Fatty acid profiles of polar and non-polar lipids of Pleurotus ostreatus and P. cornucopiae var. ‘citrino-pileatus’ grown at different temperatures

The application of fatty acid (FA) composition data has now extended to studies of physiology, chemotaxonomy, and intrageneric differentiation, as well as to studies of human nutrition. Environmental factors such as nutritional components, oxygen, and temperature are known to affect lipid content and composition in living organisms, including fungi. In the present study, the polar and non-polar lipid content of Pleurotus ostreatus and P. cornucopiae var. citrino-pileatus fruiting bodies produced at temperatures ranging from 12–27 °C and from 17–27 °C, respectively, were analysed to evaluate the effect of temperature on lipid composition in these mushrooms. Results showed that lowering the growth temperature below 17 °C generally provided an expected increase in FA unsaturation in polar and non-polar lipids of P. ostreatus. Although raising the temperature above 17 °C did not show any clear-cut tendency in FA unsaturation, it did reveal that growth temperature had a differential effect on the FA profiles in fruiting bodies of P. ostreatus and P. cornucopiae. This study suggests that care should be taken when using FA content and unsaturation data for physiological, chemotaxonomic, and intrageneric differentiation studies, and that it may be possible to manipulate lipid unsaturation in Pleurotus spp. through modified growth temperatures.     

Characterization of fatty acid composition in healthy and bleached corals from Okinawa, Japan

Under bleaching conditions, corals lose their symbiotic zooxanthellae, and thus, the ability to synthesize fatty acids (FAs) from photosynthetically derived carbon. This study investigated the lipid content and FA composition in healthy and bleached corals from the Odo reef flat in Okinawa, southern Japan, following a bleaching event. It was hypothesized that the FA composition and abundance would change as algae are lost or die, and possibly microbial abundance would increase in corals as a consequence of bleaching. The lipid content and FA composition of three healthy coral species (Pavona frondifera, Acropora pulchra, and Goniastrea aspera) and of partially bleached and completely bleached colonies of P. frondifera were examined. The FA composition did not differ among healthy corals, but differed significantly among healthy, partially bleached, and completely bleached specimens of P. frondifera. Completely bleached corals contained significantly lower lipid and total FA content, as well as lower relative amounts of polyunsaturated FAs and higher relative amounts of saturated FAs, than healthy and partially bleached corals. Furthermore, there was a significantly higher relative concentration of monounsaturated FAs and odd-numbered branched FAs in completely bleached corals, indicating an increase in bacterial colonization in the bleached corals.     

Characterization of Armillaria spp. from peach orchards in the southeastern United States using fatty acid methyl ester profiling

Limited information is available regarding the composition of cellular fatty acids in Armillaria and the extent to which fatty acid profiles can be used to characterize species in this genus. Fatty acid methyl ester (FAME) profiles generated from cultures of A. tabescens, A. mellea, and A. gallica consisted of 16–18 fatty acids ranging from 12–24 carbons in length, although some of these were present only in trace amounts. Across the three species, 9-cis,12-cis-octadecadienoic acid (9,12-C18:2), hexadecanoic acid (16:0), heneicosanoic acid (21:0), 9-cis-octadecenoic acid (9-C18:1), and 2-hydroxy-docosanoic acid (OH-22:0) were the most abundant fatty acids. FAME profiles from different thallus morphologies (mycelium, sclerotial crust, or rhizomorphs) displayed by cultures of A. gallica showed that thallus type had no significant effect on cellular fatty acid composition (P > 0.05), suggesting that FAME profiling is sufficiently robust for species differentiation despite potential differences in thallus morphology within and among species. The three Armillaria species included in this study could be distinguished from other lignicolous basidiomycete species commonly occurring on peach (Schizophyllum commune, Ganoderma lucidum, Stereum hirsutum, and Trametes versicolor) on the basis of FAME profiles using stepwise discriminant analysis (average squared canonical correlation = 0.953), whereby 9-C18:1, 9,12-C18:2, and 10-cis-hexadecenoic acid (10-C16:1) were the three strongest contributors. In a separate stepwise discriminant analysis, A. tabescens, A. mellea, and A. gallica were separated from one another based on their fatty acid profiles (average squared canonical correlation = 0.924), with 11-cis-octadecenoic acid (11-C18:1), 9-C18:1, and 2-hydroxy-hexadecanoic acid (OH-16:0) being most important for species separation. When fatty acids were extracted directly from mycelium dissected from naturally infected host tissue, the FAME-based discriminant functions developed in the preceding experiments classified all samples (n = 16) as A. tabescens; when applied to cultures derived from the same naturally infected samples, all unknowns were similarly classified as A. tabescens. Thus, FAME species classification of Armillaria unknowns directly from infected tissues may be feasible. Species designation of unknown Armillaria cultures by FAME analysis was identical to that indicated by IGS-RFLP classification with AluI.     

