Pilot-scale production of mosquitocidal toxins by Bacillus thuringiensis and Lysinibacillus sphaericus under solid-state fermentation

Mosquitocidal toxins of Bacillus thuringiensis israelensis (Bti) and Lysinibacillus sphaericus 14N1 (Ls14N1) were produced under solid-state fermentation using agro-industrial wastes. Sugar beet pulp–sesame meal (1:1) and wheat germ meal–linen meal (1:1) at 9% were the efficient substrate mixtures for the growth and toxin production of Bti and Ls14N1, respectively. Bti was more active after the addition of beef extract (0.2%) or yeast extract (0.5%) to the medium. On the other hand, the addition of yeast extract (0.2%) or NYSM salts (2%) significantly enhanced the toxicity produced by Ls14N1. The optimum conditions for the maximum toxicity of Bti were at pH 7–8, 20–30% moisture, 4–10% inoculum and 7 days incubation. For Ls14N1, the best conditions were pH 6.5–7.5, 20–30% moisture, 4–10% inoculum and 5 days incubation. It was found that the best thickness of carrier-substrates in the plate (15?cm in diameter) for the maximum mosquitocidal activity was about 0.5?cm for Bti and 0.5–1?cm for Ls14N1. Pilot-scale production in aluminium trays applying the above conditions showed a decrement of toxicity of fermented cultures and some plates were contaminated. These problems were dissolved by reducing the moisture content to 15%, increasing inoculum to 10% and manual agitation of trays every-day.     

Association of Mycobacterium infections in patients with Mendelian susceptibility to mycobacterial disease with venous thromboembolism

An association between a hypercoagulable state and Mendelian susceptibility to mycobacterial disease (MSMD) has been established in a few studies; resultant thrombosis is considered rare. In a case‐control study, the prevalence of factor V Leiden, prothrombin G20210A and methylenetetrahydrofolate reductase (MTHFR) C677T, A1298C mutations were investigated in mycobacterium‐infected patients. The study comprised 30 patients with mycobacterial infections (invasive, disseminated and/or recurrent infections with Bacille Calmette–Guerin or non‐tuberculosis mycobacteria and Mycobacterium Tuberculosis with positive results for acid‐fast bacilli and tuberculin skin tests) and 30 normal healthy controls. Forty female (66.7%) and 20 male subjects (33.3%) aged from 3 to 70 years were recruited into this study. Genotyping of targeted genes was performed by RT‐PCR and cytokine TNF‐α concentrations were quantified using a commercially available ELISA kit. Significant associations between mycobacterial infection and TNF‐α production after stimulating peripheral blood mononuclear cells with LPS alone and with IFN‐γ plus LPS were identified. Moreover, genotyping analysis in the studied population revealed a significant association between MTHFR c.677C>T (OR, 3.28; 95% CI, 1.35–7.92; P < 0.05), MTHFR c.1298A>C (OR, 2.33; 95% CI, 1.10–4.93; P < 0.05) and mycobacterial infection in affected patients, indicating susceptibility to venous thromboembolism according to previous studies. Additionally, mycobacterium‐infected patients had a significantly greater prevalence of MTHFR C677T and A1298C mutations than controls.     

Molecular dynamics study of biodegradation of azo dyes via their interactions with AzrC azoreductase

Azo dyes are one of the most important class of dyes, which have been widely used in industries. Because of the environmental pollution of azo dyes, many studies have been performed to study their biodegradation using bacterial systems. In present work, the AzrC of mesophilic gram-positive Bacillus sp. B29 has been considered to study its interaction with five common azo dyes (orange G, acid red 88, Sudan I, orange I, and methyl red). The molecular dynamics simulations have been employed to study the interaction between AzrC and azo dyes. The trajectory was confirmed using root mean square deviation and the root mean square fluctuation analyses. Then, the hydrogen bond and alanine scanning analyses were performed to reveal active site residues. Phe105 (A), Phe125 (B), Phe172 (B), and Pro132 (B) have been found as the most important hydrophobic residues whereas Asn104 (A), Tyr127 (B), and Asn187 (A) have key role in making hydrogen bond. The results of molecular mechanics Poisson–Boltzmann surface area and molecular mechanics generalized Born surface area calculations proved that the hydrophobic azo dyes like Acid red 88 binds more tightly to the AzrC protein. The calculated data suggested MR A 121 (B) I as a potential candidate for improving the AzrC–MR interactions.     

