Isolation and Identification of Psychrophilic Species of Bacillus from Milk

Forty isolates from 97 raw milk samples (heated to 80 C for 10 min and stored at 4 to 7 C for 3 to 4 weeks) were sporeforming, aerobic, gram-positive or gram-variable, rod-shaped bacteria. Fifteen isolates that were identified had characteristics similar to species of Bacillus, except that they had lower growth temperature ranges, were gram-variable, and were somewhat different in sugar fermentations. Four isolates grew well within 2 weeks at 0 C, but they grew faster at 20 to 25 C. These psychrophilic sporeforming bacteria, the importance of which is discussed, are considered to be variant strains of mesophilic bacilli adapted to low temperatures.     

Effect of Nutrient Concentration on the Growth of Escherichia coli

The relationship between specific growth rate of Escherichia coli and the concentration of limiting nutrient (glucose or phosphate or tryptophan) has been determined for populations in a steady state. At high concentrations the specific growth rate is independent of the concentration of nutrient, but at low concentrations the specific growth rate is a strong function of the nutrient concentration. Such a relationship was predicted by Monod; however, Monod's equation does not predict the relationship over the entire range of nutrient concentration. If parameters of the equation are estimated from the results obtained at low concentrations, then at high concentrations of nutrient, the specific growth rate is significantly higher than that predicted by Monod's equation. These results were interpreted on the basis that the rate of growth is controlled by at least two parallel reactions and that the affinities of the enzymes catalyzing these reactions are different. The relationship between specific growth rate and mean cell volume was also measured, and the results indicate that mean cell volume depends not only on the specific growth rate but also on the nature of the limiting nutrient. There are different mean cell volumes at the same specific growth rate established by different limiting nutrients. Therefore, the mean cell volume is not uniquely determined by the specific growth rate.     

Effect of deoxynivalenol (DON) on growing pigs and its modification by modified yeast cell wall or modified yeast cell wall and bentonite

The study examined effect of two adsorbents on the toxicity of Deoxynivalenol (DON) in growing pigs in a feeding trial. 24 male growing pigs (average initial body weight 11.5 kg) were assigned to one of six dietary treatments: control (uncontaminated diet); control + 0.5% adsorbent I; DON contaminated diet (1.73 mg/kg); DON contaminated diet + 0.5% adsorbent I; control + 0.5% adsorbent II and DON contaminated diet + 0.5% adsorbent II. Two digestibility trials were conducted on the second and fourth week of the feeding period with a sampling period of 7 days to determine the digestibility of the nutrients and the amounts of DON in faeces and urine. At the end of the experiments, the pigs were slaughtered, followed by blood haematology and biochemi analys. These data suggest that the addition of 0.5% modified yeast cell wall or a combination of modified yeast cell wall and bentonite to the naturally DON — contaminated diets reduce the effect of DON on the immune system of pigs but do not play an significant role in detoxification of DON in growing pigs.     

Pre-irradiation dental care: Ready-to-use templates for oropharyngeal cancers

Aim

To develop a tool in order to guide pre-irradiation dental care (PIDC) for patients with oropharyngeal cancers.

Turfgrasses as model assay systems for high-throughput <Emphasis Type="Italic">in planta</Emphasis> screening of beneficial endophytes isolated from cereal crops

Cereal crops including maize (Zea mays L.) are inhabited by non-disease causing microbes known as endophytes that can promote plant growth, aid in host nutrient acquisition and promote host pathogen resistance. Screening endophytes for beneficial traits in planta using large, slow-growing cereals is challenging, thus a rapid but relevant in planta system is needed. Here, we propose that turfgrasses can be used as high-throughput assay systems for screening cereal microbes for beneficial nutrient traits. Turfgrasses are genetic relatives of cereals, but small with fast growth rates; they can be grown in test tubes under sterile conditions on defined media. Five turfgrass genotypes were evaluated for traits ideal for assaying endophytes with nutrient acquisition traits. Based on these criteria, annual ryegrass (Lolium multiflorum) was selected as a high-throughput assay system. Annual ryegrass was then used to test a collection of maize endophytes for their ability to promote plant biomass in the absence of nitrogen. Out of 75 bacterial endophytes tested, one strain (an Enterobacter sp) consistently promoted root and shoot biomass. We discuss the potential of annual ryegrass as a model assay system to test cereal endophytes for acquisition of various nutrients, changes in root/shoot architecture as well as anti-pathogen traits.     

Isolation and identification of indigenous entomopathogenic nematode (EPN) isolate from Egyptian fauna

Soil samples from different Egyptian Governorates as Giza, Behera, Alexandria, Sohag, Qulupeia, El-Sadat City, Sharkia, Bani-Swif, North Sinai (El-Arish) and South Sinai (Ras-Seder), Tanta, Fayoum and Suez have been surveyed for isolation of new entomopathogenic nematode isolates. One isolate coded as IB was isolated from Sharkia (Belbies). Based on morphometric characters, the isolate was found to belong to Heterorhabditidae and identified as Heterorhabditis indica. The isolate individuals were reproduced by in vivo method using sixth larval instars of Galleria mellonella. The survival of native isolate H. indica was better at low temperature (15 °C) compared to room temperature (27 °C).The bioassay results showed reduction in stored IJs activity against G. mellonella compared with fresh IJs where the median lethal concentration LC₅₀ which recorded to be 46.87 for fresh IJs/ml then increased to 571.38 and to 1181.87 IJs/ml after storage for 2 and 4 weeks, respectively.     

Dracaena Leaf Proliferosis, a Newly Recorded Disease Affecting Dracaena sanderiana in Egypt

Dracaena leaf proliferosis is a newly reported disease affecting Dracaena sanderiana in Egypt. A cause and effect relationship between this disease and the fungus,Fusarium proliferatum var. minus has been established. In addition to D. sanderiana the fungus was found to be pathogenic, when tested in the laboratory, to several other members of the family Liliaceae. While the in vitro growth of the fungus is optimum at 25 °C, symptom expression is best at 30°C. Twelve fungicides were tested for their in vitro effect on fungal growth. Benlate, Rubigan, Saprol, Cercobin and Vitavax-200 came first on the list and inhibited growth at 2.5, 12.0, 55.0, 75.0, and 94.0 μg/ml, respectively. Although, Benlate was the most effective fungicide in this respect it failed to demonstrate similar effect on disease development when applied to plants artificially inoculated with the fungus. Fungal growth was completely inhibited on PDA medium by a bacterium belonging to Bacillus sp. but when the bacterium at a concentration of 1 × 10¹¹ cell/ml was applied 24 h before, at the same time with, or 24 h after inoculation no control of the disease was achieved. Naturally-infected plants could, however, be freed from infection when subjected to a hot air treatment at 35 ± 5 °C during day time and 25 ± 5° C at night for 3 months.