共查询到20条相似文献,搜索用时 31 毫秒
1.
M. Veselova V. Lipasova M. A. Protsenko N. Buza I. A. Khmel 《Folia microbiologica》2009,54(5):401-408
Pseudomonas chlororaphis strain 449 isolated from the rhizosphere of maize suppresses numerous plant pathogens in vitro. The strain produces phenazine antibiotics and synthesizes at least three types of quorum sensing signaling molecules, N-acylhomoserine lactones. Here we have shown that the rhizospheric P. chlororaphis strains 449, well known strain 30–84 as well as two other P. chlororaphis strains exhibit polygalacturonase activity. Using mini-Tn5 transposon mutagenesis, four independent mutants of strain P. chlororaphis 449 with insertion of mini-Tn5 Km2 in gene gacS of two-component GacA-GacS system of global regulation were selected. All these mutant strains were deficient in production
of extracellular proteinase(s), phenazines, N-acylhomoserine lactones synthesis, and did not inhibit the growth of G+ bacteria in comparison with the wild type strain. The P. chlororaphis 449-06 gacS
− mutant studied in greater detail was deficient in polygalacturonase, pectin methylesterase activities, swarming motility
and antifungal activity. It is the first time the involvement of GacA-GacS system in the regulation of enzymes of pectin metabolism,
polygalacturonase and pectin methylesterase, was demonstrated in fluorescent pseudomonads. 相似文献
2.
G. Kozianowski F. Canganella F. A. Rainey H. Hippe G. Antranikian 《Extremophiles : life under extreme conditions》1997,1(4):171-182
A novel thermophilic spore-forming anaerobic microorganism (strain Ab9) able to grow on citrus pectin and polygalacturonic
acid (pectate) was isolated from a thermal spa in Italy. The newly isolated strain grows optimally at 70°C with a growth rate
of 0.23 h−1 with pectin and 0.12 h−1 with pectate as substrates. Xylan, starch, and glycogen are also utilized as carbon sources and thermoactive xylanolytic
(highest activity at 70°–75°C), amylolytic as well as pullulolytic enzymes (highest activity at 80°–85°C) are formed. Two
thermoactive pectate lyases were isolated from the supernatant of a 300-l culture of isolate Ab9 after growth on citrus pectin.
The two enzymes (lyases a and b) were purified to homogeneity by ammonium sulfate treatment, anion exchange chromatography, hydrophobic chromatography and
finally by preparative gel electrophoresis. After sodium dodecylsulfate (SDS) gel electrophoresis, lyase a appeared as a single polypeptide with a molecular mass of 135 000 Da whereas lyase b consisted of two subunits with molecular masses of 93 000 Da and 158 000 Da. Both enzymes displayed similar catalytic properties
with optimal activity at pH 9.0 and 80°C. The enzymes were very stable at 70°C and at 80°C with a half-life of more than 60
min. The maximal activity of the purified lyases was observed with orange pectate (100%) and pectate-sodium salt (90%), whereas
pectin was attacked to a much lesser extent (50%). The K
m values of both lyases for pectate and citrus pectin were 0.5 g·l−1 and 5.0 g·l−1, respectively. After incubation with polygalacturonic acid, mono-, di-, and tri-galacturonate were detected as final products.
A 2.5-fold increase of activity was obtained when pectate lyases were incubated in the presence of 1 mM Ca2+. The addition of 1 mM ethylenediaminetetraacetic acid (EDTA) resulted in complete inhibition of the enzymes. These heat-stable
enzymes represent the first pectate-lyases isolated and characterized from a thermophilic anaerobic bacterium. On the basis
of the results of the 16S rRNA sequence comparisons and the observed phenotypic differences, we propose strain Ab9 as a new
species of Thermoanaerobacter, namely Thermoanaerobacter italicus sp. nov.
Received: May 25, 1997 / Accepted: June 5, 1997 相似文献
3.
