Perceived Cost of Auxotrophic Amino Acids in Two Bacterial Species

2009 ◽  
Author(s):  
Esley M. Heizer ◽  
Douglas W. Raiford ◽  
Michael L. Raymer ◽  
Dan E. Krane
Keyword(s):  
Amino Acids ◽  
Bacterial Species

Analysis of type IV pilus and its associated motility in Myxococcus xanthus using an antibody reactive with native pilin and pili

Microbiology ◽  
2005 ◽  
Vol 151 (2) ◽  
pp. 353-360 ◽  
Author(s):  
Yinuo Li ◽  
Renate Lux ◽  
Andrew E. Pelling ◽  
James K. Gimzewski ◽  
Wenyuan Shi
Keyword(s):  
Amino Acids ◽  
Current Model ◽  
Bacterial Species ◽  
Myxococcus Xanthus ◽  
Type Iv Pili ◽  
Gliding Motility ◽  
Soluble Form ◽  
Truncated Form ◽  
Type Iv ◽  
Oligomerization Domain

Myxococcus xanthus possesses a social gliding motility that requires type IV pili (TFP). According to the current model, M. xanthus pili attach to an external substrate and retract, pulling the cell body forward along their long axis. By analogy with the situation in other bacteria employing TFP-dependent motility, M. xanthus pili have been assumed to be composed of pilin (PilA) subunits, but this has not previously been confirmed. The first 28 amino acids of the M. xanthus PilA protein share extensive homology with the N-terminal oligomerization domain of pilins in other bacterial species. To facilitate purification, the authors engineered a truncated form of M. xanthus PilA lacking the first 28 amino acids and purified this protein in soluble form. Polyclonal antibody generated against this protein was reactive with native pilin and pili. Using this antibody, it was confirmed that TFP of M. xanthus are indeed composed of PilA, and that TFP are located unipolarly and required for social gliding motility via retraction. Using tethering as well as motility assays, details of pili function in M. xanthus social motility were further examined.

scholarly journals A new method for the extraction and purification of K99 pili from enterotoxigenic Escherichia coli and their characterization

1982 ◽  
Vol 201 (3) ◽  
pp. 505-513 ◽  
Author(s):  
K Altmann ◽  
N A Pyliotis ◽  
T K S Mukkur
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Amino Acid ◽  
Average Length ◽  
Bacterial Species ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Enterotoxigenic Escherichia Coli ◽  
Total Amino Acid ◽  
Apparent Homogeneity

It was found that K99 pili from enterotoxigenic Escherichia coli (of bovine origin) could be extracted by treatment with 3M-KSCN solution. The K99 pili were purified by preparative isoelectric focusing to apparent homogeneity as judged by the presence of a single band on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis; the molecular weight of this component was calculated to be 12 600 +/- 300. This indicated that the K99 pili were composed of a single subunit. On analytical ultracentrifugation, a single boundary with an s20,w of 12.2 S at a concentration of 0.42 mg/ml was observed. The average length of purified pili at zero concentration was approx. 160 nm and the diameter was 7.4 +/- 0.6 nm. Amino acid analysis of the purified K99 pili revealed that sulphur-containing amino acids, cysteine and methionine, were absent. Aromatic amino acids, phenylalanine and tyrosine, previously reported to be absent [Isaacson (1977) Infect. Immun. 15. 272-279], constituted 7.14% of the total amino acid residues present. On immunoelectrophoresis, purified K99 pili migrated towards the cathode and caused mannose-resistant haemagglutination of horse, but not of sheep or guinea-pig, red blood cells. Pili from enterotoxigenic E. coli of porcine and human origin and from another bacterial species, namely Fusiformis nodosus, could also be extracted by the treatment of respective micro-organisms with 3 M-KSCN.

scholarly journals Structure and function of the bacterial and fungal gut flora of Neotropical butterflies

2017 ◽  
Author(s):  
Alison Ravenscraft ◽  
Michelle Berry ◽  
Tobin Hammer ◽  
Kabir Peay ◽  
Carol Boggs
Keyword(s):  
Amino Acids ◽  
Microbial Communities ◽  
Bacterial Species ◽  
Microbial Community Composition ◽  
Structure And Function ◽  
Feeding Guilds ◽  
Gut Flora ◽  
Microbial Composition ◽  
Host Diet ◽  
And Function

