From genotype to phenotype with biothermodynamics: empirical formulas, biosynthesis reactions and thermodynamic properties of preproinsulin, proinsulin and insulin molecules.

Insulin was discovered 100 years ago and has been well studied from the perspectives of life and biomedical sciences. This paper reports chemical and biothermodynamic properties of biosynthesis of insulin. This paper reports for the first time the molecular and empirical formulas, biosynthesis reactions, and thermodynamic properties of molecules and their biosynthesis for human preproinsulin, proinsulin, insulin chain A, insulin chain B, insulin, signal peptide and intermediate peptide (C-peptide). Based on these, metabolic reactions were formulated for conversion of preproinsulin to insulin and their thermodynamic feasibility was analyzed.Communicated by Ramaswamy H. Sarma.

Phenol Removal Capacity of the Common Duckweed (Lemna minor L.) and Six Phenol-Resistant Bacterial Strains From Its Rhizosphere: In Vitro Evaluation at High Phenol Concentrations.

The main topic of this study is the bioremediation potential of the common duckweed, Lemna minor L., and selected rhizospheric bacterial strains in removing phenol from aqueous environments at extremely high initial phenol concentrations. To that end, fluorescence microscopy, MIC tests, biofilm formation, the phenol removal test (4-AAP method), the Salkowski essay, and studies of multiplication rates of sterile and inoculated duckweed in MS medium with phenol (200, 500, 750, and 1000 mg L-1) were conducted. Out of seven bacterial strains, six were identified as epiphytes or endophytes that efficiently removed phenol. The phenol removal experiment showed that the bacteria/duckweed system was more efficient during the first 24 h compared to the sterile duckweed control group. At the end of this experiment, almost 90% of the initial phenol concentration was removed by both groups, respectively. The bacteria stimulated the duckweed multiplication even at a high bacterial population density (>105 CFU mL-1) over a prolonged period of time (14 days). All bacterial strains were sensitive to all the applied antibiotics and formed biofilms in vitro. The dual bacteria/duckweed system, especially the one containing strain 43-Hafnia paralvei C32-106/3, Accession No. MF526939, had a number of characteristics that are advantageous in bioremediation, such as high phenol removal efficiency, biofilm formation, safety (antibiotic sensitivity), and stimulation of duckweed multiplication.

Endogenous levels of cytokinins, indole-3-acetic acid and abscisic acid in in vitro grown potato: A contribution to potato hormonomics.

A number of scientific reports published to date contain data on endogenous levels of various phytohormones in potato (Solanum tuberosum L.) but a complete cytokinin profile of potato tissues, that would include data on all particular molecular forms of cytokinin, has still been missing. In this work, endogenous levels of all analytically detectable isoprenoid cytokinins, as well as the auxin indole-3-acetic acid (IAA), and abscisic acid (ABA) have been determined in shoots and roots of 30 day old in vitro grown potato (cv. Désirée). The results presented here are generally similar to other data reported for in vitro grown potato plants, whereas greenhouse-grown plants typically contain lower levels of ABA, possibly indicating that in vitro grown potato is exposed to chronic stress. Cytokinin N-glucosides, particularly N7-glucosides, are the dominant cytokinin forms in both shoots and roots of potato, whereas nucleobases, as the bioactive forms of cytokinins, comprise a low proportion of cytokinin levels in tissues of potato. Differences in phytohormone composition between shoots and roots of potato suggest specific patterns of transport and/or differences in tissue-specific metabolism of plant hormones. These results represent a contribution to understanding the hormonomics of potato, a crop species of extraordinary economic importance.

Esterase and peroxidase isoforms in different stages of morphogenesis in Fritillaria meleagris L. in bulb-scale culture.

Morphogenesis in vitro is a complex and still poorly defined process. We investigated esterase and peroxidase isoforms detected in bulb scale, during Fritillaria meleagris morphogenesis. Bulbs were grown either at 4 °C or on a medium with an increased concentration of sucrose (4.5%) for 30 days. After these pre-treatments, the bulb scales were further grown on nutrient media that contained different concentrations of 2,4-dichlorophenoxyacetic acid (2,4-D) and kinetin (KIN) or thidiazuron (TDZ). Regeneration of somatic embryos and bulblets occurred at the same explant. The highest numbers of somatic embryos and bulblets were regenerated on the medium containing 2,4-D and KIN (1mg/L each), while morphogenesis was most successful at a TDZ concentration between 0.5 and 1mg/L. Monitoring of esterases and peroxidases was performed by growing bulb scales on a medium enriched with 2,4-D and KIN or TDZ (1mg/L), and the number and activity of isoforms were followed every 7 days for 4 weeks. In control explants, six isoforms of esterase were observed. Three isoforms of peroxidase were not detected in the control bulb scale, which has not begun its morphogenesis process.