Bacillus subtilis polymers

More recently, the chemo-enzymatic synthesis of inulin-containing hydrogels was reported [54]. The key point was the solubility of inulin [a mixture of oligomers and polymers containing 2-60 (or more) 5-2,1 linked D-fructose molecules having a glucose unit as the initial residue] in dimethylformamide (DMF), a fact that allowed its esterification by action of a protease from Bacillus subtilis. 

All of the ribitol teichoic acids so far examined are composed of chains of ribitol residues joined through phosphodiester groups at C-l and C-5. Each chain is terminated by a phosphomonoester residue, and the ribitol residues bear glycosyl and D-alanine ester substituents. Detailed structures have been proposed for the polymers from Bacillus aubtilis and Lactobacillus arabinosus, and from two strains of Staphylococcus aureus. The structure of the teichoic acid from Bacillus subtilis was the first to be established in detail the other polymers differ mainly in the nature of the glycosyl substituents. 

Levansucrase is a transfructosylase which converts sucrose to levan , a largely p(2 6)-linked fructofuranose polymer, and has been investigated because of its synthesis by oral bacteria. The levans and dextrans produced from dietary sucrose are sparingly water soluble and contribute to the build-up of dental plaque on the teeth. The enzyme from Bacillus subtilis was shown to have ping-pong kinetics,and the intermediacy of a covalent, fructosylated... 

DeAngelis 50) transferred the glycosaminoglycan (GAG) synthase genes into Bacillus subtilis to produce GAG polymers. Well-defined GAG oligosaccharides were also produced using engineered variants of these enzymes. 

Widner, W. Behr, R. Sloma, A. DeAngelis, P. L. Weigel, P. Guillaumie, F. Brown, S. Hyaluronic acid production by recombinant Bacillus subtilis strains ACS Polymer Preprints, 2006, 47(2), 213. 

Polymers of ribitol phosphate Lactobacillus arabinosus (I), Bacillus subtilis and Staphylococcus aureus NA [91]... 

Peptidoglycan-polysaccharide (PG-PS) fragments are isolated from S. pyogenes [34] to study the reactivation of induced inflammation. Peptidoglycan polymers [35] are isolated from bacterial cell walls. The peptidoglycan and related polymers are obtained from penicillin treated Bacillus subtilis [36], Streptococcus pyogenes, Staphylcoccus epidermis, Nocardia corynebacteriodes and Streptomyces... 

To measure the antibacterial activities of amphiphilic cationic polynorbornene derivatives, they developed a slightly different method based on optical density (OD). In this method, bacteria were grown in suspensions (Escherichia coli D31 and Bacillus subtilis ATCC 8037 ) of Miieller-Hinton broth (MHB) overnight at 37 °C, diluted with fresh MHB to an OD of 0.1 at 600 nm and further diluted by a factor of 10. This suspension was mixed with different concentrations of freshly prepared polymer solutions in rm-buffered saline (pH 6.5-7.0), by serial dilution in a 96-well plate, and incubated for 6 h at 37 °C. The OD 600 nm was measured for bacteria suspensions that were incubated in the presence of a polymer solution or fm-buffered saline only. After 6 h, the MIC for 90% inhibition of growth was determined. 

The polypyrrole (Ppy)/dextrin nanocomposite is synthesised via in situ polymerisation and the preparation of this nanocomposite is shown in Figure 5.4. The backbone chain of this nanocomposite polymer contains hydrophobic side chains, which disrupt the microbial cell membrane leading to leakage of the cytoplasm in bacteria including Escherichia coli. Pseudomonas aeruginosa. Staphylococcus aureus and Bacillus subtilis. This material can be implemented in the fields of biomedicine, biosensors and food packaging due to the biodegradable property of dextrin as well as the antibacterial properties of the Ppy [79]. 

The activity of all monomers and polymers against Escherichia coli (Gram-negative bacteria) and Bacillus subtilis (Gram-positive bacteria), as representative bacteria, was investigated. Increasing the number of carbons in the alkyl substituent led to the generation of more potent polymers. 

Both the antibacterial and haemolytic activities increased wheji the alkyl chain length was >C6. The activity of each polymer at two different MW (Mn, th = 3 and 10 kDa) was determined against Escherichia coli. Bacillus subtilis and human RBC (Table 9.1). Haemolytic activity was assessed as HCsolthe concentration of peptide required for 50% haemolysis), while the reported minimum inhibitory concentration (MIC) caused greater than 90% inhibition and was typically resulted in >99% inhibition. Increasing the alkyl substituent chain length caused an increase in activity, which indicates that hydrophobicity plays a major role in the antibacterial activity of the polymers. 

I.-L Shih, L.-D. Chen, and J.-Y. Wu, Levan production using Bacillus subtilis natto cells immobilized on alginate. Carbohydr. Polym. 82(1), 111-117 (2010). 

Amides and esters are particularly important in biological systems. The phosphate and pyrophosphate derivatives found in DNA and RNA were illustrated in Section 20.12. The structure and chemistry of these compounds will be elaborated upon in Chapter 28. Peptides (discussed in Chapter 27, Section 27.4) are polymers composed of discrete amino acid units. They are joined together by so-called peptide bonds, which are actually amide bonds. Many natural peptides are produced by bacteria via nonribosomal peptide synthesis. Bacillus subtilis produces the heptapeptide surfactin (224), which has antibiotic and antifungal activity. ... 

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