AbstractThe relationship between animals and their gut flora is simultaneously one of the most common and most complex symbioses on Earth. Despite its ubiquity, our understanding of this invisible but often critical relationship is still in its infancy. We employed adult Neotropical butterflies as a study system to ask three questions: First, how does gut microbial community composition vary across host individuals, species and dietary guilds? Second, how do gut flora compare to food microbial communities? Finally, are gut flora functionally adapted to the chemical makeup of host foods? To answer these questions we captured nearly 300 Costa Rican butterflies representing over 50 species, six families and two feeding guilds: frugivores and nectivores. We characterized the bacteria and fungi in guts, wild fruits and wild nectars via amplicon sequencing and assessed the catabolic abilities of the gut flora via culture-based assays.Gut communities were distinct from food communities, suggesting that the gut environment acts as a strong filter on potential colonists. Nevertheless, gut flora varied widely among individuals and species. On average, a pair of butterflies shared 21% of their bacterial species and 6% of their fungi. Host species explained 25-30% of total variation in microbial communities while host diet explained 4%. However, diet was still relevant at the individual microbe level—half of the most abundant microbial species differed in abundance between frugivores and nectivores. Diet was also related to the functional profile of gut flora: compared to frugivores, nectivores’ gut flora exhibited increased catabolism of sugars and sugar alcohols and decreased catabolism of amino acids, carboxylic acids and dicarboxylic acids. Since fermented juice contains more amino acids and less sugar than nectar, it appears that host diet filters the gut flora by favoring microbes that digest compounds abundant in foods.By quantifying the degree to which gut communities vary among host individuals, species and dietary guilds and evaluating how gut microbial composition and catabolic potential are related to host diet, this study deepens our understanding of the structure and function of one of the most complex and ubiquitous symbioses in the animal kingdom.

scholarly journals Feeding a Low-protein Maternal Diet Affects Qinghai Bamei Piglet Jejunal Microbiome-metabolome Response

2021 ◽  
Author(s):  
Jipeng Jin ◽  
Liping Zhang ◽  
Qian Chen ◽  
Cunming Ma ◽  
Jianlei Jia ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Bacterial Species ◽  
Relative Weight ◽  
Integrated Approach ◽  
Intestinal Microbiome ◽  
Rrna Gene ◽  
Metabolic Profiles ◽  
Microbial Composition ◽  
Suckling Piglets

Abstract This experiment investigated the impacts of feeding a maternal low-CP concentration diet having iso-essential amino acids on new born suckling piglets intestinal microbial composition and metabolic profiles. The Bamei swine breed was selected due to high meat quality and flavor, but demonstrates slower growth rates which may be related to jejunal nutrient supply. Forty randomly selected purebred Bamei sows were divided into two groups and fed a low dietary CP (12%, LP) or a normal CP (14%, CON) diet, respectively, but formulated to contain similar (iso-) essential amino acid concentrations per current recommendations. At 21 days, 12 piglets were randomly selected from each treatment and euthanized with jejunum content samples collected. The 16S rRNA gene sequencing and mass spectrometry-based metabolomics profiling were combined as an integrated approach for evaluating the functional impact of maternal CP concentrations on piglet intestinal microbiome. Even though piglets demonstrated similar 0 to 21 d ADG among treatments, the jejunum relative weight, villus width, crypt depth and muscular thickness were increased (P < 0.05), while villus height, and villus height:crypt depth were reduced (P < 0.05) for the material LP compared to the maternal fed CON diet. Maternal CP concentrations can modify the intestinal microbial composition of Bamei suckling piglets. The relative abundances of the bacterial species Escherichia-Shigella, Actinobacillus, Clostridium_sensu_stricto_1, Veillonella, and Turicibacter were increased (P < 0.05) in the maternal LP fed diet compared with the maternal fed CON diet. Jejunal digesta metabolomics analysis indicated that several amino acids were metabolized (i.e. cys, met, tyr phe and trp), biosynthesized (arg phe, tyr, and trp), or degraded (lys) were enriched (P < 0.05) for the maternal fed LP compared with the maternal fed CON. Correlation analysis demonstrated that certain intestinal bacterial genera were highly related to the histomorphology and altered intestinal microbiota metabolites. In conclusion, maternal dietary CP concentrations in excess of protein and amino acid requirements not only altered suckling Bamei piglets histomorphology, microbial composition and function, but also modulated jejunum microbial metabolic profiles, which aids in understanding the beneficial effects when feeding a maternal LP diet on piglet intestinal health.

scholarly journals Shewanella putrefaciens mtrB Encodes an Outer Membrane Protein Required for Fe(III) and Mn(IV) Reduction

1998 ◽  
Vol 180 (23) ◽  
pp. 6292-6297 ◽  
Author(s):  
Alexander S. Beliaev ◽  
Daad A. Saffarini
Keyword(s):  
Amino Acids ◽  
Outer Membrane ◽  
Molecular Mechanisms ◽  
Signal Sequence ◽  
Bacterial Species ◽  
Shewanella Putrefaciens ◽  
Electron Acceptors ◽  
Nitrite Reduction ◽  
Metal Reduction ◽  
Wild Type

