Production of a New Acidic Polysaccharide,Succinoglucan by Alcaligenes faecalis var. myxogenes

A slimy non-spore-forming bacterium strain 10C3 isolated from soil was motile with peritrichous flagella and named Alcaligenes faecalis var. myxogenes. Studies were made on the conditions necessary for maximal production of a new acidic succinoglucan polysaccharide by this strain in shaken cultures. Much production was observed with sucrose, glucose, xylose, galactose, cellobiose, maltose, fructose, mannose and rhamnose. The yield was greatest with sucrose and decreased in order with the above sugars from about 36 to 23 per cent. The most suitable medium contained 4 per cent sugar, 0.5 per cent yeast extract and one per cent calcium carbonate in tap water. The optimum temperature was 28°C.     

黄花川西獐牙菜的组织培养

1　植物名称　黄花川西獐牙菜 (Ｓｗｅｒｔｉａｍｕｓｓｏｔｉｉｖａｒ.ｆｌａｖｅｓｃｅｎｓ)。2　材料类别　叶、带节茎段、不带节茎段、顶芽。3　培养条件　基本培养基为ＭＳ培养基。诱导愈伤组织及芽分化培养基 :( 1 )ＭＳ ＮＡＡ 0 .0 6ｍｇ·Ｌ- 1 (单位下同 ) ＩＡＡ 0 .0 6 ＫＴ 0 .1 2 ;( 2 )ＭＳ ＮＡＡ 0 .0 6 ＩＡＡ 0 .0 6 ＫＴ 0 .2 ;( 3)ＭＳ ＮＡＡ0 .0 6 ＩＡＡ 0 .0 6 ＫＴ 0 .3;( 4 )ＭＳ ＮＡＡ 0 .0 6 ＩＡＡ 0 .0 6 ＫＴ 0 .4;( 5 )ＭＳ ＮＡＡ 0 .1 ＩＡＡ 0 .1 ＫＴ 1 .0。生根培养基 :( 6) 1 /2ＭＳ ;( 7) …     

Production of a Firm,Resilient Gel-forming Polysaccharide by a Mutant of Alcaligenes faecalis var. myxogenes 10C3

Isolation and purification procedures of yeast pro-proteinase C are described. In order to obtain a good yield of the proenzyme, it was necessary to repeat the inactivating treatment of coexisting yeast proteinase A and to perform purification procedures as rapidly as possible at low temperature. The purified protein was homogeneous with respect to chromatographic, electrophoretic and sedimentation criteria. The proenzyme possessed no inherent activity for acetyl-l-tyrosine ethylester but a slight activation seemed to occur during the activity assay. The molecular weight of the proenzyme was 79,200 as determined by the sedimentation and diffusion methods. Its other physicochemical properties were compared with those of proteinase C. The proenzyme as well as proteinase C was shown to be a glycoprotein which contains 8~12% true sugars.     

Structural studies of the capsular polysaccharide of a non-neoformans Cryptococcus species identified as C. laurentii, which was reclassified as Cryptococcus flavescens, from a patient with AIDS

Cryptococcus flavescens, a strain originally identified as C. laurentii, was isolated from the cerebrospinal fluid of an AIDS patient, and the soluble capsular polysaccharide of the yeast was investigated. Glucuronoxylomannan (GXM) was obtained from C. flavescens under conditions similar to those used to obtain C. neoformans polysaccharide. However, the GXM differed from C. neoformans polysaccharide in the decreased O-acetyl group content. The structure of GXM was determined by methylation analysis, partial acid hydrolysis, NMR analyses, and controlled Smith degradation. These analyses indicated that GXM has the following structure: an alpha-(1-->3)-D-mannan backbone with side chains of beta-D-glucuronic acid residues bound to the C-2 position of the mannose residue. The C-6 position of the mannose is substituted with D-man-beta-(1-->4)-D-xyl-beta-(1--> disaccharide. Furthermore, the existence of side chains containing more than two xylose residues was suggested. This mannosylxylose side chain is a novel structure in polysaccharides of C. neoformans and other Cryptococcus species.     

