ABSTRACT
The microflora of an ancient Greek manuscript parchment was studied using different microscopic techniques. The manuscript was found to be infected with a large number of both Gram-positive and Gram-negative bacteria and with occasional micromycetes. The localisation of cells in the parchment was established, and the information was obtained pertinent to the functional state and the ultrastructural organisation of bacteria, as well as to the character of their interaction with the structural elements of the parchment.
Subject(s)
Gram-Negative Bacteria , Gram-Positive Bacteria , Mycoplasma , Paper , Gram-Negative Bacteria/ultrastructure , Gram-Positive Bacteria/ultrastructure , Microscopy, Electron , Mycoplasma/ultrastructureABSTRACT
The work was aimed at studying how the herbicide semerone affected the ultrastructure of two soil microorganisms, Mycobacterium rubrum and Streptomyces bacillaris. Depending on its concentration, the herbicide inhibited growth processes so that biomass yield decreased, cell division was interfered with, and giant and misshapen cells appeared. The herbicide taken at a concentration of 50-100 mg/ml increased the amount of membrane structures of the respiration type in some cells. This compound at a concentration of 400-500 mg/ml changed the nucleoid structure in certain cells. The decrease number of ribosomes and their peculiar distribution in the cell cytoplasm are most typical responses of the cells to the herbicide action. These responses were found in all cells at any of the tested herbicide concentrations. The results of cytological experiments are supported by statistically reliable data on the effect of the herbicide on RNA and protein synthesis. RNA synthesis is inhibited at a semerone concentration as low as 1 mg/ml, which is a very sensitive indicator of its presence in the medium.
