The stability and solubility of various compounds in compost is influenced by the pH of the compost [31, 32]. Microbial population Kell et al. [33] studied that at the simplest level, bacteria may be classified into two physiological groups: those that can, and those that cannot readily be grown to detectable levels in vitro. The viable count usually refers to the number of individual LY2109761 organisms in compost that can be grown to a detectable

level, in vitro by forming colonies on an agar-based medium. However, the number of viable cells approximates to the number of colony forming units [34]. Changes in bacterial population were analyzed by cultivation-based method (cfu g-1) to reveal changes in the number of mesophilic and thermophilic bacteria during the composting process. Hargerty et al. [35] reported that there was maximum increase in microbial population in the early stages of composting which was dependent on initial substrate used and environmental conditions of the composting. High content of degradable organic compound in the initial mixture might have stimulated

microbial growth involved in self-heating during initial stage of composting [36]. An equivalent tendency does not occur with regard to mesophilic and thermophilic bacteria in the present study when the population density decreased from 109 to 107 cfu g-1. However from thermophilic to cooling and maturation phase, the gradual decrease in 107 to 105 cfu g-1 could be due to the unavailability of nutrients during maturation phase. During peak heating the bacterial populations declined by approximately 10-fold at 40°C and MK-4827 molecular weight 100-fold at 50°C, Amoxicillin followed by population growth at cooling phase, which decreased by 1000 fold as compared to the mesophilic (starting) phase of composting [7]. The Gram-positive bacteria dominated the composting process as they accounted for 84.8% of total population and the remaining 15.2% were Gram-negative as illustrated in Figure 2. For bacteria, 16S rRNA gene sequence analysis is a widely accepted tool for molecular

identification [37, 38]. Franke-Whittle et al. [39] also investigated the microbial communities in compost by using a microarray consisting of oligonucleotide probes targeting selleck chemicals llc variable regions of the 16S rRNA gene. During the present investigation, thirty three bacterial isolates were cultured, out of which twenty six isolates (78.8%) belonged to class firmicutes; two isolates (6.1 %) belonged to actinobacteria; three isolates (9.0 %) belonged to class γ-proteobacteria and the remaining two isolates (6.1%) showed sequence similarity to class β-proteobacteria (Figure 3). Table 4 and Figure 4 summarizes all the bacterial taxa reported in agricultural byproduct compost based on sequence similarity, which were categorized in four main classes: Firmicutes, β-proteobacteria, γ-proteobacteria and actinobacteria in concurrence with the findings of Ntougias et al.