六盘山鸡爪大黄多糖含量变化规律

采用苯酚硫酸比色法对六盘山鸡爪大黄不同生长发育时期营养器官大黄多糖的含量变化规律进行分析,以明确大黄多糖在营养器官中的动态积累特征.结果显示:(1)随着植物的不断成熟,不同发育时期根和根茎中大黄多糖的总含量及其各组织中大黄多糖的含量表现为逐渐增高的趋势,次生维管组织是根和根茎大黄多糖贮藏的主要组织;(2)随着茎和叶的发育,大黄多糖的含量初期有一定程度的增加,在发育的后期略有下降;(3)与根和根茎相比,茎和叶中大黄多糖含量较少.研究结果表明,六盘山鸡爪大黄根和根茎是大黄多糖贮藏的主要器官,其中次生维管组织是大黄多糖贮藏的主要组织,次生维管组织中大黄多糖的贮藏积累方式为逐渐累积的方式,而且大黄多糖含量与各营养器官的发育程度存在着一定的相关性.     

New flavonoids from the underground parts of Eriosema laurentii

Pharmacological, toxicological and phytochemical investigations of aerial parts of Eriosema laurentii De Wild. (Leguminosae), a plant used in traditional African medicine, showed a complex pattern of very rare and several new exceptional phenolic compounds. In continuation of the phytochemical work and based on the activity of an extract from the underground parts, the presented study showed the occurrence of a new pyranoisoflavone, named methyleriosemaone D, and a new highly prenylated (2S,3S)-6,8,3′-triprenyl-3,5,7,2′,4′-pentahydroxyflavanone in these parts of E. laurentii. In addition, the very rare pyranoisoflavone eriosemaone D was proven in this plant for the first time. All structures were elucidated unambiguously by extensive MS- and one and two-dimensional NMR-experiments. Detailed NMR spectra of eriosemaone D were included to rationalize the correction of some of the previously reported carbon signals in the ¹³C NMR spectrum. The estrogenic activity of the extract and isolated compounds was tested in an estrogen receptor α yeast transactivation assay.     

Production of a Capsular Polysaccharide by a Marine Filamentous Fungus

The spent seawater medium of 4-day-old-cultures of the filamentous marine fungus Leptosphaeria albopunctata had a high viscosity after the fungus was collected by high-speed centrifugation. Microscopic examination of uncentrifuged mycelium suspended in India ink revealed that the viscosity resulted from capsular material. These capsules became disassociated from the mycelium during centrifugation. Precipitation of the medium of centrifuged cultures with 95% ethyl alcohol yielded a highly anthrone-positive polysaccharide material, composed of large amounts of glucose and minute amounts of mannose. Time course studies of the nutritional requirements for capsular polysaccharide production revealed that the capsular material was produced in large amounts, and on a wide variety of sugars, during the period of rapid growth, but was quickly degraded and presumably remetabolized in older cultures. The amount of capsular material produced was enhanced by NaCl concentrations above that of artificial seawater, and KCl could be substituted for NaCl. The salts MgCl(2) and CaCl(2) were also required for capsule production by L. albopunctata, although growth was obtained in cultures without added amounts of these constituents. The possible role of these salts in the metabolism of the fungus is discussed.     

New sources of gutta-percha in Garrya flavescens and G. wrightii

Analyses of extracts from whole-plant samples revealed that Garrya flavescens and Garrya wrightii produced gutta (trans-1,4-polyisoprene) as the major hydrocarbon in yields of 1.2 and 0.4 %, respectively. The average MWs of gutta were 142000 for G. flavescens and 10000 for G. wrightii. These species also yielded moderate amounts of ‘oil’ and ‘polyphenol’. To our knowledge, these are the first species of Garryaceae reported to produce gutta.     

Polysaccharide Produced by the Genus Pullularia: I. Production of Polysaccharide by Growing Cells

A dextranlike polysaccharide was found to be produced on substrates of sucrose, maltose, glucose, and fructose by growing cells of various strains of the genus Pullularia. The polysaccharide, obtainable in amounts as large as 2 to 3 g per 100 ml of culture medium using various carbohydrates as the carbon source, was soluble in cold water but not in 50% alcohol. The polysaccharide obtained had a α_d = +197.5° (c = 0.2 in water), and its molecular weight, determined by the light-scattering method, was found to be approximately 250,000.     

New antibiotic, parvulomycin, produced by a culture of Actinomyces parvullus var. chromogenes var. nov]

Actinomycete LIA-O784 was isolated from a soil sample. By its morphological and cultural properties the isolate was close to Act. parvullus but differed from it in synthesis of melanoid pygment, thyrosinase, hydrogen sulphide and pronounced antifungal activity. The actinomycete was classified as a new variant and designated as Actinomyces parvullus var. chromogenes var. nov. The culture produced a new polyglycoside antibiotic named parvulomycin. The physico-chemical characteristics of the antibiotic is presented.     

