Modern pollen dispersal in relation to present vegetation distribution and land use in the Baspa valley, Kinnaur, western Himalayas.

Interpretation of a fossil pollen data for the vegetation and climate reconstruction of any region needs a modern pollen-vegetation analogue for its calibration. We analyzed the surface sediments and moss polsters for the pollen and microcharcoal records to understand the modern pollen-vegetation relationship and human activities in the Baspa Valley, Kinnaur, Himachal Pradesh. Presently, valley is occupied by the arboreal and non-arboreal vegetation of temperate to subalpine habitats and land use activities. The recovered pollen assemblages showed variability in the dispersal behavior of pollen of taxa growing along the valley transect and also captured the signals of human activities over land use. The overall dominance of arboreal pollen in the recovered pollen assemblage corresponds with the dominant growth of conifers and broadleaf tree taxa and represents the valley vegetation at a regional scale. However, the profuse pollen production of a few arboreal taxa and long distance pollen transport from one vegetation zone to other by the strong upthermic valley winds could bias the pollen representation of in-situ vegetation. The high pollen frequency of non-arboreal taxa in the open meadows represents the near vicinity to their plant source. Human activities like fire burning and cultivation by the local population are evident by the recovery of microcharcoal particles and pollen of plants belonging to Cerealia Poaceae, Asteraceae, Amaranthaceae, Polygonaceae, Rosaceae, Juglandaceae, etc. The dataset taken as modern pollen-vegetation analogue is useful to assess past changes in the vegetation and land cover in relation to climate and human factors for future sustenance.

Understanding Caffeine's Role in Attenuating the Toxicity of α-Synuclein Aggregates: Implications for Risk of Parkinson's Disease.

Epidemiological studies report a beneficial relationship between drinking coffee and the risk of developing Parkinson's disease (PD). This is likely due to caffeine, a constituent of coffee, acting as an adenosine A2A receptor antagonist. This study was planned to investigate whether caffeine has any effect on the aggregation of α-synuclein, present in Lewy bodies, the pathological hallmark of PD, which may account for this positive association. Aggregation of recombinant α-synuclein was followed in vitro and in a well-validated yeast proteotoxicity model of PD. Caffeine was found to have twin effects: it accelerated the process of aggregation and also altered the nature of mature aggregates. Aggregates formed in the presence of caffeine displayed amorphous as well as fibrillar morphology. In the presence of caffeine, the toxicity of oligomers and aggregates was diminished, with concomitant reduction in intracellular oxidative stress, decreased oxidative proteome damage, and increased cell survival. Caffeine-treated samples showed improved binding to phospholipids, a property likely to be important in cellular functioning of α-synuclein. Far-UV CD spectroscopy and fluorescence quenching analysis revealed that caffeine induced transient changes in this intrinsically disordered protein, forming a non-native species that enhanced the rate of aggregation of α-synuclein and modified the population of mature aggregates, introducing a higher fraction of amorphous, less toxic species. Increasingly, it is felt that the process of fibrillation itself, along with the nature of mature aggregates, dictates the cytotoxicity of the process. Our results provide a rationale for the observed epidemiological link between drinking coffee and developing PD.

Proteomics analysis of Bacillus licheniformis in response to oligosaccharides elicitors.

The role of oligosaccharides as biotic elicitors has been recognised in the enhanced production of antibiotics from fungal and bacterial cultures. The yield of bacitracin A in cultures of Bacillus licheniformis was increased after supplementation with oligoguluronate (OG), and mannan oligosaccharides (MO) and its mechanism at transcription level been established already. However, the elicitation mechanism at post transcriptional level has not been reported so far. In this paper we investigate changes in proteomics of B. licheniformis in presence of the oligosaccharide elicitors OG and MO. Differentially expressed proteins were examined using 2D-PAGE stained with colloidal Coomassie and were further identified by LC-MS/MS. We identified 19 differentially expressed proteins including those involved in carbon metabolism, energy generation, amino acid biosynthesis, oxidative and general stress response. The novel findings of this work, together with previous reports, contribute to the unravelling of the overall mechanism of elicitation in B. licheniformis cultures and reliability of the use of these elicitors for potential industrial application.

Stabilization of tetanus toxoid formulation containing aluminium hydroxide adjuvant against agitation.

The aggregation of tetanus toxoid leads to reduced bioavailability of the vaccine and failure of immunization programmes in many parts of the globe. One of the main reasons for denaturation and aggregation of tetanus toxoid formulations is agitation of the protein during transport. We have identified that agitation leads to collapse of the gel matrix of aluminium hydroxide which is used as an adjuvant in these preparations. This results in desorption of the toxoid from the matrix, which then loses its antigenicity due to agitation-induced denaturation of the protein. We show that incorporation of some compatible osmolytes like sorbitol, glucose and arginine, but not trehalose, is able to protect the adjuvant matrix from degradation, and retain the integrity of the vaccine preparation in terms of its antigenicity.

Impact of linoleic acid supplementation on lovastatin production in Aspergillus terreus cultures.

