Metabolism of Explosive Compounds by Sulfate-Reducing Bacteria

The metabolism of various explosive compounds—1,3,5-trinitrobenzene (TNB), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetraazocine (HMX)—by a sulfate-reducing bacterial consortium, Desulfovibrio spp., was studied. The results indicated that the Desulfovibrio spp. used all of the explosive compounds studied as their sole source of nitrogen for growth. The concentrations of TNB, RDX, and HMX in the culture media dropped to below the detection limit (<0.5 ppm) within 18 days of incubation. We also observed the production of ammonia from the nitro groups of the explosive compounds in the culture media. This ammonia served as a nitrogen source for the bacterial growth, and the concentration of ammonia later dropped to <0.5 mg/L. The sulfate-reducing bacteria may be useful in the anaerobic treatment of explosives-contaminated soil. Received: 23 January 1998 / Accepted: 5 March 1998     

Multi‐Scale Investigations of δ‐Ni0.25V2O5·nH2O Cathode Materials in Aqueous Zinc‐Ion Batteries

Cost‐effective and environment‐friendly aqueous zinc‐ion batteries (AZIBs) exhibit tremendous potential for application in grid‐scale energy storage systems but are limited by suitable cathode materials. Hydrated vanadium bronzes have gained significant attention for AZIBs and can be produced with a range of different pre‐intercalated ions, allowing their properties to be optimized. However, gaining a detailed understanding of the energy storage mechanisms within these cathode materials remains a great challenge due to their complex crystallographic frameworks, limiting rational design from the perspective of enhanced Zn²⁺ diffusion over multiple length scales. Herein, a new class of hydrated porous δ‐Ni_0.25V₂O₅.nH₂O nanoribbons for use as an AZIB cathode is reported. The cathode delivers reversibility showing 402 mAh g^?1 at 0.2 A g^?1 and a capacity retention of 98% over 1200 cycles at 5 A g^?1. A detailed investigation using experimental and computational approaches reveal that the host “δ” vanadate lattice has favorable Zn²⁺ diffusion properties, arising from the atomic‐level structure of the well‐defined lattice channels. Furthermore, the microstructure of the as‐prepared cathodes is examined using multi‐length scale X‐ray computed tomography for the first time in AZIBs and the effective diffusion coefficient is obtained by image‐based modeling, illustrating favorable porosity and satisfactory tortuosity.     

Inter retrotransposon based genetic diversity and phylogenetic analysis among the Musa germplasm accessions

In the present investigation, the insertional polymorphisms of retro-elements were studied in the Musa germplasm available at ICAR-NRCB field gene bank using IRAP markers. The maximum number of polymorphic bands were produced by the primer pair Nikita and LTR 6150 (48) followed by LTR 6149 and 3′LTR (47) and minimum of 35 bands were produced by the primer pair Sukkula and LTR 6150. The bands produced were scored as 0 (absent) and 1 (present) and the resultant binary data was subjected to diversity analysis. The dendrogram consisted of two major clusters with members of Eumusa and Rhodochlamys in one indicating their genetic closeness and members of the genus Ensete in another cluster. Results of principal coordinate analysis were congruent to those obtained in hierarchial cluster analysis. The molecular markers used in this study could reveal intra and inter-group diversity among the Musa germplasm accessions with similarity co-efficient ranging from 0.41 to 0.99. IRAP marker system has performed excellently clustering the accessions based on both genomic and subgroup levels. The entire germplasm was found to be robust with no duplications indicating the diverse group of accessions available at ICAR-NRCB field gene bank. It has also exhibited high polymorphism and hence could be effectively used to detect the genetic relatedness among diverse genome of Musa.     

Functional and Structural Characterization of Melanin from Brevibacillus invocatus Strain IBA

Doklady Biological Sciences - Melanin is a polyphenol or indolic dark brown to black pigment of macromolecules that has a variety of biological functions including UV defence, desiccation, and...     

Metabolism of compounds with nitro-functions by Klebsiella pnuemoniae isolated from a regional wetland

Metabolism of nitroaromatic compounds by a Klebsiella pneumoniae isolated from a regional wetland was studied. When it was grown with nitrophenol as the sole nitrogen source, the isolate had the metabolic capability of transforming nitrophenol to phenol; however, it did not use nitrophenol as the sole carbon source. The metabolic pathway showed that the K. pneumoniae reduced the nitro group to an amino group forming aminophenol as a major metabolite. This aminophenol was oxidatively deaminated to phenol. For every mole of nitrophenol metabolized, 1 mol of phenol was produced and the phenol did not undergo further metabolism. The isolate also used several other nitroaromatic compounds including nitrotoluenes and nitrobenzenes as its nitrogen source. Even though this organism did not degrade the nitroaromatics completely, it may be useful in degrading nitroaromatics in contaminated soil and water containing other aromatic degraders in a syntrophic condition in nature.     

