Assignment Brief:

Question 1: Describe the nature and composition of the microbial community underpinning anaerobic digestion and refer to the key experimental approaches that have enhanced our knowledge of the interactions between community members.

Question 2: Critically discuss microbial community development during low-temperature anaerobic digestion. Refer to experimental evidence to support your conclusions. I will like two pages on each question, please.

Ten mesophilic full-scale anaerobic digesters treating food wastewater (FW-digesters) or sewage sludge (SL-digesters) were monitored for 1 year to investigate: (1) microbial communities underpinning FW-digesters and SL-digesters, (2) the effects of total ammonia-nitrogen concentration [TAN] and Na⁺ concentration [Na⁺] on variations of these communities. [TAN] and [Na⁺] in the digester varied among digesters: 1.7–6.5 g TAN/L and 1.0–3.6 g Na⁺/L for the FW-digesters, and 0.1–2.2 g TAN/L and 0.1–1.2 g Na⁺/L for the SL-digesters; [TAN] negatively correlated with the process efficiency of the FW-digesters. Microbial communities were less diverse in the FW-digesters than in the SL-digesters.