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.

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Twenty one mite species belonging to 3 suborders and 11 families were found in grain residues and mixed flour samples collected from warehouses and mills at Great Cairo. They were 12 pest species, 7 predatory and 2 parasitic species. Species commonly found in all inspected materials at all locations were Dermatophagoides farinae Hughes, Tyrophagous putrescentiae (Sch.) and Cheyletus malaccensis Oud. However Acrus siro (Lin), Acarophenax tribolii (New.) and Pyemotes herfsi (Oud.) were often abundant. The remaining species occurred sporadically in the collected materials. Actinedid and acaridid mites were "dominant" and "constant" in mixed flour and grain residues samples, the second group was the most abundant. Whereas gamasid mites was "recedent" and "accidental". Mixed flour taken from Qaliobia Governorate harboured the highest number of mite species (15 species) followed by grain residues from Giza Governorate (13 species). While grain residues taken from Cairo Governorate harboured the lowest number (5 species).The highest infestation level with mites (2677.3 individuals) was recorded in mixed flour at Qaliobia Governorate, while the lowest one (1067 individuals) was found in grain residues at Cairo Governorate. Generally, mixed flour harboured more mite species than grain residues. Most of the collected mite species occurred during autumn and winter except P. herfsi and A. tribolii which were recorded during spring and summer, respectively. Dominance and frequency of occurrence, population fluctuations, effect of temperature and relative humidity on the population dynamics, also the relation between the predators and pests of mites were discussed in details.

A gene encoding chitinase from B. subtilis has been isolated after optimization of PCR conditions. It was cloned with two different prometers, T7 promoter of the pJET1.2/blunt cloning vector and the SP6 promoter of pGEM®-T Easy vector. After transforming E. coli DH5α, two transformants were selected, CHI-NRC-4 from the first vector and T-CHI-NRC-6 from the second vector, and used for further studies. The complete CDS sequence of chitinase gene was determined and submitted to GenBank with the accession number KX268692.1. Culture supernatants of E. coli (CHI-NRC-4) and E. coli (T-CHI-NRC-6) were investigated for their inhibitory effect on M. javanica egg hatch under laboratory conditions. Result showed up to 96% inhibition in egg hatching due to both E. coli transformants as compared to control which reflect the same expression efficiency of both used prometers. A greenhouse experiment was carried out to evaluate the nematicidal effect of culture supernatants of the two transformts E. coli (CHI-NRC-4) and E. coli (T-CHI-NRC-6) against M. javanica infected eggplant. Obtained results showed a significant reduction in nematode population in soil and roots and enhancement in eggplant growth parameters as compared to control.