Optimization of submerged fermentation conditions for immunosuppressant mycophenolic acid production by Penicillium roqueforti isolated from blue-molded cheeses: enhanced production by ultraviolet and gamma irradiation

Mycophenolic acid (MPA) is a promising drug owing to its immunosuppressive and biological activities. In this study, two strains of Penicillium roqueforti designated as AG101 and LG109 were selected among several strains isolated from Roquefort cheese samples on the basis of their activity for MPA-producing ability. The appropriate fermentation conditions necessary for MPA biosynthesis by the two respective fungal strains were investigated. These conditions included selection of the cultivation medium, agitation rate, incubation temperature, fermentation time, pH value, inoculum size, and fermentation medium volume. Maximum MPA productivities were maintained when the fermentation process was carried out using a medium composed of (g l^?1): Sucrose, 30; peptone, 5.0; KH₂PO₄, 1.0; MgSO₄·7H₂O, 0.5 and KCl, 0.5; pH 6.0, inoculated with an inoculum size of 6.0 % (v/v), and incubated at 25 °C for 10 days at 120 rpm. The potentiality of both P. roqueforti strains for further improvement of MPA production was applied by mutagenesis through exposure to irradiation by ultraviolet rays (UV, 254 nm) for different periods of time and gamma rays at various doses (KGy). The dry cell weight of both irradiated fungal strains showed a greater reduction when irradiated either with UV or gamma rays. However, the MPA yield of both strains was increased by 1.27–1.39 fold when irradiated with UV rays and by 2.11–2.33 fold when irradiated with gamma rays, as compared with the respective controls (non-irradiated cultures). These findings indicate the future possibility to reduce the cost of producing fermentation-based drugs.     

Combined effect of gamma radiation,hot water and sodium bicarbonate on quality and chemical constituents of stored mandarin fruits

The combined effect of gamma radiation and both hot water and sodium carbonate on physiological decay and chemical constituents of stored mandarin fruits was investigated in this work. In this consideration, the studied fruits were gamma irradiated at doses of 0, 0.3, 0.6, 1.2 and 2.4 KGy. Then, the irradiated and non-irradiated fruits were treated either by hot water or sodium bicarbonate to examine their capacity to give a further maintenance and increasing shelf life or storage periods of mandarin. Treated and non-treated fruit samples were taken at intervals of 10 days and up to 60 days. Physiological decay, total acidity, vitamin C, total sugars and TSS were investigated during the different intervals. Gamma radiation treatments showed a promising effect for maintaining the studied fruits and retarding the development of decay. On the other hand, applying both hot water and sodium bicarbonate as a further combined treatments induced a powerful effect on delaying decay development, keeping the chemical constituents near to the normal level and in turn maximizing shelf life and storage periods of the fruits under investigation.     

Radiation causes increased production and decreased utilization of IL-2 in human mononuclear cells

The effects of radiation on the kinetics of Interleukin-2 (IL-2) production and utilization by mononuclear cells (MNCs) were studied. Mononuclear cells from normal, healthy individuals were subjected to various doses of radiation ranging from 0 to 2,000 rad and cultured in the presence of PHA. Supernatants from these cultures were harvested at various periods and their IL-2 contents determined by both the standard bioassay and ELISA. A radiation dose of 800 rad and higher had a marked effect on both IL-2 production and consumption. Although the supernatants from both the irradiated and non-irradiated MNCs contained maximal concentrations of IL-2 between 8 and 24 h of culture, the former had three times as much IL-2 as the latter. An increase in IL-2-mRNA levels was also noticed in irradiated, PHA-stimulated cells. Moreover, the supernatants from irradiated MNCs collected as late as 72 h after the initiation of culture contained more than 30% of the total IL-2 produced compared to less than 8% in supernatants from non-irradiated cells. Supernatants from non-irradiated cells incubated further with irradiated cells contained relatively higher quantities of IL-2 than those incubated continuously with non-irradiated cells. Supernatants from co-cultures of irradiated and non-irradiated MNCs contained less than expected amounts of IL-2 in two of the three subjects. Despite a difference in both the production and consumption of IL-2 between the irradiated and non-irradiated cells, there was no difference in their ability to generate IL-2 receptors. The results indicate that inactivation of radiosensitive suppressor T cells is associated with superinduction of IL-2 mRNA, increased production and decreased consumption of IL-2 by MNCs, thereby resulting in increased accumulation of IL-2.     

