Low Intensity Electromagnetic Irradiation with 70.6 and 73 GHz Frequencies Affects <Emphasis Type="Italic">Escherichia coli</Emphasis> Growth and Changes Water Properties

The low intensity electromagnetic irradiation (EMI) of the 70.6 and 73 GHz frequency is resonant for Escherichia coli but not for water. In this study, E. coli irradiation with this EMI during 1 h directly and in bi-distilled water or in the assay buffer with those frequencies resulted with noticeable changes in bacterial growth parameters. Furthermore, after EMI, 2 h rest of bacteria renewed their growth in 1.2-fold, but repeated EMI—had no significant action. Moreover, water absorbance, pH, and electric conductance were changed markedly after such irradiation. The results point out that EMI of the 70.6 and 73 GHz frequency can interact with bacteria affecting growth and in the same time with the surrounding medium (water) as well.     

Novel radio-chromic solution dosimeter for radiotherapy treatment planning

Nitro blue tetrazolium (NBT) solution dosimeters were prepared and investigated based on radiation-induced reduction of NBT²⁺. NBT solution dosimeters containing different concentrations of NBT dye from 1 to 5 mM were prepared in a solution of ethanol. The dosimeters were irradiated with 6 MV X-ray beam at doses up to 30 Gy. The dose sensitivity of NBT solution increases strongly with increase of concentrations of NBT dye. The dose response of NBT dosimeters increases remarkably by addition of various concentrations of sodium formate (0.5, 2.5 and 5 mM). It becomes more remarkable with increasing pH value of NBT-sodium formate dosimeters. The sensitivity of the solution increased fairly with increase of irradiation temperature, therefore, the response of the solutions has to be corrected under actual processing conditions. The stability of solution dosimeters after irradiation was very high up to 30 days.     

The effects of electromagnetic radiation of extremely high frequency and low intensity on the growth rate of bacteria Escherichia coli and the role of medium pH

It has been shown that coherent electromagnetic irradiation (EMI) of extremely high frequency (45-53 GHz) or millimeter waves (wavelength 5.6-6.7 mm) of low intensity (flux capacity 0.06 mW/cm2) of Escherichia coli K12, grown under anaerobic conditions during the fermentation of sugar (glucose) for 30 min or 1 h, caused a decrease in their growth rate, the maximum inhibitory effect being achieved at a frequency of 51.8 or 53 GHz. This effect depended on medium pH when the maximal action was determined at pH 7.5. In addition, separate 30-min of 1-h irradiation (frequency 51.8 or 53 GHz) of doubly distilled water or some inorganic ions contained in Tris-phosphate buffer where the cells were transferred induced oppositely directed changes in further growth of these bacteria under anaerobic conditions; irradiation of water caused a decrease in the growth rate of bacteria. A significant change in pH of water (0.5-1.5 unit) was induced by a 30-irradiation at a frequency of 49, 50.3, 51.8, or 53 GHz, when the initial pH value was 6.0 or 8.0, but not 7.5. These results indicate the changes in the properties of water and its role in the effects of EMI of extremely high frequency. The marked effect of EMI on bacteria disappeared upon repeated irradiation for 1 h at a frequency of 51.8 or 53 GHz with an interval of 2 hours. This result indicates some compensatory mechanisms in bacteria.     

Effect of Extraction Procedures on Functional Properties of Eruca sativa Seed Mucilage

The effect of different extraction procedures on functional properties of mucilage extracted from Eruca sativa seed were investigated using response surface methodology. A Central Composite Face Design (CCFD) with three independent variables: temperature (25–85 °C), pH (4–10) and water to seed ratio (20:1–60:1) was used to study the response variables (yield, viscosity, emulsion stability, foam stability, solubility and water absorption capacity). For each response, a second-order polynomial model was developed using multiple linear regression analysis. The results indicated that extraction temperature and pH significantly (p < 0.05) affected all functional properties. Applying desirability function method, optimum operating conditions were found to be extraction temperature of 65.5 °C, pH: 4 and water to seed ratio of 60:1. At this optimum point, maximum extraction yield, viscosity, emulsion stability (ES), foam stability (FS), solubility and water absorption capacity (WAC) were found to be 10.3 (%), 357 (mPas), 87 (%), 87.5 (%), 28.5 (%) and 9.3 (g/g), respectively.     

