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1.
Kalnoi S. M. Goncharov V. I. Vasilenko N. F. 《Applied Biochemistry and Microbiology》2004,40(2):192-198
The feasibility of rendering erythrocytes magnetic and thereby creating magnetic biosorbents through a room temperature exposure to 25–37% iron (II) sulfate solution for 48 ± 2 h followed by exposure to 15–25% aqueous ammonia solution for 48 ± 2 h (with drying after each procedure) was demonstrated. The feasibility of immobilizing ligands on magnetic erythrocytes and obtaining biological magnetic immunosorbents (BMISs) for further use in EIAs for plague and tularemia antigens was demonstrated. The sensitivity of EIAs involving BMISs amounted to 10 ng/ml and 100 microbial cells per 1 ml. The relative error did not exceed 8%. 相似文献
2.
V. Chopra T. V. Dinh E. V. Hannigan 《In vitro cellular & developmental biology. Animal》1997,33(6):432-442
Summary The purpose of this study is to understand the multicellular interaction between tumor epithelial (TEC) and human umbilical
vein endothelial cells (HUVEC). The development of in vitro systems in which to coculture these cells as multicellular aggregates is very critical. Cell lines were established from
cervical tumor cells (n=6) and two from HUVEC (n=2) and they were cultured as three-dimensional (3-D) multicellular-cultures
using Cytodex-3 microcarrier beads in the rotating wall vessel (RWV). After a 240-h incubation, TEC and HUVEC proliferated
exponentially to 4.2×107 and 2.2 × 107 cells/ml, respectively, without requiring a feeder layer; in contrast to the two-dimensional (2-D) cultures that average
about 8 × 106 cells/ml. Phase contrast microscopy indicated formation of 3-D aggregates that varied in size from 0.5 to 5 mm. The size
of the aggregates (1–5 mm, 6⊋ash;14 microcarriers) increased over time; however, the number of aggregates (0.5–1 mm, 2–5 microcarriers)
decreased over a long-term incubation (240 h) because the cells merged to form large clumps. Maximum aggregation was observed
with TEC at 120 h and HUVEC at 96 h. The culture of TEC in the absence of HUVEC produced minimal differentiation in contrast
to cocultures. The TEC and HUVEC as cocultures in RWV proliferated at an accelerated rate (1.3 × 107 cells/ml, 96 h). The TEC-HUVEC coculture presented tubular structures penetrating the tumor cell masses, forming aggregates
larger in size than the monocultures and typically with greater cell mass and number. The cells were viable (trypan blue exclusion)
and metabolically active (glucose utilization) until 240 h. These data suggest that RWV provides a new model that allows us
to investigate the regulatory factors that govern tumor angiogenesis. 相似文献
3.
Wang H Van Blitterswijk CA Bertrand-De Haas M Schuurman AH Lamme EN 《In vitro cellular & developmental biology. Animal》2004,40(8-9):268-277
Summary The number of medical applications using autologous fibroblasts is increasing rapidly. We investigated thoroughly the procedure
to isolate cells from skin using the enzymatic tissue dissociation procedure. Tissue digestion efficiency, cell viability,
and yield were investigated in relation to size of tissue fragments, digestion volume to tissue ratio, digestion time, and
importance of other protease activities present in Clostridium histolyticum collagenase (CHC) (neutral protease, clostripain, and trypsin). The results showed that digestion was optimal with small
tissue fragments (2–3 mm3) and with volumes tissue ratios ≥2 ml/g tissue. For incubations ≤10 h, the digestion efficiency and cell isolation yields
were significantly improved by increasing the collagenase, neutral protease, or clostripain activity, whereas trypsin activity
had no effects. However, a too high proteolytic activity of one of the proteases present in CHC digestion solution or long
exposure times interfered with cell viability and cell culture yields. The optimal range of CHC proteases activities per milliliter
digestion solutions was determined for digestions ≤10 h (collagenase 2700–3900 Mandl U/ml, neutral protease 5100–10,000 caseinase
U/ml, and clostripain 35–48 BAEE U/ml) and for longer digestions (>14 h) (collagenase 1350–3000 U/ml, neutral protease 2550–7700
U/ml, and clostripain 18–36 U/ml). Using these conditions, a maximum fibroblast expansion was achieved when isolated cells
were seeded at 1×104 cells/cm2. These results did not only allow selection of optimal CHC batches able to digest dermal tissue with an high cell viability
but also significantly increased the fibroblast yields, enabling us to produce autologous dermal tissue in a clinically acceptable
time frame of 3 wk. 相似文献
4.
