Production of bioactive metabolites by Nocardia levis MK-VL_113

Aims: To isolate and identify the bioactive compounds produced by Nocardia levis MK‐VL_113. Methods and Results: Cultural characteristics of Noc. levis isolated from laterite soils of Guntur region were recorded on International Streptomyces Project media. Morphological studies of the strain through scanning electron microscopy revealed the clear pattern of its hyphal fragmentation into rod‐shaped bacilli. Chemical examination of the secondary metabolites of the strain grown on sucrose–tryptone broth led to the isolation of three fractions active against Bacillus cereus. Further analysis of second fraction resulted in the isolation of two active subfractions. Two different phthalate esters, namely, bis‐(2‐ethylhexyl) phthalate and bis‐(5‐ethylheptyl) phthalate, were purified from the first active subfraction, and the structural elucidation of these compounds was confirmed on the basis of FT‐IR, mass and NMR spectroscopy. The partially purified second subfraction subjected to Gas Chromatography–Mass spectroscopy contained nine components: decanedioic acid; 2,6‐piperdione monooxime; 1‐eicosanol; beta‐1‐arabinopyranoside, methyl; cyclopentaneundecanoic acid; hexadecanoic acid; silane, trichloro eicosyl; 1‐hexacosanol; and 1,2‐dodecanediol. The antimicrobial activity of the bioactive compounds produced by Noc. levis was expressed in terms of minimum inhibitory concentration. Conclusions: The present study clearly revealed that the metabolites of Noc. levis act as bioactive compounds against Gram‐positive and Gram‐negative bacteria, yeast and filamentous fungi. It also supports the idea that there are a number of rare actinomycetes remained to be explored for new bioactive compounds. Significance and Impact of the Study: Metabolites of Noc. levis exhibited antibacterial and antifungal activities. This is the first report of bis‐(5‐ethylheptyl) phthalate as well as the nine partially purified compounds from actinomycetes. In addition, this is also the first report of bis‐(2‐ethylhexyl) phthalate from the genus Nocardia.     

Modeling Human TBX5 Haploinsufficiency Predicts Regulatory Networks for Congenital Heart Disease

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Toxicity mechanism of Cu2+ ion individually and in combination with Zn2+ ion in characterizing the molecular changes of Staphylococcus aureus studied using FTIR coupled with chemometric analysis

Copper and zinc have a high binding affinity with a Staphylococcus aureus bacterial community. This causes a change in the biomolecular composition of S. aureus. Our study aims at understanding the resistance mechanism of Cu and Zn either or in various combinations using FTIR and chemometric techniques. Zn toxicity resulted in a significant change in lipid content (3100-2800 cm⁻¹) compared to Cu. A significant decrease in protein content is observed for Cu treatment in the amide region. The bio-concentration factor shows a higher value for Cu compared to Zn. The increase in band area of carbohydrates moieties 1059 cm⁻¹ shows the secretion of EPS due to Cu toxicity. A significant change in nucleic acid compositions was noted in the region1200-900 cm⁻¹ due to Zn treatment. Secondary structural change in protein shows β sheet formation. The result of the finding shows Cu has greater toxicity than Zn. Further toxicity effects were greatly enhanced for metal mixtures ratio (Cu:2Zn). This shows Zn exhibits synergism effect with Cu. The obtained ROC (receiver operating characteristic) curve area gives good reliability of the experiments. The study attempts to understand the mechanism of toxicity removal of Cu and Zn metal mixtures by bacterial population using FTIR coupled with chemometric techniques. Open in a separate windowGraphical abstract     

Fuzzy estimator for plasmid-bearing microorganism

Fuzzy estimator is developed for determining the concentration of plasmid-bearing microorganism (x ⁺) in a continuous bioreactor. Membership functions, fuzzy ranges for the inputs and outputs are defined. A fuzzy rule base is constructed relating the inputs to the output based on operators experience. A defuzzification method is selected and the non-fuzzy value of x ⁺ is obtained. The results are compared with the actual values of x ⁺ which are obtained by numerically solving the model equations of the system. The estimator is also tested for the other operating conditions. The estimator performs well for other operating conditions also.     

OligoSpawn: a software tool for the design of overgo probes from large unigene datasets

Background  

Expressed sequence tag (EST) datasets represent perhaps the largest collection of genetic information. ESTs can be exploited in a variety of biological experiments and analysis. Here we are interested in the design of overlapping oligonucleotide (overgo) probes from large unigene (EST-contigs) datasets.