The aim of this study was to isolate and identify algicidal bacteria against the dinoflagellate Cochlodinium polykrikoides, and to determine the algicidal activity and algicidal range. During the declining period of C. polykrikoides blooms, seven algicidal bacteria were isolated. The algicidal bacteria against C. polykrikoides were enumerated using the most probable number (MPN) method. The number of algicidal bacteria was high (3.7 × 103 mL−1). Algicidal bacteria were identified on the basis of biochemical and chemotaxonomic characteristics, and analysis of 16S
rDNA sequences. Seven algicidal bacteria isolated in this study belonged to the genera Bacillus, Dietzia, Janibacter, and Micrococcus. The most algicidal bacterium, designated Micrococcus luteus SY-13, is assumed to produce secondary metabolites. When 5% culture filtrate of this strain was applied to C. polykrikoides cultures, over 90% of C. polykrikoides cells were destroyed within 6 h. M. luteus SY-13 showed significant algicidal activities against C. polykrikoides and a wide algicidal range against various harmful algal bloom (HAB) species. Taken together, our results suggest that M. luteus SY-13 could be a candidate for controlling HABs. 相似文献
4.
M. Galiotou-Panayotou M. Kapantai O. Kalantzi 《Applied microbiology and biotechnology》1997,47(4):425-429
A wild type of Aspergillus sp. ATHUM-3482 produced extracellular polygalacturonase when grown in liquid medium containing citrus pectin as sole carbon
source. A number of factors affecting enzyme activity were investigated. Polygalacturonase activities as high as␣4.3 U␣ml−1(reducing-group-releasing activity) and 17␣U␣ml−1 (viscosity-diminishing activity) were obtained under optimum growth conditions. With sugar-beet as sole carbon source the
respective activities were 6.5 U␣ml−1 and 40 U ml−1, the highest achieved in this work. Under these conditions no pectin lyase or pectinesterase activity was detected. The above
yields of polygalacturonase activity compare favourably with those reported for fungi grown under similar growth conditions.
Received: 5 March 1996 / Received last revision: 29 October 1996 / Accepted: 2 November 1996 相似文献
5.
Fong JC Svenson CJ Nakasugi K Leong CT Bowman JP Chen B Glenn DR Neilan BA Rogers PL 《Extremophiles : life under extreme conditions》2006,10(5):363-372
In a search for potential ethanologens, waste compost was screened for ethanol-tolerant thermophilic microorganisms. Two thermophilic bacterial strains, M5EXG and M10EXG, with tolerance of 5 and 10% (v/v) ethanol, respectively, were isolated. Both isolates are facultative anaerobic, non-spore forming, non-motile, catalase-positive, oxidase-negative, Gram-negative rods that are capable of utilizing a range of carbon sources including arabinose, galactose, mannose, glucose and xylose and produce low amounts of ethanol, acetate and lactate. Growth of both isolates was observed in fully defined minimal media within the temperature range 50–80°C and pH 6.0–8.0. Phylogenetic analysis of the 16S rDNA sequences revealed that both isolates clustered with members of subgroup 5 of the genus Bacillus. G+C contents and DNA–DNA relatedness of M5EXG and M10EXG revealed that they are strains belonging to Geobacillus thermoglucosidasius. However, physiological and biochemical differences were evident when isolates M5EXG and M10EXG were compared with G. thermoglucosidasius type strain (DSM 2542T). The new thermophilic, ethanol-tolerant strains of G. thermoglucosidasius may be candidates for ethanol production at elevated temperatures. 相似文献
6.
Farrakh Mehboob Howard Junca Gosse Schraa Alfons J. M. Stams 《Applied microbiology and biotechnology》2009,83(4):739-747
Microbial (per)chlorate reduction is a unique process in which molecular oxygen is formed during the dismutation of chlorite.
The oxygen thus formed may be used to degrade hydrocarbons by means of oxygenases under seemingly anoxic conditions. Up to
now, no bacterium has been described that grows on aliphatic hydrocarbons with chlorate. Here, we report that Pseudomonas chloritidismutans AW-1T grows on n-alkanes (ranging from C7 until C12) with chlorate as electron acceptor. Strain AW-1T also grows on the intermediates of the presumed n-alkane degradation pathway. The specific growth rates on n-decane and chlorate and n-decane and oxygen were 0.5 ± 0.1 and 0.4 ± 0.02 day−1, respectively. The key enzymes chlorate reductase and chlorite dismutase were assayed and found to be present. The oxygen-dependent
alkane oxidation was demonstrated in whole-cell suspensions. The strain degrades n-alkanes with oxygen and chlorate but not with nitrate, thus suggesting that the strain employs oxygenase-dependent pathways
for the breakdown of n-alkanes. 相似文献
7.
