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Mucoadhesive drug delivery systems are those that provide intimate contact of the drug with the mucosa for an extended period of time. In our present work, mucoadhesive chitosan microspheres were prepared by emulsion solvent method. Formulations were characterized for various physicochemical attributes, shape, surface morphology, size, and size distribution, drug payload, swelling ability, and mucoadhesion. The effect of drug, citric acid, and permeation enhancer concentration on the physicochemical properties was studied. Crosslinked chitosan microspheres showed very good mucoadhesion, which was decreased on increasing the drug concentration and citric acid concentration, and slightly improved upon incorporation of permeation enhancer. The in vitro drug release and in vitro drug permeability through mucous membrane were performed, and slow release/permeation was noted with chitosan citrate complexed microspheres compared with noncomplexed chitosan microspheres. The in vivo performance of mucoadhesive microspheres formulations showed prolonged and controlled release of salbutamol as compared with oral administration of conventional dosage form.

This study examines response of Anabaena sp. PCC 7120 to salt and UV-B stress by combining physiological, biochemical, proteomics and bioinformatics approaches. Sixty five significantly altered protein spots corresponding to 51 protein genes identified using MALDI-TOF MS/MS were divided into nine functional categories. Based on relative abundance, these proteins were grouped into four major sets. Of these, 27 and 5 proteins were up- and downregulated, respectively, both under salt and UV-B while 8 and 11 proteins showed accumulation in salt and UV-B applied singly. Some responses common to salt and UV-B included (i) enhanced expression of FeSOD, alr3090 and accumulation of MDA indicating oxidative stress, (ii) accumulation of PDH, G6P isomerase, FBPaldolase, TK, GAPDH and PGK suggesting enhanced glycolysis, (iii) upregulation of 6-PGD, 6PGL and NADPH levels signifying operation of pentose phosphate pathway, (iv) upregulation of Dps, NDK and alr3199 indicating DNA damage, and (v) accumulation of proteins of ribosome assembly, transcriptional and translational processing. In contrast, enhanced expression of RUBISCO, increased glycolate oxidase activity and ammonium content under salt signify the difference. Salt was found to be more damaging than UV-B probably due to a cumulative effect of ionic, osmotic and oxidative damage. A group of proteins having common expression represent decreased toxicity of salt and UV-B when applied in combination.

Increasing concerns on environmental and economic issues linked to fossil fuel use has driven great interest in cyanobacteria as third generation biofuel agents. In this study, the biodiesel potential of a model photosynthetic cyanobacterium, Fremyella diplosiphon, was identified by fatty acid methyl esters (FAME) via direct transesterification. Total lipids in wild type (Fd33) and halotolerant (HSF33-1 and HSF33-2) strains determined by gravimetric analysis yielded 19% cellular dry weight (CDW) for HSF33-1 and 20% CDW for HSF33-2, which were comparable to Fd33 (18% CDW). Gas chromatography-mass spectrometry detected a high ratio of saturated to unsaturated FAMEs (2.48-2.61) in transesterified lipids, with methyl palmitate being the most abundant (C16:0). While theoretical biodiesel properties revealed high cetane number and oxidative stability, high cloud and pour point values indicated that fuel blending could be a viable approach. Significantly high FAME abundance in total transesterified lipids of HSF33-1 (40.2%) and HSF33-2 (69.9%) relative to Fd33 (25.4%) was identified using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry, indicating that robust salt stress response corresponds to higher levels of extractable FAME. Alkanes, a key component in conventional fuels, were present in F. diplosiphon transesterified lipids across all strains confirming that natural synthesis of these hydrocarbons is not inhibited during biodiesel production. While analysis of photosynthetic pigments and phycobiliproteins did not reveal significant differences, FAME abundance varied significantly in wild type and halotolerant strains indicating that photosynthetic pathways are not the sole factors that determine fatty acid production. We characterize the potential of F. diplosiphon for biofuel production with FAME yields in halotolerant strains higher than the wild type with no loss in photosynthetic pigmentation.

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This paper provides the first proteomic evidence of arsenic (As) tolerance and interactive regulatory network between primary and secondary metabolism in the medicinal plant, Artemisia annua. While chlorophyll fluorescence and photosynthetic rate depicted mild inhibition, there was a significant enhancement in PSI activity, whole chain, ATP, and NADPH contents in 100 μM As treatments compared to the control plants. However, a decrease in the above variables was recorded under 150 μM treatments. Proteomic decoding of the survival strategy of A. annua under As stress using 2-DE followed by MALDI-MS/MS revealed a total of 46 differentially expressed protein spots. In contrast to other plants where As inhibits photosynthesis, A. annua showed appreciable photosynthetic CO2 assimilation and allocation of carbon resources at 100 μM As concentration. While an increased accumulation of ATP synthase, ferredoxin-NADP(H) oxidoreductase, and FeS-rieske proteins supported the operation of cyclic electron transport, mdr ABC transporter protein and pcs gene might be involved in As detoxification. The most interesting observation was an increased accumulation of LEAFY like novel protein conceivably responsible for an early onset of flowering in A. annua under As stress. This study not only affirmed the role of energy metabolism proteins but also identified potential candidates responsible for As tolerance in plants.

Microbial interactions with plant roots play an imperial role in tomato plant growth and defense against the Rhizoctonia solani. This study performed a field experiment with two antagonistic bacteria (Pseudomonas and Bacillus) inoculated in healthy and Rhizoctonia solani treated soil in tomato rhizosphere to understand the metabolic pattern and microbial function during plant disease suppression. In the present study, we assessed soil and microbial enzymes, bacterial and fungal cell forming unit (CFU), and carbon utilization profiling through Bio-Eco plates of rhizoplane samples. Antagonist bacteria and pathogen interaction significantly (p < 0.05) influenced the bacterial count, soil enzymes (chitinase and glucanase), and bacterial function (siderophore and chitinase production). These results indicated that these variables had an imperial role in disease suppression during plant development. Furthermore, the metabolic profiling showed that carbon source utilization enhanced under fruit development and ripening stages. These results suggested that carbon sources were essential in plant/pathogen/antagonist interaction. Substrates like β-methyl-D-glucoside, D-mannitol, D-galacturonic acid, N-acetyl-D-glucosamine, and phenylethylamine strongly connect with the suppuration of root rot disease. These carbon sources may help to propagate a healthy microbial community to reduce the pathogen invasion in the plant root system, and these carbon sources can be stimulators of antagonists against pathogens in the future.