Auxosporulation in Chaetoceros acadianus sp. nov. (Bacillariophyceae), a new member of the Section Compressa

We document the fine structure of auxospores in a Chaetoceros species isolated from the Acadian coast of New Brunswick, Canada. Auxospore development in this species occurs in a terminal rather than lateral position, a characteristic never before observed in this genus. Our observations suggest that auxosporulation was uniparental, probably an extreme form of autogamy with sister nuclei fusing following meiosis II. Mature auxospores were adze-shaped to sub-globular and contained both scales and transverse perizonia in their walls. The transverse perizonial band structure was similar to longitudinal perizonial bands found in other species of Chaetoceros and differed from the pinnate bands of pennate transverse perizonia, which consisted of a central rib and bilateral fimbria. Instead, the band structure in C. acadianus was more similar to unilateral fimbriate bands in cymatosiroids. We also propose that our diatom represents a species new to science and is a member of the Chaetoceros Section Compressa. We provide its morphological, molecular and reproductive characterization.     

L-Lysine production by auxotrophic mutants of Arthrobacter globiformis

By mutagenesis with N-methyl N-nitro-N-nitrosoguanidine, in two steps, a number of methionine plus threonine double auxotrophs have been isolated from a glutamate producing Arthrobacter globiformis, excreting L-lysine in good amounts. For the three potent mutants tested the medium of WHITE was adjudged to be the best. Biotin, ammonium chloride and glucose was found to be optimum at 5 μg l^?1, 40 mM and 4% level, respectively. With such optimal C and N source, the strain MT 35 yielded 28.0 g lysine l^?1 of medium in flask culture.     

Bioconversion of Progesterone by the Activated Immobilized Conidia of Aspergillus ochraceus TS

Progesterone was transformed to its 11α-hydroxy derivative (100% e.e) by the activated immobilized conidia of Aspergillus ochraceus TS. The immobilized preparation retained 79% of free conidial activity. The immobilized conidia, activated by nutrients, exhibited an increase in 11α-hydroxylation, and it was free of the side product 6β, 11α-dihydroxy progesterone. The half life and turnover of immobilized and activated immobilized conidia were 14 and 12 days and 187 and 416 μmoles of the product/g of conidia respectively. The pH and temperature profiles of the free conidia remained unaltered after immobilization and activation. Some germination of conidia inside the matrix owing to incubation with nutrients was detected by scanning electron microscopy. Received: 18 March 1999 / Accepted: 1 July 1999     

Study on Folate Binding Domain of Dihydrofolate Reductase in Different Plant species and Human beings

Data base (NCBI and TIGR) searches are made to retrieve protein sequences of different plant species namely Medicago truncatula, Pisum sativum, Ricinus communis, Arabidopsis thaliana, Vitis vinifera, Glycine max, Daucus carota, Oryza sativa Japonica Group, Arabidopsis lyrata subsp. lyrata, Brachypodium distachyon, Oryza sativa Indica Group, Zea mays and careful alignment of derived sequences shows 95% or higher identity. Similarly, DHFR sequence of human being is also retrieved from NCBI. A phylogenetic tree is constructed from different plant and human DHFR domain using the Neighbour – Joining method in MEGA 5.05. Conservation score is performed by using PARALINE. Result suggests that folate binding domain of dihydrofolare reductase is conserved (score 8.06) and excepting some minor variations the basic structure of the domain in both plant species and human being is rather similar. Human DHFR domain contains PEKN sequence near active site, though proline is common for all the selected organisms but the other sequences are different in plants. The plant domain is always associated with TS (Thymidylate synthase). Plant based system is predicted to be an effective model for assessment of MTX (Methotrexate) and other antifolate drugs.     

Fluoride Stress-Mediated Regulation of Tricarboxylic Acid Cycle and Sugar Metabolism in Rice Seedlings in Absence and Presence of Exogenous Calcium

Journal of Plant Growth Regulation - The aim of the current study was to investigate the regulation of tricarboxylic acid (TCA) cycle and sugar metabolism in the seedlings of the rice variety,...     

Prevention of congenital Chagas through treatment of girls and women of childbearing age

It is currently unknown whether treatment of Chagas disease decreases the risk of congenital transmission from previously treated mothers to their infants. In a cohort of women with Chagas disease previously treated with benznidazole, no congenital transmission of the disease was observed in their newborns. This finding provides support for the treatment of Chagas disease as early as possible.     

Isozymes of <Emphasis Type="Italic">α</Emphasis>-amylases from newly isolated <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> CKB19: Production from immobilized cells

The aim of this study was to produce two isozymes of α-amylase by immobilization of a newly isolated soil bacterium. The bacterium was identified as Bacillus thuringiensis CKB19 on the basis of its 16S rRNA profile. Enzyme production by free cells increased linearly with cell growth up to 34 h in starch containing enriched liquid media. The active bacterial cells were immobilized in Caalginate beads, and operational stability of the entrapped cell was optimized for amylase production. Enzyme production was optimal at an alginate concentration of 2 g% (w/v), calcium chloride concentration of 1 M, and with 300 beads (each bead contained 2 × 10⁷ cells)/250 mL flask. Amylase production by the immobilized cells was about 3 times higher than free cell fermentation after 34 h of incubation. It was observed that the immobilized bacterium secreted two different amylases (Am-I and Am-II) into the culture fluid. The molecular masses of Am-I and Am-II were 59.6 and 44.7 kd, respectively, and showed optimum activity at pH 5.0 and 9.0. Both amylases showed optimum activity at 40°C and were stable at the same temperature, with losses of only 10 and 20% (for Am I and Am II, respectively) of their original activities after 24 h of incubation. Further, both amylases were salt tolerant (up to 4 M NaCl) and hydrolyzed raw starchy foods into glucose. All these characteristics make this enzyme mixture suitable for use as a digestive aid and for the improvement of digestibility of animal feed ingredients.     

Paternal contributors in recurrent pregnancy loss: Cues from comparative proteome profiling of seminal extracellular vesicles

Recent evidence entail paternal factors as plausible contributors in spontaneous recurrent pregnancy loss (RPL). Seminal extracellular vesicles secreted from cells of male reproductive tract carry regulatory proteins and RNAs. They are proposed to regulate sperm maturation and function while their fusion to endometrial stromal cells helps in decidualization. Nevertheless, the mechanism(s) involved in these processes are poorly understood. This study aims at elucidating the molecular basis of paternal contribution by comparative proteomics (label‐free LC‐MS/MS) of isolated seminal extracellular vesicles from fertile men and partners of patients with RPL (n = 21 per group). Bioinformatics analysis revealed the identified differentially expressed proteins to be involved in DNA replication, recombination and repair, gene expression, cellular assembly and organization, cell death, and survival. Major disease pathways affected were identified as developmental, hereditary, and immunological disorders. Of the three identified hub genes regulating the above disease pathways, two (HNRNPC and HNRNPU) are overexpressed while RUVBL1 is underexpressed along with over expression of HIST1H1C, DDX1, surmising defective chromatin packaging, and histone removal in spermatozoa resulting in improper expression in paternal genes thereby leading to abnormal embryo development. Besides, alteration in GSTP1 expression points oxidative predominance in RPL group. Differential expression of C3, C4a/C4b, CFB, and GDF 15 may be involved in altered maternal immune response to paternal antigens resulting in impaired decidualization.