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1.
More than 80% of diphenyl phthalate (DPP) at 100 mg l−1 was degraded by Sphingomonas chungbukensis KCTC 2955 in a mineral salts medium at pH 7.0 and 30°C within 48 h. The maximum specific degradation rate was 5 mg DPP l−1 h−1. It was rapidly converted to monophenyl phthalate and phthalic acid which were further degraded. 相似文献
2.
Xueling Wu Yangyang Wang Qinyun Dai Renxing Liang Decai Jin 《World journal of microbiology & biotechnology》2011,27(11):2611-2617
Four aerobic bacterial strains capable of utilizing di-n-butyl phthalate (DBP) as the sole source of carbon and energy were isolated from river sediments. Based on the morphology,
biochemical characterization, and 16S rRNA gene sequence analysis, they were identified as Gordonia sp. The optimal conditions for DBP degradation by these strains were found to be pH 7.0, 30°C, and stirring at 175 rpm. These
four strains could degrade, respectively, 96, 98, 98, and 78% of DBP (400 mg l−1) as well as dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-octyl phthalate (DOP), di-isooctyl phthalate (DIOP), and di-isononyl phthalate (DINP). Furthermore, partial sequences of
the gene for 3,4-phthalate dioxygenase were obtained from all four strains. To our knowledge, this is the first time that
the 3,4-phthalate dioxygenase gene has been successfully cloned from Gordonia sp. 相似文献
3.
A plant growth-promoting rhizobacterium (PGPR) was isolated and identified as Gordonia sp. S2RP-17, which showed ACC deaminase and siderophore synthesizing activities. Its maximum specific growth rate was 0.54 ± 0.12 d−1 at 5,000 mg L−1 of total petroleum hydrocarbon (TPH), and its maximum diesel degradation rate was 2,434.0 ± 124.4 mg L−1 d−1 at 20,000 mg L−1 of TPH. The growth of Zea mays was significantly promoted by the inoculation of Gordonia sp. S2RP-17 in the diesel-contaminated soil. Measured TPH removal efficiencies by various means were 13% by natural attenuation,
84.5% by planting Zea mays, and 95.8% by the combination of Zea mays and Gordonia sp. S2RP-17. The S2RP-17 cell counts were maintained at 1 × 106 CFU g-soil−1 during the remediation period, although they slightly decreased from their initial numbers (2.94 × 107 CFU g-soil−1). These results indicate that rhizoremediation using both Zea mays and Gordonia sp. S2RP-17 is a promising strategy for enhancing remediation efficiency of diesel-contaminated soils. 相似文献
4.
Biodegradation of BTEX by a microbial consortium isolated from a closed municipal landfill was studied using respirometric
techniques. The kinetics of biodegradation were estimated from experimental oxygen uptake data using a nonlinear parameter
estimation technique. All of the six compounds were rapidly degraded by the microbial culture and no substrate inhibition
was observed at the concentration levels examined (200 mg L−1 as COD). Microbial growth and contaminant degradation were adequately described by the Monod equation. Considerable differences
were observed in the rates of BTEX biodegradation as seen from the estimates of the kinetic parameters. A three-fold variation
was seen in the values of the maximum specific growth rate, μmax. The highest value of μmax was 0.389 h−1 for p-xylene while o-xylene was characterized by a μmax value of 0.14 h−1, the lowest observed in this study. The half saturation coefficient, K
s, and the yield coefficient, Y, varied between 1.288–4.681 mg L−1 and 0.272–0.645 mg mg−1, respectively. Benzene and o-xylene exhibited higher resistance to biodegradation while toluene and p-xylene were rapidly degraded. Ethylbenzene and m-xylene were degraded at intermediate rates. In biodegradation experiments with a multiple substrate matrix, substrate depletion
was slower than in single substrate experiments, suggesting an inhibitory nature of substrate interaction.
Received 15 February 1998/ Accepted in revised form 5 July 1998 相似文献
5.