This study was aimed at identifying the roles of caffeine and acriflavine, two repair inhibitors, on UV sensitivity of iron-oxidizing
Thiobacillus ferrooxidans ATCC 13728. The UV-dose response survival curve was inflected in nature, suggesting the population heterogeneity of the isolate.
Caffeine and acriflavine potentiated the UV-induced killing of the organism. With the increase in concentrations of these
compounds, the extent of survival decreased. Similarly, the inhibitory effects of caffeine and acriflavine increased with
the increase in dose of UV-irradiation. The cells irradiated with 10 s (equivalent to 5.6 × 10−5 J/m2/s) of UV-exposure tended to become resistant to the inhibitory effects of caffeine and acriflavine, as evidenced by the time
course study of recovery. The cells appear to stage a dramatic recovery from UV damage in the presence of caffeine (3.0 mg/ml)
and acriflavine (20 μg/ml) over a period of 25–30h and 35–40h respectively, when grown in the presence of energy sources.
Received: 4 December 2000/Accepted: 10 January 2001 相似文献
5.
Summary. We report that a novel substance named dictyopyrone C (DPC) has remarkable effects on growth and differentiation of Dictyostelium discoideum Ax-2 cells, in a dose-dependent manner. In the presence of 3–15 μM DPC, differentiation of starving Ax-2 (clone MS) cells
was greatly enhanced in submerged culture, when vegetative MS cells were harvested at the mid-late-exponential growth phase
(>3 × 106 cells per ml) and starved. In contrast, DPC above 30 μM markedly impaired the progression of differentiation including cell
aggregation, most of starved cells being round after 3–4 h of DPC application and then lysed during further incubation. In
the presence of 30 μM DPC however, MS cells that had been harvested at the early exponential growth phase (<5 × 105 cells per ml) and starved became neither round nor lysed and exhibited rather enhanced differentiation. Essentially the same
results were obtained in cultures of starved cells on nonnutrient agar. With respect to the DPC effect on MS cells growing
in axenic medium, cell lysis and growth inhibition by DPC at concentrations higher than 15 μM were realized in the mid-late-exponential-growth-phase
cells (>3 × 106 cells per ml) but not in the early-exponential-growth-phase cells (<5 × 105 cells per ml). Moreover, analysis using synchronized MS cells has demonstrated that the DPC effect changes in a cell-cycle-dependent
manner. In contrast to such unique DPC actions, the pyrone ring of DPC had no effects on growth and differentiation within
the range of 3–120 μM tested. These findings strongly suggested the importance of the combined structure of the pyrone ring
and the linear carbon chain in revelation of the DPC activities.
Received August 5, 2002; accepted November 11, 2002; published online April 8, 2003
RID="*"
ID="*" Correspondence and reprints: Department of Developmental Biology and Neurosciences, Graduate School of Life Sciences,
Tohoku University, Aoba, Sendai 980-8578, Japan. E-mail: ymaeda@mail.cc.tohoku.ac.jp 相似文献
6.
The feasibility of rendering erythrocytes magnetic and thereby creating magnetic biosorbents (MB Ss) through room temperature exposure to 25-37% iron (II) sulfate solution for 48 +/- 2 h, followed by exposure to 15-35% ammonia water solution for 48 +/- 2 h (with drying after each procedure) was demonstrated. The feasibility of immobilizing ligands on magnetic erythrocytes (ME) and obtaining biological magnetic immunosorbents (BMISs) for further use in EIAs for plague and tularemia antigens was demonstrated. The sensitivity of EIAs involving BMISs amounted to 10 ng/ml and 100 microbial cells per 1 ml. The relative error did not exceed 8%. 相似文献
7.
