Bioconversion of Hydrocortisone by Cyanobacterium Fischerella ambigua PTCC 1635

Summary The bioconversion of hydrocortisone by a locally isolated strain of cyanobacterium Fischerella ambigua PTCC 1635 was investigated. Fischerella ambigua had not been previously examined for this potential. The fermentation led to production of 11β,17α, 20β, 21-tetrahydroxypregn-4-en-3-one and 11β-hydroxyandrost-4-en-3,17-dione. The metabolites were isolated and purified by chromatographic methods and identified using instrumental analyses.     

Comparison of assimilable organic carbon and UV-oxidizable carbon for evaluation of ultrapure-water systems.

Bacterial growth potential was measured in an ultrapure-water pilot plant by modified assimilable organic carbon (AOC) and UV-oxidizable carbon tests. An ion-exchange unit increased UV-oxidizable carbon, yet did not significantly (P greater than or equal to 0.05) alter AOC values. UV radiation decreased UV-oxidizable carbon and increased AOC.     

Oligotrophic bacteria in ultra-pure water systems: Media selection and process component evaluations

Summary Presently, tryptic soy agar (TSA) medium is used in the semiconductor industry to determine the concentration of viable oligotrophic bacteria in ultra-pure water systems. Deionized water from an ultra-pure water pilot plant was evaluated for bacterial growth at specific locations, using a non-selective medium (R2A) designed to detect injured heterotrophic as well as oligotrophic bacteria. Results were compared to those obtained using Tryptic Soy Agar. Statistically greater numbers of bacteria were observed when R2A was used as the growth medium. Total viable bacterial numbers were compared both before and after each treatment step of the recirculating loop to determine their effectiveness in removing bacteria. The reduction in bacterial numbers for the reverse osmosis unit, the ion exchange bed, and the ultraviolet sterilizer were 97.4%, 31.3%, and 72.8%, respectively, using TSA medium, and 98.4%, 78.4%, and 35.8% using R2A medium. The number of viable bacteria increased by 60.7% based on TSA medium and 15.7% based on R2A medium after passage of the water through an in-line 0.2-m pore size nylon filter, probably because of the growth of bacteria on the filter. Our results suggest that R2A medium may give a better representation of the microbial water quality in ultra-pure water systems and therefore a better idea of the effectiveness of the various treatment processes in the control of bacteria.     

Organic osmolytes betaine,sorbitol and inositol are potent inhibitors of erythrocyte membrane ATPases

Organic osmolytes are used in animal and plant cells to adapt to hyper- and hypoosmolar stress. We used our RBC-membrane model to investigate the effects of the osmolytes betaine, sorbitol and myo-inositol on Na(+)/K(+)-ATPase, Ca(2+)-ATPase and calmodulin-stimulated Ca(2+)-ATPase (CaM). Our results show that betaine inhibited ATPases by more than 61%: Na(+)/K(+)-ATPase (75 +/- 5.9 vs 27 +/- 2.2), Ca(2+)-ATPase (236 +/- 18.9 vs 62 +/- 4.9), and CaM (450 +/- 18 vs 174 +/- 6.9) (microM pi/min/mg protein, control (0 microM betaine) vs 100 micromol/L betaine). Sorbitol (100 micromol/L) inhibited the Ca(2+)-ATPases by 41% (126 +/- 7.6 vs 74 +/- 4.4) and CaM by 42% (253 +/- 17.7 vs 147 +/- 10.3). Inositol (100 micromol/L) inhibited Na(+)/K(+)-ATPase strongest (37 +/- 1.9 vs 20 +/- 1.0; 47% inhibition) while it showed a lesser effect on the Ca(2+)-ATPases (136 +/- 6.8 vs 102 +/- 5.1; 25% inhibition). All osmolytes inhibited RBC membrane ATPases at concentrations above 50 micromol/L, which corresponds to high normal physiologic range for organic osmolytes in serum. Furthermore, the presence of osmolytes (250 micromol/L) decreased hypoosmotic stress induced hemolysis by 42%. Together these data indicate an important regulatory role of organic osmolytes on human RBC membrane ATPases and a protective function of osmolytes in RBCs against hypoosmotic stress.     