Effects of Moisture Content and Temperature on Aflatoxin Production in Corn

Samples of freshly harvested and remoistened corn, of various moisture contents, were stored at different temperatures; analyses for aflatoxin content were made periodically. At moisture levels above 17.5% and at temperatures of 24 C or warmer, aflatoxins were formed by Aspergillus flavus present in the original epiphytic mycoflora. Remoistened dried corn was subject to more rapid fungal deterioration and aflatoxin formation than freshly harvested corn. Screening of the fungi present in the corn revealed aflatoxin production only by A. flavus. The toxigenic strains produced only aflatoxins B(1) and B(2).     

Effect of irradiation on female painted apple moth Teia anartoides (Lep., Lymantriidae) sterility and attractiveness to males

Abstract:  Live female painted apple moths are being used to monitor the distribution of this invasive species in Auckland as part of a major eradication effort, and the goal of this project was to develop a method to minimize the risk of unwanted live insect propagation from the trapping programme as a result of vandalism or 'eco-terrorism'. Female pupae were irradiated with a range of doses and their egg viability assessed, and also tested to determine the impact of irradiation on male moth catch in the field. Female painted apple moth pupae, irradiated at a range of doses from 100 to 500 Gy, were placed in cages in traps at 10 m spacings from non-irradiated females, near a central release site of irradiated males. Untreated control females alternated along orthogonal transects with irradiated females. The results indicated no significant effect of female irradiation on catch of males. There was no correlation between dose and catch, within the range of exposures tested. There was a very low hatch rate of eggs from females irradiated at all doses tested (100–500 Gy). These results suggest that irradiated females could be used in traps to reduce potential risks of deliberate spread of the unwanted organism by activists, without affecting the effectiveness of monitoring males.     

Application of combined biocides and gamma radiation for keeping good quality stored grapefruits

Grapefruits were irradiated with gamma rays at doses of 0.4, 0.8, 1.6 and 3.2 KGy. Irradiated and non-irradiated fruits were soaked in biocides formulated from essential oils of fennel, peppermint and caraway oil. All treated and non-treated fruits were stored at room temperature (20 ± 1°C) for a period of 70 days. Samples were taken every 14 days for different quality determinations. Non-treated fruits were decayed continuously alongside the different storage periods. However, exposing the studied fruits to gamma radiation induced a promising effect for retarding this decay. Moreover, soaking citrus fruits in the formulated biocides induced further interruption of fruit decay. In addition, the applied treatment exhibited other positive effects for keeping the good quality of the studied fruits during storage.     

渭北塬区不同龄苹果园土壤微生物空间分布特征

以渭北塬区塬面5、10、15和20龄苹果园为对象,距树干1.0、1.5、2.0 m处用土钻法分层采集0—30 cm土样,稀释平板法测定土壤微生物数量,平行测定土壤有机碳、总氮和总磷,分析不同龄果园土壤微生物的空间分布状况及其与土壤碳、氮、磷的关系。结果表明:土壤真菌数量随树龄增大而增加,龄间差异显著(P0.05);与对照农田相比,各龄果园放线菌数量及5龄和20龄果园细菌数量偏低,10龄和15龄果园细菌数量偏高;各龄果园土壤真菌、细菌和放线菌数量均随深度增加而减小。就相同深度土层而言,真菌数量随果园年限增大而增加,细菌则以10龄和15龄果园较多,同深度土层的放线菌龄间差异随深度增加而减小。在沿树干向外的径向水平方向上,真菌数量随果园年限的增加相应增多;10龄和15龄果园土壤细菌和放线菌高于5龄果园和20龄果园。5龄果园土壤总氮有沿树干向外、沿表层向下逐步降低的趋势,果园从5龄经10龄到15龄,其"高氮点"则逐步向外、向下移动。塬区果园土壤C∶N比偏低。     

Investigation of the radiation effects on Brown Rot disease of Golden Delicious apples,inoculated with the fungus Monilinia fructigena

The effects of 0, 1.5 and 3 KGy gamma-irradiation on Brown Rot disease affecting Golden Delicious apples are investigated. The apples were artificially inoculated with Monilinia fructigena fungus before and after irradiation. Results show clearly that radiation induces a delay in fungus development, even when it is not directly affected. The effect of radiation on the apples' substrate seems to be considerable, being the main factor affecting fungal growth. Radiation doses of 1.5 and 3 KGy do not seem to produce strong differences in the fungal growth. Irradiation, however, is very effective, producing important changes of practical interest for apples infected before or after irradiation. This revised version was published online in June 2006 with corrections to the Cover Date.     

