It was also shown that the antagonistic effects of indigenous
microorganisms peak in young compost and gradually
declined with its maturation owing to a decrease in nutrient availability
that led to a decrease in microbial diversity and abundance
(Sidhu et al., 2001). Mature thermophilic compost, which harboured
lower abundances of indigenous microbes, or sterilized
compost, had been shown to allow regrowth of pathogens such
as Salmonella spp. when proper humidity and temperature conditions
were restored (Sidhu et al., 2001). Furthermore, endospore
forming bacterial pathogens such as C. perfringens, can survive
through the thermophilic phase of traditional composting, and
can be quite common in composts (though rarely monitored under
regulatory guidelines) (Lasaridi et al., 2006).