Ribosomal Encoded Bacteriocins: Their Functional Insight and Applications

Singh, Jitendra; Ghosh, Chaitali

doi:10.5923/j.microbiology.20120202.04

Cited by 9 publications

(9 citation statements)

References 67 publications

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“…Comparisons of specific activity of inulosucrase cloned into periplasmic expression vector, transformed and expressed in E. coli 16 and E. coli BL21 demonstrated that extracellular expression is achieved only in colicin producing microorganism. Various reports suggested that BRP protein is responsible for the release of colicin such as colicin A, E1, E2, K, N, U, and Y into the extracellular medium (Cascales et al, 2007;Sommer et al, 2010;Singh et al, 2012). There are reports that extracellular secretion could be achieved in E. coli strain by coexpression of a lysis-promoting protein (Sommer et al, 2010).…”

Section: Discussionmentioning

confidence: 99%

“…Sommer et al (2010) constructed a plasmid which contains bacteriocin release proteins (BRP) that allow secretion of recombinant protein from the periplasm into the culture medium (Sommer et al, 2010). It was known that BRP or lysis proteins are responsible for the release of colicins such as A, E1, E2, K, N, U, and Y (Cascales et al, 2007;Singh et al, 2012). Previously, we had reported E. coli 16 isolated from rat fecal matter to possess characteristic such as acid tolerance, antibiotic sensitivity, no pathogenicity and antimicrobial activity against the members of Enterobacteriacae family.…”

Section: Introductionmentioning

confidence: 99%

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In vitro comparism of the extracellular secretion of inulosucrase enzyme in potential probiotic Escherichia coli 16 and BL-21

Kumar¹,

Gopalakrishnan²,

Kumar³

2013

Afr. J. Biotechnol.

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Escherichia coli 16 has potential probiotic properties including antimicrobial activity due to extracellular secretion of colicins E1/1a1b. Inulosucrase (InuJ) enzyme catalyses the polymerization of a fructose moiety of sucrose leading to the formation of fructooligosaccharides. The present investigation compared the activity of InuJ enzymes cloned into pMAL-p2ΔlacI Q a deletion vector and transformed into E. coli 16 and standard strain that is, E. coli BL21. Specific activities of InuJ enzyme were estimated in supernatant, periplasm and lysate. Specific activities of InuJ activity in cell lysate were similar in E. coli 16 and E. coli BL21 without induction of tac promoter with isopropyl thio-β-Dgalactoside (IPTG). InuJ activity is mainly present in the periplasm of E. coli BL21 whereas in E. coli 16, most of the activity is in the supernatant. Superantant of E. coli 16 strain also showed good antibacterial activity due to colicin E1/Ia1b. Colicin E1/1a1b transport system could allow extracellular secretion of InuJ proteins in probiotic E. coli 16.Key words: Colicin, extracellular, E. coli, fructooligosaccharide, inulosucrase, prebiotic, probiotic. INTRODUCTIONPrebiotics are a category of nutraceutical product that has the ability to promote the growth of specific beneficial gut bacteria (Kelly, 2008). In 2007, Roberfroid defined prebiotics as "a selectively fermented ingredient that allows specific changes, both in the composition and/or activity in the gut microflora that confers health benefit". Fructooligosaccharides (FOS) has been used as prebiotic and is considered as a functional food ingredient (Cherbut, 2002;Fanaro et al., 2005;Bouhnik et al., 2006;Roberfroid, 2007;Paineau et al., 2008). FOS is the common name for fructose oligomers that are mainly composed of 1-kestose (GFS2), 2-nystose (GF3) among others in which fructose units are bound at the β-2, 1 position of sucrose through the transfructosylating enzymes such as glucosyltransferases, fructosyltransferases and inulosucrase (Yun et al., 1996). Inulosucrase has been previously shown to be involved in the synthesis of FOS (Van Hijum et al., 2006).Escherichia coli, a Gram negative bacterium is widely used as a host strain for recombinant protein production in industry. Some natural E. coli strains secrete protein extracellulally but their mechanisms of secretion are not clearly understood, nor are they widely exploited for recombinant protein production and metabolic engineering (Ni and Chen, 2009). In some case, recombinant proteins directed to the periplasm were found in the medium but the process is not known (Choi and Lee, 2004;Mergulhao et al., 2005). Sommer et al. (2010) constructed a plasmid which contains bacteriocin release proteins (BRP) that allow secretion of recombinant protein from the periplasm into the culture medium (Sommer et al., 2010). It was known that BRP or lysis proteins are responsible for the release of colicins such as A, E1, E2, K, N, U, and Y (Cascales et al., 2007;Singh et al., 2012). Previously, we had reported E. coli ...