White rot fungi are a promising option to treat recalcitrant organic molecules, such as lignin, polycyclic aromatic hydrocarbons,
and textile dyes, because of the lignin-modifying enzymes (LMEs) they secrete. Because knowledge of the kinetic parameters
is important to better design and operate bioreactors to cultivate these fungi for degradation and/or to produce LME(s), these
parameters were determined using Trametes versicolor ATCC 20869 (ATCC, American Type Culture Collection) in a magnetic stir bar reactor. A complete set of kinetic data has not
been previously published for this culture. Higher than previously reported growth rates with high laccase production of up
to 1,385 U l−1 occurred during growth without or glucose limitation. The maximum specific growth rate averaged 0.94 ± 0.23 day−1, whereas the maximum specific substrate consumption rates for glucose and ammonium were 3.37 ± 1.16 and 0.15 ± 0.04 day−1, respectively. The maximum specific oxygen consumption rate was 1.63 ± 0.36 day−1. 相似文献
8.
Xu XJ Chen CQ Wang ZY Zhang Y Hou AX Li CH Liu Y 《Biological trace element research》2009,127(3):269-277
The antibacterial effect of Zn(II), tetraphenyl porphyrin (TPP), propdioxyl bridged tetraphenyl bisporphyrin 1, and its metallobisporphyrin complexes (ZnMnbisporphyrin 2 and ZnZnbisporphyrin 3) towards Staphylococcus aureus growth was investigated by microcalorimetry at 37°C. Differences in their capacities to inhibit the growth metabolism of
S. aureus were observed. By analyzing the power–time curves, crucial parameters such as the rate constant of bacterial growth (k), inhibitory ratio (I), and generation time (t
G) were determined. The growth rate constant (k) of S. aureus (in the log phase) in the presence of the drugs decreased linearly with increasing concentrations of the complexes. The sequence
of the antibacterial activities of these compounds tested was 3 > 2 > 1 > Zn(II) > TPP. ZnZnbisporphyrin 3 is proposed to benefit from the synergetic effects of Zn(II) and 1. 相似文献
9.
The actions of two novel diselenide-bridged bis(porphyrin)s (1 and 2) on Staphylococcus aureus growth was investigated by microcalorimetry at 37.00°C, compared with that of Na2SeO3. Differences in their capacities to inhibit the growth metabolism of S. aureus were observed. By analyzing the power–time curves, crucial parameters such as the rate constant of bacterial growth (k), inhibitory rate (I), and generation time (t
G) were determined. The growth rate constant (k) of S. aureus (in the log phase) in the presence of the drugs decreased with increasing concentrations of the drugs regularly. The relationship
of k and c is nearly linear for diselenide-bridged bis(porphyrin) 2. The sequence of the antibacterial activities of these selenium compounds tested was 2 > 1 > Na2SeO3. 相似文献
10.
Xiuping Zou Demou Li Xiaoying Luo Keming Luo Yan Pei 《In vitro cellular & developmental biology. Plant》2008,44(3):169-177
Highly efficient Agrobacterium-mediated transformation of trifoliate orange (Poncirus trifoliata (L.) Raf.) was achieved via indirect shoot organogenesis. Stable transformants were obtained from epicotyl segments infected
with Agrobacterium strain EHA 105 harboring the binary vector pBI121, which contained the neomycin phosphotransferase gene (NPTII) as a selectable
marker and the β-glucuronidase (GUS) gene as a reporter. The effects of regeneration and selection conditions on the transformation
efficiency of P. trifoliata (L.) Raf. have been investigated. A 7-d cocultivation on a medium with 8.86 μM 6-benzylaminopurine (BA)+1.43 μM indole-3-acetic
acid (IAA) was used to improve callus formation from epicotyl segments after transformation. A two-step selection strategy
was developed to select kanamycin-resistant calluses and to improve rooting of transgenic shoots. Transgenic shoots were multiplied
on shoot induction medium with 1.11 μM BA + 5.71 μM IAA. Using the optimized transformation procedure, transformation efficiency
and rooting frequency reached 417% and 96%, respectively. Furthermore, the number of regenerated escape shoots was dramatically
reduced. Stable integration of the transgenes into the genome of transgenic citrus plants was confirmed by GUS histochemical
assay, PCR, and Southern blot analysis. 相似文献
11.