I. S. Kulichevskaya S. E. Belova V. T. Komov S. N. Dedysh G. A. Zavarzin 《Microbiology》2011,80(4):549-557
Fluorescent in situ hybridization (FISH) with rRNA-specific oligonucleotide probes was used to assess the numbers and phylogenetic
diversity of prokaryotic microorganisms in the water of small boreal lakes and peatland catchments of the swampy upper Volga
basin. The abundance of bacterioplankton in lake water was found to vary from 1.6 to 8.7 × 106 cells ml−1, with the highest values detected in neutral eutrophic lakes. The total cell numbers in the peat of ombrotrophic bogs were
3.9–4.3 × 108 cells g−1 of wet peat. The proportion of bacteria identified by the group-specific probes decreased from 79–85% in neutral (pH 6.6–6.9)
mesotrophic and eutrophic lakes to 65–69% in acidic (pH 4.4–5.5) dystrophic lakes and to 51–58% in the peat of acidic (pH
3.6–3.9) ombrotrophic bogs. The diversity of bacterial communities was highest in lakes with neutral water. These communities
were dominated by members of the phylum Actinobacteria (31–44% of the total bacterial number), while the contribution of Alphaproteobacteria (16–19%), Bacteroidetes (6–16%), Betaproteobacteria (6–7%), Planctomycetes (2–8%), and Gammaproteobacteria (4–5%) was also significant. In acidic dystrophic lakes, Actinobacteria (25–35%) and Betaproteobacteria (25–34%) predominated, while peatland catchments were dominated by the Alphaproteobacteria (20–23%). The presence of acidobacteria and some planctomycetes common for bogs in the water of acidic dystrophic lakes,
as well as the high proportion of bacteria (31–49%) that were not identified by the group-specific probes, suggest the impact
of microbial processes in peatland catchments on the microbial composition of the receiving waters. 相似文献
8.
S. V. Zubova D. S. Kabanov A. Yu. Ivanov E. V. Voloshina I. I. Proskuryakov I. B. Klenina I. R. Prokhorenko 《Biochemistry (Moscow) Supplemental Series A: Membrane and Cell Biology》2011,5(2):135-142
Undifferentiated THP-1 cells from Cell Culture Collection of the Institute of Cytology, RAS (St. Petersburg), are characterized
by weak expression of Toll-like receptor-4 (TLR4) on the cell surface (up to 2%) and by almost undetectable expression of
CD14 and CD11b receptors. Differentiation agent phorbol-12-myristate-13-acetate independently of its concentration (2 × 10−7 M or 10−8 M) and incubation time (24 or 48 h) did not initiate CD11b surface expression and did not change the parameter Sapp (0.605 ± 0.005 at 37°C) reflecting the cell membrane viscosity. Differentiation of THP-1 cells induced by another differentiation
agent, 1α,25-dihydroxyvitamin D3, caused expression of CD14 (up to 70–80%) and CD11b (up to 15–20%) receptors, again without changes in plasma membrane viscosity.
The rate constants of the reduction of 5- and 16-doxyl-stearic acids by THP-1 cells were in the range of 6–8 × 10−3 s−1 at 37°C. During cell differentiation significant changes in cell electrophoretic mobility (EM, μm s−1 V−1 cm) were observed. Mean value of EM for undifferentiated THP-1 cells was −1.332 ± 0.011, whereas for phorbol-12-myristate-13-acetate-
and 1α,25-dihydroxyvitamin D3-treated cells it was −1.432 ± 0.030 and −1.212 ± 0.016, respectively. 相似文献
9.
S. V. N. Vijayendra N. K. Rastogi T. R. Shamala P. K. Anil Kumar L. Kshama G. J. Joshi 《Indian journal of microbiology》2007,47(2):170-175
Polyhydroxyalkanotes (PHAs), the eco-friendly biopolymers produced by many bacteria, are gaining importance in curtailing
the environmental pollution by replacing the non-biodegradable plastics derived from petroleum. The present study was carried
out to economize the polyhydroxybutyrate (PHB) production by optimizing the fermentation medium using corn steep liquor (CSL),
a by-product of starch processing industry, as a cheap nitrogen source, by Bacillus sp. CFR 256. Response surface methodology (RSM) was used to optimize the fermentation medium using the variables such as
corn steep liquor (5–25 g l−1), Na2HPO4 2H2O (2.2–6.2 g l−1), KH2PO4 (0.5–2.5 g l−1), sucrose (5–55 g l−1) and inoculum concentration (1–25 ml l−1). Central composite rotatable design (CCRD) experiments were carried out to study the complex interactions of the variables.
