Effect of Fungicides and Insecticides on Growth and Enzyme Activity of Four Cyanobacteria

Cyanobacterial populations introduced into crop fields as biofertilizer become non-target organisms for the pesticides and fungicides applied in the field. Effect of four commonly used pesticides viz. Bagalol, Mancozeb (fungicides), Thiodan and Phorate (insecticides) was studied on growth and different enzymes of four cyanobacterial species viz. Nostoc ellipsosporum, Scytonema simplex, Tolypothrix tenuis, and Westiellopsis prolifica. EC 50 concentration of each pesticide was determined for all cyanobacteria. Bagalol and Thiodan were found to be the most toxic. Both the fungicides and insecticides inhibited the activity of nitrogenase and glutamine synthetase (GS) at EC 50 concentration in all the four species studied. Bagalol incurred maximum inhibition of nitrogenase and GS activity on N. ellipsosporum and S. simplex while Thiodan and Phorate had maximum effect on T. tenuis, and W. prolifica. Mancozeb had lesser effect on all the above enzymes. One catabolic enzyme of carbohydrate metabolism, isocitrate dehydrogenase (ICDH) and one anabolic enzyme isocitrate lyase (ICL), which is related to glyoxylate pathway as well as gluconeogenesis, were also assayed. Cell free extracts of cyanobacteria treated with pesticides for 7 days show a drastic reduction of ICDH activity. ICL activity was induced in the organisms when treated with pesticides.     

Managing Spatial and Temporal Switchgrass Biomass Yield Variability

Biorefineries that plan to use switchgrass exclusively will encounter year-to-year variability in feedstock production. The economic success of the biorefinery will depend in part on the ability of the management team to strategically identify land for conversion from current use to the production of switchgrass enabling a flow of feedstock for the life of the biorefinery. The objective of this research is to determine the optimal quality, quantity, and location of land to lease while considering the spatial and temporal variability of switchgrass biomass yield. A calibrated biophysical simulation model was used to simulate switchgrass biomass yields for 50 years based on historical weather data from 1962 to 2011, for three land capability classes for each of 30 counties. Mathematical programming models were constructed and solved to determine the optimal leasing scheme for each of three strategies for a biorefinery that requires 2,000 Mg/day. As expected, a model based on the assumption that the average yield would be obtained in each year finds that production from land identified for leasing would be insufficient to fulfill the biorefinery’s needs in half of the years. In the absence of other sources of biomass, the feedstock shortage would require forced idling of the biorefinery for an average of 29.5 days during these years. Results of a strategy of leasing sufficient land to cover feedstock needs in the worst year from among 50 years for which data are available are compared to that of a strategy enabling year-to-year storage.     

Nanoparticle-induced morphological transition of Bombyx mori nucleopolyhedrovirus: a novel method to treat silkworm grasserie disease

Grasserie, a polyorganotrophic disease caused by Bombyx mori nucleopolyhedrovirus (BmNPV), accounts for lethal infection to fifth instar silkworm larvae. It was found that nanoparticle (NP)-induced morphological transformation of BmNPV polyhedra could reduce the infectivity of BmNPV both in cell line and in silkworm larvae. Initially, 11 NPs were screened for evaluation of their nature of interaction with polyhedra surface through scanning electron microscopy. Amongst these NPs, lipophilically coated silica nanoparticle (SNPL), alumina nanoparticles in the hexagonal close-packed α structure and aspartate capped gold nanoparticle transformed polyhedra were tested for their infectivity in B. mori cell line using cytopathic effect and plaque reduction assay. SNPL was evaluated for its bio-efficacy in fifth instar silkworm larvae. The study of polyhedra morphology as a function of NP concentration showed severe ‘roughening’ of the polyhedra with replacement of the regular facets by a large number of irregular ones by SNPL, and this caused transition of highly infectious polyhedra into a nearly spherical, non-infectious structure. A moderate polyhedra roughening was observed for alumina NPs, and no roughening was noticed for gold NPs. The morphological changes could be correlated with reduction of virus-induced cytopathic effect and plaque formation, and increased survival rate of SNPL transformed polyhedra infected silkworm larvae to 70.09?±?6.61 % after 96 h. In this group, 61.04?±?8.03 % larvae formed normal cocoons from which moths eclosed, laid eggs and larvae emerged. This study could lead to open up newer pathways for designing nano pharmaceuticals to combat other viral diseases.     