Vishal Gupta Manoj Kumar Puja Kumari C. R. K. Reddy Bhavanath Jha 《Journal of applied phycology》2011,23(2):209-218
This study reports on the optimization of protoplast yield from two important tropical agarophytes Gracilaria dura and Gracilaria verrucosa using different cell-wall-degrading enzymes obtained from commercial sources. The conditions for achieving the highest protoplast
yield was investigated by optimizing key parameters such as enzyme combinations and their concentrations, duration of enzyme
treatment, enzyme pH, mannitol concentration, and temperature. The significance of each key parameter was also further validated
using the statistical central composite design. The enzyme composition with 4% cellulase Onozuka R-10, 2% macerozyme R-10,
0.5% pectolyase, and 100 U agarase, 0.4 M mannitol in seawater (30‰) adjusted to pH 7.5 produced the highest protoplast yields
of 3.7 ± 0.7 × 106 cells g−1 fresh wt for G. dura and 1.2 ± 0.78 × 106 cells g−1 fresh wt for G. verrucosa when incubated at 25°C for 4–6 h duration. The young growing tips maximally released the protoplasts having a size of 7–15 μm
in G. dura and 15–25 μm in G. verrucosa, mostly from epidermal and upper cortical regions. A few large-size protoplasts of 25–35 μm, presumably from cortical region,
were also observed in G. verrucosa. 相似文献
12.
Symptoms of fairy rings caused by Lepista sordida have been reported on Zoysiagrass (Zoysia spp.) turf maintained at fairway height (2 cm), but not on bentgrass (Agrostis spp.) maintained at putting green height (0.5 cm). The mycelia of this fungus inhabit primarily the upper 0–2 cm layer of
the soil extending into the thatch. To compare conditions for the mycelial growth in Z. matrella turf to those in A. palustris turf, we examined the effects of nutrients, temperature, water potential, and pH in the field as well as in the laboratory.
Greater growth of the mycelia was observed in medium that included hot water extracts from soil of the 0–1 cm zone in Z. matrella turf compared to that from A. palustris. The upper soil layer in Z. matrella turf contained more organic matter from clippings than that in A. palustris. The temperature and water potential of the 0–2 cm soil zone in Z. matrella turf were also more favorable for the mycelial growth. The soil pH values of this zone in Z. matrella turf were less favorable compared to A. palustris but within the range for accelerating mycelial growth.
Part of this study was presented orally at the 46th meeting of the Mycological Society of Japan in 2002 相似文献
13.
Honoré G. Ouattara Ban L. Koffi Germain T. Karou Abdourahamane Sangaré Sebastien L. Niamke Jacques K. Diopoh 《World journal of microbiology & biotechnology》2008,24(9):1753-1760
The role of bacilli in cocoa fermentation is not well known. Their potential of production of pectinolytic enzymes during
this process was evaluated. Bacillus growth was monitored and pectinolytic strains were screened for their use of pectin as sole carbon source. Effects of cocoa
fermentation parameters susceptible to influence on enzyme production were analysed. Among 98 strains isolated, 90 were positive
for pectin degradation and 80% of them presented detectable pectinolytic activities in submerged fermentation. Forty-eight
strains produced polygalacturonase (PG), 47 yielded pectin lyase (PL) and 23 strains produced both enzymes. Bacilli growth
was not significantly affected during fermentation. PL production was favoured by galactose, lactose, glucose as sugars, and
arginine, glutamine, cysteine and ammonium sulphate as nitrogen compounds. Pectin at low concentration (0.05%) and iron stimulated
PL production. It was strongly repressed by galacturonic acid (1%), and negatively affected by nitrogen starvation, zinc and
temperatures above 45°C. PL yield was very weak below pH 4.0 and in anaerobic conditions. PG production was weakened by sucrose
and cation depletion. It was increased slightly by cysteine, ammonium nitrate and nitrogen starvation and significantly above
40°C. PG synthesis was not affected by acidic pH (3.0–6.0) or oxygen availability. As fermentation products, lactate and acetate
lowered the production of both enzymes while ethanol had no effect. The high proportion of pectinolytic producers among the
strains studied and analysis of factors influencing pectinolytic enzymes production, suggest that Bacillus sp. is liable to produce at least one enzyme during cocoa fermentation. 相似文献
14.
Ringø E Salinas I Olsen RE Nyhaug A Myklebust R Mayhew TM 《Cell and tissue research》2007,328(1):109-116
Furunculosis and vibriosis are diseases that cause severe economic losses in the fish-farming industry. The foregut of the
Atlantic salmon (Salmo salar L.) was exposed in vitro to two fish pathogens, Aeromonas salmonicida (causative agent of furunculosis) and Vibrio anguillarum (causative agent of vibriosis), and to one probiotic strain, Carnobacterium divergens, at 6 × 104 or 6 × 106 viable bacteria per milliliter. Histological changes following bacterial exposure were assessed by light and electron microscopy.
