Abstract: Novel polystrene-bound Schiff bases and their Pt(IV)
complexes have been prepared from condensation reaction of
polystyrene-A-NH2 with 2-hydroxybenzaldehyde and 5-fluoro-3-
bromo-2-hydroxybenzaldehyde. The structures of Pt(IV) complexes
with polystyrene including Schiff bases have been determined by
elemental analyses, magnetic susceptibility, IR, 1H-NMR, UV-vis,
TG/DTA and AAS. The antibacterial and antifungal activities of the
synthesized compounds have been studied by the well-diffusion
method against some selected microorganisms: (Bacillus cereus spp.,
Listeria monocytogenes 4b, Micrococcus luteus, Staphylococcus
aureus, Staphylococcus epidermis, Brucella abortus, Escherichia
coli, Pseudomonas putida spp., Shigella dysenteria type 10,
Salmonella typhi H).
Abstract: This study mainly aims at assessing the level of
microbial pollution of the water used in the chair system in dental
clinics. For this purpose 36 samples have been randomly collected
from a number of dental surgeries in the city of Tripoli in Libya.
However, 32 of the samples have tested positive to microbial
pollution including 13 of the samples, which have tested positives to
Pseudomonas aeruginosa. Based on the results of the test a further
investigation of the biofilms incorporated within the dental chair
system has been conducted. The laboratory tests of biofilms with
similar design to those found in dental chairs have proved that
bacterial pollution takes place through saliva of the patients who use
the chairs, and that this saliva is rich with nutrients which provides a
suitable breeding ground for all types of bacteria.
Abstract: Alcohol and water extracts of Cymbopogon citratus
was investigated for anti-bacterial properties and phytochemical
constituents. The extract was screened against four gram-negative
bacteria Escherichia coli, Klebsiella pneumoniae, Pseudomonas
aeruginosa, Proteus vulgaris) and two grampositive bacteria Bacillus
subtilis and Staphylococcus aureus at four different concentrations
(1:1, 1:5, 1:10 and 1:20) using disc diffusion method. The antibacterial
examination was by disc diffusion techniques, while the
photochemical constituents were investigated using standard
chemical methods. Results showed that the extracts inhibited the
growth of standard and local strains of the organisms used. The
treatments were significantly different (P = 0.05). The minimum
inhibitory concentration of the extracts against the tested
microorganisms ranged between 150mg/ml and 50mg/ml. The
alcohol extracts were found to be generally more effective than the
water extract. The photochemical analysis revealed the presence of
alkaloids and phenol but absence of cardiac and cyanogenic
glycosides. The presence of alkaloid and phenols were inferred as
being responsible for the anti-bacterial properties of the extracts.
Abstract: Platinum oxide nanoparticles were prepared by a
simple hydrothermal route and chemical reduction using
carbohydrates (Fructose and sucrose) as the reducing and
stabilizing agents. The crystallite size of these nanoparticles was
evaluated from X-ray diffraction (XRD), atomic force microscopy
(AFM) and transmission electron microscopy (TEM) and was
found to be 10 nm as shown in figure 1, which is the
demonstration of EM bright field and transmission electron
microscopy. The effect of carbohydrates on the morphology of the
nanoparticles was studied using TEM (Figure 1). The
nanoparticles (100 μg/ml) were administered to the Pseudomonas
Stutzeri and Lactobacillus cultures and the incubation was done at
35 oC for 24 hours. The nanocomposites exhibited interesting
inhibitory as well as bactericidal activity against P. Stutzeri and
and Lactobacillus species. Incorporation of nanoparticles also
increased the thermal stability of the carbohydrates.
Abstract: Production of biogas from bakery waste was enhanced
by additional bacterial cell. This study was divided into 2 steps. First
step, grease waste from bakery industry-s grease trap was initially
degraded by Pseudomonas aeruginosa. The concentration of byproduct,
especially glycerol, was determined and found that glycerol
concentration increased from 12.83% to 48.10%. Secondary step, 3
biodigesters were set up in 3 different substrates: non-degraded waste
as substrate in first biodigester, degraded waste as substrate in
secondary biodigester, and degraded waste mixed with swine manure
in ratio 1:1 as substrate in third biodigester. The highest
concentration of biogas was found in third biodigester that was
44.33% of methane and 63.71% of carbon dioxide. The lower
concentration at 24.90% of methane and 18.98% of carbon dioxide
was exhibited in secondary biodigester whereas the lowest was found
in non-degraded waste biodigester. It was demonstrated that the
biogas production was greatly increased with the initial grease waste
degradation by Pseudomonas aeruginosa.
