Dietary gangliosides increase the content and molecular percentage of ether phospholipids containing 20:4n-6 and 22:6n-3 in weanling rat intestine

This study was conducted to determine whether dietary ganglioside (GG) increases the content of ether phospholipids (EPL) in intestinal mucosa. Weanling Sprague-Dawley rats were fed a semipurified diet consisting of 20% fat as a control diet. Two experimental diets were formulated by adding either 0.1% (w/w fat) GGs (GG diet) or 1.0% (w/w fat) sphingomyelin (SM diet) to the control diet. Fatty acid methyl esters from the alkenylacyl, alkylacyl and diacyl subclasses of phospholipids were measured to determine total and molecular percentage of EPL comprising the choline phosphoglyceride (CPG) and ethanolamine phosphoglyceride (EPG) fraction. Animals fed the GG diet significantly increased total EPL content both in CPG (by 36%) and in EPG (by 66%), and the molecular percentage of EPL in CPG (by 76%) and in EPG (by 59%) compared to animals fed the control diet. Dietary GG-induced increase in EPL resulted in a higher level of polyunsaturated fatty acids (PUFA) specifically in 20:4n-6 and 22:6n-3 compared to control animals, leading to a decrease in the ratio of saturated fatty acids (SFA) to PUFA both in CPG and in EPG. Feeding animals the SM diet showed a higher level of EPL than control animals with a concomitant increase in 22:6n-3 in EPL. The present data demonstrate that dietary GG increases the content and composition of EPL containing PUFA in the weanling rat intestine.     

In vitro polymerization of Mycobacterium leprae FtsZ OR Mycobacterium tuberculosis FtsZ is revived or abolished, respectively, by reciprocal mutation of a single residue

A single residue that dramatically influences polymerization of principal cell division protein FtsZ of Mycobacterium leprae (MlFtsZ) and Mycobacterium tuberculosis (MtFtsZ) has been identified. Soluble, recombinant MlFtsZ did not show polymerization in vitro, in contrast to MtFtsZ, which polymerised. Mutation of the lone non-conserved residue T172 in the N-terminal domain of MlFtsZ to A172, as it exists in MtFtsZ, showed dramatic polymerization of MlFtsZ-T172A in vitro. Reciprocal mutation of A172 in MtFtsZ to T172, as it exists in MlFtsZ, abolished polymerization of MtFtsZ-A172T in vitro. While T172A mutation enhanced weak GTPase activity of MlFtsZ, reciprocal A172T mutation marginally reduced GTPase activity of MtFtsZ in vitro. These observations demonstrate that the residue at position 172 plays critical role in the polymerization of MlFtsZ and MtFtsZ. A possible evolutionary correlation between the presence of polymerization-adversive or polymerization-favouring residue at position 172 in FtsZ and generation time of the respective bacterium are discussed.     

Improvement of Biomass Partitioning, Flowering and Yield by Triadimefon in UV-B Stressed Vigna radiata (L.) Wilczek

Elevated UV-B radiation (12.2 kJ m^–2 d^–1) as against the ambient level of 10 kJ m^–2 d^–1 affected flowering, productivity and biomass partitioning of green gram [Vigna radiata (L.) Wilczek cv. KM-2]. UV-B stress delayed flowering initiation and achievement of 50 % flowering, reduced flower retention by 25 %, potential yield by 18 % and all yield attributes such as pod number (25 %), pod mass (41 %), seed number (32 %) and seed mass (45 %). Harvest index and shelling percentage were also reduced by 31 and 7 %, respectively. Application of triadimefon (20 mg dm^–3) to unstressed plants accelerated flowering and enhanced flower retention (21 %), potential yield (15 %) and yield attributes (7 to 44 %). The partitioning of biomass between plant parts also showed improvement over the control plants. In UV-B-stressed plants, triadimefon treatment compensated the inhibitions to varying extents.     

Analysis of degradation of bacterial cell division protein FtsZ by the ATP-dependent zinc-metalloprotease FtsH in vitro

The identity of protease(s), which would degrade bacterial cell division protein FtsZ in vivo, remains unknown. However, we had earlier demonstrated that Escherichia coli metalloprotease FtsH degrades E. coli cell division protein FtsZ in an ATP- and Zn(2+)-dependent manner in vitro. In this study, we examined FtsH protease-mediated degradation of FtsZ in vitro in detail using seven different deletion mutants of FtsZ as the substrates, which lack different extents of specific regions at the N- or C-terminus. FtsH protease assay in vitro on these mutants revealed that FtsH could degrade all the seven deletion mutants irrespective of the deletions or the extent of deletions at the N- or C-terminus. These observations indicated that neither the N-terminus nor the C-terminus was required for the degradation of FtsZ, like already known in the case of the FtsH substrate sigma(32) protein. The recombinant clones expressing full-length FtsZ protein and FtsZ deletion mutant proteins would be useful in investigating the possibility of FtsZ as a potential in vivo substrate for FtsH in ftsH-null cells carrying ftsH suppressor function and ectopically expressed FtsH protease.     

Phenotypic and phylogenic groups to evaluate the diversity of Citrobacter isolates from activated biomass of effluent treatment plants

The diversity of Citrobacter isolated from effluent treatment plants (ETPs) was studied using three different parameters. Thirty Citrobacter strains were isolated from different ETPs treating wastewaters generated at various industries. All the isolates were characterized based on biochemical tests, antibiotic assay/functional analysis, and phylogenetic analysis. Results demonstrated that the pattern of grouping varied based on the selected criteria for analysis. Species that clustered together by biochemical analysis were found to vary by functional and 16S rDNA analysis and vice versa. This suggests that multiple methods approach needs to be carried out to understand the microbial diversity. Bacteria in effluent treatment plants are exposed to diverse categories of pollutants. Salicylate is a key intermediate formed during biodegradation of several aromatic compounds, a scenario expected in ETPs. Hence, the Citrobacter isolates were screened for their capability to utilize salicylate. In future studies, these isolates can be incorporated in a bioremediation program.     

