Impact of Phanerochaete chrysosporium inoculation on indigenous bacterial communities during agricultural waste composting

This research was conducted to distinguish between the separate effects of the Phanerochaete chrysosporium inoculation and sample property heterogeneity induced by different inoculation regimes on the indigenous bacterial communities during agricultural waste composting. P. chrysosporium was inoculated during different phases. The bacterial community abundance and structure were determined by quantitative PCR and denaturing gradient gel electrophoresis analysis, respectively. Results indicated a significant stimulatory effect of P. chrysosporium inoculation on the bacterial community abundance. The bacterial community abundance significantly coincided with pile temperature, ammonium, and nitrate (P < 0.006). Variance partition analysis showed that the P. chrysosporium inoculation directly explained 20.5 % (P = 0.048) of the variation in the bacterial communities, whereas the sample property changes induced by different inoculation regimes indirectly explained up to 35.1 % (P = 0.002). The bacterial community structure was significantly related to pile temperature, water-soluble carbon (WSC), and C/N ratio when P. chrysosporium were inoculated. The C/N ratio solely explained 7.9 % (P = 0.03) of the variation in community structure, whereas pile temperature and WSC explained 7.7 % (P = 0.026) and 7.5 % (P = 0.034) of the variation, respectively. P. chrysosporium inoculation affected the indigenous bacterial communities most probably indirectly through increasing pile temperature, enhancing the substrate utilizability, and changing other physico-chemical factors.