The optimum conditions for maximum PHB production were (g l−1): CSL-25, Na2HPO4 2H2O-2.2, KH2PO4 − 0.5, sucrose − 55 and inoculum − 10 (ml l−1). After 72 h of fermentation, the amount of PHA produced was 8.20 g l−1 (51.20% of dry cell biomass). It is the first report on optimization of fermentation medium using CSL as a nitrogen source,
for PHB production by Bacillus sp. 相似文献
10.
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
11.
Summary Hybridoma cells were cultured for two months in the dual hollow fiber bioreactor (DHFBR) which had been successfully used
for high cell density cultures of various microbial cells. In batch suspension culture the concentration of monoclonal antibody
(Mab) against human Chorionic Gonadotropin (hCG) and the cell density of Alps 25-3 hybridoma cells were obtained in 30 μg/mL
and 2.35×106 cells/mL, respectively. The continuous culture with DHFBR produced Mab of 100–130 μg/mL for 30 days and the estimated cell
density in the extracapillary space of DHFBR was 1.87×108 cells/mL based on the antibody production rate. The productivity of Mab was 205 mg/day per litre of the total reactor volume
while that of the batch suspension culture was only 10 mg/L day. 相似文献
12.
The performance of a laboratory-scale sewage treatment system composed of an up-flow anaerobic sludge blanket (UASB) reactor
and a moving bed biofilm reactor (MBBR) at a temperature of (22–35 °C) was evaluated. The entire treatment system was operated
at different hydraulic retention times (HRT’s) of 13.3, 10 and 5.0 h. An overall reduction of 80–86% for CODtotal; 51–73% for CODcolloidal and 20–55% for CODsoluble was found at a total HRT of 5–10 h, respectively. By prolonging the HRT to 13.3 h, the removal efficiencies of CODtotal, CODcolloidal and CODsoluble increased up to 92, 89 and 80%, respectively. However, the removal efficiency of CODsuspended in the combined system remained unaffected when increasing the total HRT from 5 to 10 h and from 10 to 13.3 h. This indicates
that, the removal of CODsuspended was independent on the imposed HRT. Ammonia-nitrogen removal in MBBR treating UASB reactor effluent was significantly influenced
by organic loading rate (OLR). 62% of ammonia was eliminated at OLR of 4.6 g COD m−2 day−1. The removal efficiency was decreased by a value of 34 and 43% at a higher OLR’s of 7.4 and 17.8 g COD m−2 day−1, respectively. The mean overall residual counts of faecal coliform in the final effluent were 8.9 × 104 MPN per 100 ml at a HRT of 13.3 h, 4.9 × 105 MPN per 100 ml at a HRT of 10 h and 9.4 × 105 MPN per 100 ml at a HRT of 5.0 h, corresponding to overall log10 reduction of 2.3, 1.4 and 0.7, respectively. The discharged sludge from UASB–MBBR exerts an excellent settling property.
Moreover, the mean value of the net sludge yield was only 6% in UASB reactor and 7% in the MBBR of the total influent COD
at a total HRT of 13.3 h. Accordingly, the use of the combined UASB–MBBR system for sewage treatment is recommended at a total
HRT of 13.3 h. 相似文献
13.
14.
Grafting of methoxypoly(ethylene glycol) (mPEG) to cells and biomaterials is a promising non-pharmacological immunomodulation
technology. However, due to the labile nature of cells, surface-plasma interactions are poorly understood; hence, a latex
bead model was studied. PEGylation of beads resulted in a density and molecular weight dependent decrease in total adsorbed
protein with a net reduction from (159.9±6.4) ng cm−2 on bare latex to (18.4±0.8) and (52.3±5.3) ng cm−2 on PEGylated beads (1 mmol L−1 of 2 or 20 kD SCmPEG, respectively). SDS-PAGE and iTRAQ-MS analysis revealed differential compositions of the adsorbed protein
layer on the PEGylated latex with a significant reduction in the compositional abundance of proteins involved in immune system
activation. Thus, the biological efficacy of immunocamouflaged cells and materials is mediated by both biophysical obfuscation
of antigens and reduced surface-macromolecule interactions. 相似文献
15.
