Effects of the Psychrotrophic Bacteria and Thermophilic Actinomycetes Consortium Inoculation on Human Faeces Composting Process under Moderate Cold Climate Conditions in Northern Vietnam

• Published in: Biology bulletin of the Russian Academy of Sciences Vol. 49; no. Suppl 1; pp. S51 - S59
• Main Authors: Do Thi Tuyen, Phuong, Dang Thi Hong, Van Thang, Le, Thanh, Nguyen Thi Kim, Hong, Do Thi Thu, Cuong, Ngo Cao, Hoai, Nguyen Thu, Balakirev, A. E., Huan, Le Duc
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-02-2022; Springer Nature B.V
• Subjects: Actinomycetes; Biochemistry; Biomedical and Life Sciences; Carbon/nitrogen ratio; Cell Biology; Cellulase; Cold; Composting; Decomposition; Ecology; Feces; Inoculation; Life Sciences; Low temperature; Maturity; Microbiology; Psychrotrophic bacteria; Sawdust; Thermophilic bacteria; Thermophilic microorganisms; Zoology; Vietnam; composting; psychrotrophic bacteria consortium; thermophilic cellulolytic actinomycetes consortium; psychrotrophic-thermophilic microbial consortium
• ISSN: 1062-3590; 1608-3059
• DOI: 10.1134/S1062359022130210

Composting, or controlled organic decomposition, is one of the most important ways to utilize human waste (faeces) on water shortaged regions and cold climate conditions. However, the adding a thermophilic microbial agent on the human faeces composting process was limited because of the low efficiency and composting activity of inoculant under cold climate conditions. This research was performed to evaluate the effect of the psychrotrophic bacteria and thermophilic actinomycetes consortium inoculation, as a microbial inoculant during human faeces composting under low temperature condition (15–20°C) in Northern Vietnam. Mixtures of human faeces and sawdust were inoculated with the psychrotrophic Bacillus consortium (PBC), thermophilic Streptomyces consortium (TAC), and mixed psychrotrophic-thermophilic microbial consortium (PTMC) agents, the ambient temperature at initial composting phase was within 15–20°C. Sterile water used as a control (CK). The results showed that the start of composting process clearly promoted by inoculation with PBC or PTMC as indicated by the quick changes of physicochemical parameters (the temperature, pH, C/N ratio, activity of cellulase, etc.). In the PTMC-inoculated compost piles, temperatures reached the thermophilic stage (over 50°C) and run 5–10 days faster than piles inoculated with TAC, PBC or in control. In addition, compost maturity was promoted by inoculation with TAC or PTMC by a longer thermophilic phase and a greater reduced carbon-nitrogen ratio. Meanwhile, inoculation with PTMC agent in the initial phase favored the composting process by setting up of sufficiently impactful microbial population. The highest thermophilic temperature of 56.9°C increased cellulase activity in the maturity phase and promoted the maturity of composting in general. Accordingly, this is first research on promoting effects of psychrotrophic-thermophilic microbial consortium (PTMC) agents inoculation on human faeces decomposition under cold climate conditions.