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1.
Klaus-Peter Michel Pablo Exss-Sonne Gabriele Scholten-Beck Uwe Kahmann Hans Georg Ruppel Elfriede K. Pistorius 《Planta》1998,205(1):73-81
Iron-deficiency-induced protein A (IdiA) with a calculated molecular mass of 35 kDa has previously been shown to be essential
under manganese- and iron-limiting conditions in the cyanobacteria Synechococcus PCC 6301 and PCC 7942. Studies of mutants indicated that in the absence of IdiA mainly photosystem II becomes damaged, suggesting
that the major function of IdiA is in Mn and not Fe metabolism (Michel et al. 1996, Microbiology 142: 2635–2645). To further elucidate the function of IdiA, the immunocytochemical localization of IdiA
in the cell was examined. These investigations provided evidence that under mild Fe deficiency IdiA is intracellularly localized
and is mainly associated with the thylakoid membrane in Synechococcus PCC 6301. The protein became distributed throughout the cell under severe Fe limitation when substantial morphological changes
had already occurred. For additional verification of a preferential thylakoid membrane association of IdiA, these investigations
were extended to the thermophilic Synechococcus elongatus. In this cyanobacterium Mn deficiency could be obtained more rapidly than in the mesophilic Synechococcus PCC 6301 and PCC 7942, and the thylakoid membrane structure proved to be more stable under limiting growth conditions. The
immunocytochemical investigations with this cyanobacterium clearly supported a thylakoid membrane association of IdiA. In
addition, evidence was obtained for a localization of IdiA on the cytoplasmic side of the thylakoid membrane. All available
data support a function of IdiA as an Mn-binding protein that facilitates transport of Mn via the thylakoid membrane into
the lumen to provide photosystem II with Mn. A possible explanation for the observation that IdiA was not only expressed under
Mn deficiency but also under Fe deficiency is given in the discussion.
Received: 28 July 1997 / Accepted: 26 November 1997 相似文献
2.
L. Lesage-Meessen M. Haon M. Delattre J.-F. Thibault B. Colonna Ceccaldi M. Asther 《Applied microbiology and biotechnology》1997,47(4):393-397
The effects of adding cellobiose on the transformation of vanillic acid to vanillin by two strains of Pycnoporus cinnabarinus MUCL39532 and MUCL38467 were studied. When maltose was used as the carbon source in the culture medium, very high levels
of methoxyhydroquinone were formed from vanillic acid. When cellobiose was used as the carbon source and/or added to the culture
medium of P. cinnabarinus strains on day 3 just before vanillic acid was added, it channelled the vanillic acid metabolism via the reductive route
leading to vanillin. Adding 3.5 g l−1 cellobiose to 3-day-old maltose cultures of P. cinnabarinus MUCL39532 and 2.5 g l−1 cellobiose to 3-day-old cellobiose cultures of P. cinnabarinus MUCL38467, yielded 510 mg l−1 and 560 mg l−1 vanillin with a molar yield of 50.2 % and 51.7 % respectively. Cellobiose may either have acted as an easily metabolizable
carbon source, required for the reductive pathway to occur, or as an inducer of cellobiose:quinone oxidoreductase, which is
known to inhibit vanillic acid decarboxylation.
Received: 24 July 1996 / Received revision: 29 November 1996 / Accepted: 29 November 1996 相似文献
3.
Evaluation of four fresh-water unicellular cyanobacteria as potential hosts for mosquitocidal toxins
Summary For biocontrol of mosquitoes, mosquitocidal toxin genes from Bacillus thuringiensis subsp. israelensis and Bacillus sphaericus have been cloned into a number of cyanobacteria. However, little is known about the persistence of such recombinant cyanobacteria in mosquito larval habitats. Four fresh water unicellular cyanobacteria, Synechococcus PCC6301, PCC7425, PCC7942 and Synechocystis PCC 6803, were evaluated under laboratory conditions related to mosquito breeding environments. Results indicated that Synechococcus PCC6301 was potentially the most suitable organism for use in the natural mosquito habitat as it could tolerate a wide range of temperatures, salinities, and biological and chemical insecticides. Moreover, strain PCC6301 could be ingested and digested by Culex quinquefasciatus larvae and could support the development of larvae to full insect maturity. 相似文献
4.