Effect of the high polycyclic aromatic hydrocarbon, benzo[a]pyrene, on the lipid content of Fusarium solani

The purpose of the present paper was to study the effect of the high polycyclic aromatic hydrocarbon (PAH), benzo[a]pyrene, on the lipid [fatty acid (FA) and sterol] composition and content of the fungi Fusarium solani and F. oxysporum, respectively recognized as good and poor PAH degraders. The major FAs and the major sterol that characterized the tested Fusarium strains were C16:0, C18:1, C18:2, and ergosterol. Lipid profiles of F. solani remained unchanged with the addition of benzo[a]pyrene in the culture media at all concentrations and duration of treatment. However, in the presence of benzo[a]pyrene, significant decreases in FA content, which reached 18 % in young cultures and 28 % in mature colonies, were registered. Similarly, the sterol content of F. solani was reduced by 27 % in the presence of benzo[a]pyrene. In contrast, no modification in lipid profile and lipid content were observed with F. oxysporum, a strain recognized as a low benzo[a]pyrene degrader.     

The polar lipid composition of Mesorhizobium ciceri

The extractable lipid composition of Mesorhizobium ciceri strain HAMBI 1750 grown in a phosphate sufficient medium (79CA) is reported. Cardiolipin (CL—27% of total lipids), phosphatidylglycerol (PG—18%), phosphatidylethanolamine (PE—1%), phosphatidylcholine (PC—30%) and two methylated derivatives of PE, i.e. phosphatidyl-N, N-dimethylethanolamine (DMPE—1%) and phosphatidyl-N-monomethylethanolamine (MMPE—1%), were found to make up the phospholipids of the analysed bacteria. Nonphosphorus, ornithine-containing lipid (OL—10%) was also detected. Polar groups of phospholipids were predominantly acylated with cis-11,12-methyleneoctadecanoyl (lactobacillic) residues, whereas the ornithine lipid contained mainly 3-hexadecanoyloxy-11,12-methyleneoctadecanoic acid bound to the α-amino group.     

Influence of nitrogen deficiency on biochemical composition of the green alga <Emphasis Type="Italic">Botryococcus</Emphasis>

A study has been carried out to investigate the influence of nitrogen deficiency on intracellular lipid composition, including total fatty acid composition of lipids, polar lipids, and triacylglycerols, of the alga Botryococcus braunii Kütz IPPAS H-252 in batch culture. Under nitrogen limitation, the alga accumulates lipids as triacylglycerols and the total fatty acid (FA) composition changes: trienoic acids decrease (from 52.8–57.2 to 19.5–24.7% of the total FAs) and the oleic acid increases (from 1.1–1.2 to 17.1–24.4%) as does the saturated acids (from 23.7–26 to 32.9–46.1%). A similar rearrangement in the FA spectrum occurs at later times in the control culture, but it is less pronounced. Under nitrogen limitation, considerable changes in the polar lipid FAs are registered at day 13: saturated acids increase (from 28.6–35.5 to 76.8%) and all polyenoic acids markedly decrease (from 56.9–64.1 to 6.8%). Changes in the triacylglycerol fatty acid spectrum are seen on day 7: the oleic acid increases (from 14.7 to 34.2%) and remains at a high level till the end of the culture. In the control, triacylglycerols with large contents of oleic acid are detected at day 13, the total lipids and triacylglycerols still remaining unchanged.     

