Influence of process parameters on anaerobic digestion microbiome in bioenergy production: Towards an improved understanding.

During the anaerobic digestion (AD) of waste and production of methane as an alternative fuel, unpredictability and instability of bioreactors are a challenge. Leading cause of such failure is the lack of knowledge about the microbial consortia involved in AD under different process conditions or perturbations during field applications. Over the last decade, microbiome in AD has been extensively studied with culture-independent molecular microbiology techniques, which have shed light into their structure and function. Hence, a critical discussion and consolidation of efforts made in these studies towards linking microbiome to reactor performance are required. This review focuses on how such molecular information can provide improved insight in correlation of microbiome structure and reactor performance to attain a stable and efficient AD. Studies describing microbial community dynamics under different process conditions have been briefly discussed along with the molecular approaches used. Furthermore, interesting developments toward the inclusion of diversity to mathematical modeling of AD systems are discussed. Based on the present state of the advancements, the review endeavors to critically evaluate the current knowledge gaps and research questions that must be resolved in the future in order to address the problem of instability associated with AD

Biological wastewater treatment to achieve pollution control and resource recovery : role of anaerobic digestion

A rapid increase in waste generation has quickly become one of the key challenges of today’s world. However, the wastes originating from a range of sources, including industries and residences, can be used as a potential resource—if managed properly. This management includes developing technologies to safely reuse waste, and the conversion of waste to valuable materials and energy (i.e., valorization), which is an emerging trend aiming at “zero-waste” society and circular economy. Microbial treatment of wastewater serves both the purposes—(i) microorganisms transform pollutants to nontoxic products so that the subsequently cleaned water is available for reuse, (ii) during this biotransformation process several metabolites such as industrially relevant chemicals (e.g., acetate and ethanol), and energy (e.g., methane and hydrogen) are produced. In this chapter, we focus on anaerobic digestion (AD), which serves the dual purpose of pollution control and resource recovery in the form of methane. We discuss how microbial consortium involved in AD responds to different process parameters and, subsequently, shifts the complex metabolic network influencing the stability of the system