Researchers have isolated deep-sea PVC superphylum bacteria capable of degrading laminarin, according to a study published in Nature Communications on July 31, 2026. The study combined 16S rRNA gene amplicon sequencing, metagenomics, and metatranscriptomics to examine prokaryotic communities across cold seeps, hydrothermal vents, and seamounts sampled in 2018 and 2022.
The study identified extensive polysaccharide degradation capabilities within the Planctomycetota-Verrucomicrobiota-Chlamydiota (PVC) superphylum. Researchers isolated two specific bacterial strains—Planctomycetota strain WC338 and Lentisphaerota strain WC36—by using laminarin enrichment. Growth experiments and transcriptomics confirmed that both strains strictly depend on laminarin to grow and deploy distinct glycoside hydrolase families to break down the compound.
Sampling efforts relied on assistance from the crew of the research vessel RV KEXUE and the FAXIAN remotely operated vehicle. The researchers found spatio-temporal community heterogeneity driven by geochemical gradients across the sampled deep-sea habitats. They demonstrated that laminarin acts as an effective selective substrate to enrich and isolate bacteria from the deep-sea PVC superphylum, showing that these microbes actively participate in laminarin turnover in deep-sea environments.
Rikuan Zheng, Chong Wang, and Chaomin Sun authored the study through affiliations including the Institute of Oceanology at the Chinese Academy of Sciences in Qingdao, the Qingdao National Laboratory for Marine Science and Technology Center, and the University of Chinese Academy of Sciences in Beijing. The research was submitted on November 6, 2025, accepted on July 7, 2026, and received funding support from the National Natural Science Foundation of China and the Key R&D Program of Shandong Province.