Fatty acid composition in lipid fractions lengthwise the mycelium of Mortierella isabellina and lipid production by solid state fermentation

This paper investigates the correlation between mycelial age and fatty acid biosynthesis. The correlation was investigated by analyzing the lipid composition lengthwise the mycelium of the oleaginous fungus Mortierella isabellina, a potential producer of γ-linolenic acid (GLA). Young mycelia were rich in polar lipids (glycolipids plus sphingolipids and phospholipids), while neutral lipid content increased in aged mycelia. In young mycelia, each polar lipid fraction contained almost 40% (w/w) polyunsaturated fatty acids (PUFAs), but this content decreased to less than 30% (w/w) in aged mycelia. On the other hand, PUFA content in neutral lipids fluctuated slightly with age. These results indicate that PUFA biosynthesis is favored in young, fast growing mycelia, while it decreases significantly in aged mycelia. This trend was also observed when we grew M. isabellina on pear pomace, an agro-industrial waste. Pear pomace cultures yielded significant amounts of lipid, which reached 12% (w/w) in dry fermented mass. The produced lipid was rich in GLA and the maximum GLA content in dry fermented mass was 2.9 mg/g.     

Fatty Acid Patterns of Seeds of Some Salvia Species from Iran – A Chemotaxonomic Approach

In this study, the seed oil content and fatty acid (FA) profile of 21 populations from 16 wild Salvia species of Iran were analyzed by GC. Patterns of chemical variations of the oils among species were identified via numerical analyses and also the taxonomic status of the infrageneric grouping was outlined in the genus. Salvia species were scored based on the contents of main FAs using principal coordinate analysis (PCO). The results showed that the total oil content in the seeds varied significantly, and ranged from 6.68 to 38.53% dry weight. α‐Linolenic (18:3ω3, 1.69 – 53.56%), linoleic (18:2ω6, 13.04 – 60.64%), oleic (18:1ω9, 6.15 – 27.06%), palmitic (16:0, 3.77 – 9.27%), and stearic (18:0, 1.78 – 3.05%) acid were identified as five major FAs in the oils. The amount of ω‐3 and ω‐6 FAs ranged between 1.90 – 53.80% and 13.46 – 60.83% of total FAs in the seed oils, respectively. The results confirmed that FA profiles were distinctive among the species and that they can be used as chemotaxonomic markers. The discrimination of Salvia species according to their botanical classification at intersectional level was supported. In general, seed oils of Salvia species were rich sources of polyunsaturated FAs, except in linoleic and α‐linolenic acid, and may be valuable for food and pharmaceutical industries.     

Lipopolysaccharides in four strains of the unicellular cyanobacterium Synechocystis

The results of the cross reactions of the 27 strains of Azospirillum spp. with 4 fluorescent antibodies (FA) show a neat differentiation between the two species. A. lipoferum represents a more homogenous group in respect to FA reactions and highly fluorescent preparations were obtained with strains from a large scope origin against Sp59 FA, the type strain. In contrast A. brasilense contains at least three sub groups in respect to FA reactions. The first includes all denitrifing strains (nir⁺) which react with FA from Sp7 the type strain. None of the nir^- strains reacted strongly with Sp7 FA. One part of the A. brasilense nir^- group which includes the strains isolated from well sterilized rice and wheat roots (Sp 107, 107 st, 106 and 109 st) reacts with FA of their reference strain Sp107 but not with that of Sp28 FA. The strains isolated from unsterilized roots and soils reacted with SP28 FA and not with that of Sp107 FA. In addition there were 3 strains (Sp A4, 34 and 67) which reacted with neither of the FAs.Abbreviations Fa fluorescent antibody - FITC fluorescein isothiocyanate - Rh ITC gelatin-rhodamine isothiocyanate - nir⁺ nitrite reductase positive - nir^- nitrite reductase negative     

