scholarly journals Glycopeptidolipid Acetylation Affects Sliding Motility and Biofilm Formation in Mycobacterium smegmatis

2001 ◽  
Vol 183 (19) ◽  
pp. 5718-5724 ◽  
Author(s):  
Judith Recht ◽  
Roberto Kolter
Keyword(s):  
Polyvinyl Chloride ◽  
Mycobacterium Smegmatis ◽  
Biofilm Formation ◽  
Physical Characterization ◽  
Colony Morphology ◽  
Partial Inhibition ◽  
Transposon Insertion ◽  
Biosynthesis Gene ◽  
Sliding Motility

ABSTRACT The absence of glycopeptidolipids (GPLs) abolishes the ability of mycobacteria both to slide over the surface of motility plates and to form biofilms on polyvinyl chloride. In a screen for biofilm-defective mutants of Mycobacterium smegmatis mc2155, a new mutant was obtained that resulted in partial inhibition of both processes and also showed an intermediate rough colony morphology. Themariner transposon insertion mapped to a GPL biosynthesis gene (atf1) which encodes a putative acetyltranferase involved in the transfer of acetyl groups to the glycopeptide core. Physical characterization of the GPLs from the atf1 mutant demonstrated that they were not acetylated.

scholarly journals Roles of Lsr2 in Colony Morphology and Biofilm Formation of Mycobacterium smegmatis

2006 ◽  
Vol 188 (2) ◽  
pp. 633-641 ◽  
Author(s):  
Jeffrey M. Chen ◽  
Greg J. German ◽  
David C. Alexander ◽  
Huiping Ren ◽  
Tracy Tan ◽  
...  
Keyword(s):  
Cell Wall ◽  
Mycobacterium Smegmatis ◽  
Biofilm Formation ◽  
Mycolic Acid ◽  
Colony Morphology ◽  
Insertion Mutant ◽  
Transposon Insertion ◽  
Layer Chromatography ◽  
Wall Components

ABSTRACT The lipid-rich cell wall is a defining feature of Mycobacterium species. Individual cell wall components affect diverse mycobacterial phenotypes including colony morphology, biofilm formation, antibiotic resistance, and virulence. In this study, we describe a transposon insertion mutant of Mycobacterium smegmatis mc2155 that exhibits altered colony morphology and defects in biofilm formation. The mutation was localized to the lsr2 gene. First identified as an immunodominant T-cell antigen of Mycobacterium leprae, lsr2 orthologs have been identified in all sequenced mycobacterial genomes, and homologs are found in many actinomycetes. Although its precise function remains unknown, localization experiments indicate that Lsr2 is a cytosolic protein, and cross-linking experiments demonstrate that it exists as a dimer. Characterization of cell wall lipid components reveals that the M. smegmatis lsr2 mutant lacks two previously unidentified apolar lipids. Characterization by mass spectrometry and thin-layer chromatography indicate that these two apolar lipids are novel mycolate-containing compounds, called mycolyl-diacylglycerols (MDAGs), in which a mycolic acid (α- or α′-mycolate) molecule is esterified to a glycerol. Upon complementation with an intact lsr2 gene, the mutant reverts to the parental phenotypes and MDAG production is restored. This study demonstrates that due to its impact on the biosynthesis of the hydrophobic MDAGs, Lsr2 plays an important role in the colony morphology and biofilm formation of M. smegmatis.

scholarly journals Deletion of the rpoZ gene, encoding the ω subunit of RNA polymerase, results in pleiotropic surface-related phenotypes in Mycobacterium smegmatis

Microbiology ◽  
2006 ◽  
Vol 152 (6) ◽  
pp. 1741-1750 ◽  
Author(s):  
Renjith Mathew ◽  
Raju Mukherjee ◽  
Radhakrishnan Balachandar ◽  
Dipankar Chatterji
Keyword(s):  
Rna Polymerase ◽  
Mycobacterium Smegmatis ◽  
Biofilm Formation ◽  
Physiological Role ◽  
Wild Type ◽  
Gene Encoding ◽  
Biofilm Growth ◽  
Mutant Bacterium ◽  
Sliding Motility

The ω subunit, the smallest subunit of bacterial RNA polymerase, is known to be involved in maintaining the conformation of the β′ subunit and aiding its recruitment to the rest of the core enzyme assembly in Escherichia coli. It has recently been shown in Mycobacterium smegmatis, by creating a deletion mutation of the rpoZ gene encoding ω, that the physiological role of the ω subunit also includes providing physical protection to β′. Interestingly, the mutant had altered colony morphology. This paper demonstrates that the mutant mycobacterium has pleiotropic phenotypes including reduced sliding motility and defective biofilm formation. Analysis of the spatial arrangement of biofilms by electron microscopy suggests that the altered phenotype of the mutant arises from a deficiency in generation of extracellular matrix. Complementation of the mutant strain with a copy of the wild-type rpoZ gene integrated in the bacterial chromosome restored both sliding motility and biofilm formation to the wild-type state, unequivocally proving the role of ω in the characteristics observed for the mutant bacterium. Analysis of the cell wall composition demonstrated that the mutant bacterium had an identical glycopeptidolipid profile to the wild-type, but failed to synthesize the short-chain mycolic acids characteristic of biofilm growth in M. smegmatis.

