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1.
A non-axenic strain of the microalga Botryococcus braunii Kützing, isolated from a small lake in Portugal, when cultured at 25°C in mineral medium and under continuous illumination, showed a poor production of hydrocarbons (5% of the dry biomass) but excreted remarkably high quantities of an exopolysaccharide (4–4·5 g litre−1) into the medium. The production of the soluble polysaccharide, which contains galactose, fucose and uronic acid residues, occurs mainly after the exponential phase of growth.The rheological properties of broth during growth were studied. The increase of polysaccharide concentration as a consequence of its continuous biosynthesis, changes the medium behaviour from Newtonian to non-Newtonian with a flow characterized by a power-law equation. This behaviour becomes Newtonian again, when the culture is maintained for a longer period of time. 相似文献
2.
S. Guillouet J. H. Choi C. K. Rha A. J. Sinskey 《Applied microbiology and biotechnology》1999,51(2):235-240
Although many studies have examined the influence of culture conditions on the production and composition of polysaccharides,
little is known about the factors influencing the quality of exopolysaccharides (EPS). In this work we studied the effect
of yeast extract on the production, composition and molecular weight of the EPS zooglan produced by Zoogloea ramigera 115SLR. This bacterium was grown on a new completely defined synthetic medium and on a medium containing yeast extract. Growth
and polysaccharide production performances were comparable on the two media with a glucose to exopolysaccharide conversion
yield of 35% (g/g). The polysaccharides produced on these two media have an identical composition but a different molecular
weight and molecular weight distribution. The yeast extract medium leads to a more homogeneous polysaccharide solution.
Received: 12 June 1998 / Received revision: 19 September 1998 / Accepted: 11 October 1998 相似文献
3.
M. W. Breedveld L. P. T. M. Zevenhuizen H. C. J. Canter Cremers A. J. B. Zehnder 《Antonie van Leeuwenhoek》1993,64(1):1-8
The influence of growth rate and medium composition on exopolymer production byRhizobium leguminosarum was studied. When grown in medium containing 10g/l mannitol and 1g/l glutamic acid,Rhizobium leguminosarum biovartrifolii TA-1 synthesized up to 2.0g/l of extracellular polysaccharide (EPS), and up to 1.6g/l of capsular polysaccharide (CPS). Under non-growing cell conditions in medium without glutamic acid, CPS synthesis by strain TA-1 could proceed to 2.1g/l, while EPS-production remained relatively low (0.8g/l). Maximal CPS-yield was 2.9g CPS/l medium in a medium containing 20g/l mannitol and 2g/l glutamic acid. TheEPS-deficient strain R. leguminosarum RBL5515,exo4::Tn5 was able to produce CPS to similar levels as strain TA-1, but CPS-recovery was easier because of the low viscosity of the medium and growth of the cells in pellets. With strain TA-1 in nitrogen-limited continuous cultures with a constant biomass of 500mg cell protein/l, EPS was the most abundant polysaccharide present at every dilution rate D (between 0.12 and 0.02 h–1). The production rates were 50–100mg/g protein/h for EPS and 15–20mg/g protein/h for CPS. Only low amounts of cyclic -(1,2)-glucans were excreted (10–30 mg/l) over the entire range of growth rates.Abbreviations bv
biovar
- CPS
capsular polysaccharide
- EPS
extracellular polysaccharide
- HMr
high molecular mass
- LMr
low molecular mass
- YEMCR
Yeast Extract-Mannitol-Congo Red agar 相似文献
4.
Physiological conditions enhancing rhamnose-containing polysaccharide synthesis by Klebsiella I-714 were studied in batch culture (0.3-l and 2-l bioreactors). The four carbon sources tested, sucrose, sorbitol, Neosorb
and Cerelose, allowed exopolysaccharide production. Larger amounts of polymer were produced when high carbon/nitrogen ratios
and complex nitrogen sources were used. Exopolysaccharide synthesis was greatest at 30 °C, which was a suboptimal growth temperature.
A reduction in the phosphate content of the medium enhanced rhamnose-containing polysaccharide production. When the initial
carbon source concentration was augmented, byproducts other than exopolysaccharide were formed. Rhamnose-containing polysaccharide
rheology can be modulated by changing the phosphate content of the medium.
Received: 11 April 1997 / Received revision: 19 June 1997 / Accepted: 23 June 1997 相似文献
5.
