Removal of PCBs by various white rot fungi in liquid cultures

The ability ofPhanerochœte chrysosporium, Trametes versicolor, Coriolopsis polyzona, andPleurotus ostreatus growing in a nitrogen-limited mineral medium (NMM) to degrade PCBs in a commercial, Delor 106 mixture at a concentration of 0.9 ppm was compared. The respective amounts of PCBs removed from the fungal cultures within 3 weeks were 25, 50, 41, and 0%. The capacities of the individual fungal species to remove PCBs correlated to some extent with their capabilities of decolorization of NMM agar containing both Poly R-478 or Remazol Brilliant Blue R dyes. Enzyme estimations indicated that both high and relatively stable activities of Mn-dependent peroxidase, Mn-independent peroxidase, lignin peroxidase, and laccase characterized efficient PCB degraders. The work was supported by a grant of theAcademy of Sciences of the Zech Republic no. A6301501 and a grant of theAgency of the Zech Republic no. 204/94/1190.     

Real-time ultrasonography of ovaries and breeding of the one-humped camel (Camelus dromedarius) during the early postpartum period

Ovaries of 17 adult, pleuriparous, and lactating one-humped she-camels (Camelus dromedarius) were examined per rectum for uterine involution and for presence of follicles (>/=1.0 cm diameter) by real-time ultrasonography at the National Research Centre on Camel at Bikaner, India at 30, 45, 60, 75, and 90 days postpartum. Involution was completed from 25 to 30 days postpartum and follicles (>/=1.0 cm diameter) could be found in only nine camels (52.7%) from 34 to 70 days postpartum. These nine camels were mated with virile studs. Four conceived and were confirmed pregnant at 60 days.     

Physical and Chemical Limnology of 34 Lentic Waterbodies along a Tropical‐to‐Alpine Altitudinal Gradient in Nepal

Physical and chemical factors were studied in 34 lentic waterbodies distributed along a steep altitudinal gradient ranging from tropical (77 m) to high alpine (up to 4,980 m) environments in Nepal. Bicarbonate and calcium were dominant among anions and cations, respectively, reflecting a strong influence of carbonate weathering and watershed area, rather than altitudinal climate. The relative patterns of dominant ions were similar among lakes in all altitudinal regions, although total concentrations increased with decreasing altitude. Total suspended solids were relatively high in the study lakes, as is also typical of rivers in the Ganges watershed. Suspended solids had a greater influence on water transparency than did algal biomass in the study lakes. In general, high‐altitude waterbodies were oligotrophic, while those at low altitude were eutrophic. The productivity of high‐altitude study lakes appeared to be limited by both available phosphorus and nitrogen, while lowland ones were nitrogen‐limited. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Microbial and Carbohydrate Active Enzyme profile of buffalo rumen metagenome and their alteration in response to variation in the diet

Rumen microbiome represents rich source of enzymes degrading complex plant polysaccharides. We describe here analysis of Carbohydrate Active Enzymes (CAZymes) from 3.5 gigabase sequences of metagenomic data from rumen samples of Mehsani buffaloes fed on different proportions of green or dry roughages to concentrate ration. A total of 2597 contigs encoding putative CAZymes were identified by CAZyme Analysis Toolkit (CAT). The phylogenetic analysis of these contigs by MG-RAST revealed predominance of Bacteroidetes, followed by Firmicutes, Proteobacteria, and Actinobacteria phyla. Moreover, a higher abundance of oligosaccharide degrading and debranching enzymes in buffalo rumen metagenome and that of cellulases and hemicellulases in termite hindgut was observed when we compared glycoside hydrolase (GH) profile of buffalo rumen metagenome with cow rumen, termite hindgut and chicken caecum metagenome. Further, comparison of microbial profile of green or dry roughage fed animals showed significantly higher abundance (p-value < 0.05) of various polysaccharide degrading bacterial genera like Fibrobacter, Prevotella, Bacteroides, Clostridium and Ruminococcus in green roughage fed animals. In addition, we found a significantly higher abundance (p-value < 0.05) of enzymes associated with pectin digestion such as pectin lyase (PL) 1, PL10 and GH28 in green roughage fed animals. Our study outlines CAZyme profile of buffalo rumen metagenome and provides a scope to study the role of abundant enzyme families (oligosaccharide degrading and debranching enzymes) in digestion of coarse feed.     