H. De Wever S. De Cort I. Noots H. Verachtert 《Applied microbiology and biotechnology》1997,47(4):458-461
2-Hydroxybenzothiazole (OBT) is present in wastewaters from the industrial production of the rubber vulcanization accelerator
2-mercaptobenzothiazole (MBT). We have achieved the first isolation of axenic bacterial cultures capable of the degradation
of OBT and growth on this substrate as the sole source of carbon, nitrogen and energy. All isolates had similar characteristics
corresponding to one particular isolate, which was studied in more detail and identified as Rhodococcus rhodochrous. The strains were also capable of degrading benzothiazole (BT) but not MBT or benzothiazole-2-sulphonate (BTSO3). OBT was degraded at a concentration of up to 600 mg · l−1. BT was toxic above 300 mg · l−1. MBT inhibited OBT degradation. Growth on OBT was not significantly different at pH values of between 6.3 and 7.9 or salt
concentrations between 1 % and 3 %. In shake flasks the cells clumped together, which resulted in a lower rate of oxygen transfer
and slower degradation as compared to cells grown on OBT in a stirred reactor.
Received: 22 August 1996 / Received revision: 29 November 1996 / Accepted: 29 November 1996 相似文献
5.
Gabaculine (2,3-dihydro 3-amino benzoic acid) is a potent inhibitor of tetrapyrrole biosynthesis in organisms that use the
C5 pathway for the synthesis of δ-aminolaevulinic acid. Glutamate semialdehyde aminotransferase (GSA-AT), the enzyme catalysing the formation of this key precursor
of tetrapyrroles, is normally inhibited by concentrations of gabaculine in the order of 5 μM. However, in Synechococcus 6301 strain GR6, a cyanobacterium that is resistant to 100 μM gabaculine, this enzyme has undergone two changes in structure:
a deletion of three amino acids from positions 5 to 7 and the substitution of isoleucine for methionine at position 248. To
establish the effect in vivo of these specific changes in the gene for GSA-AT (hemL), a suicide vector (pHS7) containing an antibiotic cassette was constructed to achieve the replacement, by homologous recombination,
of the wild-type hemL gene in the chromosome by a modified form of the gene. Recombinant strains of Synechococcus 7942 obtained using pHS7-hemL
GR6 were indistinguishable from Synechococcus 6301 GR6 in terms of the resistance of growth and of chlorophyll accumulation to high concentrations of gabaculine, while
a wild-type recombinant produced using pHS7-hemL
WT had retained its sensitivity. Southern hybridisation using gene probes for hemL, amp
r
and cm
r
confirmed that chromosomal integration of the plasmids had occurred in both WT and GR6 recombinants. Growth and chlorophyll
accumulation in equivalent strains with the hemL gene containing either the deletion or the transition characteristic of Synechococcus 6301 GR6 were inhibited by 10 μM gabaculine. Consequently, resistance in vivo to high concentrations of this compound is
dependent on both the changes in gene/enzyme structure. This investigation has established the effectiveness of the suicide
vector pHS7 for studying the effect in vivo of specific changes in the hemL gene. It has also demonstrated that replacement of the wild-type gene by that from Synechococcus 6301 GR6 is sufficient to confer resistance in vivo to high concentrations of gabaculine.
Received: 7 October 1996 / Accepted: 15 January 1997 相似文献
6.
7.
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
8.
Lipids are important entomopathogenic nematode nutritional components because they are energy reserves and serve as indicators
of nematode quality. The composition and concentration of the media lipid component determine bacterial and nematode yields.