Donatella Cimini Odile Francesca Restaino Angela Catapano Mario De Rosa Chiara Schiraldi 《Applied microbiology and biotechnology》2010,85(6):1779-1787
The production of industrially relevant microbial polysaccharides has recently gained much interest. The capsular polysaccharide
of Escherichia coli K4 is almost identical to chondroitin, a commercially valuable biopolymer that is so far obtained from animal tissues entailing
complex and expensive extraction procedures. In the present study, the production of capsular polysaccharide by E. coli K4 was investigated taking into consideration a potential industrial application. Strain physiology was first characterized
in shake flask experiments to determine the optimal culture conditions for the growth of the microorganism and correlate it
to polysaccharide production. Results show that the concentration of carbon source greatly affects polysaccharide production,
while the complex nitrogen source is mainly responsible for the build up of biomass. Small-scale batch processes were performed
to further evaluate the effect of the initial carbon source concentration and of growth temperatures on polysaccharide production,
finally leading to the establishment of the medium to use in following fermentation experiments on a bigger scale. The fed-batch
strategy next developed on a 2-L reactor resulted in a maximum cell density of 56 gcww/L and a titre of capsular polysaccharide equal to 1.4 g/L, approximately ten- and fivefold higher than results obtained in
shake flask and 2-L batch experiments, respectively. The release kinetics of K4 polysaccharide into the medium were also explored
to gain insight into the mechanisms underlying a complex aspect of the strain physiology. 相似文献
6.
Y Li P Li Y Mou J Zhao T Shan C Ding L Zhou 《World journal of microbiology & biotechnology》2012,28(4):1407-1413
This study is the first report of the enhancement of diepoxin ζ production in liquid culture of the endophytic fungus Berkleasmium sp. Dzf12 by the polysaccharides from its host plant Dioscorea zingiberensis which serve as elicitors. Three polysaccharides, namely water-extracted polysaccharide (WEP), sodium hydroxide-extracted
polysaccharide and acid-extracted polysaccharide were sequentially prepared from the rhizomes of D. zingiberensis. Among them, WEP was found to be the most effective elicitor to enhance diepoxin ζ production. When WEP was added to the
medium at 400 mg l−1 on day 3 of culture, the maximal diepoxin ζ yield (intracellular diepoxin ζ in mycelia plus extracellular diepoxin ζ in medium)
of 350.76 mg l−1 on day 15 was achieved, which was about 2.69-fold in comparison with that (130.43 mg l−1) of the control. 相似文献
7.
J. Koníček G. Y. Daraselia M. Koníčková-Radochova J. Lasik M. Wurst T. Koza 《Folia microbiologica》1990,35(5):394-401
Mutant strains ofMycobacterium sp. V-649 producing highly mucous colonies on a solid cultivation medium were prepared after treatment with N-methyl-N′-nitro-N-nitrosoguanidine
and production of the exocellular polysaccharide was tested. The strains were cultivated in media with suitable sugar sources
under submerged conditions. It was found thatMycobacterium sp. V649/15 produces a maximum of 15–19% polymer after a 5–6-d cultivation. Gas chromatography indicated that the exocellular
polysaccharide produced by this strain is of glucan type. 相似文献
8.
Maintenance of pH 7.0 during the fermentation period favors accumulation of high molecular weight polysaccharide-containing components called lipopolysaccharide–protein and polysaccharide–lipid complexes in the capsules and culture medium. Increased pH of the culture medium to 8.0 reduced the period of exponential growth and the yield of polysaccharide-containing complexes as compared to optimal conditions. Maintenance of pH 5.5 suppressed the culture growth and polysaccharide production. The polysaccharide–lipid complexes obtained when pH was stabilized at the level of 7.0–8.0 had relatively low molecular weights and included only acidic polysaccharides. The use of potassium gluconate instead of sodium malate as a source of carbon in the culture medium changed the polysaccharide composition and increased the content of glucosamine, which increased the affinity of polysaccharides for wheat germ agglutinin. Prolongation of Azospirillum cultivation to five days introduced new glucose-containing polysaccharide components in the capsule. 相似文献
9.