A protocol for plant regeneration from mesophyll and callus protoplasts of Robinia pseudoacacia L. was developed. For leaves from in vitro raised shoots, an enzyme combination of 2.0% cellulose and 0.3% macerozyme for
a digestion period of 20 h resulted in the best yield of protoplasts (9.45 × 105 protoplast/g fresh weight). Mesophyll-derived protoplasts started cell wall regeneration within 24 h of being embedded in
Nagata and Takebe (NT) medium supplemented with 5 μM NAA and 1 μM BAP followed by the first cell division on day three of
culture and micro-colony (32 cells) formation within day 7–10 in the same medium. However, using callus as the starting material,
a combination of 2.0% cellulose and 1.0% macerozyme for a digestion period of 24 h gave the highest protoplast yield (3.2 × 105 protoplast/g fresh weight). Cell wall regeneration in callus-derived protoplasts started within 24 h followed by the first
cell division on the day three (96 h) and the appearance of microcolonies of more than 32 cells by the end of first week (144 h)
of culture on solid WPM medium supplemented with 5 μM NAA and 1 μM BAP. Microcalli were visible to the naked eye after 45 days
on solid WPM medium. Proliferation of macro-calli was successfully accomplished on solid Murashige and Skoog (MS) medium with
5 μM NAA and 5 μM BAP. Both mesophyll and callus protoplast-derived calli produced shoots on MS medium with 0.5 μM NAA and
1 μM BAP within 25–30 days and multiplied on MS medium with 1.25 μM BAP. Excised microshoots were dipped in 1–2 ml of 2.0 μM
IBA for 24 h under dark aseptic conditions and transferred to double sterilized sand for rooting. The flasks containing sand
were inoculated with Rhizobium for in vitro nodulation. Forty-five plants transferred to pots in the glasshouse established well. 相似文献
16.
Su C Zhou W Fan Y Wang L Zhao S Yu Z 《Journal of industrial microbiology & biotechnology》2006,33(12):1037-1042
In order to obtain an industrial strain with higher chitosanase yield, the wild strain Bacillus sp. S65 cells were mutated by a novel mutagen, nitrogen ion beam, with energy of 15 keV and dose ranging from 2.6 × 1014 to 5.2 × 1015 ions/cm2. One mutant, s65F5 with high yield of chitosanase was isolated. Results showed that the production of chitosanase of s65F5 was dramatically increased from 4.1 U/ml in s65 to 25 U/ml by ion beam implantation, while the fermentation time was shortened from 72 to 56 h, both of which greatly increased efficiency and reduced the cost of industrial production. Besides, the mutagenic effects of low-energy ion beam on survival rate showed characteristic down–up–down pattern, which was different from the traditional mutagens such as UV and γ-ray and the possible mutation mechanism was discussed. 相似文献
17.
In this study, four real-time polymerase chain reaction (PCR) primer sets were developed for the 16S rRNA genes of specific ammonia-oxidizing bacteria (AOB) found in activated sludge of sewage treatment systems. The primer sets target two of several sequence types of the Nitrosomonas oligotropha cluster, members within the Nitrosomonas communis cluster, and all members of the Nitrosomonas europaea–Nitrosococcus mobilis cluster. The detection limit of each primer set was in the range of 3×101–6×102 genes reaction−1. Reliable quantification of the target AOB DNA was obtained when the target AOB DNA comprised more than 0.1% of total AOB DNA in the sample. The application of the primer sets to samples taken from five sewage treatment systems showed that, in all systems, the majority of the AOB population was comprised of one sequence type of the N. oligotropha cluster (3.9±1.5×109–1.7±0.5×1010 cell l−1) and, in most systems, followed by members within the N. communis cluster (2.8±0.3×109–1.0±0.1×1010 cell l−1) or/and another sequence type of the N. oligotropha cluster (1.5±0.6×108–5.5±0.5×108 cell l−1). N. europaea–N. mobilis cluster arose solely in small numbers (4.9±0.8×108 cell l−1) in one system. Real-time PCR-amplified products obtained from genomic DNA extracted from samples were verified using clone library, and it revealed that only the target AOB DNA were PCR amplified, without amplification of the nontarget sequences. 相似文献
18.
