Thalassospira australica sp. nov. isolated from sea water

Abstract

Two Gram-negative, non-pigmented, motile bacteria were isolated from a sea water sample collected at St. Kilda Beach, Port Philip Bay, Victoria, Australia. The two strains were found to grow between 4 and 40 °C, pH 5-10 and tolerate up to 10 % NaCl. A phylogenetic study, based on a 16S rRNA gene sequence analysis indicated that strains NP 3b2(T) and H 94 belong to the genus Thalassospira. The sequence similarity of the 16S rRNA gene between the two new isolates is 99.8 % and between these strains and all validly named Thalassospira species was found to be in the range of 95-99.4 %. The DNA-DNA relatedness between the two strains was found to be 80.2 %, while relatedness with other validly named species of the genus Thalassospira was between 53 and 65 %. The average nucleotide identity (ANI) and the in silico genome-to-genome distance (GGD) between the two bacteria and T. profundimaris WP0211(T), T. xiamenensis M-5(T), 'T. permensis' NBRC 106175(T) and T. lucentensis QMT2(T) was 76-82 % and 21-25 %, respectively. The results of phylogenetic and genomic analysis, together with physiological and biochemical properties, indicated that the two strains represent a new species of the genus Thalassospira. Based on these data, a new species, Thalassospira australica, is proposed with strain NP 3b2(T) (=KMM 6365(T) = JCM 31222(T)) as the type strain.

Computational prediction of microRNAs in marine bacteria of the genus Thalassospira

“…xiamenensis M-5 T were available in the NCBI database, the small RNA sequence reads were aligned to these genome sequences. The remaining 5 Thalassospira species that did not have the whole genome sequence were aligned to these references based on their phylogenetically closest species [14] ( S1 Table, S1 Fig ). By aligning 34.23 million collapsed reads from nine species of the genus Thalassospira to the genome sequences available in NCBI, it was found that a proportion of cleaned reads was mappable to the reference genomes, ranging from 38.42% to 71.94% for 4 species with available genome sequences and from 2.55% to 28.16% for the remaining 5 species without whole genome sequenced ( Table 1 ).…”

“…coli is an enteric bacterium commonly found in low intestine of humans and animals [36], S . mutans is an oral pathogen that causes human dental caries [37], while bacteria of the Thalassospira genus are environmental bacteria [14]. The differences in their characteristics may influence the low degree of conservation of miRNAs among these bacteria.…”

“…alkalitolerans JCM 18968 T shared 95.3% and 94.9% of 16S rRNA sequence similarity, respectively, with T . lucentensis QMT2 T [14]. Conserved miRNA sequences found in these species may indicate a close genetic relationship and that these miRNAs have a similar role in the regulation of the growth and development of bacteria.…”

“…The genus Thalassospira includes Gram-negative, aerobic and halophilic bacteria dwelling in a marine environment [11]. Bacteria of this genus are involved in the biodegradation of a variety of hydrocarbons [12–14]. For example, T .…”

“…povalilytica Zumi 95 T have the ability to degrade polycyclic aromatic hydrocarbons and polyvinyl alcohol [12, 13]; and T . australica NP 3b2 T is able to utilise poly (ethylene) terephthalate (PET) plastic as a carbon source [14]. Currently the genus Thalassospira is comprised of 10 validly named species, of which the whole genome sequences of four species ( T .…”