Polysaccharide production by Aureobasidium pullulans: factors affecting polysaccharide formation

Aureobasidium pullulans NRRL 6220 synthesized polysaccharide most actively in media containing sucrose, fructose or maltose with (NH₄)₂SO₄ (0.6 g/l) or ammonium acetate giving greatest yields of the polysaccharide. With (NH₄)₂SO₄ at 1.2 g/l, production of polysaccharide was decreased considerably. Polysaccharide production was highest with an initial pH of 6.5 while biomass formation was better below an initial pH of 5.5. Optimum phosphate concentration for polysaccharide production was 0.03 m.S.M. Badr-Eldin, H.G. El-Masry and O.A. Abd El-Rahman are with the Microbial Chemistry Department, National Research Center, Dokki, Cairo, Egypt; F.H.A. Mohamad is with the Chemical Engineering and Pilot Plant Department, National Research Center, Dokki, Cairo, Egypt. O.M. El-Tayeb is with the Microbiology Department, Faculty of Pharmacy, Cairo University, Egypt.     

Sesquiterpene lactones from Centaurea glomerata

The investigation of the aerial parts of Centaurea glomerata afforded four new sesquiterpene lactones of the germacradienolide type and the lignan lactone arctigenin. Their structures were elucidated by spectroscopic methods.     

Protection against cisplatin-induced nephrotoxicity by Cu(II)2(3,5-diisopropylsalicylate)4

The ability of Cu(II)(2)(3,5-diisopropylsalicylate)(4), CuDIPS, which exhibits superoxide dismutase (SOD)-like activity, to prevent cisplatin-induced nephrotoxicity was examined in rats. Rats were divided into four groups and treated as follows: (i) vehicle control; (ii) cisplatin (16 mg/kg, intraperitoneally); (iii) CuDIPS (10 mg/kg, intraperitoneally); and (iv) cisplatin plus CuDIPS. Rats were sacrificed 3 days post-treatment. Cisplatin alone resulted in significantly increased plasma creatinine and urea. Administration of 10 mg/kg CuDIPS prevented the cisplatin-induced elevation of plasma creatinine and urea and protected against kidney damage. Relative to controls, rats that received cisplatin treatment displayed a decrease of reduced glutathione (GSH) and elevated platinum and thiobarbituric acid reactive substances (TBARS) levels in the kidney. In comparison with controls, activities of antioxidant enzymes (SOD, CAT, GSH-Px and GSH-Rd) were also reduced in the kidney of rats treated with cisplatin. Administration of 10 mg/kg CuDIPS prevented cisplatin-induced alterations in renal platinum, GSH, TBARS, and antioxidant enzyme activities. This study suggests that the protection offered by CuDIPS against cisplatin-induced nephrotoxicity is partly related to maintenance of renal antioxidant systems.     

Modulation of immobilized enzyme activity by altering the hydrophobicity of nylon-grafted membranes: Part 2: Non-isothermal conditions

Lactose hydrolysis by β-galactosidase immobilized on two nylon membranes, differently grafted, has been studied in a bioreactor operating under isothermal and non-isothermal conditions. One membrane (M₁) was obtained by chemical grafting of methylmethacrylate (MAA); the other one (M₂) by a double chemical grafting: styrene (Sty) and MAA. Hexamethylenediamine was used as a spacer between the grafted membranes and the enzyme. Both membranes have been physically characterized studying their permeabilities in presence of pressure or temperature gradients. Under non-isothermal conditions, the increase in activity of membrane M₂ was higher than that of membrane M₁. The and β coefficients, giving the percentage of activity increase when a temperature difference of 1°C is applied across the catalytic membranes, have been calculated. Results have been discussed with reference to the greater hydrophobicity of membrane M₂ with respect to membrane M₁, the hydrophobicity being a prerequisite for the occurrence of the process of thermodialysis.     

Bioremediation of Vegetable Oil and Grease from Polluted Wastewater Using a Sand Biofilm System

Pseudomonas sp. (L1), P. diminuta(L2) were among eight bacterial strains isolated from vegetable grease and oil-contaminated industrial wastewater, four of which only were found to have the ability to degrade oil and grease. They were identified and investigated for oil and grease degradation either individually or in combinations in previous unpublished work by the authors. Since the combination M1 (Pseudomonas sp. andP. diminuta) produced the highest degradative activity, it was used in the present study in a biofilm sand filter system for vegetable oil and grease removal. This system was tested either as one unit or two units in sequence where different flow rates (30, 50, 100 ml/h) were applied compared to a control unit(s). Results showed that both biofilm systems reduced oily wastewater, even in cases of high degree of pollution (fat, oil & grease (FOG), 7535 ppm; biochemical oxygen demand (BOD₅), 525 ppm; chemical oxygen demand (COD), 1660 ppm). Results also showed a removal of FOG with efficiency at 100%; BOD₅ at 95.9% and COD at 96%, at 50 ml/h flow rate using one unit of biofilm system. On using two units in sequence, a complete removal of FOG, BOD₅ and COD with efficiency 100%, at flow rate 100 ml/h was achieved. In conclusion, the previous biofilm results indicated the efficiency of such a system in treating oily polluted wastewater (vegetable oil origin) on the basis of bacterial isolates being used, the optimum flow rate, and the number of biofilm units used in sequence to obtain the highest removal capacity of such a system. This revised version was published online in July 2006 with corrections to the Cover Date.     