Alkaloid profile and antimicrobial activity of <Emphasis Type="Italic">Lupinus angustifolius</Emphasis> L. alkaloid extract

Purpose of the present study was to evaluate alkaloid profile of the aerial parts of Lupinus angustifolius growing in Turkey by capillary gas chromatography-mass spectrometry (GC-MS). Fifteen alkaloids were identified by capillary GC-MS. 13α-Hydroxylupanine (50.78%) and lupanine (23.55%) were determined as the main alkaloids in the aerial parts of L. angustifolius. Ammodendrine, isoangustifoline, tetrahydrorhombifoline, angustifoline, α-isolupanine, 5,6-dehydrolupanine, 11,12-dehydrolupanine, 13α-acetoxylupanine, 13α-isovaleroyloxylupanine, 13α-valeroyloxylupanine, 13α-tigloyloxylupanine, 13α-cis-cinnamoyloxylupanine and 13α-cis-cinnamoyloxy-17-oxolupanine were identified as the minor alkaloids of the plant. Furthermore, antibacterial and antifungal activities of L. angustifolius alkaloid extract were tested against standard strains of the following bacteria; Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus as well as the fungi; Candida albicans and C. krusei. The alkaloid extract showed significant activity on B. subtilis, S. aureus and P. aeruginosa while it was weakly active on E. coli. On the other hand, the extract possessed moderate activity against C. albicans and C. krusei.     

The role of cis-carotenoids in abscisic acid biosynthesis

Evidence has been obtained which is consistent with 9-cis-neoxanthin being a major precursor of abscisic acid (ABA) in higher plants. A mild, rapid procedure was developed for the extraction and analysis of carotenoids from a range of tissues. Once purified the carotenoids were identified from their light-absorbance properties, reactions with dilute acid, high-performance liquid chromatography R_ts, mass spectra and the quasiequilibria resulting from iodine-catalysed or chlorophyllsensitised photoisomerisation. Two possible ABA precursors, 9-cis-neoxanthin and 9-cis-violaxanthin, were identified in extracts of light-grown and etiolated leaves (of Lycopersicon esculentum, Phaseolus vulgaris, Vicia faba, Pisum sativum, Cicer arietinum, Zea mays, Nicotiana plumbaginifolia, Plantago lanceolata and Digitalis purpurea), and roots of light-grown and etiolated plants (Lycopersicon, Phaseolus and Zea). The 9,9-di-cisisomer of violaxanthin was synthesised but its presence was not detected in any extracts. Levels of 9-cis-neoxanthin and all-trans-violaxanthin were between 20- to 100-fold greater than those of ABA in light-grown leaves. The levels of 9-cis-violaxanthin were similar to those of ABA but unaffected by water stress. Etiolated Phaseolus leaves contained reduced amounts of carotenoids (15–20% compared with light-grown leaves) but retained the ability to synthesise large amounts of ABA. The amounts of ABA synthesised, measured as increases in ABA and its metabolites phaseic acid and dihydrophaseic acid, were closely matched by decreases in the levels of 9-cis-neoxanthin and all-trans-violaxanthin. In etiolated seedlings grown on 50% D₂O, deuterium incorporation into ABA was similar to that into the xanthophylls. Relative levels of carotenoids in roots and light-grown and etiolated leaves of the ABA-deficient mutants, notabilis, flacca and sitiens were the same as those found in wild-type tomato tissues.Abbreviations ABA abscisic acid - DPA dihydrophaseic acid - GC-MS gas chromatography-mass spectrometry - HPLC high-performance liquid chromatography - PA phaseic acid - t trans - Xan xanthoxin - flc flacca - not notabilis - sit sitiens The authors would like to thank the following for their help and advice: G. Britton (Department of Biochemistry, University of Liverpool, UK), B.H. Davies (Department of Biochemistry, University of Wales, Aberystwyth), P. Molnar, J. Szabolcs, D.C. Walton (Department of Biology, Suny, Syracuse, N.Y., USA), and Mr. J.K. Heald for his expert operation of the mass spectrometer. A.D.P. was supported initially by a Science and Engineering Research Council CASE award with Shell Biosciences, Sittingbourne, Kent, UK, and later by a Agricultural and Food Research Council (AFRC) grant. M.J.B. received a NATO fellowship. The mass spectrometer and HPLC-photodiode-array detector were purchased with funds provided by the AFRC.     