SENSORY EVALUATION OF IRRADIATED BEEF AND BACON

Vacuum-packed beef and bacon were treated with gamma- radiation (1–10 KGy) from CO⁶⁰ and stored for 3 months at + 4°C. The samples were evaluated by a trained sensory laboratory panel, directly after irradiation, and after 3 months. Samples given 1.0 KGy and higher doses were found to be significant different from nonirradiated samples at both times of testing. A higher intensity of off-taste, rancidity, metallic taste and sweetness, and a lower intensity of juiciness and color saturation were found in all the irradiated samples. Off-taste and rancidity were found to increase with increasing doses, and were best explained when analyzed by Principal Component Analysis (PCA).     

In vitro clonal multiplication of an apple rootstock by culture of shoot apices and axillary buds

In vitro clonal multiplication of apple rootstock MM 111 using axillary buds and shoot apices were carried out. Vegetative axillary buds of the size of 0.2-2.0 cm and shoot apices measuring 4 mm in length were initiated to shoot proliferation on MS medium supplemented with BA (0.5 - 1.0 mgl(-1)), GA3(0.5 mgl(-1)), with or without IBA(0.05 - 0.1 mgl(-1)). Small size explants showed less phenol exudation and less contamination. Following establishment phase, the small shoots emerged from explants were subcultured on MS medium supplemented with different combinations and concentrations of growth regulators. BA (1.0 mgl(-1)) and GA3 (0.5 mgl(-1)) combination showed highest multiplication rate (1:5), andcl also produced longer shoots. Two step rooting was done by transferring microcuttings to auxin free solid medium after root initiation in dark on 1/2 strength MS liquid medium containing IBA (0.5 mgl(-1) ). Rooted plantlets were transferred to peat containing paper cups and resulting plants of MM 111 acclimated successfully for transfer to field.     

Response surface methodology-mediated improvement of the irradiated endophytic fungal strain,Alternaria brassicae AGF041 for Huperzine A-hyperproduction

Huperzine A (HupA) is an anti-Alzheimer’s therapeutic and a dietary supplement for memory boosting that is extracted mainly from Huperziacae plants. Endophytes represent the upcoming refuge to protect the plant resource from distinction but their HupA yield is still far from commercialization. In this context, UV and gamma radiation mutagenesis of the newly isolated HupA-producing Alternaria brassicae AGF041 would be applied in this study for improving the endophytic HupA yield. Compared to non-irradiated cultures, UV (30–40 min, exposure) and γ (0·5 KGy, dose) irradiated cultures, each separately, showed a significant higher HupA yield (17·2 and 30·3%, respectively). While, application of a statistically optimized compound irradiation (0·70 KGy of γ treatment and 42·49 min of UV exposure, sequentially) via Response Surface Methodology (RSM) resulted in 53·1% production increase. Moreover, a stable selected mutant strain CM003 underwent batch cultivation using a 6·6 l bioreactor for the first time and was successful for scaling up the HupA production to 261·6 µg l⁻¹. Findings of this research are demonstrated to be valuable as the employed batch fermentation represents a successful starting step towards the promising endophytic HupA production at an industrial scale.     

Concentration of T3 and T4 in blood of non-irradiated and irradiated with different doses rats fasted for two days beforehand

There were no changes in concentration of T3 and T4 in blood of the rats that were irradiated with a dose of 0.5, 1, 2, 4 and 6 Gy in comparison with non-irradiated rats, if the animals were not fed for two days before decapitation. This suggests that the effect of ionizing radiation on thyroid function is mediated by anorexia syndrome. The decrease in concentration of T4 after exposure to 8 Gy cannot be explained by postradiative anorexia and most likely is connected with starting enterotoxemy in difficult cases of acute radiation sickness.     