Sesquiterpene lactones from Chrysanthemum coronarium

The flower heads of Chrysanthemum coronarium afforded a new sesquiterpene lactone, dihydrocumambrin A, in addition to the known cumambrin A.     

Extent and Mode of Action of Cationic Legume Proteins against Listeria monocytogenes and Salmonella Enteritidis

The methylated soybean protein and methylated chickpea protein (MSP and MCP) with isoelectric points around pI 8 were prepared by esterifying 83 % of their free carboxyl groups and tested for their interactions with Listeria monocytogenes and Salmonella Enteritidis. The two substances exhibited a concentration-dependent inhibitory action against the two studied bacteria with a minimum inhibitory concentration of about 100 μg/mL. The IC_50 % of the two proteins against L. monocytogenes (17 μg/mL) was comparable to penicillin but comparatively much lower (15 μg/mL) than that of penicillin (85 μg/mL) against S. Enteritidis. The two proteins could inhibit the growth of L. monocytogenes and S. Enteritidis by about 97 and 91 %, respectively, after 6–12 h of incubation at 37 °C. The constituting subunits of MSP (methylated 11S and methylated 7S) were both responsible for its antimicrobial action. Transmission electron microscopy of the protein-treated bacteria showed various signs of cellular deformation. The cationic proteins can electrostatically and hydrophobically interact with cell wall and cell membrane, producing large pores, pore channels and cell wall and cell membrane disintegration, engendering higher cell permeability leading finally to cell emptiness, lysis and death.     

Prenylated flavonoids of Erythrina lysistemon grown in Egypt

Three prenylated flavonoid derivatives; 5,7,4′-trihydroxy-8-(3-methylbut-2-enyl)-6-(2″-hydroxy-3″-methylbut-3″enyl) isoflavone (isoerysenegalensein E), 5,7,2′-trihydroxy-4′-methoxy-5′-(3″-methylbut-2″-enyl) isoflavanone (lysisteisoflavanone), 5, 4′-dihydroxy-6-(3-methylbut-2-enyl)-2″-hydroxyisopropyl dihydrofurano [4″,5″:8,7] isoflavone (isosenegalensin), together with the four known flavonoids abyssinone V-4′-methylether, alpinumisoflavone, wighteone and burttinone were isolated from the stem bark of Erythrina lysistemon Hutch. (Leguminosae). Structures were elucidated by spectroscopic methods.     

Interplay of LncRNAs NEAT1 and TUG1 in Incidence of Cytokine Storm in Appraisal of COVID-19 Infection

Background: In 2019, the coronavirus pandemic emerged, resulting in the highest mortality and morbidity rate globally. It has a prevailing transmission rate and continues to be a global burden. There is a paucity of data regarding the role of long non-coding RNAs (lncRNAs) in COVID-19. Therefore, the current study aimed to investigate lncRNAs, particularly NEAT1 and TUG1, and their association with IL-6, CCL2, and TNF-α in COVID-19 patients with moderate and severe disease.Methods: The study was conducted on 80 COVID-19 patients (35 with severe and 45 with moderate infection) and 40 control subjects. Complete blood count (CBC), D-dimer assay, serum ferritin, and CRP were assayed. qRT-PCR was used to measure RNAs and lncRNAs.Results: NEAT1 and TUG1 expression levels were higher in COVID-19 patients compared with controls (P<0.001). Furthermore, CCL2, IL-6, and TNF-α expressions were higher in COVID-19 patients compared to controls (P<0.001). CCL2 and IL-6 expression levels were significantly higher in patients with severe compared to those with moderate COVID-19 infection (P<0.001). IL-6 had the highest accuracy in distinguishing COVID-19 patients (AUC=1, P<0.001 at a cutoff of 0.359), followed by TUG1 (AUC=0.999, P<0.001 at a cutoff of 2.28). NEAT1 and TUG1 had significant correlations with the measured cytokines, and based on the multivariate regression analysis, NEAT1 is the independent predictor for survival in COVID-19 patients (P=0.02).Conclusion: In COVID-19 patients, significant overexpression of NEAT1 and TUG1 was observed, consistent with cytokine storm. TUG1 could be an efficient diagnostic biomarker, whereas NEAT1 was an independent predictor for overall survival.