This work proposes a novel approach for enhancing the yield of lovastatin in Aspergillus terreus cultures by exploiting linoleic acid-derived signalling molecules, which are potentially involved in fungal cell-cell communication. High-performance liquid chromatography analysis revealed that production of lovastatin was enhanced up to 1.8-fold upon exogenous addition of the oxylipin precursor linoleic acid to low cell density cultures of A. terreus. Real-time PCR analysis showed that supplementation of linoleic acid also resulted in an increase in transcriptional levels of lovastatin biosynthetic genes lovB and lovF, indicating a transcriptional control of fatty acids (linoleic acid) on these genes in A. terreus. This study therefore demonstrates for the first time the potential of an oxylipin molecule as an enhancer of a fungal secondary metabolite production with positive impact for industrial exploitation.

In vitro biocompatibility of 45S5 Bioglass-derived glass-ceramic scaffolds coated with poly(3-hydroxybutyrate).

The aim of this work was to study the in vitro biocompatibility of glass-ceramic scaffolds based on 45S5 Bioglass, using a human osteosarcoma cell line (HOS-TE85). The highly porous scaffolds were produced by the foam replication technique. Two different types of scaffolds with different porosities were analysed. They were coated with a biodegradable polymer, poly(3-hydroxybutyrate) (P(3HB)). The scaffold bioactivity was evaluated by soaking in a simulated body fluid (SBF) for different durations. Compression strength tests were performed before and after immersion in SBF. These experiments showed that the scaffolds are highly bioactive, as after a few days of immersion in SBF a hydroxyapatite-like layer was formed on the scaffold's surface. It was also observed that P(3HB)-coated samples exhibited higher values of compression strength than uncoated samples. Biocompatibility assessment was carried out by qualitative evaluation of cell morphology after different culture periods, using scanning electron microscopy, while cell proliferation was determined by using the AlamarBlue assay. Alkaline phosphatase (ALP) and osteocalcin (OC) assays were used as quantitative in vitro indicators of osteoblast function. Two different types of medium were used for ALP and OC tests: normal supplemented medium and osteogenic medium. HOS cells were seeded and cultured onto the scaffolds for up to 2 weeks. The AlamarBlue assay showed that cells were able to proliferate and grow on the scaffold surface. After 7 days in culture, the P(3HB)-coated samples had a higher number of cells on their surfaces than the uncoated samples. Regarding ALP- and OC-specific activity, no significant differences were found between samples with different pore sizes. All scaffolds containing osteogenic medium seemed to have a slightly higher level of ALP and OC concentration. These experiments confirmed that Bioglass/P(3HB) scaffolds have potential as osteoconductive tissue engineering substrates for maintenance and normal functioning of bone tissue.

Elicitation effects of oligosaccharides on the transcriptional level of bacitracin ABC transporter genes in Bacillus licheniformis.

Bacitracin ABC transporter comprises a self-resistance system in Bacillus licheniformis against its own product (bacitracin). Elicitation effects of carbohydrates on transcription level of bcrABC genes encoding bacitracin ABC transporter system were investigated through quantification by real-time PCR. Increases of 68% and 29% in bacitracin A yields after 36 h were achieved in cultures supplemented with oligoguluronate and oligoguluronate/mannan oligosaccharide combination. Cultures with combined elicitors showed 3, 2.6 and 3 transcriptional fold-changes in bcrA, bcrB and bcrC, respectively, compared to control. This could be due to a secondary effect caused by increased bacitracin A yield through elicitation.

Effect of oligosaccharide elicitors on bacitracin A production and evidence of transcriptional level control.

The role of oligosaccharides as biotic elicitors for the enhanced production of antibiotics and enzymes has been established in recent years. These findings could have significant promise for the pharmaceutical and biotechnology industries. Before the elicitors could be used at large-scale, reproducible production and high levels of enhancement are essential. In order to ensure the robustness of elicitation and exploit the process an understanding of this phenomenon at the molecular level is required. Bacitracin produced by Bacillus licheniformis is widely used as an animal feed additive and antibiotic against Gram-positive bacteria. In this work we report, the effect of single and multiple additions of different elicitors to B. licheniformis cultures for the production of bacitracin A. The results obtained showed that single addition of oligoguluronate to the cultures enhanced the levels of bacitracin A by 23.3%. Moreover, multiple elicitor addition of oligoguluronate and mannan oligosaccharide further enhanced the production of bacitracin A by 13.2% and 36.5% compared to single elicitor addition and control cultures, respectively. In addition, for the first time, it was found that elicitor supplementation of cultures increased the transcription level of the bacitracin biosynthetic genes bacABC, indicating transcriptional level control of the elicitor.

A smart bioconjugate of alginate and pectinase with unusual biological activity toward chitosan.

The commercial preparation of pectinase (Pectinex Ultra SP-L) was conjugated to alginate by noncovalent interactions by employing 1% alginate during the conjugation protocol. The optimum "immobilization efficiency" was 0.76. The pH optimum and the thermal stability of the enzyme remained unchanged upon conjugation with alginate. The soluble bioconjugate showed a 3-fold increase in V(max)/K(m) as compared to the free enzyme when the smart biocatalyst was used for chitosan hydrolysis. Time course hydrolysis of chitosan thus showed higher conversion of chitosan into reducing oligosaccharides/sugars. The smart bioconjugate could be reused five times without any detectable loss of chitosanase activity.