Influence of indole-3-butyric acid and propagation method on growth and development of in vitro- and ex vitro-derived lowbush blueberry plants

The effects of four indole-3-butyric acid (IBA) concentrations and two propagation methods were studied in a lowbush blueberry (Vaccinium angustifolium Ait.) clone collected from natural stands in Newfoundland and Labrador, Canada. Lowbush blueberry cultures were established in vitro from nodal explants on a modified cranberry (V. macrocarpon Ait.) tissue culture medium containing zeatin (2 μM). Blueberry plants propagated by in vitro shoot proliferation (TC) and by conventional softwood cuttings (SC) were evaluated for growth and morphology. Significant interactions for morphological characteristics were observed among the treatments. The IBA concentration had an effect on morphology of propagated plants, increasing the concentration of IBA increased stem length and leaves per stem across propagation methods. Stems per plant increased with IBA concentration up to 20 μM in SC plants, but not in TC plants. Plant vigor was affected by neither IBA concentration nor propagation method. The TC plants produced longer and more stems with more leaves per stem than the conventional cuttings. In vitro culture on zeatin-containing nutrient medium apparently induces the juvenile branching characteristics that favored enhanced vegetative growth with more stems and leaf production. It is suggested that IBA may serve as a physiologically active form of auxin in contributing to increased stem and leaf production in lowbush blueberry SC plants but not in TC plants.     

Autophagy in malignant transformation and cancer progression

Autophagy plays a key role in the maintenance of cellular homeostasis. In healthy cells, such a homeostatic activity constitutes a robust barrier against malignant transformation. Accordingly, many oncoproteins inhibit, and several oncosuppressor proteins promote, autophagy. Moreover, autophagy is required for optimal anticancer immunosurveillance. In neoplastic cells, however, autophagic responses constitute a means to cope with intracellular and environmental stress, thus favoring tumor progression. This implies that at least in some cases, oncogenesis proceeds along with a temporary inhibition of autophagy or a gain of molecular functions that antagonize its oncosuppressive activity. Here, we discuss the differential impact of autophagy on distinct phases of tumorigenesis and the implications of this concept for the use of autophagy modulators in cancer therapy.     

Does autophagy contribute to cell death?

Autophagy (specifically macroautophagy) is an evolutionarily conserved catabolic process where the cytoplasmic contents of a cell are sequestered within double membrane vacuoles, called autophagosomes, and subsequently delivered to the lysosome for degradation. Autophagy can function as a survival mechanism in starving cells. At the same time, extensive autophagy is commonly observed in dying cells, leading to its classification as an alternative form of programmed cell death. The functional contribution of autophagy to cell death has been a subject of great controversy. However, several recent loss-of-function studies of autophagy (atg) genes have begun to address the roles of autophagy in both cell death and survival. Here, we review the emerging evidence in favor of and against autophagic cell death, discuss the possible roles that autophagic degradation might play in dying cells, and identify salient issues for future investigation.     

Bioprospecting Micromonospora from Kaziranga National Park of India and their anti-infective potential

Large number of strains was isolated from soils of Kaziranga National Park of North-East India using selective isolation procedure. They were assigned to the genus Micromonospora on the basis of their typical colonial and pigmentation features. The taxonomic identities of the isolates were confirmed on the basis of their molecular characters (16SrDNA). A total of one hundred Micromonospora strains were isolated during the present investigation. The diagnostic cell wall sugar and amino acids were determined from these Micromonospora strains. After preliminary screening most of the isolates exhibited excellent anti-infective activity against human bacterial pathogens Staphylococcus aureas, Bacillus subtilis, Proteus vulgaris, Echerichia coli, Pseudomonas aeroginosa and fungal pathogens Aspergillus niger, Fusarium oxysporum and Candida albicans. Among these isolates one strain designated as HK-10 showed promising activity against human pathogens S. aureas, B. subtilis, P. vulgaris and P. aeroginosa.     

Potent anti-mycobacterial and immunomodulatory activity of some bioactive molecules of Indian ethnomedicinal plants that have the potential to enter in TB management

Tuberculosis (TB) is one of the deadliest infectious diseases of human civilization. Approximately one-third of global population is latently infected with the TB pathogen Mycobacterium tuberculosis (M.tb). The discovery of anti-TB antibiotics leads to decline in death rate of TB. However, the evolution of antibiotic-resistant M.tb-strain and the resurgence of different immune-compromised diseases re-escalated the death rate of TB. WHO has already cautioned about the chances of pandemic situation in TB endemic countries until the discovery of new anti-tubercular drugs, that is, the need of the hour. Analysing the pathogenesis of TB, it was found that M.tb evades the host by altering the balance of immune response and affects either by killing the cells or by creating inflammation. In the pre-antibiotic era, traditional medicines were only therapeutic measures for different infectious diseases including tuberculosis. The ancient literatures of India or ample Indian traditional knowledge and ethnomedicinal practices are evidence for the treatment of TB using different indigenous plants. However, in the light of modern scientific approach, anti-TB effects of those plants and their bioactive molecules were not established thoroughly. In this review, focus has been given on five bioactive molecules of different traditionally used Indian ethnomedicinal plants for treatment of TB or TB-like symptom. These compounds are also validated with proper identification and their mode of action with modern scientific approaches. The effectiveness of these molecules for sensitive or drug-resistant TB pathogen in clinical or preclinical studies was also evaluated. Thus, our specific aim is to highlight such scientifically validated bioactive compounds having anti-mycobacterial and immunomodulatory activity for future use as medicine or adjunct-therapeutic molecule for TB management.