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Wild mushrooms are gathered and consumed in many regions of the world. Edible mushrooms are a good source of valuable nutritious ingredients but they also are able to accumulate heavy metals from the environment. Participation of polysaccharide components of mushroom cell walls in biosorption is poorly understood, therefore, our investigations focussed on an alkali-soluble polysaccharide derived from the cell wall of Boletus edulis. Its chemical structure is described based on chemical analysis, GPC, NMR and FT-IR and other instrumental techniques. The polysaccharide contained mainly C-3 substituted α- d -glucose and α- d -mannose. The ratio between these components was 10:4. We postulate the polymer is a (1 → 3)-linked α- d -glucan decorated by α-(1 → 3)- d -mannose chains. The molecular mass of the polysaccharide was estimated at about 850 kDa. Biosorption of heavy metal ions (Cd, Cu, Zn and Pb) by the tested polymer was measured using AAS techniques. The polysaccharide has a high ability to accumulate lead and cadmium.

This review focuses on the chemistry and structures of (Brady)rhizobium lipids A, indispensable parts of lipopolysaccharides. These lipids contain unusual (ω-1) hydroxylated very long chain fatty acids, which are synthesized by a very limited group of bacteria, besides rhizobia. The significance and requirement of the very long chain fatty acids for outer membrane stability as well as the genetics of the synthesis pathway are discussed. The biological role of these fatty acids for bacterial life in extremely different environments (soil and intracellular space within nodules) is also considered.

This paper describes the electrokinetic, adsorption and stability properties of the silica–exopolysaccharide Sinorhizobium meliloti (EPS). Exopolysaccharide adsorbs on the silica surface in the whole pH range, but the adsorption amount increases with the pH growth (at pH 9 approx. 0.8 mg/m2). The EPS adsorption affects the electrokinetic and stability properties of the system. At low pH values (3 and 4.6) the increase in the system stability occurs (electrosteric interactions), whereas at higher (7.6 and 9) the light system destabilization was noted (formation of a single polymer bridges between particles).

The chemical structures of the unusual hopanoid-containing lipid A samples of the lipopolysaccharides (LPS) from three strains of Bradyrhizobium (slow-growing rhizobia) have been established. They differed considerably from other Gram-negative bacteria in regards to the backbone structure, the number of ester-linked long chain hydroxylated fatty acids, as well as the presence of a tertiary residue that consisted of at least one molecule of carboxyl-bacteriohopanediol or its 2-methyl derivative. The structural details of this type of lipid A were established using one- and two-dimensional NMR spectroscopy, chemical composition analyses, and mass spectrometry techniques (electrospray ionization Fourier-transform ion cyclotron resonance mass spectrometry and MALDI-TOF-MS). In these lipid A samples the glucosamine disaccharide characteristic for enterobacterial lipid A was replaced by a 2,3-diamino-2,3-dideoxy-d-glucopyranosyl-(GlcpN3N) disaccharide, deprived of phosphate residues, and substituted by an α-d-Manp-(1→6)-α-d-Manp disaccharide substituting C-4' of the non-reducing (distal) GlcpN3N, and one residue of galacturonic acid (d-GalpA) α-(1→1)-linked to the reducing (proximal) amino sugar residue. Amide-linked 12:0(3-OH) and 14:0(3-OH) were identified. Some hydroxy groups of these fatty acids were further esterified by long (ω-1)-hydroxylated fatty acids comprising 26-34 carbon atoms. As confirmed by mass spectrometry techniques, these long chain fatty acids could form two or three acyloxyacyl residues. The triterpenoid derivatives were identified as 34-carboxyl-bacteriohopane-32,33-diol and 34-carboxyl-2β-methyl-bacteriohopane-32,33-diol and were covalently linked to the (ω-1)-hydroxy group of very long chain fatty acid in bradyrhizobial lipid A. Bradyrhizobium japonicum possessed lipid A species with two hopanoid residues.