Osmotic response in Lactobacillus casei ATCC 393: biochemical and biophysical characteristics of membrane

The biochemical and biophysical properties of the membrane and some general characteristics of the response of Lactobacillus casei ATCC 393 (reclassified Lactobacillus zeae) to hyperosmotic conditions were studied. Under hypertonic conditions, the hydrophobicity and the bile salt sensitivity of the cultures were increased. The glycolipid AcylH3DG is only present in membranes of NaCl containing medium, whereas, H4DG undergoes a significant increment and H2DG a significant decrease. The fluidity of both the purified membranes and the total lipid vesicles, as determined with the fluorescent probe DPH, did not change in conditions of high salinity. This was coincident with changes in the fatty acid (FA) composition where an increase in the saturated/unsaturated FA ratio was compensated by a rise in the fluidifying 11,12-methyleneoctadecanoic FA (cyc 19:0). Under osmotic stress conditions, Laurdan and acridine orange in total lipid vesicles showed increased lateral lipid packing and proton permeability, respectively.     

Fatty Acids from the Sea of Japan Sponge Halichondria panicea

The fatty acid (FA) composition of total lipids isolated from the marine sponge Halichondria panicea inhabiting Peter the Great Bay of the Sea of Japan was studied. GC and GC-MS techniques were used in identification of 63 FAs, with the main attention being paid to FAs with 14–22 carbon atoms. 4,8,12-Trimethyl-13:0 FA was for the first time identified as a main saturated FA, along with the branched FAs br-25:1, br-27:1, and br-27:2. The contents of arachidonic, eicosapentaenoic, docosapentaenoic, and the major demospongic acids [26:3(5,9,19), 26:3(5,9,17), 27:3(5,9,20), and 28:3(5,9,21)] considerably differed from those previously found for H. panicea, which may be due to seasonal changes in the species composition of organisms consumed by the sponge.     

Effect of biodelignification of rice straw on humification and humus quality by Phanerochaete chrysosporium and Streptomyces badius

The effect of biodelignification of rice straw by two different ligninolytic organisms, Phanerochaete chrysosporium (white-rot fungus) and Streptomyces badius (actinomycetes), on humus quality was investigated during a 56-day incubation at 30 °C. Lignin degradation, the release of humic extract (HE), humic acid (HA) and fulvic acid (FA), E4/E6 ratio of HA, and humification index (HI, HA/FA) were measured during the incubation. Lignin was degraded by both organisms, but to different extents. Lignin was degraded to 41% and 31% by P. chrysosporium and S. badius, respectively. HE released by P. chrysosporium and S. badius were, respectively, 2.10 and 2.13 times larger than that in the control at the maximum values. A significant correlation between lignin degradation and humus-related parameters involving HA fraction showed that both organisms are converting lignin to humic substances.     