Effect of Nitrogen on Polysaccharide Production in a Porphyridium sp

Porphyridium cultures grown on either nitrate or ammonium as the nitrogen source showed similar patterns of growth and cell wall polysaccharide production. The effect of nitrogen on growth and cell wall polysaccharide production was studied by applying three regimens of supply: batch mode, in which nitrate was supplied at the beginning of the experiment and became depleted at day 6; continual mode, in which nitrate was added daily; and deficient mode, in which the cells were cultured in a nitrate-free medium. Growth was similar in the batch- and continual-mode cultures, whereas it was totally inhibited in the deficient-mode culture. Polysaccharide content (per volume) was highest in the batch-mode culture and lowest in the deficient-mode culture. However, polysaccharide production per cell was similar in the continual- and deficient-mode cultures, the highest value being found in the batch-mode culture. In addition to its effect on polysaccharide content, nitrogen affected the polysaccharide distribution between soluble and bound polysaccharides. In the deficientmode culture, most of the cell wall polysaccharide was dissolved in the medium.     

Production of Phosphatase by Aspergillus awamori var. kawachii in a Low Phosphate Medium

The effect of phosphate on the production of phosphatases by Aspergillus awamori var. kawachii was studied. In a high phosphate medium, little phosphatase was produced, and the phosphatase activity was predominately for beta-glycerophosphate. In a low phosphate medium, the production of phosphatase was increased and activity for glucose-6-phosphate predominated. Medium containing 1 mg of phosphorus per 100 ml was optimal, and the amount of phosphatase produced in this medium was about 200 times that produced in a high phosphate medium. By means of column chromatography on diethylaminoethyl cellulose, the phosphatase produced in the high phosphate medium was found to be eluted mainly at fraction e; the phosphatase of the low phosphate medium was separated into fractions a, b, c, and d. Thus, the phosphatase fractions produced in the low phosphate medium were different from those of the high phosphate medium. Since no specific effect on the production of esterases was observed when various phosphate esters were used as substrates, the enzymes of phosphate metabolism appear to be activated by nonspecific phosphate sources.     

Production of a Novel Extracellular Polysaccharide by Lactobacillus sake 0-1 and Characterization of the Polysaccharide

A novel exopolysaccharide (EPS) produced by Lactobacillus sake 0-1 (CBS 532.92) has been isolated and characterized. When the strain was grown on glucose, the produced EPS contained glucose and rhamnose in a molar ratio of 3:2 and the average molecular mass distribution (M(infm)) was determined at 6 x 10(sup6) Da. At a concentration of 1%, the 0-1 EPS had better viscosifying properties than xanthan gum when measured over a range of shear rates from 0 to 300 s(sup-1), while shear-thinning properties were comparable. Rheological data and anion-exchange chromatography suggested the presence of a negatively charged group in the EPS. Physiological parameters for optimal production of EPS were determined in batch fermentation experiments. Maximum EPS production was 1.40 g (middot) liter(sup-1), which was obtained when L. sake 0-1 had been grown anaerobically at 20(deg)C and pH 5.8. When cultured at lower temperatures, the EPS production per gram of biomass increased from 600 mg at 20(deg)C to 700 mg at 10(deg)C but the growth rate in the exponential phase decreased from 0.16 to 0.03 g (middot) liter(sup-1) (middot) h(sup-1). EPS production started in the early growth phase and stopped when the culture reached the stationary phase. Growing the 0-1 strain on different energy sources such as glucose, galactose, mannose, fructose, lactose, and sucrose did not alter the composition of the EPS produced.     

Agglutination of Erwinia stewartii Strains with a Corn Agglutinin: Correlation with Extracellular Polysaccharide Production and Pathogenicity

A bacterial agglutinin was extracted from ground corn (WI hybrid 64A × W117) seed with phosphate-buffered saline (pH 6.0) and precipitated with (NH₄)₂SO₄ at 70% saturation. The activities of this agglutinin against 22 strains of Erwinia stewartii (agent of bacterial wilt of corn) that varied in virulence were determined. Specific agglutination (agglutination titer per milligram of protein per milliliter) values were correlated negatively with virulence ratings. Strains with high specific agglutination values (15 or higher) were avirulent or weakly virulent; strains with low specific agglutination values (10 or lower) were highly virulent, with two exceptions. Avirulent strains produced butyrous colonies and released only small amounts of extracellular polysaccharide (EPS) into the medium, and the cells lacked capsules; virulent strains produced fluidal colonies and released large amounts of EPS, and the cells were capsulated. There was a strong correlation between the amount of EPS produced by each strain (as determined by increase in viscosity of the medium) and the specific agglutination value; in contrast, lipopolysaccharide compositions were similar in all strains. When cells of six fluidal strains were washed by repeatedly centrifuging and resuspending them in buffer, they were agglutinated more strongly by corn agglutinin than were unwashed cells. When avirulent cells were washed, their specific agglutination values did not increase significantly. Eight EPS-deficient mutants of E. stewartii, selected for resistance to the capsule-dependent bacteriophage K9, had lower virulence but higher specific agglutination than did their corresponding wild-type parents. Production of EPS appears to be essential for virulence; EPS may prevent agglutination of bacteria in the host, thus allowing their multiplication.     