Abstract: Sediment and mangrove root samples from Iko River
Estuary, Nigeria were analyzed for microbial and polycyclic
aromatic hydrocarbon (PAH) content. The total heterotrophic
bacterial (THB) count ranged from 1.1x107 to 5.1 x107 cfu/g, total
fungal (TF) count ranged from 1.0x106 to 2.7x106 cfu/g, total
coliform (TC) count ranged from 2.0x104 to 8.0x104cfu/g while
hydrocarbon utilizing bacterial (HUB) count ranged from 1.0x 105 to
5.0 x 105cfu/g. There was a range of positive correlation (r = 0.72 to
0.93) between THB count and total HUB count, respectively. The
organisms were Staphylococcus aureus, Bacillus cereus,
Flavobacterium breve, Pseudomonas aeruginosa, Erwinia
amylovora, Escherichia coli, Enterobacter sp, Desulfovibrio sp,
Acinetobacter iwoffii, Chromobacterium violaceum, Micrococcus
sedentarius, Corynebacterium sp, and Pseudomonas putrefaciens.
The PAH were Naphthalene, 2-Methylnaphthalene, Acenapthylene,
Acenaphthene, Fluorene, Phenanthene, Anthracene, Fluoranthene,
Pyrene, Benzo(a)anthracene, Chrysene, Benzo(b)fluoranthene,
Benzo(k)fluoranthene, Benzo(a)pyrene, Dibenzo(a,h)anthracene,
Benzo(g,h,l)perylene ,Indeno(1,2,3-d)pyrene with individual PAH
concentrations that ranged from 0.20mg/kg to 1.02mg/kg, 0.20mg/kg
to 1.07mg/kg and 0.2mg/kg to 4.43mg/kg in the benthic sediment,
epipellic sediment and mangrove roots, respectively. Total PAH
ranged from 6.30 to 9.93mg/kg, 6.30 to 9.13mg/kg and 9.66 to
16.68mg/kg in the benthic sediment, epipellic sediment and
mangrove roots, respectively. The high concentrations in the
mangrove roots are indicative of bioaccumulation of the pollutant in
the plant tissue. The microorganisms are of ecological significance
and the detectable quantities of polycyclic aromatic hydrocarbon
could be partitioned and accumulated in tissues of infaunal and
epifaunal organisms in the study area.
Abstract: Environmental micro-organisms include a large number of taxa and some species that are generally considered nonpathogenic, but can represent a risk in certain conditions, especially for elderly people and immunocompromised individuals. Chemotaxonomic identification techniques are powerful tools for environmental micro-organisms, and cellular fatty acid methyl esters (FAME) content is a powerful fingerprinting identification technique. A system based on an unsupervised artificial neural network (ANN) was set up using the fatty acid profiles of standard bacterial strains, obtained by gas-chromatography, used as learning data. We analysed 45 certified strains belonging to Acinetobacter, Aeromonas, Alcaligenes, Aquaspirillum, Arthrobacter, Bacillus, Brevundimonas, Enterobacter, Flavobacterium, Micrococcus, Pseudomonas, Serratia, Shewanella and Vibrio genera. A set of 79 bacteria isolated from a drinking water line (AMGA, the major water supply system in Genoa) were used as an example for identification compared to standard MIDI method. The resulting ANN output map was found to be a very powerful tool to identify these fresh isolates.
Abstract: The high world interest given to the researches concerning the study of moderately halophilic solvent-tolerant bacteria isolated from marine polluted environments is due to their high biotechnological potential, and also to the perspective of their application in different remediation technologies. Using enrichment procedures, I isolated two moderately halophilic Gram-negative bacterial strains from seawater sample, which are tolerant to organic solvents. Cell tolerance, adhesion and cells viability of Aeromonas salmonicida IBBCt2 and Pseudomonas aeruginosa IBBCt3 in the presence of organic solvents depends not only on its physicochemical properties and its concentration, but also on the specific response of the cells, and the cellular response is not the same for these bacterial strains. n-hexane, n-heptane, propylbenzene, with log POW between 3.69 and 4.39, were less toxic for Aeromonas salmonicida IBBCt2 and Pseudomonas aeruginosa IBBCt3, compared with toluene, styrene, xylene isomers and ethylbenzene, with log POW between 2.64 and 3.17. The results indicated that Aeromonas salmonicida IBBCt2 is more susceptible to organic solvents than Pseudomonas aeruginosa IBBCt3. The mechanisms underlying solvent tolerance (e.g., the existance of the efflux pumps) in Aeromonas salmonicida IBBCt2 and Pseudomonas aeruginosa IBBCt3 it was also studied.