Heterorhabditis bacteriophora and its symbiont, Photorhabdus luminescens, were cultured in media containing various lipid sources. As lipid concentration increased from 2.5% to 8.0% (w/v), the final
yield and productivity [calculated from the number of infective juveniles (IJ)] increased significantly from 2.1 × 105 IJ ml−1 to 2.8 × 105 IJ ml−1 (P < 0.05) and from 8.9 × 105 IJ l−1 day−1 to 11.8 × 105 IJ l−1 day−1 (P < 0.05), respectively. The nematode yield coefficient (IJ per gram of media), however, decreased from 2.8 × 106 to 2.2 × 106 (P < 0.05), while recovery increased from 45.3% to 58.0% (P < 0.05). Bacterial cell mass remained constant at 4.6 mg ml−1 with changing lipid content (P > 0.05). The largest nematode yield (2.8 × 105 IJ ml−1) was achieved within 8 days, using a medium containing an 8% (w/v) olive and canola oil (50:50 w/v) combination. Moreover,
developmental synchrony was achieved in this medium with 96% infective juveniles. In short, lipid sources rich in mono-unsaturated
fatty acids and poor in saturated fatty acids produced optimal nematode growth.
Received: 1 May 2000 / Received revision: 17 July 2000 / Accepted: 27 July 2000 相似文献
9.
K. Kirimura T. Sato N. Nakanishi M. Terada S. Usami 《Applied microbiology and biotechnology》1997,47(2):127-131
Interspecific protoplast fusion between␣Aspergillus terreus, an itaconic acid producer, and A.␣usamii, a glucoamylase producer, was done to breed new koji molds producing itaconic acid from starch. Protoplast fusion between auxotrophic mutant strains by poly(ethylene glycol) treatment
produced prototrophic fusants with a fusion frequency of 10−5−10−4. The stabilities of some fusants obtained were confirmed by successive subcultures. Conidial analyses of DNA contents and
the number of nuclei indicated that the fusants obtained were haploids like the parental strains. One of the stable fusants,
F-112, morphologically resembled A. terreus, and produced maximally 35.9 mg/ml itaconic acid from soluble starch (120 mg/ml) at day 6 of cultivation. This productivity
from soluble starch was five times as high as that of A. terreus and 70 % of that of A. terreus from glucose (120 mg/ml).
Received: 28 June 1996 / Received revision: 3 September 1996 / Accepted: 29 September 1996 相似文献
10.
Cyanobacteria were a major constituent of phototrophic communities in the lakes, ponds and streams of Bylot Island, in the
Canadian high Arctic. The waters spanned a range of temperatures (1.8–16.8°C in late July), pH regimes (6.2–9.2) and conductivities
(1.5–1700 μS cm−1) but nutrient concentrations were consistently low (< 1 μg dissolved reactive P l−1 at all sites; < 10 μg NO3-N l−1 at most sites). Picoplanktonic species (Synechococcus spp.) were often the numerical dominants in the plankton, and periphytic filamentous species (Oscillatoriaceae) commonly
formed thick (5–50 mm) benthic mats. Bloom-forming species of cyanobacteria were either absent or poorly represented even
in Chla-rich ponds. The total community biomass ranged from 0.1 to 29.8 μg Chla l−1 in the plankton and from 1.1 to 34.8 μg Chla cm−2 in the benthos. The in vivo absorbance characteristics of isolates from these environments indicated a genetically diverse
range of species in each group of Arctic cyanobacteria. Growth versus irradiance relationships were determined for each of
the isolates and similarly revealed large genetic differences (maximum growth rates from 0.17 to 0.61 day−1), even between morphologically identical taxa. A comparison of nutrients, pigment concentrations and species composition
underscores the strong similarities between freshwater ecosystems in the north and south polar zones.
Received: 3 June 1996 / Accepted: 3 November 1996 相似文献
11.
H. Sudo A. Yamada K. Kokatsu N. Nakamura T. Matsunaga 《Applied microbiology and biotechnology》1997,47(1):78-82
The marine photosynthetic bacterium Chromatium sp. successfully removed orthophosphate when grown phototrophically. The phosphate-uptake rate was almost constant at more
than 5.0 mg- PO4
3−/l in synthetic medium. Addition of seawater causes flocculation of this strain. The successful use of seawater as an inexpensive
source of magnesium could prove to be effective in the removal of photosynthetic bacterial cells from a medium. A semicontinuous
culture system was used for the removal of low concentrations of phosphate and the phosphate-uptake activity of Chromatium sp. was maintained under 0.1 day−1 dilution rate. This strain was also able to remove high concentrations of phosphate from domestic sewage.