Production of Extracellular Polysaccharide by Zoogloea ramigera

In batch cultures of Zoogloea ramigera the maximum rate of exopolysaccharide synthesis occurred in a partly growth-linked process. The exopolysaccharide was attached to the cells as a capsule. The capsules were released from the cell walls after 150 h of cultivation, which caused the fermentation broth to be highly viscous. Ultrasonication could be used to release capsular polysaccharide from the microbial cell walls. Treatment performed after 48 to 66 h of cultivation revealed exopolysaccharide concentration and apparent viscosity values in accordance with values of untreated samples withdrawn after 161 h of cultivation. The yield coefficient of exopolysaccharide on the basis of consumed glucose was in the range of 55 to 60% for batch cultivations with an initial glucose concentration of 25 g liter⁻¹. An exopolysaccharide concentration of up to 38 g liter⁻¹ could be attained if glucose, nitrogen, and growth factors were fed into the batch culture. The oxygen consumption rate in batch fermentations reached 25 mmol of O₂ liter⁻¹ h⁻¹ during the exopolysaccharide synthesis phase and then decreased to values below 5 mmol of O₂ liter⁻¹ h⁻¹ during the release phase. The fermentation broth showed pseudoplastic flow behavior, and the polysaccharide was not degraded when growth had ceased.     

Production and Characteristics of Avicel-Disintegrating Endoglucanase from a Protease-Negative Humicola grisea var. thermoidea Mutant

Mutational experiments were performed to decrease the protease productivity of Humicola grisea var. thermoidea YH-78 using UV light and N-methyl-N′-nitro-N-nitrosoguanidine. A protease-negative mutant, no. 140, exhibited higher endoglucanase activity than the parent strain in mold bran culture at 50°C for 4 days. The culture extract rapidly disintegrated filter paper but produced a small amount of reducing sugar. About 30% of total endoglucanase activity in the extract was adsorbed onto Avicel. The electrophoretically homogeneous preparation of Avicel-adsorbable endoglucanase (molecular weight, 128,000) showed intensive filter-paper-disintegrating activity but did not release reducing sugar. The preparation also exhibited a highly synergistic effect with the cellulase preparation from Trichoderma reesei in the hydrolysis of microcrystalline cellulose. This endoglucanase was observed via scanning electron microscopy to disintegrate Avicel fibrils layer by layer from the surface, yielding thin sections with exposed chain ends. A mutant, no. 191, producing higher protease activity and an Avicel-unadsorbable, Avicel-nondisintegrating endoglucanase was isolated. The purified enzyme (molecular weight, 63,000) showed no disintegrating activity on filter paper and Avicel and a less synergistic effect with the T. reesei cellulase in hydrolyzing microcrystalline cellulose than did the former enzyme. Endoglucanase was therefore divided into two types, Avicel disintegrating and Avicel nondisintegrating.     

Production of a Novel Extracellular Polysaccharide by a Bacillus Strain Isolated from Soil

A bacterium that was isolated from soil and identified as Bacillus circulans was found to produce a highly viscous extracellular polysaccharide when it was grown aerobically in a medium containing glucose as a sole source of carbon. The product was characterized by TLC and GC analyses as a novel heteropolysaccharide consisted of rhamnose, mannose, galactose, and mannuronic acid as sugar components. A maximal yield of polysaccharide reached about 2 g/liter by jar-fermentor culture at 30°C for 48 hr with a medium containing 1% glucose, 0.05% asparagine, 0.005% yeast extract, and small amounts of inorganic salts. Some culture conditions for the production of polysaccharide were investigated with flask culture; an optimal production was attained with a medium containing 0.1–1 % glucose and 0.01–0.05% asparagine, pH 7–8, at 30°C under aerobic conditions.