Bacillus cereus excretes large amounts of penicillinase
into growth media during incubation, hence the
widely-used penicillin selection technique for isolating
biochemical mutants of bacteria is not applicable to this
species. Genetic transfer in B. cereus has not been
reported; this is partly due to the lack of an effective
isolation...
This study involved an investigation of lactic streptococci which
had irreversibly lost ability to produce the high levels of acid in milk
necessary during the manufacture of certain fermented dairy products.
The slow acid producing mutants studied were obtained from
a normal acid producing strain by natural selection following induction...
In this study of toxigenic and non-toxigenic strains of Clostridium
botulinum type E, attempts were made to induce toxin production
in non-toxigenic cultures by exposure to mutagenic agents
and to differentiate the organisms by immunodiffusion. First, cultures
of non-toxic Cl. botulinum type E were exposed to various
mutagenic agents in...
A primary goal of population genetics is to identify the role of
microevolutionary forces in producing observed patterns of molecular and phenotypic
variation. I conducted four studies in the northern leopard frog, Rana pipiens, to
determine just how mutation, migration, genetic drift, and selection influenced,
genetic structure of mitochondrial DNA...