ABSTRACT Iron and manganese oxides or oxyhydroxides are abundant transition metals, and in aquatic environments they serve as terminal electron acceptors for a large number of bacterial species. The molecular mechanisms of anaerobic metal reduction, however, are not understood.Shewanella putrefaciens is a facultative anaerobe that uses Fe(III) and Mn(IV) as terminal electron acceptors during anaerobic respiration. Transposon mutagenesis was used to generate mutants of S. putrefaciens, and one such mutant, SR-21, was analyzed in detail. Growth and enzyme assays indicated that the mutation in SR-21 resulted in loss of Fe(III) and Mn(IV) reduction but did not affect its ability to reduce other electron acceptors used by the wild type. This deficiency was due to Tn5inactivation of an open reading frame (ORF) designated mtrB. mtrB encodes a protein of 679 amino acids and contains a signal sequence characteristic of secreted proteins. Analysis of membrane fractions of the mutant, SR-21, and wild-type cells indicated that MtrB is located on the outer membrane of S. putrefaciens. A 5.2-kb DNA fragment that contains mtrB was isolated and completely sequenced. A second ORF, designated mtrA, was found directly upstream of mtrB. The two ORFs appear to be arranged in an operon. mtrA encodes a putative 10-hemec-type cytochrome of 333 amino acids. The N-terminal sequence of MtrA contains a potential signal sequence for secretion across the cell membrane. The amino acid sequence of MtrA exhibited 34% identity to NrfB from Escherichia coli, which is involved in formate-dependent nitrite reduction. To our knowledge, this is the first report of genes encoding proteins involved in metal reduction.

scholarly journals THE CULTIVATION OF THE LEPROSY BACILLUS FROM THE HUMAN TISSUES WITH SPECIAL REFERENCE TO THE AMINO-ACIDS AS CULTURE MEDIA

1911 ◽  
Vol 13 (3) ◽  
pp. 365-373 ◽  
Author(s):  
Charles W. Duval
Keyword(s):  
Amino Acids ◽  
Special Reference ◽  
Culture Medium ◽  
Culture Media ◽  
Bacterial Species ◽  
The Body ◽  
The Other ◽  
Tryptic Digestion ◽  
Initial Growth ◽  
Human Tissues

In the cultivation of Bacillus lepræ the initial multiplication outside the body cannot be obtained unless amino-acids are present in the medium. The amino-acids are believed to be essential nutritives for the initial growth of the organisms. It has been demonstrated that the primary growth of the leprosy bacilli occurs only in the presence of the products of tryptic digestion. Hence, putrefactive and other bacteria which are capable of splitting nucleo-proteids into their end acid products are, in consequence, of value in the isolation and cultivation of the leprosy bacilli. Amebæ are not necessary for securing the primary multiplication of the leprosy bacilli upon artificial media and are detrimental since they feed with avidity upon the bacilli themselves. Two methods may be employed for recovering in culture Bacillus lepræ from the tissues. In one (the direct), tryptophane or a mixture of albumen and trypsin are employed with a culture medium; in the other (indirect), bacterial species capable of digesting the albumen constituent of the culture medium are introduced into the medium. In both, the end result is identical, since they both provide for the presence of the amino-acids in the medium, without which the primary multiplication of the leprosy bacilli cannot be secured.

scholarly journals Molecular characterization of the TonB2 protein from the fish pathogen Vibrio anguillarum

2009 ◽  
Vol 418 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Claudia S. López ◽  
R. Sean Peacock ◽  
Jorge H. Crosa ◽  
Hans J. Vogel
Keyword(s):  
Amino Acids ◽  
Solution Structure ◽  
Bacterial Species ◽  
Vibrio Anguillarum ◽  
Fish Pathogen ◽  
E Coli ◽  
Terminal Domain ◽  
C Terminus

In the fish pathogen Vibrio anguillarum the TonB2 protein is essential for the uptake of the indigenous siderophore anguibactin. Here we describe deletion mutants and alanine replacements affecting the final six amino acids of TonB2. Deletions of more than two amino acids of the TonB2 C-terminus abolished ferric-anguibactin transport, whereas replacement of the last three residues resulted in a protein with wild-type transport properties. We have solved the high-resolution solution structure of the TonB2 C-terminal domain by NMR spectroscopy. The core of this domain (residues 121–206) has an αββαβ structure, whereas residues 76–120 are flexible and extended. This overall folding topology is similar to the Escherichia coli TonB C-terminal domain, albeit with two differences: the β4 strand found at the C-terminus of TonB is absent in TonB2, and loop 3 is extended by 9 Å (0.9 nm) in TonB2. By examining several mutants, we determined that a complete loop 3 is not essential for TonB2 activity. Our results indicate that the β4 strand of E. coli TonB is not required for activity of the TonB system across Gram-negative bacterial species. We have also determined, through NMR chemical-shift-perturbation experiments, that the E. coli TonB binds in vitro to the TonB box from the TonB2-dependent outer membrane transporter FatA; moreover, it can substitute in vivo for TonB2 during ferric-anguibactin transport in V. anguillarum. Unexpectedly, TonB2 did not bind in vitro to the FatA TonB-box region, suggesting that additional factors may be required to promote this interaction. Overall our results indicate that TonB2 is a representative of a different class of TonB proteins.