Microbial–meiofaunal interrelationships in coastal sediments of the Red Sea

Population density and biomass of bacteria and meiofauna were investigated seasonally in the sediments of the north-western bank of Red Sea. Samples of sediments were collected seasonally from three different stations to determine microphytobenthic biomass (chlorophyll a), protein, lipid, carbohydrate, and total organic matter concentrations. These investigations revealed that microbial components tended to increase their dominancy, whereas sensitive meiofauna were extremely reduced during the entire study period. Thus a very low density of the total meiofauna (with an annual average of 109 ± 26 ind./10 cm²) was recorded whilst the benthic microbial population densities exhibited higher values (ranging from 0.31 ± 0.02 × 10⁸ to 43.67 ± 18.62 × 10⁸/g dry sediment). These changes in the relative importance analysis of benthic microbial components versus meiofaunal ones seem to be based on the impact of organic matter accumulation on the function and structure of these benthic communities. Proteins, lipids and carbohydrates showed very low concentration values, and the organic matter mostly consisted of carbohydrates, reflecting lower nutritional values for benthic fauna in general and meiofauna in particular. The distribution of microbial and meiofaunal communities seems to be dependent on the quality of the organic matter rather than on its quantity. Total organic matter concentrations varied between 5.8 and 7.6 mg/g, with organic carbon accounting for only 32% of the total organic matter. Chlorophyll a attained very low values, fluctuating between 0.11 and 0.56 μg/g, indicating the oligotrophy of the studied area. The very low concentration of chlorophyll a in the Red Sea sediment suggests that the sedimentary organic matter, heterotrophic bacteria and/or protozoa constitute an alternative resource that is consumed by meiofauna when algae are less abundant. Protozoa, therefore, represent the “missing link in bacteria–meiofauna interaction in the Red Sea marine sediment ecosystem.     

Sulfur and molybdenum fractionation in marine and riverine alluvium paddy soils

Intermittently submergence and drainage status of paddy fields can cause alterations in morphological and chemical characteristics of soils. We conducted a sequential fractionation study to provide an insight into solubility of Sulfur (S) and Molybdenum (Mo) in flooded alluvial paddy soils. The samples (0–15 and 15–30 cm) were taken from marine and riverine alluvial soils in Kedah and Kelantan areas, respectively, and were sequentially extracted with NaHCO₃, NaOH, HCl, and HClO₄–HNO₃. Total S in upper and lower layers of Kedah and Kelantan ranged between 273 and 1121 mg kg^?1, and 177 to 1509 mg kg^?1, respectively. In upper layers and subsoil of Kedah, average total Mo were 0.34 and 0.27 mg kg^?1, respectively. Average total Mo in Kelantan were 0.25 mg kg^?1 (surface layer) and 0.28 mg kg^?1 (subsoil). Cation exchange capacity (CEC) was positively correlated with plant available amounts of Mo in upper layers of Kedah area. Also, total and medium-term plant-available S was correlated with total carbon (C) at lower layers of Kelantan soil series. But in surface layers of Kelantan soil series, CEC was strongly correlated with total and medium-term plant-available S. Our results indicates that the influence of flooding conditions on soil S and Mo contents in paddy fields may cause long-term changes in S and Mo chemical reactivities.     

BMP2 Transfer to Neighboring Cells and Activation of Signaling

Morphogen gradients and concentration are critical features during early embryonic development and cellular differentiation. Previously we reported the preparation of biologically active, fluorescently labeled BMP2 and quantitatively analyzed their binding to the cell surface and followed BMP2 endocytosis over time on the level of single endosomes. Here we show that this internalized BMP2 can be transferred to neighboring cells and, moreover, also activates downstream BMP signaling in adjacent cells, indicated by Smad1/5/8 phosphorylation and activation of the downstream target gene id1. Using a 3D matrix to modulate cell–cell contacts in culture we could show that direct cell–cell contact significantly increased BMP2 transfer. Using inhibitors of vesicular transport, transfer was strongly inhibited. Interestingly, cotreatment with the physiological BMP inhibitor Noggin increased BMP2 uptake and transfer, albeit activation of Smad signaling in neighboring cells was completely suppressed. Our findings present a novel and interesting mechanism by which morphogens such as BMP2 can be transferred between cells and how this is modulated by BMP antagonists such as Noggin, and how this influences activation of Smad signaling by BMP2 in neighboring cells.