Control samples (foregut exposed to Ringer’s solution only) and samples exposed only to C. divergens had a similar appearance to intact intestinal mucosal epithelium, with no signs of damage. However, exposure of the foregut
to the pathogenic bacteria resulted in damaged epithelial cells, cell debris in the lumen, and disorganization of the microvilli.
Co-incubation of the foregut with a pathogen and C. divergens did not reverse the damaging effects caused by the pathogen, although these were alleviated when probiotic bacteria were
used. Based on these results, we suggest that the probiotic bacterium, C. divergens, is able to prevent, to some extent, pathogen-induced damage in the Atlantic salmon foregut.
I. Salinas thanks Fundacion Seneca for a PhD studentship. 相似文献
15.
Continuous degradation of mixtures of 4-nitrobenzoate and 4-aminobenzoate by immobilized cells of Burkholderia cepacia strain PB4 总被引:1,自引:0,他引:1
Although isolated on 4-aminobenzoate, Burkholderia cepacia strain PB4 is also able to grow on 4-nitrobenzoate. Degradation of an equimolar mixture of the nitroaromatic compound 4-nitrobenzoate
and its corresponding aminoaromatic derivative 4-aminobenzoate by this strain was investigated. Batch experiments showed that,
irrespective of preculturing conditions, both compounds were degraded simultaneously. The mixture-degrading ability of B. cepacia strain PB4 was subsequently tested in continuous packed bed reactors (PBR) with the strain immobilized on Celite grade R-633
or R-635. Higher degradation rates were achieved with the larger particles of Celite R-635. Maximum simultaneous degradation
rates per liter of packed bed of 0.925 mmol l−1 h−1 4-nitrobenzoate and 4-aminobenzoate were obtained for an applied loading rate of the same value (0.925 mmol l−1 h−1 of each compound). Even when the applied load was not removed in its entirety, neither of the two compounds was degraded
preferentially but a percentage of both of them was mineralized. The present study shows the possibility for a pure strain
to biodegrade not only a nitroaromatic compound (4-nitrobenzoate) but also its corresponding amino derivative (4-aminobenzoate)
continuously and simultaneously.
Received: 23 November 1998 / Revision received: 6 April 1999 / Accepted: 9 April 1999 相似文献
16.
Yongbing Huang Xiaoli Xie Long Yang Jing Zhang Guoqing Li Daohong Jiang 《World journal of microbiology & biotechnology》2011,27(12):2799-2805
Three strains of Sclerotinia sclerotiorum, namely Ep-1PB (PB), Ep-1PK (PK) and Ep-1PNA5 (A5), were compared for the production of oxalic acid (OA) on potato dextrose
agar (PDA) and Maxwell agar medium (MAM) and for mycelial susceptibility to infection by the mycoparasite Coniothyrium minitans on PDA. Results showed that strain PB produced negligible oxalate, whereas strain PK was detected to produce oxalate, but
much less than that produced by strain A5. The three investigated strains differed slightly in mycelial growth rates and mycelial
biomass on PDA. However, colonies of strains PB and PK formed on PDA were more susceptible to invasion by C. minitans than colonies of strain A5. Meanwhile, amendment of synthetic oxalate in PDA at 0.25–2.00 mg g−1 medium suppressed aggressiveness of C. minitans in invasion of colonies of S. sclerotiorum strain PB developed on this medium. These results suggest that infection of hyphae of S. sclerotiorum is negatively affected by the presence of oxalate. The importance of oxalate degradation by C. minitans in its mycoparasitism on hyphae of S. sclerotiorum provides a clue for improvement of the biocontrol efficacy of C. minitans in the future. 相似文献
17.
Manipulation of the DNA coding for the desulphurizing activity in a new isolate of Arthrobacter sp. 总被引:3,自引:0,他引:3
A new bacterial strain able to cleave CS bonds from organosulphur heterocyclic compounds through the 4-S pathway and tentatively
classified as Arthrobacter sp. was recently isolated. In the present short article we describe the cloning and the characterization of the DNA encoding
the enzymes responsible for desulphurization in this microorganism, referred to as Arthrobacter sp. DS7. The desulphurization operon was found to be located in a large plasmid that also bears the genes conferring cadmium
and arsenic resistance. By shortening this plasmid, a new cloning vector was prepared and used to obtain a recombinant derivative
strain that desulphurizes dibenzothiophene despite of the presence of inorganic sulphur in the growth medium.
