Bacillus phage

A Bacillus phage is a member of a group of bacteriophages known to have bacteria in the genus Bacillus as host species. These bacteriophages have been found to belong to the families Myoviridae, Siphoviridae, Podoviridae, or Tectiviridae.[1][2][3][4] The genus Bacillus includes the model organism, B. subtilis, and two widely known human pathogens, B. anthracis and B. cereus. Other strains of Bacillus bacteria that phage are known to infect include B. megaterium, B. mycoides, B. pseudomycoides, B. thuringiensis, and B. weihenstephanensis. More than 1,455 bacillus phage have been discovered from many different environments and areas around the world.[5] Only 164 of these phages have been completely sequenced as of December 16, 2021.[5]

## Genome diversity

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Bacillus phage are classified based on their genome sequences. The total sequence length ranges from 7,826 (in phage pMC8) to 509,170 bp (in phage pHS181) with the GC content of these phage being an average of 38.25%.[6]

Within Bacillus phage there are 12 clusters (A-L), 28 subclusters, and 14 singletons. Clusters are groups of related genomes with the 12 clusters showing at least 50% homology between phage.[7] Singletons are phage that have no significant nucleotide similarity to others. The most conserved genes within the Bacillus phage include those that encode tail proteins and other structural proteins, holin, and a site-specific recombinase.[7] One group of gene that is highly variable between Bacillus phage are tRNA genes. The role of phage tRNAs largely depend on their bacterial host, hence the number could widely differ depending on the specific strain of bacteria.[citation needed]

Nucleotide and amino acid dot plot analysis of 93 fully sequenced Bacillus phages reveals 12 clusters (A-L) and 14 singletons. Nucleotide (top-left) and amino acid (top-right) dot plot of Bacillus genomes of less than 100 kb organized by similarity reveals 10 clusters of related phages. Nucleotide (bottom-left) and amino acid (bottom-right) dot plot of Bacillus genomes of greater than 100 kb organized by similarity reveals 2 clusters of related phages. Thick lines indicate cluster assignments, which are provided on the Y-axis (A-L).[7] Cluster | Sub. | Phages | Hosts | Genome size | %GC | # ORFS (tRNA) | Type

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A  | 2  | 5  | A                    T     | ~15000  | ~39.0  | ~30.0  | T
B  | 3  | 6  |     B    S    | ~20000  | ~37.0  | ~28.0  | P
C  | 2  | 2  |    B        W  | ~26000  | ~30.5  | ~39.5  | S
D  | 1  | 3  |   M    | ~40000  | ~41.0  | ~49.5  | P
E  | 1  | 3  |       C        T     | ~40000  | ~38.0  | ~49.0  | S
F  | 3  | 11  | A    B    C        T     | ~40000  | ~35.0  | ~53.5  | S
G  | 1  | 2  |    C        T     | ~55000  | ~36.5  | ~70.0  | S
H  | 1  | 10  |    B        M    P    | ~48000  | ~42.0  | ~74.5  | S
I  | 1  | 2  |    B    | ~65000  | ~47.5  | ~112.5  | UK
J  | 2  | 3  |    C    M    | ~81000  | ~35.0  | ~122.0  | S
K  | 2  | 5  |    B    C       S    | ~140500  | ~40.0  | ~223.0  | M
L  | 8  | 27  |    B    C        P    S    T     | ~160000  | ~39.1  | ~270.0  | M

Characteristics given are cluster assignment, number of subclusters (Sub.), number of phages in the cluster, host species from which the phages were isolated, the average genome size, average percent GC content, average number of ORFS, and the morphotype. Species abbreviations are Bacillus anthracis (A), Bacillus cereus (C), Bacillus sp. (B), Bacillus megaterium (M), Bacillus pumulis (P), Bacillus subtilis (S), Bacillus thuringiensis (T), and Bacillus westenstephanensis MG1, (W). Family/morphotype abbreviations are Tectiviridae (T), Podoviridae (P), Siphoviridae (S), and Myoviridae (M). UK is unknown/unreported.[7]

## Applications

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The DNA polymerase of Bacillus phage phi29 is a unique and efficient polymerase with proofreading activity.[8][9]

## References

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1. ^ Gillis A, Mahillon J (July 2014). "Phages preying on Bacillus anthracis, Bacillus cereus, and Bacillus thuringiensis: past, present and future". Viruses. 6 (7): 2623–2672\. doi:10.3390/v6072623. PMC 4113786. PMID 25010767.
2. ^ Lee JH, Shin H, Ryu S (May 2014). "Characterization and comparative genomic analysis of bacteriophages infecting members of the Bacillus cereus group". Archives of Virology. 159 (5): 871–884\. doi:10.1007/s00705-013-1920-3. PMID 24264384. S2CID 15058899.
3. ^ Klumpp J, Lavigne R, Loessner MJ, Ackermann HW (October 2010). "The SPO1-related bacteriophages". Archives of Virology. 155 (10): 1547–1561\. doi:10.1007/s00705-010-0783-0. hdl:20.500.11850/23338. PMID 20714761. S2CID 20320784.
4. ^ Gentry-Weeks C, Coburn PS, Gilmore MS (2002). "Phages and other mobile virulence elements in gram-positive pathogens". Current Topics in Microbiology and Immunology. 264 (2): 79–94\. PMID 12012871.
5. ^ a b "Bacillus Phage Database | Home". bacillus.phagesdb.org. Retrieved 2021-12-16.
6. ^ "Bacillus Phage Database | Detail for Phage pHS181". bacillus.phagesdb.org. Retrieved 2021-12-16.
7. ^ a b c d Grose JH, Jensen GL, Burnett SH, Breakwell DP (October 2014). "Genomic comparison of 93 Bacillus phages reveals 12 clusters, 14 singletons and remarkable diversity". BMC Genomics. 15 (1): 855. doi:10.1186/1471-2164-15-855. PMC 4197329. PMID 25280881.
8. ^ Blanco L, Salas M (September 1984). "Characterization and purification of a phage phi 29-encoded DNA polymerase required for the initiation of replication". Proceedings of the National Academy of Sciences of the United States of America. 81 (17): 5325–5329\. Bibcode:1984PNAS...81.5325B. doi:10.1073/pnas.81.17.5325. PMC 391696. PMID 6433348.
9. ^ Salas M, Blanco L, Lázaro JM, de Vega M (January 2008). "The bacteriophage phi29 DNA polymerase". IUBMB Life. 60 (1): 82–85\. doi:10.1002/iub.19. PMID 18379997. S2CID 39622915.

## External links

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* The Bacillus Phage Database