Variation of nitrogenase activity, photosynthesis and pigmentation of the cyanobacterium Fischerella ambigua strain FS18 under different irradiance and pH values

Summary Our objective was to evaluate the physiological response of Fischerella ambigua FS18 to the combined influence of pH (5, 7 and 9) and light intensity (3 and 300 μmol photon m⁻² s⁻¹). Growth rates were similar at pH 9 and pH 7. There was no growth at pH 5. Increasing light intensity did not have any considerable influence on growth rates. Chlorophyll concentration was higher at pH 7 at all light intensities. Chlorophyll concentration decreased with increasing light intensity from 3 to 300 μmol photon m⁻² s⁻¹. Synthesis of the phycobiliproteins (PBP), phycocyanin (PC) and allophycocyanin (APC) had the highest rate in pH 7. Increasing irradiance decreased the concentrations of all PBPs. The light-saturated photosynthetic rate was clearly higher at high light intensity. With respect to nitrogenase activity, the highest rate was at pH 9 and 300 μmol photon m⁻² s⁻¹. Irradiance did not affect significantly this activity at pH 7. This cyanobacterium seems to be alkalophilic with maximum nitrogenase activity and photosynthesis at pH 9. It can also adapt its photosynthetic apparatus to the variable factors that are found in rice fields.     

Biotransformation of hydrocortisone by a natural isolate of Nostoc muscorum

Hydrocortisone was converted in the culture of an isolated strain of the cyanobacterium Nostoc muscorum PTCC 1636 into some androstane and pregnane derivatives. The microorganism was, isolated during a screening program from soil samples collected from paddy fields of north of Iran. The bioproducts obtained were purified using chromatographic methods and identified as 11beta-hydroxytestosterone, 11beta-hydroxyandrost-4-en-3,17-dione and 11beta,17alpha,20beta,21-tetrahydroxypregn-4-en-3-one on the basis of their spectroscopic features.     

Predictors of response to axicabtagene‐ciloleucel CAR T cells in aggressive B cell lymphomas: A real‐world study

Chimeric antigen receptor T‐cell (CAR T) therapy has shown promising efficacy in relapsed and refractory diffuse large B cell lymphoma (DLBCL). While most patients undergo CAR T infusion with active disease, the impact of some clinical variables, such as responsiveness to the pre‐CAR T chemotherapy on the response to CAR T, is unknown. In this single‐institution study, we studied the impact of several pre‐CAR T variables on the post‐CAR outcomes. Sixty patients underwent apheresis for axicabtagene‐ciloleucel (axi‐cel) and 42 of them (70.0%) had primary refractory disease. Bridging therapy between apheresis and lymphodepletion was given in 34 patients (56.7%). After axi‐cel, the overall response rate was 63.3%. Responsiveness to the immediate pre‐CAR T therapy did not show a significant association with response to axi‐cel, progression‐free (PFS) or overall (OS) survival. Multivariable analysis determined that bulky disease before lymphodepletion was independently associated with inferior outcomes, and patients that presented with high‐burden disease unresponsive to immediate pre‐CAR T therapy had a dismal outcome. This data supports proceeding with treatment in CAR T candidates regardless of their response to immediate pre‐CAR T therapy. Interim therapeutic interventions should be considered in patients who have known risk factors for poor outcomes (bulky disease, high LDH).     

Effect of Sulfur and Zinc Nutrition on Yield and Uptake by Wheat

Journal of Plant Growth Regulation - A field trial was performed to study the effect of zinc (Zn) and sulfur (S) on yield and uptake by wheat crop at research farm, the University of Agriculture...     

Growth and photosynthesis acclimated response of the cyanobacterium Fischerella sp. FS 18 exposed to extreme conditions: alkaline pH,limited irradiance,and carbon dioxide concentration

Extremophiles - The true-branching heterocystous cyanobacterium Fischerella sp. FS 18 is widely distributed in paddy fields (North) and petroleum polluted soils (South) in Iran. This investigation...     

Side-chain cleavage and C-20 ketone reduction of hydrocortisone by a natural isolate ofChroococcus dispersus

A unicellular cyanobacterium,Chroococcus dispersus (Keissl.) Lemmermann, was isolated from paddy-field and tested in biotransformation experiments of hydrocortisone (compound 1). This strain has not been previously examined for steroid substance modification. Fermentation was carried out in BG-11 medium supplemented with 0.05% substrate at 25 °C for seven days incubation. The metabolites were chromatographically purified and characterised using spectroscopic methods. The fermentation yielded 11β,17α,20β,21-tetrahydroxypregn-4-en-3-one (compound 2), 11β,17β-dihydroxyandrost-4-en-3,17-dione (compound 3), and 11β-hydroxyandrost-4-en-3,17-dione (compound 4). Bioreaction characteristics observed were 20-ketone reduction for accumulation of compound 2 and side chain degradation of the substrate to give compounds 3 and 4. Time course study showed the accumulation of the product 2 from the second day of the fermentation and product 3 as well as product 4 from the third day. All the metabolites reached their maximum concentration in seven days. Aeration and continuous light or light duration (16/8 hours light/dark) have no effect on the transformation yield. Optimum concentration of the substrate, which gave maximum bioconversion efficiency, was 0.5 mg ml^?1 in the transformation experiment. Growth was not influenced by the addition of steroid substrate. Biotransformation was completely inhibited when steroid concentration was above 2.0 mg ml^?1.