Cellobiose dehydrogenase (CDH), an extracellular flavocytochrome produced by several wood-degrading fungi, was detected in the culture supernatant of the selective delignifier Pycnoporus sanguineus maintained on a cellulose-based liquid medium. Cellobiose dehydrogenase was purified as two active fractions: CDH1-FAD (flavin domain) (40.4 fold) with recovery of 10.9% and CDH1 (flavo-heme enzyme) (54.7 fold) with recovery of 9.8%. As determined by SDS-PAGE, the molecular mass of the purified enzyme was found to be 113.4kDa and its isoelectric point was 4.2, whereas these values for the FAD-domain were 82.7kDa and pI=6.7. The carbohydrate content of the purified enzymes was 9.2%. In this work, the cellobiose dehydrogenase gene cdh1 and its corresponding cDNA from fungus P. sanguineus were isolated, cloned, and characterized. The 2310bp full-length cDNA of cdh1 encoded a mature CDH protein containing 769 amino acids, which was preceded by a signal peptide of 19 amino acids. Moreover, both active fractions were characterized in terms of kinetics, temperature and pH optima, and antioxidant properties.

A water-soluble polysaccharide (WSP) extracted from mango (Mangifera indica L.) fruits has been suggested as a new alternative to mutan for mutanase induction in Trichoderma harzianum. Structural analyses revealed that the purified WSP was a (1→3),(1→4)-α-D-glucan with the molecular mass of ca. 760 kDa in which the (1→4)-linked and (1→3)-linked α-Glcp residues were in a ratio of 1:2.4. When the strain T harzianum CCM F-340 was grown in the presence of WSP, the maximal enzyme productivity obtained after 3 days of cultivation was 34 mU/mL. The mango WSP proved to be a very effective stimulus of mutanase expression giving a 5.1-fold higher than without WSP, transcription. It was shown that the mixture of WSP-induced mutanase and commercial dextranase had a high hydrolytic potential in the reaction with streptococcal mutan, where maximal degrees of solubilization and saccharification of this biopolymer (93.4% and 80%, respectively) were reached within 9h (solubilization) and 24h (saccharification). The mixed enzymatic preparation was also effective in degradation of streptococcal mutan and its removal from cariogenic biofilms. After 3h hydrolysis, only 18.2% of the biofilm remained adhered to the glass surface.

The O-polysaccharide was obtained from the lipopolysaccharide of the stem-nodulating nitrogen-fixing bacterium Azorhizobium caulinodans HAMBI 216 and studied by sugar and methylation analyses along with 1 H and 13 C NMR spectroscopy. The polysaccharide was found to have a linear pentasaccharide repeating unit containing d -rhamnose and its rarely occurring 2- O -methyl (Rha2 O Me) and 3- C -methyl (Rha3 C Me) derivatives and having the following structure: →3)-α- d -Rha p 2 O Me-(1→2)-β- d -Rha p 3 C Me-(1→3)-α- d -Rha p -(1→2)-β- d -Rha p 3 C Me-(1→3)-α- d -Rha p -(1→

The structure of the lipid A of the lipopolysaccharide (LPS) from Azorhizobium caulinodans, a symbiont of the tropical legume Sesbania rostrata, was investigated by chemical compositional analyses, mass spectrometry, as well as 1D and 2D NMR spectroscopy techniques. The lipid A backbone was composed of a β-(1→6)-linked 2,3-diamino-2,3-dideoxy- d -glucopyranose (GlcpN3N) disaccharide and α- d -glucuronic acid (GlcpA). Nuclear magnetic resonance spectroscopy revealed that the GlcpA was connected to the reducing end of the diaminosugar disaccharide via an α-(1→1) glycosidic bond. The lipid A was deprived of phosphate residues. ESI-MS analysis showed that the lipid A preparation was a mixture of molecules due to the occurrence of different acylation patterns. The GlcpN3N disaccharide backbone was N-acylated at the C-2, C-3, C-2′ and C-3′ positions with 3-OH-18:0, 3-OH-14:0, 3-OH-20:1 and 3-OH-14:0 fatty acids, respectively. Nonpolar fatty acids as well as 3-OH-18:0 were found to be ester-linked. They were attached to hydroxyl groups of primary 3-OH fatty acids giving three acyloxyacyl moieties. Thus, the complete lipid A from A. caulinodans comprised seven acyl residues. Part of the lipid A molecules was esterified by 3-methoxybutyric acid. Azorhizobium caulinodans did not incorporate ω-1 hydroxylated very long chain fatty acids (e.g., 27-OH-28:0) into the lipid A, which makes this variant of endotoxin unusual among rhizobial lipids A.