L. Xu U. Najeeb R. Raziuddin W. Q. Shen J. Y. Shou G. X. Tang W. J. Zhou 《In vitro cellular & developmental biology. Plant》2009,45(5):610-618
Wetland species mat rush (Juncus effusus L.) is an important economic plant, but no information is available regarding plant regeneration, callus induction, and its
proliferation from in vitro seed grown plantlets. The present study investigates the effects of growth regulator combinations and medium innovation on
tissue culture system of five mat rush varieties. Addition of N6-benzyladenine (BA) and 2,4-dichlorophenoxyacetic acid (2,4-D)
in Murashige and Skoog (MS) medium showed significantly positive effect on callus proliferation, plant regeneration, and its
multiplication compared to the medium devoid of BA. The highest callus induction frequency (80.95%, 90.48%, 75.40%, 70.83%,
and 83.33%) was observed in MS medium containing 0.5 mg L−1 (2.2 μM) BA in Yinlin-1, Nonglin-4, Gangshan, Taicao, and Taiwan green, respectively. Various growth regulator combinations
with successive subculture (medium replacement) were found essential to develop organogenic calluses and to regenerate shoots.
The combination of 0.1 mg L−1 BA (0.4 μM) and 2 mg L−1 2,4-D (9.0 μM) in MS medium was found best for callus proliferation for all the varieties under trial. The plant regeneration
required two steps involving successive medium replacements as well as optimal hormonal balances. Successful plant regeneration
(over 70%) was observed only by transferring the organogenic callus from regeneration medium I [MS medium containing 0.5 mg
L−1 BA (2. μM) and 1.0 mg L−1 kinetin (KT; 4.6 μM)] to the regeneration medium II [MS medium containing 0.5 mg L−1 BA (2.2 μM), 1.0 mg L−1 KT (4.6 μM) and 3.0 mg L−1 indoleacetic acid (IAA; 17.1 μM)]. Our results confirmed the importance of the ratio of auxin (IAA) to cytokinin (BA and
KT) in the manipulation of shoot regeneration in J. effusus L. The maximum plant survival frequency and multiplication rates (90.97% and 5.40 and 94.23% and 8.25) were recorded in the
presence of 0.5 mg L−1 BA (2.2 μM) in the 1/2 MS multiplication medium for the varieties of Nonglin-4 and Taicao, respectively. About 100% survival
rate was also observed for all the varieties in soil conditions. The efficient plant regeneration system developed here will
be helpful for rapid micropropagation and further genetic improvement in J. effusus L. 相似文献
6.
Hail Z. Rihan Mohammed Al-Issawi Stephen Burchett Michael P. Fuller 《Plant Cell, Tissue and Organ Culture》2011,107(2):243-250
An effective protocol for the mass production of cauliflower microshoots was refined using the meristematic layer of cauliflower
curd. After the meristematic layer was surface sterilized and shaved off, a commercial blender was used for homogenization
and several blending treatments were tested in the range 15–120 s and 30 s was found to be optimal in terms of the amount
explants produced and their subsequent growth ability. Explants were cultivated in S23 liquid medium (4.4 g L−1 MS (Murashige and Skoog) and 3% v/w sucrose) supplemented with several combinations of plant growth regulators (PGRs) including
1 and 2 mg L−1 of Kinetin in combination with three types of auxins (indole butyric acid (IBA), Naphthaleneacetic acid (NAA) and Indole-3-acetic
acid (IAA)), each at 1 and 2 mg L−1 concentration. The use of 2 mg L−1 Kinetin and 1 mg L−1 IBA gave the best results in terms of its effects on explant induction. Microshoots of different sizes were encapsulated
in a sodium alginate matrix and the optimal stage suitable for the production of artificial seeds was assessed in terms of
both subsequent conversion and plantlet viability. The feasibility of cultivating cauliflower artificial seeds in commercial
substrates (compost, vermiculite, perlite and sand) irrigated with different solution mixtures including sterilized distilled
water (SDW), PGRs-free S23 medium and S23 medium supplemented with Kinetin (1 and 2 mg L−1) and IBA or NAA at (1 and 2 mg L−1) was investigated. The use of 2 mg L−1 Kinetin and 2 mg L−1 NAA applied with S23 gave the optimal response with both perlite and compost. This study showed high growth capacity of cauliflower
artificial seeds in commercial substrates which is considered a promising step for their direct use in vivo. 相似文献
7.
