Tamlana laminarinivorans sp. nov. and Tamlana sargassicola sp. nov., two novel species isolated from Sargassum, show genomic and physiological adaptations for a Sargassum-associated lifestyle

Abstract

The genus Tamlana from the Bacteroidota currently includes six validated species. Two strains designated PT2-4T and 62-3T were isolated from Sargassum abundant at the Pingtan island coast in the Fujian Province of China. 16S rRNA gene sequence analysis showed that the closest described relative of strains PT2-4T and 62-3T is Tamlana sedimentorum JCM 19808T with 98.40 and 97.98% sequence similarity, respectively. The 16S rRNA gene sequence similarity between strain PT2-4T and strain 62-3T was 98.68 %. Furthermore, the highest average nucleotide identity values were 87.34 and 88.97 % for strains PT2-4T and 62-3T, respectively. The highest DNA–DNA hybridization (DDH) value of strain PT2-4T was 35.2 % with strain 62-3T, while the DDH value of strain 62-3T was 37.7 % with T. sedimentorum JCM 19808T. Growth of strains PT2-4T and 62-3T occurs at 15–40 °C (optimum, 30 °C) with 0–4 % (w/v) NaCl (optimum 0–1 %). Strains PT2-4T and 62-3T can grow from pH 5.0 to 10.0 (optimum, pH 7.0). The major fatty acids of strains PT2-4T and 62-3T are iso-C15 : 0 and iso G-C15 : 1. MK-6 is the sole respiratory quinone. Genomic and physiological analyses of strains PT2-4T and 62-3T showed corresponding adaptive features. Significant adaptation to the growth environment of macroalgae includes the degradation of brown algae-derived diverse polysaccharides (alginate, laminarin and fucoidan). Notably, strain PT2-4T can utilize laminarin, fucoidan and alginate via specific carbohydrate-active enzymes encoded in polysaccharide utilization loci, rarely described for the genus Tamlana to date. Based on their distinct physiological characteristics and the traits of utilizing polysaccharides from Sargassum, strains PT2-4T and 62-3T are suggested to be classified into two novel species, Tamlana laminarinivorans sp. nov. and Tamlana sargassicola sp. nov. (type strain PT2-4T=MCCC 1K04427T=KCTC 92183T and type strain 62-3T=MCCC 1K04421T=KCTC 92182T).

Comparative genomics reveal distinct potential of Tamlana sp. S12 for algal polysaccharide degradation

“…T. laminarinivorans, T. sargassicola, and T. sedimentorum all contain two similar PULs related to alginate utilization. These PULs contain a similar set of CAZymes as ALG PUL, consisting of PL6, 7, and 17 (Li et al, 2023). However, their gene cluster structure and arrangement differ significantly from ALG PUL, which is consistent with the lineage and phylogenetic tree results (Figure 1).…”

“…Currently, there are nine species that have been validly published under the genus Tamlana. Tamlana species have been isolated from various sources, including seawater (Yoon et al, 2008;Liu et al, 2015;Jung et al, 2019), algae (Li et al, 2020;Li et al, 2023), marine sediment (Lee, 2007;Romanenko et al, 2014), and the gut of abalone (Cao et al, 2021). Research conducted by Li et al (2023) has shown that members of Tamlana possess a wide range of CAZymes that are associated with the utilization of algal polysaccharides.…”

“…Tamlana species have been isolated from various sources, including seawater (Yoon et al, 2008;Liu et al, 2015;Jung et al, 2019), algae (Li et al, 2020;Li et al, 2023), marine sediment (Lee, 2007;Romanenko et al, 2014), and the gut of abalone (Cao et al, 2021). Research conducted by Li et al (2023) has shown that members of Tamlana possess a wide range of CAZymes that are associated with the utilization of algal polysaccharides. Tamlana laminarinivorans and Tamlana haliotis can degrade alginate, Tamlana sargassicola can degrade laminarin, and Tamlana crocina can degrade utilizing ulvan (Li et al, 2023).…”

“…Research conducted by Li et al (2023) has shown that members of Tamlana possess a wide range of CAZymes that are associated with the utilization of algal polysaccharides. Tamlana laminarinivorans and Tamlana haliotis can degrade alginate, Tamlana sargassicola can degrade laminarin, and Tamlana crocina can degrade utilizing ulvan (Li et al, 2023). Furthhermore, production of k-carrageenase and alginate lyase have been reported (Sun et al, 2010;Mostafa et al, 2020;Yin et al, 2021).…”