Abstract: Monitoring of microbial flora in aquacultured sea bream, in relation to the physicochemical parameters of the rearing seawater, ended to a model describing the influence of the last to the quality of the fisheries. Fishes were sampled during eight months from four aqua farms in Western Greece and analyzed for psychrotrophic, H2S producing bacteria, Salmonella sp., heterotrophic plate count (PCA), with simultaneous physical evaluation. Temperature, dissolved oxygen, pH, conductivity, TDS, salinity, NO3 - and NH4 + ions were recorded. Temperature, dissolved oxygen and conductivity were correlated, respectively, to PCA, Pseudomonas sp. and Shewanella sp. counts. These parameters were the inputs of the model, which was driving, as outputs, to the prediction of PCA, Vibrio sp., Pseudomonas sp. and Shewanella sp. counts, and fish microbiological quality. The present study provides, for the first time, a ready-to-use predictive model of fisheries hygiene, leading to an effective management system for the optimization of aquaculture fisheries quality.
Abstract: The aim of this study was to assess the effect of LAB
isolated from Iranian native olives on the opportunistic skin
pathogens, Pseudomonas aeruginosa and Staphylococcus aureus.
Lactic Acid Bacteria were isolated from the brine of each sample in
the prior of time. The samples were spread on MRS agar for isolation
of lactobacillus and for lactococcus. 28 strains of labs were isolated.
The labs were centrifuged, the supernatant was strewed and pellet
was used to inoculation in wells or at blank disks. 20μl of each pellet
was inoculated to blank disks and 40μl of each pellet was inoculated
to each well. The result of disk and well diffusion agar against these
pathogens were confirmed each other. The size of inhibition zone
was different according to the type of bacteria, the method and the
concentrations of labs.
Abstract: The effects of divers carbon substrates were
investigated for the tabtoxin production of an isolated pathogenic
Pseudomonas syringae pv. tabaci, the causal agent of wildfire of
tobacco and are discussed in relation to the bacterium growth. The
isolated organism was grown in batch culture on Woolley's
medium (28°C, 200 rpm, during 5 days). The growth has been
measured by the optical density (OD) at 620 nm and the tabtoxin
production quantified by Escherichia coli (K-12) bioassay
technique. The growth and the tabtoxin production were both
influenced by the substrates (sugars, amino acids, organic acids)
used, each, as a sole carbon source and as a supplement for the
same amino acids. The most significant quantities of tabtoxin were
obtained in presence of some amino acids used as sole carbon
source and/or as supplement.
Abstract: Vernonia divergens Benth., commonly known as
“Insulin Plant” (Fam: Asteraceae) is a potent sugar killer. Locally the
leaves of the plant, boiled in water are successfully administered to a
large number of diabetic patients. The present study evaluates the
putative anti-diabetic ingredients, isolated from the in vivo and in
vitro grown plantlets of V. divergens for their antimicrobial and
anticancer activities. Sterilized explants of nodal segments were
cultured on MS (Musashige and Skoog, 1962) medium in presence of
different combinations of hormones. Multiple shoots along with
bunch of roots were regenerated at 1mg l-1 BAP and 0.5 mg l-1 NAA.
Micro-plantlets were separated and sub-cultured on the double
strength (2X) of the above combination of hormones leading to
increased length of roots and shoots. These plantlets were
successfully transferred to soil and survived well in nature. The
ethanol extract of plantlets from both in vivo & in vitro sources were
prepared in soxhlet extractor and then concentrated to dryness under
reduced pressure in rotary evaporator. Thus obtainedconcentrated
extracts showed significant inhibitory activity against gram
negative bacteria like Escherichia coli and Pseudomonas
aeruginosa but no inhibition was found against gram positive
bacteria. Further, these ethanol extracts were screened for in vitro
percentage cytotoxicity at different time periods (24 h, 48 h and 72 h)
of different dilutions. The in vivo plant extract inhibited the growth of
EAC mouse cell lines in the range of 65, 66, 78, and 88% at 100, 50,
25 & 12.5μg mL-1 but at 72 h of treatment. In case of the extract of in
vitro origin, the inhibition was found against EAC cell lines even at
48h. During spectrophotometric scanning, the extracts exhibited
different maxima (ʎ) - four peaks in in vitro extracts as against single
in in vivo preparation suggesting the possible change in the nature of
ingredients during micropropagation through tissue culture
techniques.