Experimental design and metabolic flux analysis tools to optimize industrially relevant Haemophilus influenzae type b growth medium
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Mateus Ribeiro da Silva Carla Andreia Freixo Portela Silvia Maria Ferreira Albani Paola Rizzo de Paiva Martha Massako Tanizaki Teresa Cristina Zangirolami 《Biotechnology progress》2017,33(6):1508-1519
Haemophilus influenzae type b (Hib), a Gram‐negative capsulated bacterium, is a causative agent of meningitis worldwide. The capsular polysaccharide, a high molecular mass polymer consisting of the repeated units of the polyribosyl‐ribitol‐phosphate, is considered the main virulence factor and it is used as an antigen to vaccines, conjugated to a carrier protein. The industrial production of the polysaccharide requires the cultivation of Hib in rich medium, which impacts process costs and product recovery. In this study, a central composite rotational experimental design strategy was used to access the influence of key components of culture medium (soy peptone, yeast extract and glucose) on biomass formation and polysaccharide production in shake‐flasks. The optimized medium formulation, containing half of the usual yeast extract and soytone concentrations, was further validated in batch bioreactor cultivations. High polysaccharide production (~500 mg/L) was obtained in a cheaper and more competitive production process for use in Hib vaccine production. In addition, simulations of a metabolic model describing Hib central metabolism were used to assess the role of key amino acids on growth. A chemically defined medium supplemented only with amino acids from α‐ketoglutarate and oxaloacetate families as well as phenylalanine was suggested as a promising alternative for reduced acetate accumulation and enhanced polysaccharide production in Hib cultures. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1508–1519, 2017 相似文献
10.
Noscoc
flagelliforme is a terrestrial macroscopic cyanobacterium with high economic value. Free-living cells that were separated from a natural
colony of N. flagelliforme were cultivated in a 20-L photobioreactor for 16 days at five agitation rates with impeller tip speeds at 0.3, 0., 0.8, 1.0,
and 1.5 m·s−1. With different impeller tip speeds there were significant differences in the cell growth and polysaccharide production,
and different types of cell colonies appeared because of different shear forces caused by agitation. At harvest time, cell
concentrations with tip speeds of 0.8 and 1.0 m·s−1 were clearly higher than those with the other three tip speeds, but dry cell weights with the tip speeds of 0.3, 0.5, 0.8,
and 1.0 m·s−1 were almost the same. The highest RPS (polysaccharide that released into liquid medium) production was obtained with the
tip speeds of 0.8 and 1.0 m·s−1, while the highest EPS (polysaccharide that formed capsule or slime layer) production was obtained with the tip speed of
0.5 m·s−1. The tip speed of 1.5 m·s−1 was harmful for both cell growth and polysaccharide production, indicating that an appropriate shear force was needed in
the liquid suspension culture of N. flagelliforme. 相似文献
11.
Christina von Hunolstein Laura Nicolini Sandro D'Ascenzi Corrado Volpe Giovanna Alfarone 《Applied microbiology and biotechnology》1993,38(4):458-462
A fermentation process to increase type capsular polysaccharide production by different serotypes of Streptococcus agalactiae (group B Streptococcus) was established. As sialic acid is an integral component of the polysaccharide, its synthesis was used to monitor polysaccharide, its synthesis was used to monitor polysaccharide production. Culture conditions, examined both on laboratory and pilot-plant scales, allowed optimal bacterial growth and high polysaccharide production in a medium composed of ultrafiltered Todd Hewitt broth supplemented with 2% (w/v) glucose and 1.5% (w/v) Na2HPO4, at a constant pH of 7.2. Studies using different gas atmospheres (air, CO2 or their mixture) showed that air greatly enhanced polysaccharide production.
Correspondence to: C. von Hunolstein 相似文献
12.
West TP 《Journal of industrial microbiology & biotechnology》2002,29(4):185-188
A mutant strain of the bacterium Pseudomonas sp. ATCC 31461 that exhibited elevated production of the polysaccharide gellan on glucose or corn syrup as a carbon source
was isolated. Gellan production by the mutant strain was about twofold higher than its parent strain on glucose or corn syrup
after 48 h of growth, and about 1.4-fold higher after 72 h. An increase in biomass production was not correlated with enhanced
gellan synthesis by the mutant strain. The increased gellan production by the mutant strain on either carbon source resulted
in an increase in its culture medium viscosity and the viscosity of the isolated polysaccharide produced by glucose-grown
cells. No differences in the glucuronic acid content of the polysaccharides produced by the mutant and parent strains were
observed. Journal of Industrial Microbiology & Biotechnology (2002) 29, 185–188 doi:10.1038/sj.jim.7000278
Received 13 February 2002/ Accepted in revised form 20 May 2002 相似文献
13.