Reactivation of model cholinesterases by oximes and intermediate phosphyloximes: a computational study

Phosphyloximes (POX) are generated upon the reactivation of organophosphorus (OP)-inhibited cholinesterases (ChEs) by pyridinium oximes. These POXs are known to be potent inhibitors of the ChEs following reactivation. However, they can also decompose to give an OP derivative and a cyano derivative of the oxime when a base abstracts the benzylic proton. Using density functional theory, thermodynamic properties were calculated for the reactivation and decomposition pathways of three different oximes (2-PAM, 3-PAM and 4-PAM) with six different OPs (cyclosarin, paraoxon, sarin, tabun, VR and VX). For reactivation purposes, 2-PAM is predicted to be more efficient than 3- and 4-PAM. Based on atomic charges and relative energies, 2-POXs were found to be more inclined towards the decomposition process.     

Synthesis of a novel C-10 spiro-epoxide of paclitaxel.

New analogues of paclitaxel (1a, active constituent of Taxol) were synthesized containing an epoxide at the C-10 position. The introduction of the epoxide was carried out by selective removal of the C10-acetate followed by protection of the C2'- and C7-hydroxyl groups. After oxidation to yield a ketone at the C10-position, this intermediate was reacted with dimethylsulfonium ylide. Deprotection and further manipulations provide the C10-spiro epoxide of paclitaxel (1b) and the corresponding C7-MOM ether (1c).     

Nrg1 and nrg2 transcriptional repressors are differently regulated in response to carbon source

The Nrg1 and Nrg2 repressors of Saccharomyces cerevisiae have highly similar zinc fingers and closely related functions in the regulation of glucose-repressed genes. We show that NRG1 and NRG2 are differently regulated in response to carbon source at both the RNA and protein levels. Expression of NRG1 RNA is glucose repressed, whereas NRG2 RNA levels are nearly constant. Nrg1 protein levels are elevated in response to glucose limitation or growth in nonfermentable carbon sources, whereas Nrg2 levels are diminished. Chromatin immunoprecipitation assays showed that Nrg1 and Nrg2 bind DNA both in the presence and absence of glucose. In mutant cells lacking the corepressor Ssn6(Cyc8)-Tup1, promoter-bound Nrg1, but not Nrg2, functions as an activator in a reporter assay, providing evidence that the two Nrg proteins have distinct properties. We suggest that the differences in expression and function of these two repressors, in combination with their similar DNA-binding domains, contribute to the complex regulation of the large set of glucose-repressed genes.     

Light pollution affects invasive and native plant traits important to plant competition and herbivorous insects

Biological Invasions - Invasions in urban settings have been understudied in terms of how invasions are impacted by uniquely urban stressors, such as streetlights. Plant physiology and phenology...     

Interaction of aflatoxin and hepatitis B virus in the pathogenesis of hepatocellular carcinoma

Aflatoxin-B1 (AFB) and chronic hepatitis B virus (HBV) infection epidemiologically correlate with the geographic distribution of hepatocellular carcinoma (HCC). Integration of HBV DNA into the cellular genome of HCCs and the in vivo formation of adducts between AFB and nucleic acids lead us to suggest that hepatocytes with integrated HBV DNA preferentially accumulate AFB; the AFB-adducts formed may then initiate cell transformation by modifying the expression of critical host genes. The altered molecular biology of liver cells in HCC is evidenced by the fact that HBV does not replicate in HCC tissues or cell lines. The effect of AFB on the expression of cellular genes such as endogenous retrovirus(es) and possibly cellular oncogene(s) can be analyzed in HCC cell lines with and without integrated HBV DNA. In addition, human HCC tissues can be probed for HBV sequences and AFB-DNA adducts at the single-cell level. The presence of HBV and AFB can be correlated with the expression of putative transforming genes, providing a new insight into the interaction between liver cells, HBV and AFB in the pathogenesis of HCC.