations of bacterial community by red dot disease -Close association between health status of algal host (uninfected or infected) and bacterial community [190] Proteome Mechanism of stress-tolerance P. haitanensis -Investigation on the key metabolisms elucidating the mechanisms of resistance to high-temperature [175,176] P. orbicularis -Investigation on the key metabolisms elucidating the mechanisms of resistance to desiccation [177,178]…”

The cultivation of Pyropia haitanensis has important impacts on the seawater microbial community

“…For example, an analysis of the epiphytic microbial community of P. haitanensis thalli using the denaturing gradient gel electrophoresis method revealed that the microbial community varied based on growth form, culture time, and environment (Shen et al 2013). Microbial communities on Pyropia yezoensis thalli and in seawater were significantly different when infected with the oomycetic genus Pythium (Yan et al 2019). In addition, industrial cultivation of the conchocelis stage is also an important component of the Pyropia industry.…”