Microbial survival in the stratosphere and implications for global dispersal

Spores of Bacillus subtilis were exposed to a series of stratosphere simulations. In total, five distinct treatments measured the effect of reduced pressure, low temperature, high desiccation, and intense ultraviolet (UV) irradiation on stratosphere-isolated and ground-isolated B. subtilis strains. Environmental conditions were based on springtime data from a mid-latitude region of the lower stratosphere (20 km). Experimentally, each treatment consisted of the following independent or combined conditions: −70°C, 56 mb, 10–12% relative humidity and 0.00421, 5.11, and 54.64 W/m² of UVC (200–280 nm), UVB (280–315 nm), UVA (315–400 nm), respectively. Bacteria were deposited on metal coupon surfaces in monolayers of ~1 × 10⁶ spores and prepared with palagonite (particle size < 20 μm). After 6 h of exposure to the stratosphere environment, 99.9% of B. subtilis spores were killed due to UV irradiation. In contrast, temperature, desiccation, and pressure simulations without UV had no effect on spore viability up through 96 h. There were no differences in survival between the stratosphere-isolated versus ground-isolated B. subtilis strains. Inactivation of most bacteria in our simulation indicates that the stratosphere can be a critical barrier to long-distance microbial dispersal and that survival in the upper atmosphere may be constrained by UV irradiation.     

Complete conformational stability of kinetically stable dimeric serine protease milin against pH,temperature, urea,and proteolysis

Spectroscopic, calorimetric, and proteolytic methods were utilized to evaluate the stability of the kinetically stable, differentially glycosylated, dimeric serine protease milin as a function of pH (1.0–11.0), temperature, urea, and GuHCl denaturation in presence of 8 M urea at pH 2.0. The stability of milin remains equivalent to that of native at pH 1.0–11.0. However, negligible and reversible alteration in structure upon temperature transition has been observed at pH 2.0 and with 1.6 M GuHCl. Irreversible and incomplete calorimetric transition with apparent T _m > 100°C was observed at basic pH (9.0 and 10.0). Urea-induced unfolding at pH 4.0, and at pH 2.0 with GuHCl, in presence of 8 M urea also reveals incomplete unfolding. Milin has been found to exhibit proteolytic resistant in either native or denatured state against various commercial proteases. These results imply that the high conformational stability of milin against various denaturating conditions enable its potential use in protease-based industries.     

Anaerobic treatment of synthetic medium-strength wastewater using a multistage biofilm reactor

A laboratory-scale multistage anaerobic biofilm reactor of three compartments with a working volume of 54-L was used for treating a synthetic medium-strength wastewater containing molasses as a carbon source at different influent conditions. The start-up period, stability and performance of this reactor were assessed at mesophilic temperature (35 °C). During the start-up period, pH fluctuations were observed because there was no microbial selection or zoning, but as the experiment progressed, results showed that phase separation had occurred inside the reactor. COD removal percentages of 91.6, 91.6, 90.0 and 88.3 were achieved at organic loading rates of 3.0, 4.5, 6.75 and 9.0 kg COD/m³ day, respectively. A decrease in HRT from 24 to 16 h had no effect on COD removal efficiency. When HRT decreased to 8 h, COD removal efficiency was still 84.9%. Recirculation ratios of 0.5 and 1.0 had no effect on COD removal but other factors such as the volatile fatty acid (VFA) content were affected. The effect of toxic shock was also investigated and results showed that the main advantage of using this bioreactor lies in its compartmentalized structure.     

