Effect of Micromonospora sp. KSC08 on nitrogen conservation throughout composting

Abstract

Composting includes a series of reactions resulting in alterations on organic content and nitrogen amount. NH3 volatilization via ammonification and N-2 and N2O losses through nitrification are the major sources of nitrogen loss during composting. Amendment with microorganism inoculation was among recently adopted approaches to compensate for nitrogen losses and improve compost quality. Compost amendment via Micromonospora sp. KSC08, an asymbiotic free-living-(N-2)-fixing microorganism, was conducted in the present study in order to investigate microorganism's potential for nitrogen regulation. Twenty windrow systems with varying olive pomace%, microorganism amount, and addition time were prepared for statistical determination of the changes in total C, total nitrogen, and nitrate-nitrogen amounts. Analyses were evaluated in accordance with pH, humidity, and temperature measurements obtained during composting. Final part of the study included maturity evaluation and PCA modeling of FT-IR data. Micromonospora sp. KSC08 was shown to improve microbial activity and regulate nitrogen content by providing exogenous nitrogen to compost mixture. PCA models revealed entirely different structures between untreated and Micromonospora sp. KSC08-treated compost samples at the end of 120 days. The variant molecular structure of samples inoculated with Micromonospora sp. KSC08 was attributed to reactions between carboxyclic acid units and nitrogenous compounds leading to a significant increase in amide content compared to untreated mixtures. Higher amide content was due to higher nitrogen content of Micromonospora sp. KSC08-treated compost, and based on the findings, it was concluded that Micromonospora sp. KSC08 had been effective in nitrogen regulation and proposed as a possible component of microbial consortium for use in conventional composting systems.