Received 24 May 1996 / Received revision: 5 August 1996 / Accepted: 6 September 1996 相似文献
12.
The magnesium content of Saccharomyces cerevisiae was found to vary by up to fivefold at differing␣ stages of batch growth and during growth in the presence of differing magnesium
concentrations. Excess Mg was primarily sequestered in vacuoles. Mn2+-uptake experiments revealed that Mg-enriched cells had a markedly reduced capacity for Mn2+ accumulation. For example, after 6 h incubation in the presence of 50 μM Mn2+, Mn levels were approximately twofold higher in cells previously grown in unsupplemented medium than in those from Mg-supplemented
medium. These differences were further accentuated at higher Mn2+ concentrations and were not attributable to altered cell-surface charge or altered cell-surface Mn2+ binding. Cellular Mg status also influenced Mn toxicity towards S. cerevisiae. During exposure to 5 mM Mn2+, 50% reductions in the viability of cells with initial Mg contents of approximately 1400 and 2700 nmol (109 cells)−1 occurred after approximately 1.6 h and 3.6 h respectively. In cells containing 3300 nmol Mg (109 cells)−1, more than 75% viability was still maintained after 7 h incubation with 5 mM Mn2+. It is concluded that Mn2+ uptake and toxicity in S. cerevisiae are strongly influenced by intracellular Mg, possibly through Mg-dependent regulation of divalent-cation transport activity.
Received: 15 May 1996 / Received revision: 13 September 1996 / Accepted: 22 September 1996 相似文献
13.
M. S. Umikalsom A. B. Ariff Z. H. Shamsuddin C. C. Tong M. A. Hassan M. I. A. Karim 《Applied microbiology and biotechnology》1997,47(5):590-595
Studies on the feasibility of using delignified oil palm empty-fruit-bunch (OPEFB) fibres as a substrate for cellulase production
by Chaetomium globosum strain 414 were carried out in shake-flask cultures containing different types and concentrations of nitrogen source. Peptone,
as nitrogen source, gave maximum production of all the three main components of the cellulase complex (endoglucanase or carboxymethylcellulase,
cellobiohydrolase or filter-paper-hydrolysing enzyme and β-glucosidase), followed by yeast extract, urea, KNO3 and (NH4)2SO4. The maximum specific growth rate (μmax) of C. globosum strain 414 grown in medium containing OPEFB and peptone was 0.038 h−1. In all the fermentations, the fungus was able to produce all the three cellulases with significant amounts of β-glucosidase,
except when using (NH4)2SO4 as nitrogen source, where β-glucosidase was not produced. With 6 g/l peptone and 10 g/l delignified OPEFB fibres, the fungus
produced maximum concentrations of FPase, carboxymethylcellulase and β-glucosidase: 1.4, 30.8 and 9.8 U/ml, giving productivities
of 10, 214 and 24 U l−1h−1, respectively. The cellulase mixture, partially purified by ammonium sulphate precipitation, was able to hydrolyse delignified
OPEFB fibres, converting about 68 % of the cellulosics to reducing sugars after 5 days.
Received: 17 June 1996 / Received revision: 18 November 1996 / Accepted: 23 November 1996 相似文献
14.
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
15.