Occurrence of natural lectin with bacterial agglutination property in the serum of lepidopteran pest,Parasa lepida

Insects depend on lectins for non‐self recognition and clearance of invading pathogens. Naturally occurring lectin showing specificity for galactose was purified from the serum of lepidopteran pest Parasa lepida by affinity chromatography using Sepharose 6B coupled with galactose as a gel matrix. Preliminary studies on crude serum agglutinin revealed that the agglutinin molecule showed varying degrees of specificity to avian and mammalian red blood cells tested. Among them, the highest titer of 128 was recorded against rabbit red blood cell type. The agglutinin molecule in the crude serum was stable up to 60°C and at pH between 6 and 9. Also, the hemagglutinating activity was neither dependent on divalent cations nor sensitive to ethylenediaminetetraacetic acid treatment. Galactose inhibited the hemagglutinating activity at minimum inhibitory concentration of 12.5 mM and hence it was used as a ligand for affinity chromatography. Native polyacrylamide gel electrophoresis analysis revealed a single band and the molecular weight of the lectin was found to be approximately 90 kDa. Bacterial agglutination activity of the purified lectin with two significant toxin bacteria, namely Salmonella typhi and Bacillus thuringiensis, was observed.     

The role of the coiled-coil motif in interactions mediated by TPD52

TPD52 (D52)-like proteins are small coiled-coil motif-bearing proteins first identified through their expression in human breast carcinoma that mutually interact in hetero- and homomeric fashions. However, it has been unclear whether the coiled-coil motif is sufficient, or even necessary, for these interactions to occur. We have therefore examined the binding activities of a panel of C-terminally deleted D52 proteins in both the yeast two-hybrid system and pull-down assays. In the yeast two-hybrid system, interactions were only detected when regions C-terminal to the coiled-coil motif were also present. However, using pull-down assays, interactions were detected for all deletion mutants which included the coiled-coil motif. This suggests that the coiled-coil motif is indeed necessary for interactions mediated by D52 proteins, but that C-terminal protein regions facilitate and/or stabilize these interactions.     

Proteolysis of Mutant Huntingtin Produces an Exon 1 Fragment That Accumulates as an Aggregated Protein in Neuronal Nuclei in Huntington Disease

Huntingtin proteolysis has been implicated in the molecular pathogenesis of Huntington disease (HD). Despite an intense effort, the identity of the pathogenic smallest N-terminal fragment has not been determined. Using a panel of anti-huntingtin antibodies, we employed an unbiased approach to generate proteolytic cleavage maps of mutant and wild-type huntingtin in the HdhQ150 knock-in mouse model of HD. We identified 14 prominent N-terminal fragments, which, in addition to the full-length protein, can be readily detected in cytoplasmic but not nuclear fractions. These fragments were detected at all ages and are not a consequence of the pathogenic process. We demonstrated that the smallest fragment is an exon 1 huntingtin protein, known to contain a potent nuclear export signal. Prior to the onset of behavioral phenotypes, the exon 1 protein, and possibly other small fragments, accumulate in neuronal nuclei in the form of a detergent insoluble complex, visualized as diffuse granular nuclear staining in tissue sections. This methodology can be used to validate the inhibition of specific proteases as therapeutic targets for HD by pharmacological or genetic approaches.     

Brown-Vialetto-Van Laere syndrome

Monosomy 18p refers to a chromosomal disorder resulting from the deletion of all or part of the short arm of chromosome 18. The incidence is estimated to be about 1:50,000 live-born infants. In the commonest form of the disorder, the dysmorphic syndrome is very moderate and non-specific. The main clinical features are short stature, round face with short philtrum, palpebral ptosis and large ears with detached pinnae. Intellectual deficiency is mild to moderate. A small subset of patients, about 10–15 percent of cases, present with severe brain/facial malformations evocative of holoprosencephaly spectrum disorders. In two-thirds of the cases, the 18p- syndrome is due to a mere terminal deletion occurring de novo, in one-third the following are possible: a de novo translocation with loss of 18p, malsegregation of a parental translocation or inversion, or a ring chr18. Parental transmission of the 18p- syndrome has been reported. Cytogenetic analysis is necessary to make a definite diagnosis. Recurrence risk for siblings is low in de novo deletions and translocations, but is significant if a parental rearrangement is present. Deletion 18p can be detected prenatally by amniocentesis or chorionic villus sampling and cytogenetic testing. Differential diagnosis may include a wide number of syndromes with short stature and mild intellectual deficiency. In young children, deletion 18p syndrome may be vaguely evocative of either Turner syndrome or trisomy 21. No specific treatment exists but speech therapy and early educational programs may help to improve the performances of the children. Except for the patients with severe brain malformations, the life expectancy does not seem significantly reduced.