Perithecia were readily produced in culture on a suitable solid medium under
certain conditions of light and temperature, once vegetative growth was established.
Investigations into the carbon and nitrogen requirements for both vegetative
growth and fruiting showed that, whereas vegetative growth increased with increasing
carbon supplies up to10%, reproduction occurred only within a restricted range of carbon
and nitrogen concentrations. No perithecia were produced on a starvation
medium.
Factors involved in fruiting included concentration of nutrients and the balance
between them; both were important. A suitable fruiting medium required a minimum
carbon concentration of 3000 p.p.m., supplied as 0.75 % glucose or fructose, and an
optimum carbon concentration of 6000 p.p.m. supplied as 1.5 % glucose or fructose.
The maximum number of perithecia was produced on a medium containing 1%
glucose and 0.2 % asparagine (400 p.p.m. nitrogen), which had a carbonlnitrogen ratio
of 11.8. A higher than optimum nitrogen concentration was partially offset by increasing
the carbon concentration, that is by keeping the carbonlnitrogen ratio approximately
constant. The actual concentrations inhibiting and promoting fruiting of the fungus
were influenced by the balance between carbon and nitrogen supplies.
High concentrations of carbon and nitrogen increased vegetative growth but
decreased the number of perithecia. There was no sudden inhibition of perithecia with
increased carbon concentrations, but at 10% glucose (40,000 p.p.m. carbon) vegetative
growth and pigmentation were maximal but few or no perithecia developed.
No evidence was obtained that perithecial production was influenced by ageing
of the mycelium, the presence of staling factors, or exhaustion of food supplies.
Clinical features and sociodemographic factors affecting Trichomonas vaginalis infection in women attending a central sexually transmitted diseases clinic in Sri Lanka