Part I
Chapter 1. A (1). B (3). C (4).
Chapter 2. A (3). B (1, 2). C (2, 4). D (1, 3, 4). E (1, 2). F (1, 4). G (1, 2). H (1, 2, 3). I (1, 3, 4). J (2). K (2, 3, 4).
Chapter 3. A (2). B (3). C (4). D (2). E (3). F (1, 2). G. More effective medium is medium No. 1. The duration of the lag-phase depends on how quickly the bacterial culture adapts to new conditions. The more efficient and nutritious the medium for a particular microbe is, the shorter is the period of adaptation. H. Bacterial culture A - facultative anaerobe. Bacterial culture B - microaerophil. Bacterial culture C - strict aerobe. Bacterial culture D - strict anaerobe.
Chapter 4. A (1, 2, 4). B (1, 2, 4, 5). C - synbiotics. D (1, 3, 4). E (2, 3, 4). F (4). G (1, 2, 3). H (1). I (1). J (1). K (1). L (1).
Chapters 5. A (3). B (1, 2, 3). C (1, 2, 3). D (1, 2, 3). E. The identity of the isolated cultures may be established by extracting DNA from both strains and performing the restriction analysis of DNA. Comparing the restriction maps of the DNAs extracted from the different strains, their genetic relationship may be determined. It is also possible to identify the plasmid profile of isolated cultures. The plasmid profile allows for intraspecific identification of bacteria. For this purpose, the plasmid DNA is extracted from the bacterial cell; the isolated DNA is separated by agarose gel electrophoresis to assess the number and size of plasmids. If plasmid profiles of both strains are similar, a conclusion about their identity is made.
Chapter 6. A (1, 3, 4). B (2, 4). C (2, 3, 4). D (1, 2, 3). E (1, 2, 3, 4, 5). F. To fight the inactivating effect of в-lactamases, inhibitors (for example, clavulanic acid, sulbactam, and tazobactam) are used. They contain a в-lac-tam ring and can bind to в-lactamases, preventing their destructive action on в-lactam antibiotic.