Immobilization of cellulase on polyamidoamine dendrimer-grafted silica

Polyamidoamine dendrimer (PAMAM) is one of a number of dendritic polymers with precise molecular structure, highly geometric symmetry, and a large number of terminal groups, and is suitable to carry biomolecules due to its affinity and biocompatibility. In this study, PAMAM was grafted onto the surface of silica by microwave irradiation. A novel media was developed through immobilizing cellulase onto the prepared PAMAM-grafted silica by adsorption and crosslinking methods and applied in hydrolysis of carboxymethyl cellulose. The results demonstrate that the enzyme binding capacity and enzymolysis efficiency increased with generations of PAMAM. The properties of the immobilized cellulase-PAMAM-grafted silica were investigated, which possessed high enzymatic activity and exhibited better stability with respect to pH, temperature compared with free enzyme. The optimal immobilization conditions for adsorption and crosslinking method were respectively obtained at 5 and 4 mg ml⁻¹ cellulase for 2 h of immobilization. A high enzymolysis efficiency was achieved by employing pH 4.8 and 5.8 substrate solution at 60 °C for adsorbed and crosslinked cellulase, respectively. After repeated three run cycles, the retained activities were found to be 75% and 82%. The results indicate that the PAMAM has a good performance as a carrier, and can be potentially adapted to support other biomacromolecules.     

A combined physical and physiological dormancy controls seasonal seedling emergence of Geranium robertianum

Temperate forest herbs with seeds exhibiting both a physical and a physiological dormancy mechanism are rare, and knowledge on the factors regulating germination of these species is fragmentary. The biennial Geranium robertianum L. grows mainly in temperate woodlands, but can also be found in exposed habitats. Seedlings of G. robertianum are known to emerge from spring until autumn, but little is known about the environmental factors regulating germination. In this study, phenology of seedling emergence and of physical dormancy loss was examined for seeds buried at shaded or sunny exposed locations. The role of temperature in regulating dormancy and germination was analysed by incubating seeds in temperature sequences simulating temperatures that seeds experience in nature. The results indicate that most seeds of G. robertianum buried in sunny conditions germinate immediately after physical dormancy loss in summer. Seeds buried in shaded conditions also lose physical dormancy mainly during summer, but remain physiologically dormant and do not germinate until late winter or early spring. Besides physical dormancy, seeds of G. robertianum also initially have a high level of physiological dormancy, which is reduced during dry storage. Physiological dormancy is reduced through chilling in winter, thus enabling the seeds to germinate at low temperatures. We conclude that a complex combination of physical and physiological dormancy ensures that G. robertianum seeds germinate in summer at exposed sites and in early spring at shaded sites.     

Expression,characterization and 2,4,6-trichlorophenol degradation of laccase from <Emphasis Type="Italic">Monilinia fructigena</Emphasis>

A novel laccase gene from Monilinia fructigena was synthesized chemically according to the yeast bias codon and integrated into the genome of Pichia pastoris GS115 by electroporation. The expressed enzyme was recovered from the culture supernatant and purified. The result of enzyme activity assay and SDS-PAGE demonstrated that the recombinant laccase was induced and extracellularly expressed in P. pastoris. Main biochemical properties of this laccase, such as thermodependence and thermostability, optimal pH and pH stability, and the effect of metal ions and inhibitors, were characterized. With 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonate (ABTS) as the substrate, MfLcc had its optimal pH at 3.5 and optimal temperature at 45°C. The Km values of the ABTS, guaiacol were 0.012 and 0.016 Mm, respectively, and the corresponding V _max values are 243.9 and 10.55 Um min⁻¹ mg⁻¹, respectively. The recombinant laccase degraded 80% 2,4,6-trichlorophenol after 8 h under the optimal conditions. The recombinant strain and its laccase can be considered as candidate for treating waste water polluted with trichlorophenols.     

