Supplementary file 1_Cultivar-specific microbiome dynamics and substrate-dependent growth of Ulva compressa during brine-based cultivation.zip

Under laboratory cultivation in brine C2019, maintained a more diverse core microbiome and in the scaled-up experiment this cultivar exhibited higher specific growth rates than C1952 on PET and PA substrates. Bacterial genera previously identified as producers of algal growth- and morphogenesis-promoting factors (AGMPFs) - including Roseobacter, Maribacter, Zobellia, Sulfitobacter, and Marivita - remained consistently associated with C2019 throughout brine cultivation in all conducted experiments despite substantial microbiome restructuring.

The transition from artificial seawater to brine induced transient changes in fatty acid composition during acclimatization, which stabilized after prolonged exposure.</p>Discussion<p>Together, these findings demonstrate that cultivar-specific host–microbiome interactions are closely associated with successful acclimatization to inland brine cultivation. They highlight the importance of considering the algal holobiont when developing resilient land-based Ulva production systems.</p>