The O-specific polysaccharide obtained by mild-acid degradation of the lipopolysaccharide from Aeromonas veronii bv. sobria strain K49 was studied by sugar and methylation analyses along with (1)H and (13)C NMR spectroscopy. The sequence of the sugar residues was determined using (1)H,(1)H NOESY and (1)H,(13)C HMBC experiments. The O-specific polysaccharide was found to be a high molecular mass polysaccharide composed of repeating units of the structure: →2)-β-D-Quip3NAc-(1→3)-α-L-Rhap-(1→3)-α-L-Rhap-(1→2)-α-L-Rhap-(1→3)-α-D-FucpNAc-(1→ ESI MS confirmed the pentasaccharide structure of the repeating unit, as the molecular mass peaks seen in the spectrum differed by 812.34 u, a value corresponding to the calculated molecular mass of the O-unit.

The structure of lipid A from Azospirillum lipoferum, a plant-growth-promoting rhizobacterium, was investigated. It was determined by chemical analysis, mass spectrometric methods, as well as 1D and 2D NMR spectroscopy. Because of the presence of substituents, the investigated lipid A differs from typical enterobacterial lipid A molecules. Its backbone is composed of a beta-(1,6)-linked D-glucosamine disaccharide but lacks phosphate residues. Moreover, the reducing end of the backbone (position C-1) is substituted with alpha-linked d-galacturonic acid. 3-hydroxypalmitoyl residues are exclusively connected to amino groups of the glucosamine disaccharide. Hydroxyls at positions C-3 and C-3' are esterified with 3-hydroxymyristic acids. Primary polar fatty acids are partially substituted by nonpolar fatty acids (namely, 18:0, 18:1 or 16:0), forming acyloxyacyl moieties.

Polar lipid compositions of seven strains belonging to the four species of the Mesorhizobium genus were described. The lipid patterns of Mesorhizobium strains were very similar. Only quantitative differences were observed. Diphosphatidylglycerol (DPG), phosphatidylglycerol (PG), phosphatidylethanolamine (PE), and phosphatidylcholine (PC) were found to be the major phospholipids of the analysed bacteria. In addition, two methylated derivatives of PE were observed: phosphatidyl-N,N-dimethylethanolamine (DMPE) and phosphatidyl-N-monomethylethanolamine (MMPE). Polar head groups of those phospholipids were predominately acylated with lactobacillic (19:0 cyclopropane) acid. Ornithine-containing lipid (OL) was also identified. 3-hydroxy fatty acids found in the lipid preparations were derived exclusively from the ornithine lipid. 3-hydroxylactobacillic was the main acyl residue amide linked to the ornithine.

The structure of the O-specific polysaccharide isolated by mild acid hydrolysis of the lipopolysaccharide of Mesorhizobium huakuii IFO15243T was studied using methylation analysis and various one- and two-dimensional 1 H and 13 C NMR experiments. The O-antigen polysaccharide was found to be linear polymer constituted by a trisaccharide repeating unit of the following structure: →2 )- α - l -6 dTal p-(1 →3 )- α - l -6 dTal p-(1 →2 )- α - l - Rha p-(1 →