Response in Cadmium Tolerance of Penicillium cyclopium Westling Subsequent to Exposure to Gamma Irradiation

Role of gamma irradiation in modulating 1.1 times more cadmium (Cd) tolerance in Penicillium cyclopium Westling has been detailed in this paper. Augmentation in metal tolerance was recognized by escalation in response to Cadmium and Cd removal efficacies than that of their un-irradiated group. FTIR spectra and electron microscopic photographs further strengthen the role of low absorbed dose of gamma in modulating Cd tolerance in P.cyclopium. Up regulated activities of anti-oxidatives in gamma exposed fungal groups might be the reason for enhanced Cd tolerance than that of their un-irradiated counter parts. This findings reveal a positive and eco-friendly step for heavy metal bioremediation and metal stressed lignocellulosic waste degradation.

The Effect of a Magnetic Field and Low-Intensity Laser Irradiation on the Destructive Activity of Filamentous Fungi During their Growth on a Number of Industrial Products

An assessment of the impact of low-intensity laser irradiation (LILI) and magnetic field (MF) on the biodegradation of a number of industrial products: wood fiberboard (WFB) and polyester caused by filamentous fungi is presented. It has been established that the magnetic field is capable of causing intensive destruction of wood fiberboard and polyester by fungi Alternaria alternata, Aspergillus niger, then the destructive process of WFB in the case of Penicillium cyclopium remained at the control level, and in the case of polyester it slowed down. The action of LILI, on the contrary, increased the destructive activity of Penicillium cyclopium in variants with WFB, and for polyester in the fungi Alternaria alternata, Aspergillus niger. Differences in the change in the resistance of products to fungi under the action of LILI and MF can be associated with both the physiological and biochemical characteristics of fungi and the aging process of polymers under the influence of the studied physical factors.

Preparation of the Hybrids of Hydrotalcites and Chitosan by Urea Method and Their Antimicrobial Activities

Hybrid nano-supra molecular structured materials can boost the functionality of nano- or supra-molecular materials by providing increased reactivity and conductivity, or by simply improving their mechanical stability. Herein, the studies in materials science exploring hybrid systems are investigated from the perspective of two important related applications: healthcare and food safety. Interfacing phase strategy was applied, and ZnAl layered double hydroxide-chitosan hybrids, prepared by the urea method (U-LDH/CS), were successfully synthesized under the conditions of different chitosan(CS) concentrations with a Zn/Al molar ratio of 5.0. The structure and surface properties of the U-LDH/CS hybrids were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectrometer(FTIR), scanning electronmicroscopy (SEM), ultravioletvisible (UV-Vis), and zero point charge (ZPC) techniques, where the effect of CS concentration on the structure and surface properties was investigated. The use of the U-LDH/CS hybrids as antimicrobial agents against Escherichia coli, Staphylococcus aureus, and Penicillium cyclopium was investigated in order to clarify the relationship between microstructure and antimicrobial ability. The hybrid prepared in a CS concentration of 1.0 g∙L−1 (U-LDH/CS1) exhibited the best antimicrobial activity and exhibited average inhibition zones of 24.2, 30.4, and 22.3mm against Escherichia coli, Staphylococcus aureus, and Penicillium cyclopium, respectively. The results showed that the appropriate addition of CS molecules could increase antimicrobial ability against microorganisms.

Purification, Characterization and Degradation Performance of a Novel Dextranase from Penicillium cyclopium CICC-4022

A novel dextranase was purified from Penicillium cyclopium CICC-4022 by ammonium sulfate fractional precipitation and gel filtration chromatography. The effects of temperature, pH and some metal ions and chemicals on dextranase activity were investigated. Subsequently, the dextranase was used to produce dextran with specific molecular mass. Weight-average molecular mass (Mw) and the ratio of weight-average molecular mass/number-average molecular mass, or polydispersity index (Mw/Mn), of dextran were measured by multiple-angle laser light scattering (MALS) combined with gel permeation chromatography (GPC). The dextranase was purified to 16.09-fold concentration; the recovery rate was 29.17%; and the specific activity reached 350.29 U/mg. Mw of the dextranase was 66 kDa, which is similar to dextranase obtained from other Penicillium species reported previously. The highest activity was observed at 55 °C and a pH of 5.0. This dextranase was identified as an endodextranase, which specifically degraded the α-1,6 glucosidic bonds of dextran. According to metal ion dependency tests, Li+, Na+ and Fe2+ were observed to effectively improve the enzymatic activity. In particular, Li+ could improve the activity to 116.28%. Furthermore, the dextranase was efficient at degrading dextran and the degradation rate can be well controlled by the dextranase activity, substrate concentration and reaction time. Thus, our results demonstrate the high potential of this dextranase from Penicillium cyclopium CICC-4022 as an efficient enzyme to produce specific clinical dextrans.