Received: 25 May 1998 / Received revision: 4 September 1998 / Accepted: 13 September 1998 相似文献
18.
A. M. Fauzi David J. Hardman Alan T. Bull 《Applied microbiology and biotechnology》1996,46(5-6):660-666
The degradation of low concentrations of 1,3-dichloro-2-propanol (1,3-DCP) and related halohydrins by whole cells and cell-free
extracts of soil bacteria has been investigated. Three bacteria (strains A1, A2, A4), isolated from the same soil sample,
were distinguished on the basis of cell morphology, growth kinetics and haloalcohol dehalogenase profiles. Strain A1, probably
an Agrobacterium sp., dehalogenated 1,3-DCP with the highest specific activity (0.33 U mg protein−1) and also had the highest affinity for 1,3-DCP (K
m, 0.1 mM). Non-growing cells of this bacterium dehalogenated low concentrations of 1,3-DCP with a first-order rate constant
(k
1) of 1.13 h−1 . The presence of a non-dehalogenating bacterium, strain G1 (tentatively identified as Pseudomonas mesophilius), did not enhance the dehalogenation rate of low 1,3-DCP concentrations. However, the mixed-species consortium of strains
A1 and G1 had greater stability than the mono-species culture at DCP concentrations above 1.0 gl−1.
Received: 30 April 1996 / Received revision: 30 July 1996 / Accepted: 5 August 1996 相似文献
19.
A. Q. Hurtado A. T. Critchley A. Trespoey G. Bleicher-Lhonneur 《Journal of applied phycology》2008,20(5):551-555
Kappaphycus striatum var. sacol was grown in two separate studies: (1) at two stocking densities, and (2) at four different depths, each for three different
durations of culture (30, 45 and 60 days) in order to determine the growth rate of the seaweed and evaluate the carrageenan
content and its molecular weight. The results demonstrated that stocking density, duration of culture and depth significantly
(P < 0.01) affected the growth rate, carrageenan content and molecular weight of K. striatum var. sacol. Decreasing growth rate was observed at both stocking densities and at four depths as duration of culture increased. A lower
stocking density (500 g m−1line−1) showed a higher growth rate for the shortest durations, i.e. 30 days, as compared to those grown at a higher density. Likewise,
decreasing growth rate was observed as depth increased, except at 50 cm after 60 days of culture. A 45-day culture period
produced the highest molecular weight at both stocking densities (500 g m−1line−1 = 1,079.5 ± 31.8 kDa, 1,000 g m−1line−1 = 1,167 ± 270.6 kDa). ‘Sacol’ grown for 30 days at 50 cm (1,178 kDa) to 100 cm (1,200 kDa) depth showed the highest values
of molecular weight of carrageenan extracted. The results suggested that K. striatum var. sacol is best grown at a stocking density of 500 g m−1line−1, at a depth of 50–100 cm, and for a duration of 30 days in order to provide the highest growth rate, carrageenan content
and molecular weight. 相似文献
20.
G. H. van Geel-Schutten F. Flesch B. ten Brink M. R. Smith L. Dijkhuizen 《Applied microbiology and biotechnology》1998,50(6):697-703
A total of 182 Lactobacillus strains were screened for production of extracellular polysaccharides (EPS) by a new method: growth in liquid media with
high sugar concentrations. Sixty EPS-positive strains were identified; 17 strains produced more than 100 mg/l soluble EPS.
Sucrose was an excellent substrate for abundant EPS synthesis. The ability to produce glucans appears to be widespread in
the genus Lactobacillus. The monosaccharide composition of EPS produced by Lactobacillus reuteri strain LB 121 varied with the growth conditions (solid compared to liquid medium) and the sugar substrates (sucrose or raffinose)
supplied in the medium. Strain LB 121 produced both a glucan and a fructan on sucrose, but only a fructan on raffinose. This
is the first report of fructan production by a Lactobacillus species. EPS production increased with increasing sucrose concentrations and involved extracellular sucrase-type enzymes.
Received: 20 March 1998 / Received revision: 12 August 1998 / Accepted: 12 August 1998 相似文献