Tackling <Emphasis Type="Italic">Salmonella</Emphasis> Persister Cells by Antibiotic–Nisin Combination via Mannitol

Bacterial persisters (defined as dormant, non-dividing cells with globally reduced metabolism) are the major cause of recurrent infections. As they neither grow nor die in presence of antibiotics, it is difficult to eradicate these cells using antibiotics, even at higher concentrations. Reports of metabolites (which help in waking up of these inactive cells) enabled eradication of bacterial persistence by aminoglycosides, suggest the new potential strategy to improve antibiotic therapy. Here we propose, mannitol enabled elimination of Salmonella persister cells by the nisin–antibiotic combination. For this, persister cells were developed and characterized for their typical properties such as non-replicative state and metabolic dormancy. Different carbon sources viz. glucose, glycerol, and mannitol were used, each as an adjunct to ampicillin for the eradication of persister cells. The maximum (but not complete) killing was observed with mannitol–ampicillin, out of all the combinations used. However, significant elimination (about 78%) could be observed, when nisin (an antimicrobial peptide) was used with ampicillin in presence of mannitol, which might have mediated the transfer of antibiotic–nisin combination at the same time when the cells tried to grab the carbon molecule. Further, the effectiveness of the trio was confirmed by flow cytometry. Overall, our findings highlight the potential of this trio-combination for developing it as an option for tackling Salmonella persister cells.     

Photo‐switchable microbial fuel‐cells

Regulation of Bio‐systems in a clean, simple, and efficient way is important for the design of smart bio‐interfaces and bioelectronic devices. Light as a non‐invasive mean to control the activity of a protein enables spatial and temporal control far superior to other chemical and physical methods. The ability to regulate the activity of a catalytic enzyme in a biofuel‐cell reduces the waste of resources and energy and turns the fuel‐cell into a smart and more efficient device for power generation. Here we present a microbial‐fuel‐cell based on a surface displayed, photo‐switchable alcohol dehydrogenase. The enzyme was modified near the active site using non‐canonical amino acids and a small photo‐reactive molecule, which enables reversible control of enzymatic activity. Depending on the modification site, the enzyme exhibits reversible behavior upon irradiation with UV and visible light, in both biochemical, and electrochemical assays. The change observed in power output of a microbial fuel cell utilizing the modified enzyme was almost five‐fold, between inactive and active states.     

Early Neolithic agriculture (2700–2000 <Emphasis Type="SmallCaps">bc</Emphasis>) and Kushan period developments (<Emphasis Type="SmallCaps">ad</Emphasis> 100–300): macrobotanical evidence from Kanispur in Kashmir,India

Here we report the results of an archaeobotanical study carried out on Ceramic Neolithic (2700–2000 bc) and Kushan period (ad 100–300) deposits at Kanispur, Kashmir, northern India. Botanical evidence from the Ceramic Neolithic phase reflects a nascent agriculture based on cold-tolerant crops (barley, wheats, lentil, field pea and grass pea) related to farming patterns of adjacent cultures and possibly evidence for the earliest cultivation in the valley. The Kushan period is characterized by a double-cropping pattern, suggesting a change in agricultural practices associated with a population recovery following a post-Neolithic decline. Finds of Juglans regia, and Prunus cf. amygdalus shells in ceramic Neolithic levels, and Vitis cf. vinifera, Emblica officinalis and Ziziphus cf. nummularia in addition to J. regia, and P. cf. amygdalus during Kushan times suggest that horticulture and foraging played an important role in the diet of the occupants. The present dataset provides new absolute dates for the subsistence economy of the Ceramic Neolithic population in the Kashmir Valley. We also present the oldest directly dated wheat and barley in Kashmir.     

Seasonal incidence of aphid,Amphorophora ampullata Bukton (Homoptera: Aphididae) on fern,Hypolepis polypodioides (Blume) Hook (Hypolepidaceae) from Western Himalaya

Seasonal incidence of aphid, Amphorophora ampullata on Hypolepis polypodioides was recorded throughout the year from November 2012 to November 2013 at weekly interval. Peak incidence of aphid was recorded during third week of November 2012 (25.94 ± 2.39 aphids/pinna), later the aphid population gradually decreased from December 2012 onwards and reached below threshold level during the last week of January (0.1 ± 0 aphids/pinna). The aphid population starts building up again from first week of February 2013 (1.6 ± 0.13 aphids/pinna) and attained its peak in the last week of August (32.17 ± 1.22 aphids/pinna) then decreased gradually in the first week of September (20.82 ± 4.70 aphids/pinna). Aphid densities again increased gradually from second week of September (21.62 ± 3.02 aphids/pinna) to November 2013 and reached maximum aphid densities during November (56.55 ± 4.34 aphids/pinna). Among weather parameters, aphid population showed significant positive correlation with relative humidity during morning hours.     

Plant β-Galactosidases: Physiological Significance and Recent Advances in Technological Applications

The β-galactosidase (BGAL) is one of the oldest ubiquitous enzymes, known for more than 100 years. The enzyme is known to perform various functions in different organisms, however with similar mode of action. There is an immense literature available related to bacterial, fungal as well as animal BGAL compared to plant BGAL. Initially, it was believed that lactose is the only substrate for the enzyme. Later, it was observed that enzyme specificity is due to hydrolysable bond rather than the substrate. The present review is based on the role of BGAL in plants, the in vivo substrates and their physiological significances. Similarity as well as dissimilarity with BGAL from bacterial as well as fungal sources is also discussed. Plant BGAL would be best suited for industrial applications because of its easy availability, cost effectiveness and easy adaptability.     

Theoretical Study of Possible Reaction Mechanisms for the Formation of Carbodiimide in the Interstellar Medium (ISM) and Polarizabilities of Carbodiimide

Origins of Life and Evolution of Biospheres - The Structure of carbodiimide has been studied by using quantum chemical methods. Carbodiimide (HNCNH) has been detected towards Sagittarius B2 (N) in...