In a greenhouse experiment, the nematicidal effect of some bacterial biofertilizers including the nitrogen fixing bacteria (NFB) Paenibacillus polymyxa (four strains), the phosphate solubilizing bacteria (PSB) Bacillus megaterium (three strains) and the potassium solubilizing bacteria (KSB) B. circulans (three strains) were evaluated individually on tomato plants infested with the root-knot nematode Meloidogyne incognita in potted sandy soil. Comparing with the uninoculated nematode-infested control, the inoculation with P. polymyxa NFB7, B. megaterium PSB2 and B. circulans KSB2, increased the counts of total bacteria and total bacterial spores in plants potted soil from 1.2 to 2.6 folds estimated 60 days post-inoculation. Consequently, the inoculation with P. polymyxa NFB7 increased significantly the shoot length (cm), number of leaves / plant, shoot dry weight (g) / plant and root dry weight (g) / plant by 32.6 %, 30.8 %, 70.3 % and 14.2 %, respectively. Generally, the majority treatments significantly reduced the nematode multiplication which was more obvious after 60 days of inoculation. Among the applied strains, P. polymyxa NFB7, B. megaterium PSB2 and B. circulans KSB2 inoculations resulted in the highest reduction in nematode population comparing with the uninoculated nematode-infested control. They recorded the highest reduction in numbers of hatched juveniles/root by 95.8 %, females/root by 63.75 % and juveniles/1kg soil by 57.8 %. These results indicated that these bacterial biofertilizers are promising double purpose microorganisms for mobilizing of soil nutrients (nitrogen, phosphate and potassium) and for the biological control of M. incognita.

Representative soil samples were collected from soil apart and the rhizosphere of different plant varieties grown in five Egyptian Governorates. The presence of plant parasitic nematodes (PPN) and free living nematodes (FLN) in the collected samples were estimated. In addition, one hundred and 65 bacterial cultures which well known as biofertilizers (some are able to fix nitrogen and the others solubilize either phosphate or potassium) were isolated. The isolated bacteria were screened depending on their rate of growth. Thirty-five cultures of fast growing nitrogen fixing bacteria (NFB), phosphate solubilizing bacteria (PSB) and potassium solubilizing bacteria (KSB) and their cultural filtrates were tested in vitro as biocontrol agents against the second stage juvenile (J 2s ) of the Meloidogyne incognita. In general, higher mortality percentages of nematodes were recorded by bacterial cultures than their comparative cultural filtrates. The highest mortality percentages were recorded by cultures of NFB7, PSB2 and KSB2 (100% at dilution 1/10), while it was 99.3, 99 and 97.8% at dilution 1/100, respectively. NFB7 exhibited a high nitrogen fixation rate (4.2 lmole N 2 /mL/h), while PSB2 and KSB2 effectively solubilized phosphate and potassium comparing with the control treatments (1.94 fold of available phosphate and 2.0 fold of available potassium, respectively). NFB7, PSB2 and KSB2 isolates showed the highest protease, gelatinase and chitinase activities which were thought responsible for their nematicidal effect. The three bacterial isolates were identified as Paenibacillus polymyxa, Bacillus megaterium and Bacillus circulans, respectively.

Acrylamide (CH 2 = CHCONH 2) is an organic compound that is soluble in water and formed in food when exposed to high temperatures. Studies have shown that acrylamide is one of the causes of cancer, as well as affecting the brain and the natural balance of hormones in humans (Batoryna, Lis, & Formicki, 2017). Various studies have reported several harmful effects in experimental rats due to acrylamide administration, such as neuropathy, low tendon reflexes, muscle weakness, behavioral disorders, and toxic symptoms of the nervous system, such as tremors, convulsions paralysis, and multiple changes in levels of the neurotransmitter in different brain regions

Frankia isolates from nodules of the genera Casuarina (BR, S21, Thr), Allocasuarina (Allo2), and Gymnostoma (G80) were found to grow exponentially with high biomass yield and minimal sporangia formation in stirred propionate mineral medium when supplemented either with 2.4 μM palmitic acid (C16:0), pentadecanoic (C15:0), heptadecanoic (C17:0), or linoleic (C18:2, cis 9, 12) fatty acids. Strains also grew with lauric (C12:0) or myristic (C14:0) acids, but gave lower biomass yield. Stearic acid (C18:0) produced a good biomass yield, but cultures slowly accumulated sporangia; oleic acid (C18:1, cis-9) was detrimental to growth. Caprylic (C8:0) or capric (C10:0) acids proved to be prejudicial for long-term storage of Frankia strains. In experiments using labeled 1,2-dipalmitoyl phosphatidylcholine and palmitic acid, radioactivity bound rapidly to the insoluble, but solvent-extractable fraction of Frankia cells. In contrast, label from propionic acid accumulated in the cytosolic fraction. Therefore, the beneficial effect of some specific phospatidylcholines or free fatty acids on Frankia growth appears to result from their utilization as building blocks for the membrane, suggesting that membrane biosynthesis may be the limiting step for Frankia growth in unamended propionate mineral medium.

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