Exosomes Derived from Squamous Head and Neck Cancer Promote Cell Survival after Ionizing Radiation

Exosomes are nanometer-sized extracellular vesicles that are believed to function as intercellular communicators. Here, we report that exosomes are able to modify the radiation response of the head and neck cancer cell lines BHY and FaDu. Exosomes were isolated from the conditioned medium of irradiated as well as non-irradiated head and neck cancer cells by serial centrifugation. Quantification using NanoSight technology indicated an increased exosome release from irradiated compared to non-irradiated cells 24 hours after treatment. To test whether the released exosomes influence the radiation response of other cells the exosomes were transferred to non-irradiated and irradiated recipient cells. We found an enhanced uptake of exosomes isolated from both irradiated and non-irradiated cells by irradiated recipient cells compared to non-irradiated recipient cells. Functional analyses by exosome transfer indicated that all exosomes (from non-irradiated and irradiated donor cells) increase the proliferation of non-irradiated recipient cells and the survival of irradiated recipient cells. The survival-promoting effects are more pronounced when exosomes isolated from irradiated compared to non-irradiated donor cells are transferred. A possible mechanism for the increased survival after irradiation could be the increase in DNA double-strand break repair monitored at 6, 8 and 10 h after the transfer of exosomes isolated from irradiated cells. This is abrogated by the destabilization of the exosomes. Our results demonstrate that radiation influences both the abundance and action of exosomes on recipient cells. Exosomes transmit prosurvival effects by promoting the proliferation and radioresistance of head and neck cancer cells. Taken together, this study indicates a functional role of exosomes in the response of tumor cells to radiation exposure within a therapeutic dose range and encourages that exosomes are useful objects of study for a better understanding of tumor radiation response.     

The role of fluoride and chlorhexidine in preserving hardness and mineralization of enamel and cementum after gamma irradiation

The purpose of this study was to evaluate the effect of 0.05% sodium fluoride and 0.12% chlorhexidine mouthwashes on the micro-hardness of tooth enamel and cementum that was exposed to therapeutic doses of gamma radiation. Sixty extracted human teeth were divided into two groups, one was irradiated, the other was not irradiated. The two groups were further subdivided into three subgroups, which were each treated either with 0.05% sodium fluoride or with 0.12% chlorhexidine; the third subgroup served as a control. After demineralization–remineralization cycling, teeth from the irradiated groups showed a significantly lower micro-hardness when compared to those from the non-irradiated groups. Both in the irradiated and non-irradiated groups, teeth from the control subgroups showed a significantly lower micro-hardness, as compared to teeth treated with sodium fluoride and chlorhexidine. For non-irradiated enamel samples, those treated with chlorhexidine showed a significantly less micro-hardness compared to those treated with sodium fluoride. In contrast, irradiated enamel showed no significant difference in micro-hardness, whatever treatment (chlorhexidine or sodium fluoride) was applied. For cementum, treatment with chlorhexidine resulted in a significantly lower micro-hardness compared to sodium fluoride, both for the irradiated and non-irradiated groups. It is concluded that gamma irradiation with therapeutic doses typically used for head and neck carcinoma treatment has a direct effect in reducing micro-hardness of tooth enamel and cementum. Mouthwash protocols including, for example, application of 0.05% sodium fluoride or 0.12% chlorhexidine three times per day for 6 weeks, can protect enamel and cementum against the reduction in hardness and demineralization caused by gamma irradiation. Sodium fluoride offers more protection compared to chlorhexidine.     

Effect of ionizing radiation of the antigenic composition of typhoid bacteria

Changes in the antigenic composition of typhoid bacteria occurring during the exposure of microbial suspension to different doses of gamma irradiation [Co60] ranging between 0.5 and 3.0 Mrad were studied. Immunoelectrophoresis in agar was used to determine the antigenic composition of different samples of irradiated bacteria. The antigenic composition of bacteria irradiated with doses up to 2.5 Mrad was found to be similar to that of non-irradiated bacteria. Antigens demonstrated by means of Vi, H and O ontisera are preserved in these bacteria. However, all irradiated bacteria in general slightly differ from non-irradiated bacteria; this is manifest in a different configuration and position of the precipitation lines in the cathodic part of the immunophoreograms. The content of the component migrating rapidly towards the cathode, evidently the O antigen in the R form, in the irradiated bacteria increases with the dose of radiation. No new serologically active substances, non-existent in non-irradiated bacteria, were found to appear in the process of irradiation.     