scholarly journals A universal stress protein in Mycobacterium smegmatis sequesters the cAMP-regulated lysine acyltransferase and is essential for biofilm formation

2019 ◽  
Vol 295 (6) ◽  
pp. 1500-1516 ◽  
Author(s):  
Sintu Samanta ◽  
Priyanka Biswas ◽  
Arka Banerjee ◽  
Avipsa Bose ◽  
Nida Siddiqui ◽  
...  
Keyword(s):  
Stress Responses ◽  
Mycobacterium Smegmatis ◽  
Biofilm Formation ◽  
Stress Proteins ◽  
Response Regulator ◽  
Stress Protein ◽  
Colony Morphology ◽  
Regulator Gene ◽  
Its Gene

Universal stress proteins (USPs) are present in many bacteria, and their expression is enhanced under various environmental stresses. We have previously identified a USP in Mycobacterium smegmatis that is a product of the msmeg_4207 gene and is a substrate for a cAMP-regulated protein lysine acyltransferase (KATms; MSMEG_5458). Here, we explored the role of this USP (USP4207) in M. smegmatis and found that its gene is present in an operon that also contains genes predicted to encode a putative tripartite tricarboxylate transporter (TTT). Transcription of the TTT-usp4207 operon was induced in the presence of citrate and tartrate, perhaps by the activity of a divergent histidine kinase-response regulator gene pair. A usp4207-deleted strain had rough colony morphology and reduced biofilm formation compared with the WT strain; however, both normal colony morphology and biofilm formation were restored in a Δusp4207Δkatms strain. We identified several proteins whose acetylation was lost in the Δkatms strain, and whose transcript levels increased in M. smegmatis biofilms along with that of USP4207, suggesting that USP4207 insulates KATms from its other substrates in the cell. We propose that USP4207 sequesters KATms from diverse substrates whose activities are down-regulated by acylation but are required for biofilm formation, thus providing a defined role for this USP in mycobacterial physiology and stress responses.

scholarly journals The aceE involves in mycolic acid synthesis and biofilm formation in Mycobacterium smegmatis

2020 ◽  
Author(s):  
Suting Chen ◽  
Tianlu Teng ◽  
Shuan Wen ◽  
Tingting Zhang ◽  
Hairong Huang
Keyword(s):  
Cell Wall ◽  
Mycobacterium Smegmatis ◽  
Biofilm Formation ◽  
Morphological Changes ◽  
Acid Synthesis ◽  
Mycolic Acid ◽  
Colony Morphology ◽  
Wall Structure ◽  
Wild Type

Abstract Background: The integrity of cell wall structure is highly significant for the in vivo survival of mycobacteria. We hypothesized that changes in morphology may indicate changes in cell wall metabolism and identified an aceE gene mutant ( aceE -mut) which presented a deficient colony morphology on 7H10 agar by screening transposon mutagenesis in Mycolicibacterium smegmatis , basonym Mycobacterium smegmatis ( M. smegmatis ). This study aimed to identify the functional role of aceE gene in cell wall biosynthesis in M. smegmatis. Results: We observed that the colony morphology of aceE -mut was quite different, smaller and smoother on the solid culture medium than the wild-type (WT) strain during the transposon library screening of M. smegmatis . Notably, in contrast with the WT, which aggregates and forms biofilm, the aceE -mut lost its ability of growing aggregately and biofilm formation, which are two very important features of mycobacteria. The morphological changes in the aceE -mut strain were further confirmed by electron microscopy which indicated smoother and thinner cell envelope images in contrast with the rough morphology of WT strains. Additionally, the aceE -mut was more fragile to acidic stress and exhibited a pronounced defects in entering the macrophages as compared to the WT. The analysis of mycolic acid (MA) using LC-MS indicated deficiency of alpha-MA and epoxy-MA in aceE -mut strain whereas complementation of the aceE -mut with a wild-type aceE gene restored the composition of MA. Conclusions: Over all, this study indicates that aceE gene plays a significant role in the mycolic acid synthesis and affects the colony morphology, biofilm formation of M. smegmatis and bacteria invasion of macrophage.

scholarly journals Isolation and Characterization of Rugose Form of Vibrio cholerae O139 Strain MO10

