Effectiveness of microbial inoculants from tempeh and tapai in home scale composting

Abstract

This study evaluated the effectiveness and necessity of microbial inoculants on home scale composting (food waste: rice bran: dried leaves 2:1:1) with the attempt to divert food waste from the landfill. In this study, the feedstock was inoculated with three formulations of microbial inoculants (MI) and one control, namely 100% Tempeh solution, 100% Tapai solution, Effective MicroorganismTM (EM™) and water as control. Various physico-chemical properties and enzymatic activities were evaluated during the composting process. The quality of the end composts was evaluated by the physico-chemical properties, bioassays responds, characteristics of humic acid, nutrients content and pathogens content. It was found that the temperature of all three feedstock treated with MI can be heat up to higher level (>50oC) and did not produced foul odour compared to the control. However, for most of the monitored parameters of all treatments (with MI and control) during the composting process showed similar changes without significant differences. For the end composts (week 8), no significance difference was identified for the characteristics including pH (~7), EC (~3 dS/m), C: N (<14), organic matter content (~70%), colour (dark brown), potassium content (1-3-1.7%), phosphorus content (0.3-0.4%), odour (earthy smell), pathogen content (pass) and germination index (>100%) but all indicating well matured. Nevertheless, composts with MI showed higher content of nitrogen than the control. In comparison with composts treated with EM™, MI from Tempeh produced compost with higher nitrogen and humic content; MI from Tapai showed compost with better ability to raise the temperature to a higher degree. This study concludes that MI produced from Tempeh and Tapai showed comparable performance as the commercial brand, the Effective Microorganism™ as microbial inoculants.