An alkali-tolerant xylanase produced by the newly isolated alkaliphilic <Emphasis Type="Italic">Bacillus pumilus</Emphasis> from paper mill effluent

An alkaline active xylanase, XynBYG, was purified from an alkaliphilic Bacillus pumilus BYG, which was newly isolated from paper mill effluent. It had an optimum pH of 8.0–9.0, and showed good stability after incubated at pH 9.0 for 120 min. The optimum temperature for the activity was 50°C, and the enzyme retained below 55% of its original activity for 30 min at 55°C. The gene coding for XynBYG consists of 687 bp and encodes 229 amino acids. Similarity analysis indicated that XynBYG belong to family 11 glycosyl hydrolases. Site-directed mutagenesis was performed to replace five sites (Tyr/Ser) to Arg/Glu and the results demonstrated that the optimum temperature of the mutant Y7 (S39R-T146E) increased 5°C and the half-life of inactivation (T1/2) at 60 and 65°C was 1 h and 25 min, respectively. Thus, it provides a potential xylanase that can meet the harsh conditions in the industrial applications.     

Ultrasonic irradiation with vibration for biodiesel production from soybean oil by Novozym 435

The production of biodiesel with soybean oil and methanol through transesterification by Novozym 435 (Candida antarctica lipase B immobilized on polyacrylic resin) were conducted under two different conditions—ultrasonic irradiation and vibration to compare their overall effects. Compared with vibration, ultrasonic irradiation significantly enhanced the activity of Novozym 435. The reaction rate was further increased under the condition of ultrasonic irradiation with vibration (UIV). Effects of reaction conditions, such as ultrasonic power, water content, organic solvents, ratio of solvent/oil, ratio of methanol/oil, enzyme dosage and temperature on the activity of Novozym 435 were investigated under UIV. Under the optimum conditions (50% of ultrasonic power, 50 rpm vibration, water content of 0.5%, tert-amyl alcohol/oil volume ratio of 1:1, methanol/oil molar ratio of 6:1, 6% Novozym 435 and 40 °C), 96% yield of fatty acid methyl ester (FAME) could be achieved in 4 h. Furthermore, repeated use of Novozym 435 after five cycles showed no obvious loss in enzyme activity, which suggested this enzyme was stable under the UIV condition. These results indicated that UIV was a fast and efficient method for biodiesel production.     

Enzymatic hydrolysis of cellulose in a membrane bioreactor: assessment of operating conditions

The optimization of operating conditions for cellulose hydrolysis was systemically undertaken using an ultra-scaled down membrane bioreactor based on the parameter scanning ultrafiltration apparatus. The bioconversion of cellulose saccharification was carried out with freely suspended cellulase from Aspergillus niger as the biocatalyst. The polyethersulfone ultrafiltration membranes with a molecular weight cutoff of 10 kDa were used to construct the enzymatic membrane bioreactor, with the membrane showing a complete retaining of cellulase and cellobiase. The influence of solution pH, temperature, salt (NaCl) concentration, presence of cellobiase, cellulose-to-enzyme ratio and stirring speed on reducing sugar production was examined. The results showed that the addition of an appropriate amount of NaCl or cellobiase had a positive effect on reducing sugar formation. Under the identified optimal conditions, cellulose hydrolysis in the enzymatic membrane bioreactor was tested for a long period of time up to 75 h, and both enzymes and operation conditions demonstrated good stability. Also, the activation energy (E _a) of the enzymatic hydrolysis, with a value of 34.11 ± 1.03 kJ mol⁻¹, was estimated in this study. The operational and physicochemical conditions identified can help guide the design and operation of enzymatic membrane bioreactors at the industrial scale for cellulose hydrolysis.     

Optimization of pectin extraction from lemon by-product with acidified date juice using response surface methodology

Response surface methodology was used to optimize pectin recovery from lemon by-product using an acidified date juice as extraction solution. When enriched in pectin, this latter can be useful for preparation of date-lemon jelly. The effects of three parameters namely temperature, pH and extraction time, on pectin extraction were studied. The fitted mathematical model allowed us to plot response surfaces as well as isoresponse curves and to determine optimal extraction conditions. Results clearly indicated that the temperature was the main factor influencing the pectin yield which increased with temperature and time or decreasing pH. The selected optimal conditions were: temperature 84.34 °C; extraction time 3 h 34 min and pH 2.8. These conditions yielded about 11.21% of pectin versus 10.89% for the predicted value.     