scholarly journals Full color palette of fluorescentd-amino acids for in situ labeling of bacterial cell walls

2017 ◽  
Vol 8 (9) ◽  
pp. 6313-6321 ◽  
Author(s):  
Yen-Pang Hsu ◽  
Jonathan Rittichier ◽  
Erkin Kuru ◽  
Jacob Yablonowski ◽  
Erick Pasciak ◽  
...  
Keyword(s):  
Amino Acids ◽  
Bacterial Cell ◽  
Cell Walls ◽  
Bacterial Species ◽  
Color Palette ◽  
Full Color ◽  
Bacterial Cell Walls

Fluorescentd-amino acids (FDAAs) enable efficientin situlabeling of peptidoglycan in diverse bacterial species.

scholarly journals Antibacterial Activity of Copper and Cobalt Amino Acids Complexes

2011 ◽  
Vol 39 (2) ◽  
pp. 124 ◽  
Author(s):  
ANDREEA STĂNILĂ ◽  
Cornelia BRAICU ◽  
Sorin STĂNILĂ ◽  
Raluca M. POP
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Antibacterial Activity ◽  
Bacillus Cereus ◽  
Copper Complexes ◽  
Micrococcus Luteus ◽  
Bacterial Species ◽  
Free Ligand ◽  
Antibacterial Properties ◽  
Moderate Activity

The antibacterial properties of differently copper and cobalt amino acids complexes on agar plates was investigated in the present study. The antibacterial activity of amino acid complexes was evaluated against on three bacteria strains (Escherichia coli, Bacillus cereus, Micrococcus luteus). Generally, the amino acids complexes were mainly active against gram-positive organisms, species like Micrococcus luteus being the most susceptible strain tested. It was registered a moderate antibacterial activity against Bacillus cereus. The microorganisms Escherichia coli, which are already known to be multi-resistant to drugs, were also resistant to the amino acids complexes but also to the free salts tested. Escherichia coli were susceptible only to the CoCl2 and copper complex with phenylalanine. The complexes with leucine and histidine seem to be more active than the parent free ligand against one or more bacterial species. Moderate activity was registered in the case of complexes with methionine and phenylalanine. From the complexes tested less efficient antibacterial activity was noted in the case of complexes with lysine and valine. These results show that cobalt and copper complexes have an antibacterial activity and suggest their potential application as antibacterial agents.

Meat Spoilage and Evaluation of the Potential Storage Life of Fresh Meat

1983 ◽  
Vol 46 (5) ◽  
pp. 444-452 ◽  
Author(s):  
C.O. GILL
Keyword(s):  
Amino Acids ◽  
Meat Quality ◽  
Bacterial Species ◽  
Storage Conditions ◽  
Anaerobic Growth ◽  
Meat Composition ◽  
Meat Spoilage ◽  
Rapid Tests ◽  
Spoilage Microflora ◽  
And Storage

Microbiological processes by which meat develops qualities unacceptable to consumers vary with the composition of the meat and spoilage microflora. Composition of the spoilage microflora is affected by meat composition and storage conditions. Aerobic spoilage microfloras are usually dominated by pseudomonads. With this type of microflora, spoilage occurs when glucose in meat is no longer sufficient for the requirements of the spoilage microflora and the bacteria start to degrade amino acids. When meat is deficient in glucose, spoilage becomes evident while bacterial numbers are relatively small. Anaerobic microfloras are usually dominated by lactobacilli which produce spoilage by the slow accumulation of volatile organic acids. Meat of high utimate pH packaged anaerobically spoils rapidly because the high pH allows anaerobic growth of bacterial species of higher spoilage potential than the lactobacilli. Before overt spoilage develops, the spoilage status of meat can be accurately assessed from the bacterial numbers on meat only when there is assumption or knowledge of meat composition, storage conditions and the types of bacteria present. Methods for estimating spoilage which depend upon detection of products of amino acid degradation have little predictive value as such products will only be present after attack on amino acids has commenced and are irrelevant to spoilage under anaerobic conditions. Estimation of the concentrations of other spoilage products may be the only method applicable to assessment of incipient spoilage of meat stored anaerobically. It is, therefore, unlikely that any single test can give unequivocal information on meat quality under all circumstances, but rapid tests for meat quality could be of value for specific commercial purposes. provided such tests are appropriate to the circumstances and the inherent limitations of any test are recognized.

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