Abstract: To decompose organochlorides by bioremediation, co-culture biohydrogen producer and dehalogenation microorganisms is a useful method. In this study, we combined these two characteristics from a biohydrogen producer, Rhodopseudomonas palustris, and a dehalogenation microorganism, Pseudomonas putida, to enchance halorespiration in R. palustris. The genes encoding cytochrome P450cam system (camC, camA, and camB) from P. putida were expressed in R. palustris with designated expression plasmid. All tested strains were cultured to log phase then presented pentachloroethane (PCA) in media. The vector control strain could degrade PCA about 78% after 16 hours, however, the cytochrome P450cam system expressed strain, CGA-camCAB, could completely degrade PCA in 12 hours. While taking chlorinated aromatic, 3-chlorobenzoate, as sole carbon source or present benzoate as co-substrate, CGA-camCAB presented faster growth rate than vector control strain.
Abstract: Lactic acid alone and its combined application with
nisin were evaluated for reducing population of naturally occurring
microorganisms on chilled shrimp. Fresh shrimps were dipped in 0,
1.0% and 2.0% (v/v) lactic acid alone and their combined application
with 0.04 (g/L/kg) nisin solution for 10 min. Total plate counts of
aerobic bacteria (TPCs), Psychrotrophic counts, population of
Pseudomonas spp., H2S producing bacteria and Lactic acid bacteria
(LAB) on shrimps were determined during storage at 4 °C. The
results indicated that total plate counts were 2.91 and 2.63 log CFU/g
higher on untreated shrimps after 7 and 14 days of storage,
respectively, than on shrimps treated with 2.0% lactic acid combined
with 0.04 (g/L/kg) nisin. Both concentrations of lactic acid indicated
significant reduction on Pseudomonas counts during storage, while
2.0% lactic acid combined with nisin indicated the highest reduction.
In addition, H2S producing bacteria were more sensitive to high
concentration of lactic acid combined with nisin during storage.
Abstract: Antibacterial activity of Plumeria alba (Frangipani)
petals methanolic extracts were evaluated against Escherichia coli,
Proteus vulgaris,Staphylococcus aureus, Klebsiella pneumoniae,
Pseudomonas aeruginosa, Staphylococcus saprophyticus,
Enterococcus faecalis and Serratia marcescens by using disk
diffusion method. Concentration extracts (80 %) showed the highest
inhibition zone towards Escherichia coli (14.3 mm). Frangipani
extract also showed high antibacterial activity against
Staphylococcus saprophyticus, Proteus vulgaris and Serratia
marcescens, but not more than the zones of the positive control used.
Comparison between two broad specrum antibiotics to frangipani
extracts showed that the 80 % concentration extracts produce the
same zone of inhibition as Streptomycin. Frangipani extracts showed
no bacterial activity towards Klebsiella pneumoniae, Pseudomonas
aeruginosa and Enterococcus faecalis. There are differences in the
sensitivity of different bacteria to frangipani extracts, suggesting that
frangipani-s potency varies between these bacteria. The present
results indicate that frangipani showed significant antibacterial
activity especially to Escherichia coli.
Abstract: The removal efficiency of 4-chlorophenol with
different advanced oxidation processes have been studied. Oxidation
experiments were carried out using two 4-chlorophenol
concentrations: 100 mg L-1 and 250 mg L-1 and UV generated from a
KrCl excilamp with (molar ratio H2O2: 4-chlorophenol = 25:1) and
without H2O2, and, with Fenton process (molar ratio H2O2:4-
chlorophenol of 25:1 and Fe2+ concentration of 5 mg L-1).
The results show that there is no significant difference in the 4-
chlorophenol conversion when using one of the three assayed
methods. However, significant concentrations of the photoproductos
still remained in the media when the chosen treatment involves UV
without hydrogen peroxide. Fenton process removed all the
intermediate photoproducts except for the hydroquinone and the
1,2,4-trihydroxybenzene. In the case of UV and hydrogen peroxide
all the intermediate photoproducts are removed.
Microbial bioassays were carried out utilising the naturally
luminescent bacterium Vibrio fischeri and a genetically modified
Pseudomonas putida isolated from a waste treatment plant receiving
phenolic waste. The results using V. fischeri show that with samples
after degradation, only the UV treatment showed toxicity (IC50 =38)
whereas with H2O2 and Fenton reactions the samples exhibited no
toxicity after treatment in the range of concentrations studied. Using
the Pseudomonas putida biosensor no toxicity could be detected for
all the samples following treatment due to the higher tolerance of the
organism to phenol concentrations encountered.