In vitro mutagenesis and identification of mutants via ISSR in lily (Lilium longiflorum)

An efficient in vitro mutagenesis protocol for Lilium longiflorum Thunb. cv. White fox has been established. The effect of 6-BA and NAA on adventitious bud formation from the bulblet-scale thin cell layers was tested. Results showed that the optimal medium for adventitious bud induction is MS basal medium supplemented with 2.0?mg/l 6-BA and 0.1?mg/l NAA. The differentiation frequency and the average number of adventitious buds reached 95.55% and 3.00, respectively. Various doses (0.0, 0.5, 1.0, 1.5, 2.0, and 2.5?Gy) of gamma rays were applied to investigate the effect of radiation on adventitious bud formation from bulblet-scale thin cell layers. The forming capacity of the adventitious buds significantly decreased with the increase of radiation dose. The results suggested that the optimal irradiation dose is 1.0?Gy. Dose of 1.0?Gy treatment resulted in 55.33% survival of irradiated bulblet-scale thin cell layers and 39.27% mutagenesis rate. The genetic variations among the morphological mutants were evaluated by DNA fingerprinting using ISSR molecular marker. The genetic variation frequency reached 36.06% using seven ISSR primers. Out of the 50 mutant lines transferred to the greenhouse, 9 were observed to have significantly different morphological characters than those of the controls.     

Role of extracellular DNA oxidative modification in radiation induced bystander effects in human endotheliocytes

The development of the bystander effect induced by low doses of irradiation in human umbilical vein endothelial cells (HUVECs) depends on extracellular DNA (ecDNA) signaling pathway. We found that the changes in the levels of ROS and NO production by human endothelial cells are components of the radiation induced bystander effect that can be registered at a low dose. We exposed HUVECs to X-ray radiation and studied effects of ecDNA(R) isolated from the culture media conditioned by the short-term incubation of irradiated cells on intact HUVECs. Effects of ecDNA(R) produced by irradiated cells on ROS and NO production in non-irradiated HUVECs are similar to bystander effect. These effects at least partially depend on TLR9 signaling. We compared the production of the nitric oxide and the ROS in human endothelial cells that were (1) irradiated at a low dose; (2) exposed to the ecDNA(R) extracted from the media conditioned by irradiated cells; and (3) exposed to human DNA oxidized in vitro. We found that the cellular responses to all three stimuli described above are essentially similar. We conclude that irradiation-related oxidation of the ecDNA is an important component of the ecDNA-mediated bystander effect.     

Effects of gamma irradiation on mechanical properties of defatted trabecular bone allografts assessed by speed-of-sound measurement

New sterilization methods for human bone allografts may lead to alterations in bone mechanical properties, which strongly influence short- and medium-term outcomes. In many sterilization procedures, bone allografts are subjected to gamma irradiation, usually with 25 KGy, after treatment and packaging. We used speed-of-sound (SOS) measurements to evaluate the effects of gamma irradiation on bone. All bone specimens were subjected to the same microbial inactivation procedure. They were then separated into three groups, of which one was treated and not irradiated and two were exposed to 10 and 25 KGy of gamma radiation, respectively. SOS was measured using high- and low-frequency ultrasound beams in each orthogonal direction. SOS and Young modulus were altered significantly in the three groups, compared to native untreated bone. Exposure to 10 or 25 KGy had no noticeable effect on the study variables. The impact of irradiation was small compared to the effects of physical or chemical defatting. Reducing the radiation dose used in everyday practice failed to improve graft mechanical properties in this study.     

Isolation of radiation-resistant bacteria without exposure to irradiation.

Resistance to desiccation was utilized in the selection of highly radiation-resistant asporogenous bacteria from non-irradiated sources. A bacterial suspension in phosphate buffer was dried in a thin film at 25 degrees C and 33% relative humidity. Storage under these conditions for 15 days or more reduced the number of radiation-sensitive bacteria. Further selection for radiation-resistant bacteria was obtained by irradiation of bacteria on velveteen in the replication process, thereby avoiding the toxic effect of irradiated media. The similarity of radiation resistance and identifying characteristics in irradiated and non-irradiated isolates should allay some concerns that highly radiation-resistant bacteria have been permanently altered by radiation selection.