Annual and interannual variability in phytoplankton at a permanent station off Kerguelen Islands, Southern Ocean 总被引:4,自引:4,他引:0
From November 1992 to February 1995 a quantitative and qualitative phytoplankton study was conducted at a permanent station
(Kerfix) southwest off the Kerguelen Islands, in the vicinity of the Polar Front (50°40′S–68°25′E). Phytoplankton populations
are low in this area both during summers and winters. They consist, in order of decreasing cell abundance, of pico- and nanoflagellates
(1.5–20 μm), coccolithophorids (<10 μm), diatoms (5–80 μm) and dinoflagellates (6–60 μm). Flagellates form the dominant group
throughout the year and attain the highest summer average of 3.0 × 105 cells l−1. Next in abundance year-round are coccolithophorids with the dominant Emiliania huxleyi (highest summer 1992 average 1.9 × 105 cells l−1), diatoms (summer 1992 average 1.0 × 105 cells l−1) and dinoflagellates (average 3.8 × 104 cells l−1). Winter mean numbers of flagellates and picoplankton do not exceed 8.4 × 104 cells l−1; those of the three remaining algal groups together attain 2 × 104 cells l−1. Summer peaks of diatoms and dinoflagellates are mainly due to the larger size species (>20 μm). The latter group contributes
most to the total cell carbon biomass throughout the year. Dominant diatoms during summer seasons include: Fragilariopsis kerguelensis, Thalassionema nitzschioides, Chaetoceros dichaeta, C. atlanticus, Pseudonitzschia heimii, and P. barkleyi/lineola. This diatom dominance structure changes from summer to summer with only F. kerguelensis and T. nitzschioides retaining their first and second positions. Any one of the co-dominant species might be absent during some summer period.
The variable diatom community structure may be due to southward meandering of the Polar Front bringing “warmer” species from
the north, and to the mixing of the water masses in this area. The entire community structure characterized both during summer
and winters by the dominance of flagellates can be related to deep mixing (ca. 40–200 m) of the water column as the probable
controlling factor.
Received: 13 November 1997 / Accepted: 11 May 1998 相似文献
16.
Kinetics of the steady-state oxidation of n–alkylferrocenes (alkyl = H, Me, Et, Bu and C5H11) by H2O2 to form the corresponding ferricenium cations catalyzed by horseradish peroxidase has been studied in micellar systems of
Triton X-100, CTAB, and SDS, mostly at pH 6.0 and 25 °C. The rate of oxidation of ferrocenes with longer alkyl radicals is
too slow to be measured. The reaction obeying the [RFc]:[H2O2] = 2 : 1 stoichiometry is strictly first-order in both HRP and RFc in a wide concentration range. The corresponding observed
second-order rate constants k, which refer to the interaction of the peroxidase compound II (HRP-II) with RFc, decrease with the elongation of the alkyl
substituent R, and this in turn is accompanied by an increase in the formal redox potentials E°′ in the same medium. Increasing the surfactant concentration lowers the rate constants k, the effect being due to the nonproductive binding of RFc to micelles rather than to enzyme inactivation. The micellar effects
are accounted for in terms of the Berezin pseudo-phase model of micellar catalysis applied to the interaction of enzyme with
organometallic substrates. The oxidation was found to occur primarily in the aqueous pseudo-phase and the calculated intrinsic
second-order rate constants k
w are (1.9 ± 0.5)×105, (2.7 ± 0.1)×104, and (5.9 ± 0.6)×103 M–1 s–1 for HFc, EtFc, and n–BuFc, respectively. The data obtained were used for estimating the self-exchange rate constants for the HRP-II/HRP couple
in terms of the Marcus formalism.
Received: 15 July 1996 / Accepted: 15 November 1996 相似文献
17.
Reduction of biomass in a bioscrubber for waste gas treatment by limited supply of phosphate and potassium ions 总被引:2,自引:0,他引:2
Elimination of n-butanol from the gas phase was examined with a mixed culture in a compact bioscrubber. The extent of the cell concentration
was limited by the supply of n-butanol, phosphate or potassium, and the growth rate was determined by the dilution rate. With n-butanol as the limiting substrate the cellular yield was 0.53 g dry cell weight/g n-butanol. Phosphate limitation decreased this yield to 0.34 g and potassium limitation to 0.31 g dry cell weight/g n-butanol at a dilution rate of 0.1/h. Under these conditions n-butanol was eliminated from the gas phase by 84%–100%. In the same order of limitations the specific degradation rate ranged
from 0.19 g to 0.32 g n-butanol g dry cell weight−1 h−1. The fraction of n-butanol required to satisfy the needs for maintenance energy increased significantly depending on the limiting nutrient.