Abstract: In order to enhance the knowledge of certain
phytochemical Algerian plants that are widely used in traditional
medicine and to exploit their therapeutic potential in modern
medicine, we have done a specific extraction of terpenes and
alkaloids from the leaves of Euphorbia granulata to evaluate the
antioxidant and antibacterial activity of this extracts. After the
extraction it was found that the terpene extract gave the highest yield
59.72% compared with alkaloids extracts.
The disc diffusion method was used to determine the antibacterial
activity against different bacterial strains: Escherichia coli
(ATCC25922), Pseudomonas aeruginosa (ATCC27853) and
Staphylococcus aureus (ATCC25923). All extracts have shown
inhibition of growth bacteria. The different zones of inhibition have
varied from (7 -10 mm) according to the concentrations of extract
used.
Testing the antiradical activity on DPPH-TLC plates indicated the
presence of substances that have potent anti-free radical. As against,
the BC-TLC revealed that only terpenes extract which was reacted
positively. These results can validate the importance of Euphorbia
granulata in traditional medicine.
Abstract: This study was conducted to investigate the incidence
of pathogenic bacteria: Salmonella, Shigella, Escherichia coli O157
and Staphylococcus aureus in cakes and tarts collected from thirtyfive
confectionery producing and selling premises located within
Tripoli city, Libya. The results revealed an incidence of S. aureus
with 94.4 and 48.0 %, E. coli O157 with 14.7 and 4.0 % and Salmonella
sp. with 5.9 and 8.0 % in cakes and tarts samples respectively;
while Shigella was not detected in all samples. In order to determine
the source of these pathogenic bacteria, cotton swabs were taken
from the hands of workers on the production line, the surfaces of
preparation tables and cream whipping instruments. The results
showed that the cotton swabs obtained from the hands of workers
contained S. aureus and Salmonella sp. with an incidence of 42.9 and
2.9 %, the cotton swabs obtained from the surfaces of preparation
tables 22.9 and 2.9 % and the cotton swabs obtained from the cream
whipping instruments 14.3 and 0.0 % respectively; while E. coli
O157 and Shigella sp. were not detected in all swabs. Additionally,
other bacteria were isolated from the hands of workers and the Surfaces
of producing equipments included: Aeromonas sp., Pseudomonas
sp., E. coli, Klebsiella sp., Enterobacter sp., Citrobacter sp.,
Proteus sp., Serratia sp. and Acinetobacter sp. These results indicate
that some of the cakes and tarts might pose threat to consumer's
health. Meanwhile, occurrences of pathogenic bacteria on the hands
of those who are working in production line and the surfaces of
equipments reflect poor hygienic practices at most confectionery
premises examined in this study. Thus, firm and continuous surveillance
of these premises is needed to insure the consumer's health and
safety.
Abstract: An immunomodulator bioproduct is prepared in a
batch bioprocess with a modified bacterium Pseudomonas
aeruginosa. The bioprocess is performed in 100 L Bioengineering
bioreactor with 42 L cultivation medium made of peptone, meat
extract and sodium chloride. The optimal bioprocess parameters were
determined: temperature – 37 0C, agitation speed - 300 rpm, aeration
rate – 40 L/min, pressure – 0.5 bar, Dow Corning Antifoam M-max.
4 % of the medium volume, duration - 6 hours. This kind of
bioprocesses are appreciated as difficult to control because their
dynamic behavior is highly nonlinear and time varying. The aim of
the paper is to present (by comparison) different models based on
experimental data.
The analysis criteria were modeling error and convergence rate.
The estimated values and the modeling analysis were done by using
the Table Curve 2D.
The preliminary conclusions indicate Andrews-s model with a
maximum specific growth rate of the bacterium in the range of
0.8 h-1.
Abstract: Urinary Tract Infections (UTI) account for an estimated 25-40% nosocomial infection, out of which 90% are associated with urinary catheter, called Catheter associated urinary tract infection (CAUTI). The microbial populations within CAUTI frequently develop as biofilms. In the present study, microbial contamination of indwelling urinary catheters was investigated. Biofilm forming ability of the isolates was determined by tissue culture plate method. Prevention of biofilm formation in the urinary catheter by Pseudomonas aeruginosa was also determined by coating the catheter with some enzymes, gentamycin and EDTA. It was found that 64% of the urinary catheters get contaminated during the course of catheterization. Of the total 6 isolates, biofilm formation was seen in 100% Pseudomonas aeruginosa and E. coli, 90% in Enterococci, 80% in Klebsiella and 66% in S. aureus. It was noted that the biofilm production by Pseudomonas was prolonged by 7 days in amylase, 8 days in protease, 6 days in lysozyme, 7days in gentamycin and 5 days in EDTA treated catheter.