Body size related adaptations of the avian myocardial phospholipid fatty acyl chain composition

The myocardial phospholipid fatty acid (FA) composition (mol %) of 7 avian species was determined, in a body mass range from 150 g (Japanese quail, Coturnix coturnix japonica) to 19 kg (turkey, Meleagris gallopavo). Significant allometric increases were found for C16:1 n7 (allometric exponent: B = 0.15), C18:1 n7 (B = 0.08), C18:1 n9 (B = 0.24), C20:1 n9 (B = 0.22) and C20:3 n3 (B = 0.12); moreover, total monounsaturates (B = 0.20) and the sum of n9 FAs (B = 0.24) was also positively related to body mass. The total n3 FAs (B = − 0.36), and within them C22:5 n3 (B = − 0.41) and C22:6 n3 (B = − 0.60) showed allometric declines, such as total polyunsaturated fatty acids (PUFA; B = − 0.01), unsaturation index (B = − 0.03) and mean FA chain length (B = − 0.003). Comparing our results with earlier published data on avian skeletal muscle and divergent mammalian tissues, the allometric scaling of the above membrane forming fatty acids seems to be part of a general relationship postulated as the theory “membranes as metabolic pacemakers”. In addition, the cardiac muscle malondialdehyde concentration was negatively related to body mass (B = − 0.16), referring to a lower level of lipid peroxidation in larger birds, and vice versa, indicating a progressive myocardial lipid peroxidation in smaller-bodied species.     

<Emphasis Type="Italic">cis</Emphasis>-Cinnamoyl Glucoside as a Major Plant Growth Inhibitor Contained in <Emphasis Type="Italic">Spiraea prunifolia</Emphasis>

Crude extracts of the leaves of Spiraea prunifolia Sieb. showed high plant-growth-inhibiting activity comparable to that of S. thunbergii extracts. To isolate the causal compound in S. prunifolia, we performed bioassay-directed purification by monitoring the biological activity per unit weight of the organism containing the bioactive compound (total activity). We isolated 1-O-cis-cinnamoyl-β-D-glucopyranose (cis-CG) and identified it as the most important growth-inhibiting constituent in the crude extracts. We did not detect 6-O-(4′-hydroxy-2′-methylenebutyroyl)-1-O-cis-cinnamoyl-β-D-glucopyranose (cis-BCG) in S. prunifolia, though it is a major plant growth inhibitor in S. thunbergii together with cis-CG. We estimated the cis-CG content in S. prunifolia to be 3.84 mmol kg⁻¹ F.W. This amount is comparable to the cis-CG plus cis-BCG content in S. thunbergii (3.59 mmol kg⁻¹ F.W.). This indicates that S. prunifolia and S. thunbergii have equally high potential to inhibit plant growth, and cis-CG acts as the most important plant-growth inhibitor in S. prunifolia extracts.     

A novel unsaturated fatty acid hydratase toward C16 to C22 fatty acids from Lactobacillus acidophilus

Hydroxy FAs, one of the gut microbial metabolites of PUFAs, have attracted much attention because of their various bioactivities. The purpose of this study was to identify lactic acid bacteria with the ability to convert linoleic acid (LA) to hydroxy FAs. A screening process revealed that a gut bacterium, Lactobacillus acidophilus NTV001, converts LA mainly into 13-hydroxy-cis-9-octadecenoic acid and resulted in the identification of the hydratase responsible, fatty acid hydratase 1 (FA-HY1). Recombinant FA-HY1 was purified, and its enzymatic characteristics were investigated. FA-HY1 could convert not only C18 PUFAs but also C20 and C22 PUFAs. C18 PUFAs with a cis carbon-carbon double bond at the Δ12 position were converted into the corresponding 13-hydroxy FAs. Arachidonic acid and DHA were converted into the corresponding 15-hydroxy FA and 14-hydroxy FA, respectively. To the best of our knowledge, this is the first report of a bacterial FA hydratase that can convert C20 and C22 PUFAs into the corresponding hydroxy FAs. These novel hydroxy FAs produced by using FA-HY1 should contribute to elucidating the bioactivities of hydroxy FAs.     