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

In vitro comparism of the extracellular secretion of inulosucrase enzyme in potential probiotic Escherichia coli 16 and BL-21

Kumar¹,

Gopalakrishnan²,

Kumar³

2013

Afr. J. Biotechnol.

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“…Their structure comprises of three distinct domain organizations: (i) a domain involved in recognition of specific receptor R, (ii) a domain involved in translocation T, and (iii) a domain responsible for their toxic activity C. Molecular mass of ribosomal encoded bacteriocins vary from ~25 to 80 kDa and are broadly classified into two groups, group A and B, based on their cross-resistance [ 4 ]. These proteins have received increasing attention due to their potential use as preservatives in the food industry or in the therapeutic applications for clinical usage [ 5 ].…”

Section: Introductionmentioning

confidence: 99%

Expression, Purification, and Functional Characterization of Atypical Xenocin, Its Immunity Protein, and Their Domains from Xenorhabdus nematophila

Rathore

2013

International Journal of Bacteriology

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Xenorhabdus nematophila, a gram-negative bacterium belonging to the family Enterobacteriaceae is a natural symbiont of a soil nematode from the family Steinernematidae. In this study cloning, expression, and purification of broad range iron regulated multidomain bacteriocin called xenocin from X. nematophila (66 kDa, encoded by xcinA gene) and its multidomain immunity protein (42 kDa, encoded by ximB gene) have been done. xcinA-ximB (N′ terminal 270 bp), translocation, and translocation-receptor domain of xcinA, ximB, and its hemolysin domain were cloned, expressed, and purified by single step Ni-NTA chromatography under native conditions. In the functional characterization, neutralization of xcinA toxicity by immunity domain of ximB gene was determined by endogenous assay. Exogenous toxic assays results showed that only the purified recombinant xenocin-immunity domain (10 kDa) protein complex had toxic activity. Atypical cognate immunity protein (42 kDa) of xenocin was fusion of immunity domain (10 kDa) and hemolysin domain (32 kDa). In silico analysis of immunity protein revealed its similarity with hemolysin and purine NTPase like proteins. Hemolytic activity was not observed in immunity protein or in its various domains; however, full-length immunity protein lacking Walker motif showed ATPase activity. Finally, using circular dichroism performed secondary structural analyses of all the recombinant proteins/protein complexes.

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“…Bacteriocins are small and cationic antimicrobial peptides, ribosomally synthesized by lactic acid bacteria (LAB) (Singh, Ghosh, 2012), with antilisterial activity (Papagianni, Sergelidis, 2015) and many industrial applications (Papagianni, 2003). The industrial importance of LAB is further demonstrated by their status generally recognized as safe (GRAS) (Fan, Song, 2013).…”

Section: Introductionmentioning

confidence: 99%

Importance of the agar-media in the evaluation of bacteriocin activity against the same test-microorganisms

Azevedo

Molinari

Oliveira

2018

Braz. J. Pharm. Sci.

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Bacteriocins are peptides produced by various species of bacteria, especially lactic acid bacteria, which exhibit a large spectrum of action against spoilage bacteria and foodborne pathogens. Successful application of techniques for quantitative or qualitative bacteriocin determination relies not only on the sensitivity of the test-microorganisms, but also on the agar-medium employed. Cell free supernatants are routinely used to preliminary screen for antimicrobial activity of bacteria by means of the agar well diffusion method, but the supernatant may also include other molecules (such as medium components and/or intracellular compounds) accidentally released during cell free supernatant preparation, which may interfere with the assay. Reproducibility of bacteriocin activity against the same test-microorganisms is an important factor to be considered. Unfortunately, no specific information about bioassays standardization to determine bacteriocin activity is available in the literature. In this work, growth inhibition by means of the agar well diffusion assays were carried out on different agar-media showing a strong dependence on the agar-medium used, indicating that the inhibitory effects could also depend on the diffusion of exudates that are included in the cell-free supernatant. The results presented in this communication show that selection of the agar-medium is crucial for the bioassay response.

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Ribosomal Encoded Bacteriocins: Their Functional Insight and Applications

Cited by 9 publications

References 67 publications

In vitro comparism of the extracellular secretion of inulosucrase enzyme in potential probiotic Escherichia coli 16 and BL-21

In vitro comparism of the extracellular secretion of inulosucrase enzyme in potential probiotic Escherichia coli 16 and BL-21

Expression, Purification, and Functional Characterization of Atypical Xenocin, Its Immunity Protein, and Their Domains from Xenorhabdus nematophila

Importance of the agar-media in the evaluation of bacteriocin activity against the same test-microorganisms

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