A rice straw - cellulose utilizing mold was isolated from rotted rice straw residues. The efficient rice straw degrading microorganism was identified as Trichoderma reesei. The results showed that different carbon sources in liquid culture such as rice straw, carboxymethyl cellulose, filter paper, sugar cane bagasse, cotton stalk and banana stalk induced T. reesei cellulase production whereas glucose or Potato Dextrose repressed the synthesis of cellulase. T. reesei cellulase was produced by the solid state culture on rice straw medium. The optimal pH and temperature for T. reesei cellulase production were 6 and 25 °C, respectively. Rice straw exhibited different susceptibilities towards cellulase to their conversion to reducing sugars. The present study showed also that, the general trend of rice straw bioconversion with cellulase was more than the general trend by T. reesei. This enzyme effectively led to enzymatic conversion of acid, alkali and ultrasonic pretreated cellulose from rice straw into glucose, followed by fermentation into ethanol. The combined method of acid pretreatment with ultrasound and subsequent enzyme treatment resulted the highest conversion of lignocellulose in rice straw to sugar and consequently, highest ethanol concentration after 7 days fermentation with S. cerevisae yeast. The ethanol yield in this study was about 10 and 11 g.L−1.

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The purpose of this study was molecular characterization of the antibiotic resistance profiles of some Enterococcus isolates obtained from different hospitals in Taif governorate in KSA. Out of the 89 bacterial isolates obtained, 12 isolates of Enterococcus spp. were subjected to fingerprinting based on repetitive sequence-based polymerase chain reaction (Rep-PCR), and tested their resistance/susceptibility against some antibiotics which are commonly used in KSA. They were identified using the specific primers for different antibiotic resistance genes of Enterococcus spp. as Tuf, VanC-1, VanC-2-VanC-3 genes and sequencing fragments of 16S rDNA gene. The obtained results indicated that about 58.3% of Enterococcus isolates were Enterococcus faecium, 16.6% were Enterococcus durans and 25.1% were other Enterococcus species. Sixty-seven per cent of the isolates had multi-drug resistance patterns against gentamicin, vancomycin, erythromycin, amoxicillin, cefazolin and tetracycline. Data on the prevalence and types of antibiotic resistance in Enterococcus species may be used to describe baseline antibiotic susceptibility profiles associated with Enterococcus spp. that were isolated from the hospitals' environment. Some discrepancies were detected among the identification methods used, and the most reliable were the Tuf, VanC-1, VanC-2-VanC-3 genes, and 16S rDNA nucleotide sequencing of 12 Enterococcus isolates were deposited in Gene Bank under the accession numbers from KT366721 to KT366732, respectively. Selected isolates exhibited susceptibility to almost all studied antibiotics, and some virulence factors were detected by PCR. Finally, these Enterococcus isolates were molecularly characterized by Rep-PCR into a diverse genetic background. The data collected may also help to elucidate the role of hospitals in the transmission of antibiotic-resistant strains to human populations.

Harpophora maydis (formerly Cephalosporium maydis) is considered to be one of the most destructive pathogens causing late wilt disease of maize in Egypt. Therefore, the current investigation aimed to enlighten the relationship between the host (Zea mays) and the pathogenic agent (Harpophora maydis), included the chemical and histological differences between susceptible and resistant cultivars. Pathogen isolation was carried out through five Governorates in Egypt (Kafr El-Sheikh, El-Behera, El-Dakahlya, El-Menia and Sohage). Five obtained isolates differed in their virulence based on the pathogenicity test with five cultivars (SC.10, SC.123, TWC.310, Giza-2 and Balady). The maize cultivar (SC.10) was resistant to all the tested isolates. While the cultivar Balady showed the highest susceptibility. Isolate H. maydis No.5 isolated from Sohage Governorate was the most virulent isolate (disease incidence 25.75%), while isolate No.4 was the least virulent isolated from Menia Governorate (1.6%). Moreover, under artificial infection stress, linear increment of phenolic contents and total soluble sugars was observed with the resistant cultivar compared to susceptible one at 30, 60 and 90 days from planting. The obtained results showed highly significant (33.64 mg 10 g -1 fresh weight) with susceptible cultivars relative to resistant one (23.18 mg 10 g -1 ), for total soluble sugars contents.Also, results of phenolic contents gave a similar trend. For thickness of sheath bundle, thickness of the sheath-layer obviously increased with aging of plants, and thickness in both of resistant and susceptible cultivars was affected after infection process. Uninfected resistant plants showed increase in thickness of the scleronchymateous sheath-layer surrounding the vascular bundles compared with that of the susceptible uninfected plants. Consequently, phenolic contents may play an essential role in resistance process against late wilt disease as well as sugar contents with susceptibility process.

The main objective of this study is: Effect of two treatment of bacterial endophytes strains Azotobacter chrocooccum (E1) and Pseudomonas sp. (E2) individually whether as grains soaking and foliar application on some physiological parameters of two wheat plants (Triticum aestivum L.) cultivars (Sakha 93 and Gmiza 9) grown under three levels of irrigation water deficit stress 75, 50 and 25 % field capacity. The tested physiological parameters were chlorophyll pigment (chl. a, b and total) contents, relative water content (RWC), leaf water content (LWC), leaf water deficit (LWD), proline content and some major essential elements (NPK) contents. Negative impacts were obtained on the tested wheat cultivars grown under the different irrigation water deficit. Application of Azotobacter chrocooccum (E1) and Pseudomonas sp. (E2) strains individually were carried out by spray foliar and grains soaking treatments increased the tested physiological parameters for two cultivars compared with untreated plant, which could overcome the negative effects of drought stress.