Glass-immobilized glycated-trypsin: A novel modified trypsin that is remarkably thermostable

Porcine trypsin was glycated with glucose and covalently immobilized through its carboxyl groups onto aminated glass beads to produce porcine immobilized glycated-trypsin (IGT). On incubation at 60 °C and pH 8, IGT retained its full activity for 8 h and 50% of its activity after 24 h. In comparison, under the same conditions porcine native trypsin lost 80% of its activity in 2 h and was completely inactivated in less than 4 h. The rate of autolysis of porcine glycated-trypsin at 37 °C was 40% that of native trypsin and with IGT there was no significant autolysis, even at elevated temperatures as high as 60 °C. Glycation significantly increased the stability of trypsin and immobilization also significantly increased the stability of trypsin. The remarkable thermostability of IGT is attributed to a synergistic effect when these two modifications are combined. Tryptic fragmentation of denatured proteins with IGT can be performed at 60 °C for shorter digestion times and with smaller amounts of enzyme than normally employed to achieve complete digestion with soluble forms of trypsin. Prior denaturation of proteins for tryptic digestion is not required with IGT as in situ denaturation and digestion can be achieved simultaneously at 60 °C with an enzyme:protein mass ratio as low as 1:1000.     

Production and optimization of cellulase-free, alkali-stable xylanase by Bacillus pumilus SV-85S in submerged fermentation

This paper reports the production of a cellulase-free and alkali-stable xylanase in high titre from a newly isolated Bacillus pumilus SV-85S using cheap and easily available agro-residue wheat bran. Optimization of fermentation conditions enhanced the enzyme production to 2995.20 ± 200.00 IU/ml, which was 9.91-fold higher than the activity under unoptimized basal medium (302.2 IU/ml). Statistical optimization using response-surface methodology was employed to obtain a cumulative effect of peptone, yeast extract, and potassium nitrate (KNO₃) on enzyme production. A 2³ central composite design best optimized the nitrogen source at the 0 level for peptone and yeast extract and at the −α level for KNO₃, along with 5.38-fold increase in xylanase activity. Addition of 0.1% tween 80 to the medium increased production by 1.5-fold. Optimum pH for xylanase was 6.0. The enzyme was 100% stable over the pH range from 5 to 11 for 1 h at 37°C and it lost no activity, even after 3 h of incubation at pH 7, 8, and 9. Optimum temperature for the enzyme was 50°C, but the enzyme displayed 78% residual activity even at 65°C. The enzyme retained 50% activity after an incubation of 1 h at 60°C. Characteristics of B. pumilus SV-85S xylanase, including its cellulase-free nature, stability in alkali over a long duration, along with high-level production, are particularly suited to the paper and pulp industry.     

Hexavalent Chromium Reduction and Accumulation by <Emphasis Type="Italic">Acinetobacter</Emphasis> AB1 Isolated from Fez Tanneries in Morocco

Hexavalent chromium reduction and accumulation by Acinetobacter AB1 isolated from Fez tanneries effluents were tested. The effects of some environmental factors such as pH, temperature, and exposure time on Cr(VI) reduction and resistance were investigated. We found that this strain was able to resist to concentrations as high as 400 mg/l of Cr(VI). Moreover, pH 10 and the temperature 30°C constitute favourable conditions to the growth and reduction of Acinetobacter AB1. Complete reduction of Cr(VI) was observed at low initial Cr(VI) concentrations of 50 mg/l after 72 h of incubation. Furthermore, Transmission electron microscope (TEM) analysis showed morphological changes in AB1 strain due 48H exposure to 100 mg/l chromate concentration and revealed circular electron dense (dark black point) inclusion within the cell cytoplasm suggesting chromium deposition within the cells.     