Limitation by n-butanol, phosphate or potassium caused a maintenance requirement of 0.07, 0.16 and 0.34 g n-butanol g dry cell weight−1 h−1, thus showing a fivefold increase. This high demand for the carbon source demonstrated the feasibility of operating a bioscrubber
under mineral limitation to reduce biomass formation significantly, and to maintain a high degree of substrate elimination
from the gas phase.
Received: 22 May 1996 / Received revision: 23 July 1996 / Accepted: 5 August 1996 相似文献
18.
Gnotobiotic systems were used to assess the competitive abilities of bioluminescent Sinorhizobium meliloti strains L1 (RecA−) and L33 (RecA+) for growth and host plant nodulation in the presence of a reconstructed S. meliloti population. Three wild-type strains belonging to infective subgroups of a natural S. meliloti population were chosen as competitors in microcosm studies. Whereas the RecA+ strain L33 dominated the reconstructed population with respect to growth and alfalfa nodulation, the competitiveness of the
RecA− strain L1 was reduced compared to that of one of the field strains, but comparable to that of the other field isolates. This
result indicates that strain L1, despite its recA mutation, has the potential to compete successfully with a resident S. meliloti population after environmental release.
Received: 4 November 1996 / Received revision: 9 January 1997 / Accepted: 17 January 1997 相似文献
19.
The biodegradation of phenol by a pure culture of Pseudomonas putida was investigated in a continuously fed stirred-tank reactor, under aerobic conditions. The dilution rate was varied between
0.0174 h−1 and 0.278 h−1, covering a wide range of dissolved oxygen and the inhibition region of phenol. Through non-linear analysis of the data,
a dual-substrate growth kinetics, Haldane kinetics for phenol and Monod kinetics for oxygen, was derived with high correlation
coefficients. Respective biokinetic parameters were evaluated as μm = 0.569 h−1, K
p = 18.539 mg/l, K
i = 99.374 mg/l, K
o = 0.048 mg/l, Y
x/p = 0.521 g microorganism/g phenol and Y
x/o = 0.338 g microorganism/g oxygen, being in good agreement with other studies in the literature. Maintenance factors for both
phenol and oxygen were calculated for the first time for P. putida while the saturation coefficient for oxygen, K
o, was genuinely evaluated from the constructed model, not imported or adapted from other studies as reported in the literature.
All pertinent biokinetic parameters for P. putida have been calculated from continuous system data, which are most appropriate for use in continuous bioprocess applications.
Received: 29 July 1996 / Received revision: 18 November 1996 / Accepted: 23 November 1996 相似文献
20.
Hydrogen production with high yield and high evolution rate by self-flocculated cells of Enterobacter aerogenes in a packed-bed reactor 总被引:6,自引:1,他引:5
M. A. Rachman Y. Nakashimada T. Kakizono N. Nishio 《Applied microbiology and biotechnology》1998,49(4):450-454
Continuous hydrogen gas evolution by self-flocculated cells of Enterobacter aerogenes, a natural isolate HU-101 and its mutant AY-2, was performed in a packed-bed reactor under glucose-limiting conditions in
a minimal medium. The flocs that formed during the continuous culture were retained even when the dilution rate was increased
to 0.9 h−1. The H2 production rate increased linearly with increases in the dilution rate up to 0.67 h−1, giving maximum H2 production rates of 31 and 58 mmol l−1 h−1 in HU-101 and AY-2 respectively, at a dilution rate of more than 0.67 h−1. The molar H2 yield from glucose in AY-2 was maintained at about 1.1 at dilution rates between 0.08 h−1 and 0.67 h−1, but it decreased rapidly at dilution rates more than 0.8 h−1.
Received: 27 August 1997 / Received revision: 11 November 1997 / Accepted: 14 December 1997 相似文献