Characterization of a novel bacteriophage specific to Exiguobacterium indicum isolated from a plateau eutrophic lake

Abstract

Exiguobacterium is a versatile genus with potential in industry and agriculture. No bacteriophage that infects Exiguobacterium has been reported, despite its potential impacts on the utilization of Exiguobacterium. E. indicum EI9 was isolated from Dianchi Lake, a plateau eutrophic lake in China, which can significantly inhibit the growth of Microcystis aeruginosa. To isolate and characterize Exiguobacterium‐infecting bacteriophage, a virulent bacteriophage, DCEIV‐9 that specifically infects E. indicum EI9 was isolated from Dianchi lake water sample. DCEIV‐9 produced tiny, round, and clear plaques with 0.5–1 mm in diameter. Electron microscopy showed that DCEIV‐9 is a typical representative of the Siphoviridae, with an icosahedral head (56 nm in diameter) and a non‐contractile tail (163 nm in length). Based on a one‐step growth curve, latent period of 20 min and burst size of 51 PFU/infected cell were determined. DCEIV‐9 was sensitive to temperature over 50 °C and prefers acid environment. DCEIV‐9 was extremely sensitive to proteinase K, chloroform, ethanol, Triton X‐100 but not sensitive to SDS. Restriction endonucleases analysis indicated that DCEIV‐9 is a dsDNA virus. DCEIV‐9 can only infect E. indicum, indicates that it has a narrow host range. DCEIV‐9 is a potential new species.

Diversity and Activity of Aquatic Cellulolytic Bacteria Isolated from Sedimentary Water in the Littoral Zone of Tonle Sap Lake, Cambodia

“…Another aquatic cellulolytic bacterium of the Phylum Firmicutes found in this study was Exiguobacterium indicum. Many previous reports showed that the E. indicum were isolated from various aquatic environments, such as melted water from glaciers in India [79], a hot spring in Vietnam [80], and a freshwater lake in China [81]. There were some strains of Exiguobacterium species that might produce cellulases [82][83][84].…”

Comparative analysis of bacterioplankton assemblages from two subtropical karst reservoirs of southwestern China with contrasting trophic status

“…However, further studies are still needed to understand the role of Clostridium sensu stricto in the karst reservoir. The OTUs 18 ( Bacillus ) and 24 ( Exiguobacterium ) affiliated with Firmicutes dominating the deep layer of DL Reservoir may be relating to their inhibiting effect on eukaryotic and other prokaryotic autotrophs, including Cyanobacteria 40 , 41 . The most abundant Verrucomicrobia-related OTU 23 ( Candidatus Methylacidiphilum) in DL Reservoir has been reported as a thermoacidophilic methanotroph in tropical and summer temperate lakes 32 , which was associated with autochthonous carbon production and able to conduct assimilatory nitrate reduction and reduce NO 2 − –N to N 2 O, suggesting their important role in carbon and nitrogen cycles 5 , 42 .…”

Recent Advances in the Research on the Anticyanobacterial Effects and Biodegradation Mechanisms of Microcystis aeruginosa with Microorganisms

“…It is shown in Table 1 that the largest number of anticyanobacterial Firmicutes are the Bacillus group, accounting for 77.3% of the total number of Firmicutes, while the remaining strains are from the genera Exiguobacterium [44,45] and Staphylococcus [35]. Li et al, (2015) revealed that Bacillus sp.…”

“…The indirect attack mode has been observed in the numerous metabolites from most of the reported anticyanobacterial microorganisms, and the anticyanobacterial characteristics of these bacteria seem to be unique to M. aeruginosa. Up to now, the genus Acinetobacter [22,72,119] and Exiguobacterium [44,45,96], which firstly attach to M. aeruginosa and then cause serious damage to the cyanobacterial cell structure and morphology, are recognized as degrading M. aeruginosa by producing anticyanobacterial substances. Nevertheless, some anticyanobacteria can inhibit or kill green alga and cyanobacteria with an indirect attack simultaneously.…”