Thiocyanate-degrading microbial co-culture was isolated from thiocyanate-contaminated site and tested for thiocyanate degradation
potential and thiocyanate-toxicity tolerance and identified as Klebsiella pneumoniae and Ralstonia sp. by 16S rDNA sequencing. The co-culture was able to degrade thiocyanate with degradation rate of 500 mg L−1d−1 at 2,500 mg L−1 thiocyanate concentration at pH 6.0 and 37oC following thiocyanate hydrolase pathway. The Haldane kinetic model elucidates
the growth and thiocyanate biodegradation kinetics of the co-culture with Ki value of 1,876 mg L−1. The thiocyanate biodegradation kinetics was not affected by the additional supply of glucose. The very high activities of
thiocyanate hydrolase, cyanide oxygenase, and cytochrome P-450 content during growth on thiocyanate were observed, showing
the induction mechanism. 相似文献
8.
The responses of the pioneer submerged macroalga (Chara globularis) and the rapidly spreading floating macroalga (Hydrodictyon reticulatum) to high levels of lead (40, 80, and 160 mg L−1) at pH 7.14 were studied. Growth rate, Pb bioaccumulation, and physiological response of plants were measured after 5 and
15 days exposure. Both macroalgae efficiently postponed the deposition process of Pb from water column to soil. The Pb bioaccumulation
in C. globularis was concentration- and time-dependent increase during the experiment and the maximum bioaccumulation activity was about 3,650 mg
Pb kg−1 DW in 160 mg L−1 Pb at pH 7.14 after 15 days, whereas H. reticulatum showed saturable bioaccumulation in 5 days and the maximum was approximately 4,000 mg Pb kg−1 DW; in addition, H. reticulatum exhibited higher tolerance to Pb pollution than C. globularis. The results also showed that the antioxidant defense systems of both tested macroalgae were overwhelmed under high Pb levels
with superoxide radical and malondiadehyde levels increasing significantly. The antioxidant enzymes, superoxide dismutase,
catalase, and guaiacol peroxidase activities were inhibited severely increasing Pb levels and exposure time. These results
indicate that the pioneer species C. globularis would have difficulty growing in a habitat polluted by Pb >40 mg L−1and the rapidly spreading H. reticulatum may not grow in an environment polluted by >80 mg L−1 Pb. Because Pb levels in most water bodies are lower than 40 mg L−1, both C. globularis and H. reticulatum can be considered for phytoremediation of Pb pollution. 相似文献
9.
S. F. Baldia A. D. Evangelista E. V. Aralar A. E. Santiago 《Journal of applied phycology》2007,19(6):607-613
Phytoplankton supports fisheries and aquaculture production. Its vital role as food for aquatic animals, like mollusks, shrimp,
and fish cannot be overemphasized. Because of its contribution as a food source for fish, the growth kinetics of Microcystis aeruginosa, a dominant cyanobacterium in the lake, was studied. The regular occurrence of M. aeruginosa is experienced during the months of May to July or from September to November in Laguna de Bay, the largest freshwater lake
in the Philippines. M. aeruginosa was collected from Laguna de Bay, isolated, and established in axenic conditions. Data on the growth kinetic parameters for
nitrate-nitrogen and phosphate-phosphorus utilization by M. aeruginosa gave the following values: half-saturation constant (K
s
), 0.530 mg N. L−1 and 0.024 mg P. L−1 respectively; maximum growth rate (μ
max
), 0.671. d−1 and 0.668. d−1 respectively; maximum cell yield, 6.5 and 6.54 log, cells. ml−1 respectively; nutrient level for saturated growth yield, 8.71 mg N. L−1 and 0.22 mg P. L−1 respectively; and minimum cell quota (Q
0
), 2.82 pg N. cell−1 and 0.064 pg P. cell−1 respectively. The low K
s value and high maximum growth rate (μ
max
) for phosphorus by M. aeruginosa would suggest a high efficiency of phosphorus utilization. On the other hand, the high K
s
value for nitrogen indicated a low rate of uptake for this nutrient. 相似文献
10.
Xue-Song Shen Qi Su Zhuang-ping Qiu Jing-yi Xu Yan-xia Xie Han-fu Liu Yi Liu 《Biological trace element research》2010,136(1):117-125
The toxic effects of artesunate and dihydroartemisinin on the growth metabolism of Tetrahymena thermophila BF5 were studied by microcalorimetry. The results showed that: (1) low concentrations of artesunate (≤1 mg L−1) and dihydroartemisinin (≤ 2 mg L−1) promoted the growth metabolism of T. thermophila BF5, whereas high concentrations of artesunate (1–60 mg L−1) and dihydroartemisinin (2–60 mg L−1) inhibited its growth; (2) the half inhibition concentrations IC50 of artesunate and dihydroartemisinin were 17.5817 and 9.5089 mg L−1, respectively. It was concluded that the inhibition of dihydroartemisinin was stronger than that of artesunate. 相似文献
11.