Intracellular substrates of a heme-containing ascorbate oxidase in <Emphasis Type="Italic">Pleurotus ostreatus</Emphasis>

A novel heme-containing ascorbate oxidase isolated from oyster mushroom, Pleurotus ostreatus, catalyzes oxidation of ascorbic acid (Kim et al., 1996). In this report, we describe the identification of intracellular substrates of the enzyme in the mushroom. Six compounds, which can serve as substrate of the heme-containing ascorbate oxidase, were identified as L-ascorbic acid, D-erythroascorbic acid, 5-O-(α-D-glucopyranosyl)-D-erythroascorbic acid, 5-O-(α-D-xylopyranosyl)-D-erythroascorbic acid, 5-methyl-5-O-(α-D-gluco-pyranosyl)-D-erythroascorbic acid, and 5-methyl-5-O-(α-D-xylopyranosyl)-D-erythroascorbic acid. All of the compounds were oxidized at a significant rate by the heme-containing ascorbate oxidase. Oxidation of the compounds produced equimolar amounts of hydrogen peroxide per mole of substrate.     

New cell wall glycopolymers of the representatives of the genus Kribbella

Each of the cell walls of four representatives of the genus Kribbella (order Actinomycetales; suborder Propionibacterineae; family Nocardioidaceae) contains a neutral polysaccharide and an acidic polysaccharide with unusual structures. Common to all four strains studied is a mannan with the following repeating unit: In the cell wall of the strain VKM Ac-2541, a teichulosonic acid was identified with a monosaccharide component that has not hitherto been found in Gram-positive bacteria, viz., pseudaminic acid, and an unusual linkage type in the polymeric chain,

Full-size image (1K)

where R = Н (45%), α-d-Galp3OMe (37%) or α-d-Galp2,3OMe (18%).The anionic cell wall components of three other strains are represented by teichuronic acids with a rare constituent, viz., a diaminosugar, 2,3-diacetamido-2,3-dideoxyglucopyranose. The structures of their repeating units differ in the nature of the acidic components:→4)-β-d-Manp2,3NAcA-(1→6)-α-d-Glcp2,3NAc-(1→ (VKM Ас-2538 and VKM Ас-2540) and →4)-β-d-ManpNAcA-(1→6)-α-d-Glcp2,3NAc-(1→ (VKM Ас-2539).The structures of all the glycopolymers were established by chemical and NMR spectroscopic methods; they are identified in Gram-positive bacteria for the first time.     

Microbial production of <Emphasis Type="Italic">cis</Emphasis>-1,2-dihydroxy-cyclohexa-3,5-diene-1-carboxylate by genetically modified <Emphasis Type="Italic">Pseudomonas putida</Emphasis>

Arene cis-diols are interesting chemicals because of their chiral structures and great potentials in industrial synthesis of useful chiral chemical products. Pseudomonas putida KT2442 was genetically modified to transform benzoic acid (benzoate) to 1,2-dihydroxy-cyclohexa-3,5-diene-1-carboxylic acid (DHCDC) or named benzoate cis-diol. BenD gene encoding cis-diol dehydrogenase was deleted to generate a mutant named P. putida KTSY01. Genes benABC encoding benzoate dioxygenase were cloned into plasmid pSYM01 and overexpressed in P. putida KTSY01. The recombinant bacteria P. putida KTSY01 (pSYM01) showed strong ability to transform benzoate to DHCDC. DHCDC of 2.3 g/L was obtained with a yield of 73% after 24 h of cultivation in shake flasks incubated under optimized growth conditions. Transformation of benzoate carried out in a 6-L fermentor using a benzoate fed-batch process produced over 17 g/L DHCDC after 48 h of fermentation. The average DHCDC production rate was 0.356 g L⁻¹ h⁻¹. DHCDC purified from the fermentation broth showed a purity of more than 95%, and its chemical structure was confirmed by nuclear magnetic resonance.