Effect of Different Physical Factors on efficacy of Thevetia Peruviana leaf extract and bio-formulations

Plant extract possess various secondary metabolites which are antifungal in nature and can be used as a safer alternative to the synthetic fungicides. As we all know that the chemical fungicides are harmful not only for humans but also for animals, other vegetation and for complete ecosystem. To overcome this problem, we have to focused on another alternative which are biologically libel and nonhazardous also. In the present study, herbal formulation was prepared in various combination ratios with Thevetia peruviana leaf extracts, cow dung and neem oil cake. The major aim of this short study is to check the stability of the said plant extracts and prepared herbal formulation on various physical factors like heat, temperature, pH, sunlight and storage etc. The extracts and herbal formulations were exposed to varying conditions of the parameters selected for a precise time period, and then observing the effect as a function of change in the crude extract activity, herbal formulation activity and change minimum inhibitory concentration of plant extract against the Alternaria solani. Control set of MIC, and extract free medium were maintained for comparison in each set of experiment against Alternaria solani. Results suggested that efficacy of leaf extracts and different formulations was not affected by wet heat up to 100 °C while slight reduction in antifungal activity of the plant extract and herbal formulations were observed with dry heat at 100 °C. In addition, slight reduction in activity of extract and herbal formulations was observed with change in pH. However antifungal activity of plant extract as well as herbal formulations, remain unaffected at alkaline pH (pH 9) and neutral pH (pH7). Storage for 6 and 12 months had no negative effect on extract and herbal formulation efficacy and the antifungal activity was observed similar to freshly prepared extract activity. The present study concluded that the plant disease or plant pathogens can be controlled by plant extract and plant based bioformulations by increasing the shelf life with some little changes in the physical parameters such as light, temperature, pH and storage.     

Immobilization of trypsin on polysaccharide film from Anacardium occidentale L. and its application as cutaneous dressing

Polysaccharide obtained from Anacardium occidentale L. gum was used for trypsin entrapment using cellulose (gaze) as a support and this preparation was applied as cutaneous wound healing. Trypsin release in vitro and the influence of pH and temperature on activity, stability and storage time of entrapped enzyme were evaluated. The preparation showed that it was still capable to release enzyme even after 48 h. Entrapped enzyme presented an optimal pH and temperature of 8.6 and 55 °C, respectively. Also, it was stable at high temperature (45 °C for 60 min) and wide range of pH, retaining 80% of its initial activity when stored for 28 days at 25 °C. Histopathological analysis of mice skin wound healing under the entrapped trypsin preparation treatment showed an acceleration of fibroblast proliferation, neovascularization of granulation tissue and stimulating effect on the epithelium formation compared to the skin wound under the treatment using preparations without trypsin. These results demonstrate that the trypsin–polysaccharide–cellulose preparation could be used in cutaneous dressing applications for wound healing.     

Effects of the multiple stressors high temperature and reduced salinity on the photosynthesis of the hermatypic coral Galaxea fascicularis

This study investigates the physiological responses in the hermatypic coral Galaxea fascicularis exposed to salinity stress (from 37 ppt to 15 ppt) for 12 h, combined effects of reduced salinity (from 37 ppt to 20 ppt) and two temperatures (26 °C and 32 °C) for 12 h and combined effects of reduced salinity (from 37 ppt to 25 ppt) and two temperatures (26 °C and 29.5 °C) for 10 d. The results demonstrate that the coral is tolerant to 12 h exposure to extremely low salinity (15 ppt). The study also shows that combined effects of temperature and low salinity aggravate the damage on the photosynthesis of the symbiotic dinoflagellates in 12 h exposure to 20 ppt sea water. This study suggests that high temperature (29.5 °C) aggravates the damage of trivially low salinity (30 ppt) on the holobiont (the coral and its symbiotic dinoflagellates) in 10 d exposure. However, high temperature (29.5 °C) may have an antagonistic effect between temperature and low salinity (25 ppt) on metabolism of the holobiont. Based on the above results, we suggest that (1) the true mechanism of corals exposed to combined effects of low salinity and high temperature is complicated. This calls for more studies on different corals. Future studies should aim at investigating long-term low-level stress in order to simulate in situ conditions more accurately; (2) when corals exposed to extremely severe combined stressors for short-term or trivially severe stressors for relative long-term, the combined effects of two stressors (such as low salinity and high temperature) may be negative, otherwise, the effects may be additive.