Shungang Wan Guiying Li Taicheng An Bin Guo Lei Sun Lei Zu Ailing Ren 《Biodegradation》2010,21(6):1057-1066
In the present study, a new bacterial strain isolated from activated sludge has been identified as Lysinibacillus sphaericus based on its morphology, physiochemical properties, and the results of 16S ribosomal RNA (rRNA) gene sequence analysis. This
new bacterial strain uses ethanethiol as both carbon source and energy source. The key factors for controlling the degradation
efficiency of ethanethiol by this strain were found to be initial ethanethiol concentration, temperature, and pH value of
solutions. Under the optimized conditions, as well as 4 mg l−1 ethanethiol, 30°C, and pH = 7.0, almost 100% ethanethiol can be degraded within 96 h and sulfate as a final product was detected
in aqueous medium. The degradation reaction of ethanethiol over this newly isolated strain can be described by pseudo first-order
equation in which the maximum degradation rate constant K and the minimum half-life were respectively calculated to be 0.0308 h−1 and 22.5 h under the optimal conditions. 相似文献
12.
Anaerobic biodegradation of triphenylmethane dyes in a hybrid UASFB reactor for wastewater remediation 总被引:1,自引:0,他引:1
Anaerobic digestions have been proved more successful than aerobic systems for the degradation and destruction of dye-containing
wastewaters. The performance of a hybrid up flow anaerobic sludge-filter bed (UASFB) reactor was tested with a synthetic wastewater
containing Crystal violet (CV) as a carbon source and sodium acetate as a co-substrate. Continuous feeding of the reactor
started with an initial OLR of 0.9 g COD/l-d and then it was increased step wise to 4 g COD l−1 d−1, while maintaining constant HRT (24 h). The optimum pH value and temperature for decolorization of crystal violet by this
mixed culture species under anaerobic conditions were found to be 8–9 and 30–35°C respectively. N,N-dimethylaminophenol and N,N-bis (dimethylamino) benzophenone (Michler’s Ketone) were detected as the degradative metabolites of Crystal Violet. Subsequently,
N,N-dimethylaminophenol was further degraded to aniline in the reactor whereas Michler’s ketone was not degraded under anaerobic
conditions. The UASFB bioreactor was able to remove the CV completely up to a loading rate of 100 mg CV l−1d−1. 相似文献
13.
Phenol is one of the major toxic pollutants in the wastes generated by a number of industries and needs to be eliminated before
their discharge. Although microbial degradation is a preferred method of waste treatment for phenol removal, the general inability
of the degrading strains to tolerate higher substrate concentrations has been a bottleneck. Immobilization of the microorganism
in suitable matrices has been shown to circumvent this problem to some extent. In this study, cells of Pseudomonas sp. CP4, a laboratory isolate that degrades phenol, cresols, and other aromatics, were immobilized by entrapment in Ca-alginate
and agar gel beads, separately and their performance in a fluidized bed bioreactor was compared. In batch runs, with an aeration
rate of 1 vol−1 vol−1 min−1, at 30°C and pH 7.0 ± 0.2, agar-encapsulated cells degraded up to 3000 mg l−1 of phenol as compared to 1500 mg l−1 by Ca-alginate-entrapped cells whereas free cells could tolerate only 1000 mg l−1. In a continuous process with Ca-alginate entrapped cells a degradation rate of 200 mg phenol l−1 h−1 was obtained while agar-entrapped cells were far superior and could withstand and degrade up to 4000 mg phenol l−1 in the feed with a maximum degradation rate of 400 mg phenol l−1 h−1. The results indicate a clear possibility of development of an efficient treatment technology for phenol containing waste
waters with the agar-entrapped bacterial strain, Pseudomonas sp. CP4. 相似文献
14.
