Response of Canola productivity to integration between mineral nitrogen with yeast extract under poor fertility sandy soil condition.

Canola is one of the important oil crops and is considered the most promising oil source and adapts to reclaimed soil conditions. The current study aimed to evaluate the influence of yeast extract (YE) integrated with nitrogen (N) rates and treatments were arranged as follows: Control (without F0), 95 kg N ha-1 (F1), 120 kg N ha-1 (F2), 142 kg N ha-1 (F3), 95 kg N ha-1 + YE (F4), 120 kg N ha-1 + YE (F5) and 142 kg N ha-1 + YE (F6) on physico-chemical properties, yield and its components for three Canola genotypes i.e. AD201 (G1), Topaz and SemuDNK 234/84 under the sandy soil. In this work, Results reveal that increasing rates of Nitrogen fertilization from 95 kg N ha-1 to 142 kg N ha-1 have a great effect on physicochemical properties yield and its components. The result proved that 142 kg N ha-1 with yeast treatment was the best treatment for three Canola genotypes. Also, the result showed that seed yield was positively correlated with Chl. a/b ratio, plant height, number of branches/plant, number of pods/plant, and number of seeds/pod, and a strong negative correlation was detected between seed oil percentage when the amount of nitrogen fertilization applied without or with yeast extract is increased.

Comparative study of three predominant gut Bacillus strains and a commercial B. amyloliquefaciens as probiotics on the performance of Clarias gariepinus.

The present study was conducted to evaluate the supplementation of three autochthonous Bacillus strains (B. subtilis, B. amyloliquefaciens and B. cereus) and a commercial B. amyloliquefaciensin doses of 1 × 1010 CFU/kg on the growth performance, hematology, antioxidant activities, digestive enzyme levels, immune status and disease resistance of Clarias gariepinus. A total of 300 fish (75.23 ±â€¯1.6 g) were randomly divided into 5 groups (each group was subdivided into 2 subgroups, 30 fish/each). The control group was fed basal diet (D0). Diets D1, D2, D3 and D4were supplemented with B. subtilis, B. amyloliquefaciens, B. cereus and a commercial B. amyloliquefaciens, respectively. During the course of the experiment, D3 showed the best body weight, weight gain, specific growth rate and food conversion ratio. The measured hemogram blood parameters had the highest significant increase in D3. WBCs and monocyte counts had no significant differences among the experimental groups. The serum antioxidant and digestive enzymes were the highest in D3 and were the lowest in D0. After 15 d, the non-specific immune parameters were markedly increased in fish fed probiotic-containing diet compared with the control. After 30 d, the highest significant immune parameters were observed in D3; D1 and D2 had no significant differences in serum lysozyme activity, nitric oxide and IgM compared with D0. Myostatin cDNA levels were adversely affected by probiotic supplements compare with the control. The PACAP expression showed the highest significant value in D3 followed by D1and D4then D2. The relative survival percentages of the Aeromonas sobria challenged C. gariepinus were the highest in D3, D2, D4 and then D1. Among the three isolated Bacillus species, dietary supplementation with the B. cereus had the highest performance in C. gariepinus compared with the commercial B. amyloliquefaciens and the control group.

In Vitro Selection and Identification of Potential Probiotics Isolated from the Gastrointestinal Tract of Nile Tilapia, Oreochromis niloticus.

Fish gut bacteria can be used as probiotics for aquaculture. The aim of this study is to screen and identify beneficial probiotic bacteria from the gut of Nile tilapia, Oreochromis niloticus. Nine out of one hundred thirty-five isolates were non-pathogenic through intraperitoneal injection and had antibacterial activities with at least a strain from the five isolated fish pathogens, Aeromonas sobria, Aeromonas hydrophila, Pseudomonas aeruginosa, Pseudomonas putida, and Staphylococcus aureus. Further tests showed that such isolates can survive in the presence of high bile concentration (10%) and at different acidic pH values. A strains (14HT) was sensitive to all selected antibiotics, two strains were (9HT and 11HT) resistant to streptomycin and three strains (9HT, 11HT and 38HT) had resistance to two antibiotics. Four isolates (11HT, 33HT, 38HT and 41HT) had an amylase and a protease activities and one strain (47HT) showed only amylase activity. Based on 16S rRNA gene analysis, the isolated strains were identified as follows: Lactococcus lactis (8HT, 9HT, 11HT and 33HT); Enterococcus faecalis (14HT), Lysinibacillus sp. (38HT) and Citrobacter freundii (39HT, 41HT and 47HT).

Radon progeny in Egyptian underground phosphate mines.

In addition to the workers in uranium mines, the staff of other underground mines, such as workers in underground phosphate mines, can be exposed to 222Rn and its progeny. In this study the individual radon progeny concentrations were measured in three Egyptian underground phosphate mines to estimate the occupational exposure of the workers at those sites. A filter method was used to measure individual radon progeny concentrations (218Po, 214Pb and 214Po). The reported mean values of radon progeny concentrations exceed the action levels which are recommended by ICRP 65 (1993). Based on the measured individual radon progeny concentrations (218Po, 214Pb and 214Po) in these mines, the annual effective dose for the workers has been calculated using the lung dose model of ICRP 66 (1994). According to the obtained results, some countermeasures were recommended in this study to minimise these exposure levels.