The complete genome sequence of a south Indian isolate of Rice tungro spherical virus reveals evidence of genetic recombination between distinct isolates.

In this study, complete genome of a south Indian isolate of Rice tungro spherical virus (RTSV) from Andhra Pradesh (AP) was sequenced, and the predicted amino acid sequence was analysed. The RTSV RNA genome consists of 12,171 nt without the poly(A) tail, encoding a putative typical polyprotein of 3,470 amino acids. Furthermore, cleavage sites and sequence motifs of the polyprotein were predicted. Multiple alignment with other RTSV isolates showed a nucleotide sequence identity of 95% to east Indian isolates and 90% to Philippines isolates. A phylogenetic tree based on complete genome sequence showed that Indian isolates clustered together, while Vt6 and PhilA isolates of Philippines formed two separate clusters. Twelve recombination events were detected in RNA genome of RTSV using the Recombination Detection Program version 3. Recombination analysis suggested significant role of 5' end and central region of genome in virus evolution. Further, AP and Odisha isolates appeared as important RTSV isolates involved in diversification of this virus in India through recombination phenomenon. The new addition of complete genome of first south Indian isolate provided an opportunity to establish the molecular evolution of RTSV through recombination analysis and phylogenetic relationship.

Iodobacter arcticus sp. nov., a psychrotolerant bacterium isolated from meltwater stream sediment of an Arctic glacier.

Two novel violet-pigmented, Gram-negative, rod-shaped, non-motile bacteria, designated strains M4-16(T) and M4-9, were isolated from sediment from an Arctic glacier. The predominant fatty acids of both strains were C16 : 1ω7c and/or C16 : 1ω6c (summed feature 3), C16 : 0, C14 : 0 and C18 : 1ω7c and/or C18 : 1ω6c (summed feature 8) and both strains contained ubiquinone-8 as the respiratory quinone. The polar lipids consisted of phosphatidylethanolamine, two unidentified phospholipids and one unidentified aminolipid. 16S rRNA gene sequence analysis indicated that strains M4-16(T) and M4-9 were members of the genus Iodobacter and closely related to Iodobacter fluviatilis ATCC 33051(T) with pairwise sequence similarity of 98.9 %. The DNA-DNA relatedness between strains M4-9 and M4-16(T) was 92.5 %, while strains M4-9 and M4-16(T) had DNA-DNA relatedness values of 21.5 and 18.2 %, respectively, with Iodobacter fluviatilis JCM 9044(T). The RAPD-PCR banding patterns of strains M4-9 and M4-16(T) were similar but differed from that of Iodobacter fluviatilis JCM 9044(T). Based on data from the current polyphasic study, strains M4-16(T) and M4-9 represent a novel species of the genus Iodobacter, for which the name Iodobacter arcticus sp. nov. is proposed. The type strain of Iodobacter arcticus is M4-16(T) ( = CIP 1103011(T) = MTCC 11351(T)).