1999 ◽  
Vol 67 (2) ◽  
pp. 958-963 ◽  
Author(s):  
Yoshimitsu Mizunoe ◽  
Sun Nyunt Wai ◽  
Akemi Takade ◽  
Shin-Ichi Yoshida
Keyword(s):  
Cell Surface ◽  
Vibrio Cholerae ◽  
Microscopic Examination ◽  
Biofilm Formation ◽  
Nutrient Starvation ◽  
Colony Morphology ◽  
Isolation And Characterization ◽  
Slime Layer ◽  
Vibrio Cholerae O139

ABSTRACT An extracellular exopolysaccharide (slime) is produced byVibrio cholerae O139 MO10 in response to nutrient starvation. The presence of this slime layer on the cell surface and its subsequent release have been shown to be associated with biofilm formation and the change from a normal smooth colony morphology to a rugose one. An immunoelectron microscopic examination demonstrated that there is an epitope common to the exopolysaccharide antigen of V. cholerae O1 and that of O139 MO10.

scholarly journals Identification and Characterization of a Major Zn(II) Resistance Determinant of Mycobacterium smegmatis

2006 ◽  
Vol 188 (19) ◽  
pp. 7026-7032 ◽  
Author(s):  
Amit Grover ◽  
Rakesh Sharma
Keyword(s):  
Mycobacterium Smegmatis ◽  
In Silico Analysis ◽  
Zinc Ion ◽  
Cation Diffusion ◽  
Cation Diffusion Facilitator ◽  
Transposon Insertion ◽  
Gene Coding ◽  
Family Protein ◽  
Opportunistic Pathogenic

ABSTRACT A zinc ion-sensitive mutant of Mycobacterium smegmatis was isolated. The transposon insertion was located in zitA (MSMEG0750), a gene coding for a cation diffusion facilitator family protein. Zinc ions specifically induced expression of zitA. In silico analysis revealed that environmental and opportunistic pathogenic species contain higher numbers of cation diffusion facilitator genes than do obligate pathogens.

scholarly journals Genetic Analysis of Sliding Motility inMycobacterium smegmatis

2000 ◽  
Vol 182 (15) ◽  
pp. 4348-4351 ◽  
Author(s):  
Judith Recht ◽  
Asunción Martínez ◽  
Sandra Torello ◽  
Roberto Kolter
Keyword(s):  
Genetic Analysis ◽  
Membrane Transport ◽  
Polyvinyl Chloride ◽  
Mycobacterium Smegmatis ◽  
Transport Protein ◽  
Membrane Transport Protein ◽  
Transposon Insertions ◽  
Sliding Motility

ABSTRACT A screen for nonsliding mutants of Mycobacterium smegmatis yielded 20 mutants with transposon insertions in themps gene, which is involved in glycopeptidolipid biosynthesis. One mutant had an insertion in a gene predicted to encode a membrane transport protein. All mutants lacked glycopeptidolipids and were unable to form biofilms on polyvinyl chloride.

scholarly journals The aceE involves in mycolic acid synthesis and biofilm formation in Mycobacterium smegmatis

2020 ◽  
Author(s):  
Suting Chen ◽  
Tianlu Teng ◽  
Shuan Wen ◽  
Tingting Zhang ◽  
Hairong Huang
Keyword(s):  
Cell Wall ◽  
Mycobacterium Smegmatis ◽  
Biofilm Formation ◽  
Morphological Changes ◽  
Acid Synthesis ◽  
Mycolic Acid ◽  
Colony Morphology ◽  
Wall Structure ◽  
Wild Type

Abstract Background: The integrity of cell wall structure is highly significant for the in vivo survival of mycobacteria. We hypothesized that changes in morphology may indicate changes in cell wall metabolism and identified an aceE gene mutant (aceE-mut) which presented a deficient colony morphology on 7H10 agar by screening transposon mutagenesis in Mycolicibacterium smegmatis, basonym Mycobacterium smegmatis (M. smegmatis). This study aimed to identify the functional role of aceE gene in cell wall biosynthesis in M. smegmatis.Results: We observed that the colony morphology of aceE-mut was quite different, smaller and smoother on the solid culture medium than the wild-type (WT) strain during the transposon library screening of M. smegmatis. Notably, in contrast with the WT, which aggregates and forms biofilm, the aceE-mut lost its ability of growing aggregately and biofilm formation, which are two very important features of mycobacteria. The morphological changes in the aceE-mut strain were further confirmed by electron microscopy which indicated smoother and thinner cell envelope images in contrast with the rough morphology of WT strains. Additionally, the aceE-mut was more fragile to acidic stress and exhibited a pronounced defects in entering the macrophages as compared to the WT. The analysis of mycolic acid (MA) using LC-MS indicated deficiency of alpha-MA and epoxy-MA in aceE-mut strain whereas complementation of the aceE-mut with a wild-type aceE gene restored the composition of MA. Conclusions: Over all, this study indicates that aceE gene plays a significant role in the mycolic acid synthesis and affects the colony morphology, biofilm formation of M. smegmatis and bacteria invasion of macrophage.

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