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The article presents a study which analyses the presence of cyclic di-GMP (c-di-GMP) in Mycobacterium smegmatis, and its physiological role in the long-term survival of the organism. It notes that c-di-GMP plays an important role in biofilm formation and adaptation in several bacterial species which enable such organisms survive in changing environments. With bioinformatics analysis, it was found out that Mycobacterium smegmatis has a bifunctional single protein with GGDEF and EAL domains, having both the diguanylate cyclase (DGC) and phosphodiesterase (PDE)-A activities. It also found out that the identified bifunctional protein did not affect growth and biofilm formation of the mycobacterium, however, long-term survival under conditions of nutritional starvation was affected.

The article discusses the study which examines the role and function of an RNA polymerase interacting protein called MsRbpA which is derived from Mycobacterium smegmatis in phenotypic tolerance to rifampicin. It notes that rifampicin is leading the standard chemotherapeutic for active tuberculosis which inhibit the transcription activity of prokaryotic RNA polymerase. It implies that M. smegmatis interacts with RNA polymerase and increases the refampicin tolerance levels.

Examines the synthesis of polar glycopeptidolipid in glucose-limited culture of Mycobacterium smegmatis. Analysis of hyperglycosylated species; Emphasis on the starvation physiology of Mycobacteria to provide insights on the long-term persistence of bacilli; Mechanism on the environmental regulation of cell wall biosynthesis.

The article studies the effects of the deletion of the rpoZ gene, encoding the ω subunit of RNA polymerase by researchers from Bangalore, India. The researchers elucidates that the mutant mycobacterium has pleiotropic phenotypes including reduced sliding motility and defective biofilm formation.

The presence of a polar species of glycopeptidolipid (GPL) in carbon-starved Mycobacterium smegmatis has been reported previously. In this study, the complete structure of this GPL is established with the help of MALDI-TOF (matrix assisted laser desorption/ionization time of flight) and ESI (electrospray ionization) -MS, 13C-SEFT (spin echo Fourier transform) -NMR spectroscopy, and HPLC analysis. In the molecule, two units of a 3,4-di-O-methyl derivative of rhamnose are attached to L-alaninol via a 1↵2 linkage. Various methyl derivatives of rhamnose and 6-deoxytalose were synthesized as standards to establish this structure. The accumulation of this polar GPL in M. smegmatis is sigB dependent, as a SigB-overproducing strain of M. smegmatis shows the presence of this spot in the exponential phase, and a sigB-knockout strain of M. smegmatis does not show the presence of any polar GPLs. [ABSTRACT FROM AUTHOR]