Use of whey for production of exocellular polysaccharide by a mutant strain ofXanthomonas campestris
Growth and kinetics of the production of exocellular polysaccharide was studied in a mutant strain ofXanthomonas campestris lac
+ during cultivation in a submerged culture in a medium containing whey. The maximum production of the polymer was observed
at the initial stage of the stationary growth phase of the culture. The mean production yield was about 1.4%. The results
were comparable with those obtained during cultivation on a lactose medium.
Translated by Č. Novotny 相似文献
14.
Production of a hypoglycemic, extracellular polysaccharide from the submerged culture of the mushroom, Phellinus linteus 总被引:15,自引:0,他引:15
Dong-Hyun Kim Byung-Keun Yang Sang-Chul Jeong Jun-Bo Park Sung-Pill Cho Surajit Das Jong-Won Yun Chi-Hyun Song 《Biotechnology letters》2001,23(7):513-517
Mycelial growth and extracellular polysaccharide production of Phellinus linteus were optimal at pH 5 and 25 °C. Maximum biomass production (14.2 g l–1) was after 15 d of cultivation, whereas, extracellular polysaccharide was maximal (3.5 g l–1) after 21 d. The hypoglycemic effect of the polysaccharide, investigated in streptozotocin-induced diabetic rats, decreased plasma glucose, total cholesterol and triacylglycerol concentrations by 49%, 32%, and 28%, respectively, and aspartate aminotransferase activity by 20%. The results indicate the potential of this polysaccharide to prevent hyperglycemia in diabetic patients. 相似文献
15.
De Baets S Du Laing S François C Vandamme EJ 《Journal of industrial microbiology & biotechnology》2002,29(4):181-184
In liquid culture conditions, the yeast-like fungus Tremella mesenterica occurs in the yeast state and synthesizes an exopolysaccharide (EPS) capsule, which is eventually released into the culture
fluid. It is composed of an α-1,3-D-mannan backbone, to which β-1,2 side chains are attached, consisting of D-xylose and D-glucuronic acid. Potato dextrose broth (PDB) seemed to be an excellent medium for both growth of the yeast cells and synthesis
of the EPS. This medium is composed solely of an extract of potatoes to which glucose was added. Yet an important disadvantage
of this production medium is the presence of starch in the potato extract, since Tremella cells are not capable of metabolizing this component; furthermore, it coprecipitates upon isolation of the polymer [3]. In
this respect, it was essential to remove the starch in order to achieve high polysaccharide production and recovery. A good
method was the removal of starch through ultrafiltration of the PDB medium before inoculation of the strain. This resulted
in an excellent starch-free medium in which other components essential for polysaccharide production were still present [3].
Through implementation of single and cyclic fed-batch fermentations with glucose feed, 1.6- and 2.2-fold increases in EPS
yield were obtained, respectively. Lowering the carbon source level by using a cyclic fed-batch technique might decrease the
osmotic effect of glucose or any catabolite regulation possibly exerted by this sugar on enzymes involved in EPS synthesis.
Journal of Industrial Microbiology & Biotechnology (2002) 29, 181–184 doi:10.1038/sj.jim.7000276
Received 18 March 2002/ Accepted in revised form 20 May 2002 相似文献
16.
Variation of polysaccharide concentration in irrigation-channel sediment was determined concurrently with biological, chemical
and physical factors influencing the benthic algal community. Phenol-sulphuric acid method was used to measure polysaccharide
concentration. Polysaccharide concentration, biomass of benthic algae, and species composition changed spatially and temporally.
Fluctuations of total suspended solid (TSS) concentration and exposure of channel bed to direct sunlight had major effects
on algal growth and polysaccharide production. Polysaccharide concentration was correlated to chlorophyll a concentration (r=0.73, P<0.001) and algal biomass (r=0.57, P<0.001). Fragilaria construens and Aulacoseira (Melosira) italica were the most common diatoms in the benthic flora. Chlorophyll a concentration in the sediment showed a strong negative correlation (r=-0.99, P<0.001) with the seasonal variation of TSS concentration in channel water.