As a common pollutant, nitrite concentrations can approach 15 mg NO2−-N L−1 in some aquatic systems. Microcystis aeruginosa blooms are common and widespread in eutrophic freshwater bodies. In this study, M. aeruginosa was exposed to nitrite concentrations ranging from 0 to 15 mg NO2−-N L−1, and the responses of M. aeruginosa were investigated. The specific growth rates, maximum cell densities, light-saturated photosynthetic rates (Pm
chla
), dark respiration rates (Rd
chla
), and apparent photosynthetic efficiencies (αchla
) showed a significant decline with nitrite concentrations increasing. Electrical conductivity and malondialdehyde contents
investigation revealed cell membrane damage and apparent leakage of intracellular contents under high nitrite level conditions
due to oxidative stress enhancement. Intracellular microcystin (MC)-LR content reached the highest value at 10 mg NO2−-N L−1; however, extracellular MC-LR contents showed a continuous increase until 15 mg NO2−-N L−1 owing to the increasing leakage of intracellular contents. These results elucidated that the high-level nitrite inhibited
M. aeruginosa growth by rising oxidative stress, damaging cell membrane, and reducing photosynthesis. However, the moderate increase in
nitrite concentrations promoted toxin production and release of toxin. 相似文献
15.
Li Liu Xiaoli Fan Junwei Zhang Meiling Yan Manzhu Bao 《In vitro cellular & developmental biology. Plant》2009,45(6):673-680
In this study, we have demonstrated that Zoysia japonica callus induced from mature seeds can produce high frequencies of plant regeneration and somatic embryogenesis, even following
a prolonged period of subculturing. Initial callus cultures were induced from mature seeds of Japanese lawngrass (Z. japonica Steud.) incubated on a medium containing major N6 medium salts, minor Murashige and Skoog (MS) medium salts, and modified MS medium organic elements supplemented with 3 mg
L−1 2,4-dichlorophenoxyacetic acid (2,4-D) and 0.01–0.02 mg L−1 6-benzyladenine. Compact callus were selected and subcultured monthly on a medium containing 2 mg L−1 2,4-D, 0.5 mg L−1 kinetin, 500 mg L−1 casein hydrolysate, 500 mg L−1 proline, and 500 mg L−1 myoinositol. Callus maintained in vitro for 18 mo could be induced to regenerate plantlets with a frequency of >90%. By contrast, 36-mo-old callus cultures failed
to produce normal shoot regeneration. However, the addition of CuSO4 to the subculture media maintained >90% regeneration frequencies in such long-term callus cultures. Histological observations
revealed that plant regeneration occurred both through somatic embryogenesis and organogenesis pathways. The ability to sustainable
regeneration in long-term callus cultures will be valuable to the program of genetic transformation and somaclonal variant
selection. 相似文献
16.
K. Balaraju S. Saravanan P. Agastian S. Ignacimuthu 《Acta Physiologiae Plantarum》2011,33(4):1123-1133
An improved method of direct somatic embryogenesis (SE) was developed in Swertia chirata for the first time using leaves and roots of in vitro-grown young seedlings. In the present study, 2,4-dichlorophenoxyacetic
acid (2,4-D) was assessed individually and in combination with other auxins, as well as with cytokinin for its effectiveness
to induce somatic embryos. Leaf explants with abaxial side in the medium produced maximum number of somatic embryos. This
system omits the callus stage and thus reduces the process of SE in S. chirata by 35–45 days. Embryos at different stages of development were observed. Maturation of heart stage embryos were observed
on Murashige and Skoog (MS) medium containing 1 mg L−1 2,4-D. Upon transfer to the germination medium, they were converted to cotyledonary stage and then plantlets of 33% and 68%
of them were converted to cotyledonary stage and then plantlets on MS medium supplemented with 0.05 and 0.1 mg L-1 GA3 respectively. The 2,4-D alone at 1.0 or 1.5 mg L−1 was found to be better for embryogenic tissue initiation than 2,4-D in combination with indole-3-acetic acid or α-naphthalene
acetic acid. For further embryo development, 2,4-D was combined with cytokinins such as 6-benzylaminopurine (BAP) and kinetin
or plant growth regulator free medium or medium with 50% reduced concentration of the same hormone while subculturing. Mean
germination and percentage of survival were maximum in the medium containing 1.0 mg L−1 2,4-D in combination with 0.1 mg L−1 BAP. Regenerated plantlets were morphologically and genetically identical. This method offers a vast scope for the clonal
propagation of endangered plants. 相似文献
17.