Woody species diversity of four sacred groves in the Pondicherry region of South India

Plant wealth and diversity of four sacred groves – twoanthropogenic stands and two natural forest patches – along the southeastcoast of India adjoining Pondicherry was studied. A total of 111species, belonging to 103 genera in 53 families, were recorded from thefour sites, which together measure 15.6 ha. The number of woody species (girth at breast height(gbh) 20 cm) was 20 each in Keezbuvanagiri (KBG) andKilialamman (KLM) grove, followed by 13 in Periyakattupalayam (PKP) and 15in Periyamudaliar chavadi (PMC). Based on the important value index (IVI), PMCgrove is an association of Aglaia elaeagnoidea,Borassus flabellifer and Pterospermumsuberifolium. A two-layered forest structure resembling tropical dryevergreen forest (TDEF) was found there. Stratification was obscured in the KBGgrove, as the scrub species were abundant, indicating a scrub woodland formation.PKP and KLM were characterised by the abundance of a few species. The presenceof a stout liana of Secamone emetica (gbh 35cm), the robustness of Cretaeva magna (gbh 220cm), Syzigium cumini (gbh 207.45cm), P. suberifolium (gbh 128.7cm) and Tamarindus indica (gbh 250cm), and survival of evergreen species like A.elaeagnoidea and Pamburus missionis isbotanically significant; Polyalthia suberosa is a raretaxon found only within the groves. The persistence of the groves until thepresent time is a testimony to the sacred grove status enjoyed by them.     

Relevance of Frank's solvent classification as typically aqueous and typically non-aqueous to activities of firefly luciferase, alcohol dehydrogenase, and alpha-chymotrypsin in aqueous binaries

Effects of cosolvent concentration on activity of fire fly luciferase, alpha-chymotrypsin, and alcohol dehydrogenase from baker's yeast (Saccharomyces cerevisiae) have been studied for several solvents with varying hydrophobicities (logP from +1.0 to -1.65) and polarities (dielectric constant from 7.4 to 109). The inhibitory effect of the cosolvent is examined in light of Frank's classification of solvents into 'typically aqueous (TA)' and 'typically non-aqueous (TNA).' The solvent concentration at which the enzyme activity decreases to half, the C(50) values, for TA solvents such as 1-cyclohexyl-2-pyrrolidinone, 2-butoxyethanol, 1-methyl-2-pyrrolidinone, tetrahydrofuran, t-butanol, and ethanol correlate quite well with their critical hydrophobic interaction concentration, rather than logP, while those for TNA solvents such as acetonitrile, dimethyl formamide, formamide, and dimethyl sulfoxide correlate well with logP. The interactions of TA solvents with proteins appear to be governed mainly by hydrophobic interactions while both hydrophobic and hydrophilic interactions play important role in case of TNA solvents.     

Effect of chloride and condensable tannin in anaerobic degradation of tannery wastewaters

Toxic effect due to chloride and condensable tannin on anaerobic digestion of vegetable tanning wastewater was investigated at different hydraulic retention times viz 24, 48 and 60 hr respectively. The toxicity to anaerobic contact filter was observed at a chloride concentration of 4500 mg/l and tannin concentration of 790 mg/l respectively under synergistic condition. In the case of constant influent tannin concentration of 600 mg/l, the toxicity due to chloride on anaerobic contact filter was observed at 5500 mg/l. The COD removal percent ranged from 50% to 79% at 48 hr and 67% to 91% at 60 hr HRT respectively. In the case of constant influent chloride concentration of 4000 mg/l and at an increasing influent COD concentration, the toxicity due to tannin on anaerobic contact filter was observed at 1180 mg/l. The COD removal percent ranged from 64% to 89% at 48 hr and 78% to 96% at 60 hr HRT respectively. The results showed that at least 60 hr HRT would be desirable to have good COD removal percent.     

Fate of Mycobacterium tuberculosis inside rate peritoneal macrophages in vitro

Streptozotocin-induced diabetic rats were maintained on 0.5% curcumin containing diet for 8 weeks. Blood cholesterol was lowered significantly by dietary curcumin in these diabetic animals. Cholesterol decrease was exclusively from LDL-VLDL fraction. Significant decrease in blood triglyceride and phospholipids was also brought about by dietary curcumin in diabetic rats. In a parallel study, wherein diabetic animals were maintained on a high cholesterol diet, the extents of hypercholesterolemia and phospholipidemia were still higher compared to those maintained on control diet. Curcumin exhibited lowering of cholesterol and phospholipid in these animals also. Liver cholesterol, triglyceride and phospholipid contents were elevated under diabetic conditions. Dietary curcumin showed a distinct tendency to counter these changes in lipid fractions of liver. This effect of curcumin was also seen in diabetic animals maintained on high cholesterol diet. Dietary curcumin also showed significant countering of renal cholesterol and triglycerides elevated in diabetic rats.In order to understand the mechanism of hypocholesterolemic action of dietary curcumin, activities of hepatic cholesterol-7a-hydroxylase and HMG CoA reductase were measured. Hepatic cholesterol-7a-hydroxylase activity was markedly higher in curcumin fed diabetic animals suggesting a higher rate of cholesterol catabolism. (Mol Cell Biochem 166: 169-175, 1997)