The polysaccharides produced by benthic microorganisms play a major role in clogging channel bed and thereby reducing seepage
from earthen irrigation channels. Correlations between polysaccharide concentration and chlorophyll a (and algal biomass) further indicate the importance of benthic algae for polysaccharide production. Since availability of
light to the algal flora is critical for the production of polysaccharides, the effect of clogging can be maximized by exposing
the channel bed to direct sunlight during non-irrigation period (winter). 相似文献
17.
The cells of the red microalga Porphyridium sp. are encapsulated within a complex sulphated polysaccharide, comprising cell-wall-bound and soluble fractions. The current
study investigated the involvement of the Golgi apparatus in the production of the sulphated polysaccharide by treating the
cultures with brefeldin A (BFA), a membrane-traffic inhibitor of the Golgi apparatus. Addition of BFA (10–25 μM) upon inoculation
(logarithmic-phase cells) decreased the contents of both bound and soluble polysaccharides. Exposure of stationary-phase cultures
to BFA (20 μM) inhibited the formation of the cell-wall bound polysaccharide to a greater extent than that of the soluble
polysaccharide. Under conditions of nitrate starvation, BFA treatment had a more marked effect on soluble than on bound polysaccharide
formation, as was supported by 14C pulse-chase experiments. BFA addition up to the first 10 h of the cell cycle affected cell division and bound polysaccharide
and starch contents. An ultrastructural study showed that exposure of the cells to 20 μM BFA for 16 h disrupted the integrity
of the Golgi apparatus. The integrated results of this study demonstrate clearly that BFA affects the architecture of the
Golgi apparatus and hence polysaccharide production in algal cells. 相似文献
18.
Under the elicitation of protein elicitor isolated from the culture mycelia of Tuber melanosporum, the biosynthesis of ganoderic acids (GA) was significantly stimulated during Ganoderma lucidum fermentation. Compared with our previous results that, GA content was inhibited by polysaccharide elicitor isolated from
T. melanosporum, while improved by the elicitor of polysaccharide and protein, protein was identified to be the exact component inducing GA biosynthesis in this work. G. lucidum cell growth was significantly inhibited by elicitor of polysaccharide and protein, and polysaccharide elicitor did not inhibit the cell growth. In this work, the remarkable inhibition on the cell growth was
considerably eliminated under the elicitation of protein elicitor isolated from T. melanosporum. These suggested maybe the interaction of polysaccharide and protein components existed in the inhibition on the cell growth
of G. lucidum. Not only GA content but also total GA accumulation obtained the highest values after the elicitation of protein elicitor. The maximal GA production of 260.5 ± 5.6 mg/L was 31.2% higher than the control. Under the elicitation of protein elicitor,
the production of extracellular polysaccharide (EPS) and the content of intracellular polysaccharide (IPS) were also enhanced;
however, total IPS accumulation was lower. GA biosynthesis was also significantly affected by the addition time of protein
elicitor, whose optimal value was the culture of day 4. 相似文献
19.
Summary The effects of initial osmotic pressure (IOP) on the production of ginseng polysaccharide and ginseng saponin were studied in suspension cultures of Panax notoginseng cells. At higher IOP, the specific saponin production and intracellular carbohydrate storage were increased, while the plant cell volume, the consumption rates of major medium components and the specific cell growth rate were decreased. The specific production of polysaccharide was reduced with an increase of IOP from 4.45 to 5.18 atm, and levelled off at an even higher IOP. 相似文献
20.
Abou-Zeid A. Abou-Zeid Ahmed F. Abd El-Fattah Mohamad A. Farid 《Bioscience, biotechnology, and biochemistry》2013,77(9):1977-1980
An organism producing extracellular polysaccharide was isolated from soil and identified as Aeromonas hydrophila (Chester) Stanier. The effects of medium components and cultural conditions on production of the polysaccharide were studied. The optimal concentrations of carbon and nitrogen sources were 5% and 0.3%, respectively, for production of the polysaccharide. The optimal initial pH was 7~9. The maximum polysaccharide yield was obtained at 4~8 days of fermentation. From sucrose and raffinose as carbon source, the organism produced levan and acidic polysac-charide in the ratio of 7:3 and 4:6, respectively. From glucose, galactose, fructose, mannose, maltose and lactose, mainly acidic polysaccharide was produced. The acidic polysaccharide was found to contain galactose, mannose and glucuronic acid in a ratio of 5:4:2. The acidic polysaccharides obtained from sucrose and lactose seemed to be the same polysaccharide. 相似文献