Alginate concentrations between 2 and 4% had little effect on the degradation rate of phenol by alginate-immobilized Pseudomonas putida. Ten-degree shifts from 25°C resulted in approximately 30% slower degradation. Maximal degradation rates were favored at
pH 5.5–6.0. The response of degradation rate to increased air flow in the bubble column used was almost linear and an optimal
higher than 16 vol vol−1 was indicated, although free cells appeared in the reaction medium above 12 vol vol−1. When the initial phenol concentration was raised, degradation rate was not significantly affected until levels higher than
1200 mg ml−1 where performance was markedly reduced. Increasing the ratio of total bead volume to medium volume gave progressively smaller
increases in degradation rate. At a medium volume to total bead volume ratio of 5:1, the maximum degradation rate was 250
mg L−1 h−1.
Received 24 November 1998/ Accepted in revised form 27 January 1999 相似文献
18.
S Shashirekha L Uma G Subramanian 《Journal of industrial microbiology & biotechnology》1997,19(2):130-133
Bioremediation is a cost-effective alternative to conventional disposal methods and is a new technology which emphasizes
the detoxification and destruction of the pollutants by acclimatized microorganisms. Cyanobacteria are in a more advantageous
position than heterotrophic bacteria because of their trophic independence for nitrogen as well as carbon. Phenol, the toxic
constituent of several industrial effluents, was found to be effectively removed and degraded by the marine cyanobacterium
Phormidium valderianum BDU 30501. The organism was able to tolerate and grow at a phenol concentration of 50 mg L−1 and remove 38 mg L−1 within a retention period of 7 days. The removal and degradation were confirmed by changes in the ultraviolet absorption
spectra in the culture filtrate, colorimetric estimation of residual phenol and measuring the intracellular activity of the
inducible polyphenol oxidase and laccase enzymes. This opens up the possibility of treating a variety of phenol-containing
industrial effluents using this organism.
Received 08 August 1996/ Accepted in revised form 16 June 1997 相似文献
19.
Continuous production of acetone, n-butanol, and ethanol (ABE) was carried out using immobilized cells of Clostridium acetobutylicum DSM 792 using glucose and sugar mixture as a substrate. Among various lignocellulosic materials screened as a support matrix,
coconut fibers and wood pulp fibers were found to be promising in batch experiments. With a motive of promoting wood-based
bio-refinery concept, wood pulp was used as a cell holding material. Glucose and sugar mixture (glucose, mannose, galactose,
arabinose, and xylose) comparable to lignocellulose hydrolysate was used as a substrate for continuous production of ABE.
We report the best solvent productivity among wild-type strains using column reactor. The maximum total solvent concentration
of 14.32 g L−1 was obtained at a dilution rate of 0.22 h−1 with glucose as a substrate compared to 12.64 g L−1 at 0.5 h−1 dilution rate with sugar mixture. The maximum solvent productivity (13.66 g L−1 h−1) was obtained at a dilution rate of 1.9 h−1 with glucose as a substrate whereas solvent productivity (12.14 g L−1 h−1) was obtained at a dilution rate of 1.5 h−1 with sugar mixture. The immobilized column reactor with wood pulp can become an efficient technology to be integrated with
existing pulp mills to convert them into wood-based bio-refineries. 相似文献
20.
A novel bacterium, Cr-10, was isolated from a chromium-contaminated site and capable of removing toxic chromium species from
solution by reducing hexavalent chromium to an insoluble precipitate. Sequence analysis of 16S rRNA gene of strain Cr-10 showed
that it was most closely related to Serratia rubidaea JCM 1240T (97.68%). Physiological and chemotaxonomic data also supported that strain Cr-10 was identified as Serratia sp., a genus which was never specially reported chromate-resistant before. Serratia sp., Cr-10 was tolerant to a concentration of 1,500 mg Cr(VI) L−1, which was the highest level reported until now. The optimum pH and temperature for reduction of Cr(VI) by Serratia sp. Cr-10 were found to be 7.0 and 37 °C, respectively. The Cr(VI) reduction was significantly influenced by additional carbon
sources, and among them fructose and lactose offered maximum reduction, with a rate of 0.28 and 0.25 mg Cr(VI) L−1 h−1, respectively. The cell-free extracts and filtrate of the culture were able to reduce Cr(VI) while concentration of total
chromium remained stable in the process, indicating that the enzyme-catalyzed mechanism was applied in Cr(VI) reduction by
the isolate. Additionally, it was found that there was hardly any chromium on the cell surface of the strain, further supporting
that reduction, rather than bioadsorption, plays a major role in the Cr(VI) removal. 相似文献