A. N. Dzyuban 《Microbiology》2010,79(6):822-829
Fluctuations of methane (CH4) concentration and the dynamics of microbial methane oxidation (MO) were investigated in the water column of freshwater stratified
lakes of different trophicity levels during various seasonal periods and throughout the diurnal cycle. Characteristics of
vertical CH4 distribution and ranges of methane transformation rates were determined and found to depend upon the lake productivity as
well as seasonal and daily fluctuations of hydrological and hydrochemical parameters. The highest rate of MO was registered
in highly eutrophic lakes during summer stagnation under conditions of formation of a distinct metalimnial water layer with
MO up to 0.4–1.2 ml CH4/(l day). Under the same conditions, a maximum amount of bacterioplankton (6–13 × 106 cells/ml) was detected and CO2 bacterial dark assimilation (DA) reached 50–72 μg C/(l day). In the metalimnion layer, a strong correlation (R = 0.74) was
revealed between diurnal fluctuation dynamics of MO and DA. 相似文献
19.
Yi-Guang Chen Shu-Kun Tang Yu-Qin Zhang Zhu-Xiang Liu Qi-Hui Chen Jian-Wu He Xiao-Long Cui Wen-Jun Li 《Extremophiles : life under extreme conditions》2010,14(4):397-402
A novel moderately halophilic, alkaliphilic, non-motile, non-sporulating, catalase-positive, oxidase-negative, aerobic, coccus-shaped,
Gram-positive bacterium, designated strain JSM 071043T, was isolated from a subterranean brine sample collected from a salt mine in Hunan Province, China. Growth occurred with
0.5–20% (w/v) NaCl (optimum 5–10%) at pH 6.5–10.5 (optimum pH 8.5) and at 10–40°C (optimum 25–30°C). Good growth also occurred
in the presence of 0.5–20% (w/v) KCl (optimum 5–8%) or 0.5–25% (w/v) MgCl2·6H2O (optimum 5–10%). The peptidoglycan type was A4α (l-Lys–l-Ala–l-Glu) and major cell-wall sugars were tyvelose and mannose. The major cellular fatty acids were anteiso-C15:0, iso-C16:0 and anteiso-C17:0. Strain JSM 071043T contained MK-9 and MK-8 as the predominant menaquinones and diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol
as the major polar lipids. The DNA G + C content was 67.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed
that strain JSM 071043T was a member of the suborder Micrococcineae, and was most closely related to Zhihengliuella halotolerans YIM 70185T (sequence similarity 98.9%) and Zhihengliuella alba YIM 90734T (98.2%), and the three strains formed a distinct branch in the phylogenetic tree. The combination of phylogenetic analysis,
DNA–DNA relatedness values, phenotypic characteristics and chemotaxonomic data supports the proposal that strain JSM 071043T represents a novel species of the genus Zhihengliuella, for which the name Z. salsuginis sp. nov. is proposed. The type strain is JSM 071043T (= DSM 21149T = KCTC 19466T). 相似文献
20.
We assessed the seasonal abundance and distribution of Vibrio species as well as some selected environmental parameters in the treated effluents of two wastewater treatment plants (WWTP),
one each located in a suburban and urban community of Eastern Cape Province, South Africa. Vibrio population density ranged from 2.1×105 to 4.36×104 CFU/ml in the suburban community and from 2.80×105 to 1.80×105 CFU/ml in the urban community. Vibrio species associated with 180 μ, 60 μ, and 20 μ plankton sizes were observed at densities of 0–136×103 CFU/ml, 0–8.40×102 CFU/ml, and 0–6.80×102 CFU/ml, respectively at the suburban community’s WWTP. In the urban community, observed densities of culturable Vibrio were 0–2.80×102 CFU/ml (180 μ), 0–6.60×102 CFU/ml (60 μm), and 0–1.80× 103 CFU/ml (20 μm). The abundance of free-living Vibrio species ranged from 0 to 1.0×102 and 1.0×103 CFU/ml in the suburban and urban communities’ WWTPs, respectively. Molecular confirmation of the presumptive Vibrio isolates revealed the presence of V. fluvialis (41.38%), V. vulnificus (34.48%), and V. parahaemolyticus (24.14%) in the suburban community effluents. In the urban community molecular confirmation revealed that the same species
were present at slightly different percentages, V. fluvialis (40%), V. vulnificus (36%), and V. parahaemolyticus (24%). There was no significant correlation between Vibrio abundance and season, either as free-living or plankton-associated entities, but Vibrio species abundance was positively correlated with temperature (r=0.565; p<0.01), salinity, and dissolved oxygen (p<0.05). Turbidity and pH showed significant seasonal variation (p<0.05) across the seasons in both locations. This study underscores the potential of WWTPs to be sources of Vibrio pathogens in the watershed of suburban and urban communities in South Africa. 相似文献