Unique features of Plasmids among different Citrobacter species

The _Citrobacter_ plasmids are supposed to represent the host genetic association within the living bacterial cell. The plasmids impart various beneficial characteristics to the host, helping it to retain suitable characteristics for adaptation as well as evolution. The study aims at understanding the role of prophage in influencing host functional characteristics by horizontal gene transfer or as whole plasmids. The _Citrobacter_ plasmid can be understood by analyzing many hypothetical protein sequences within its genome. Our study included 82 hypothetical proteins in 5 _Citrobacter_ plasmids genomes. The function predictions in 31 hypothetical proteins and 3-D structures were predicted for 11 protein sequences using PS2 server. The probable function prediction was done by using Bioinformatics web tools like CDD-BLAST, INTERPROSCAN, PFAM and COGs by searching sequence databases for the presence of orthologous enzymatic conserved domains in the hypothetical sequences. This study identified many uncharacterized proteins, whose roles are yet to be discovered in _Citrobacter_ plasmids. These results for unknown proteins within plasmids can be used in linking the genetic interactions of _Citrobacter_ species and their functions in different environmental conditions

Bacteriophages as a model for studying carbon regulation in aquatic system

The interconversion of carbon in organic, inorganic and refractory carbon is still beyond the grasp of present environmentalists. The bacteria and their phages, being the most abundant constituents of the aquatic environment, represent an ideal model for studing carbon regulation in the aquatic system. The refractory dissolved organic carbon (DOC), a recently coined terminology from the microbe-driven conversion of bioavailable organic carbon into difficult-to-digest refractory DOC by microbial carbon pump (MCP), is suggested to have the potential to revolutionize our view of carbon sequestration. It is estimated that about 95% of organic carbon is in the form of refractory DOC, which is the largest pool of organic matter in the ocean. The refractory DOC is supposed to be the major factor in the global carbon cycle whose source is not yet well understood. A key element of the carbon cycle is the microbial conversion of dissolved organic carbon into inedible forms. The time studies of phage-host interaction under control conditions reveal their impact on the total carbon content of the source and their interconversion among organic, inorganic and other forms of carbon with respect to control source. The TOC- analysis statistics stipulate an increase in inorganic carbon content by 15-25 percent in the sample with phage as compared to the sample without phage. The results signify a 60-70 fold increase in inorganic carbon content in sample with phage, whereas, 50-55 fold in the case of sample without phages as compared with control. This increase in inorganic carbon content may be due to lysis of the host cell releasing its cellular constituents and utilization of carbon constituent for phage assembly and development. It also proves the role of phages in regulating the carbon flow in aquatic systems like oceans, where their concentration outnumbered other species

Bacteriophages as a model for studying carbon regulation in aquatic system

The interconversion of carbon in organic, inorganic and refractory carbon is still beyond the grasp of present environmentalists. The bacteria and their phages being the most abundant constituents of the aquatic environment, represents an ideal model for studing carbon regulation in aquatic system. The refractory dissolved organic carbon (DOC) a recently coined terminology from the microbe-driven conversion of bioavailable organic carbon into difficult-to-digest refractory DOC by microbial carbon pump (MCP) is suggested to have potential to revolutionize our view of carbon sequestration. It is estimated that about 95% of organic carbon is in the form of refractory DOC which is the largest pool of organic matter in the ocean. The refractory DOC is supposed to be the major factor in the global carbon cycle whose source is not yet well understood. A key element of the carbon cycle is the microbial conversion of dissolved organic carbon into inedible forms. The time studies of phagehost interaction under control conditions reveals their impact on the total carbon content of the source and their interconversion among organic, inorganic and other forms of carbon with respect to control source. The TOC- analysis statistics stipulate increase in inorganic carbon content by 15-25 percent in the sample with phage as compared to sample without phage. The results signify 60-70 fold increase in inorganic carbon content in sample with phage, whereas,50-55 fold in the case of sample without phages as compared with control. This increase in inorganic carbon content may be due to lysis of the host cell releasing its cellular constituents and utilization of carbon constituent for phage assembly and development. It also provesthe role of phages in regulating the carbon flow in the aquatic systems like oceans where their concentration outnumbered other species

Novel bacteriophage therapy for controlling metallo-beta-lactamase producing Pseudomonas aeruginosa infection in Catfish

Background: The bacteriophage therapy is an effective antimicrobial approach with potentially important applications in medicine and biotechnology which can be seen as an additional string in the bow. Emerging drug resistant bacteria in aquaculture industry due to unrestricted use of antibiotics warrants more sustainable and environmental friendly strategies for controlling fish infections. The isolated bacteria from fish lesions was characterised based on isolation on selective and differential medium like Pseudomonas agar, gram staining, biochemical tests and 16SrRNA sequencing. The metallo-beta-lactamase (MBL) producing bacterial isolate was evaluated using Imipenem - Ethylenediaminetetraacetic acid (EDTA) disk method. The specific bacteriophage was isolated and concentrated using coal bed developed in our lab at CSIR-NEERI. The isolated and enriched bacteriophage was characterised by nucleotide sequencing and electron microscopy. The phage therapy was applied for treating ulcerative lesion in fish. Results: The pathogenic bacterium responsible for causing ulcerative lesions in catfish species (Clarias gariepinus) was identified as Pseudomonas aeruginosa. One out of twenty P. aeruginosa isolate showing multi drug resistance (MDR) was incidentally found to be MBL producing as determined by Imipenem-EDTA disk method. The phage therapy effectively cured the ulcerative lesions of the infected fish in 8–10 days of treatment, with a sevenfold reduction of the lesion with untreated infection control. Conclusion: Bacteriophage therapy can have potential applications soon as an alternative or as a complement to antibiotic treatment in the aquaculture. We present bacteriophage therapy as a treatment method for controlling MDR P. aeruginosa infection in C. gariepinus. To the best of our knowledge this is a first report of application of phage therapy against MBL producing P. aeruginosa isolated from aquatic ecosystem. Keywords: P. aeruginosa, Multi drug resistance, Metallo-β-lactamase, Bacteriophage therapy, Catfis

Increasing the extraction efficiency of algal lipid for biodiesel production: Novel application of algal viruses

Various studies have been conducted recently using microalgal system for the production of algal lipid for biodiesel production. This study aimed at increasing the extraction efficiency of algal lipid from Chlorella sp. by the application of Chlorella viruses. The calorific value of lipid from Chlorella sp. has been reported to be higher than that of fresh water microalgae, making it a potential candidate to be used as biofuel. This is the first report on novel application of microalgal viruses for improving the extraction efficiency of algal lipid for biodiesel production through viral lysis of Chlorella vulgaris. The algal lipid extraction efficiency, increased by 11.68% in the case of Chlorella virus treated C. vulgaris when compared with Chlorella virus untreated C. vulgaris. The application of Chlorella virus and the viral encoded lytic enzymes for increasing the extraction efficiency of algal lipid will be helpful in optimizing algal biofuel industry in the future.Keywords: Micro-algal system, biodiesel, algal lipid, Chlorella viruses, viral lysis.African Journal of Biotechnology, Vol 13(15), 1666-167