Journal of Bioremediation & Biodegradation
Open Access

Methanogenesis; Fermentation; Anaerobes; Biogas

Introduction

Biodegradation is a natural process by which microorganisms metabolize and break down organic compounds into simpler substances. In aerobic conditions, oxygen serves as the primary electron acceptor, facilitating the breakdown of organic matter [1]. However, in environments devoid of oxygen, microorganisms adapt by utilizing alternative electron acceptors for their metabolic activities. This anaerobic biodegradation plays a vital role in various ecosystems, including soil, sediments, and aquatic environments [2,3].

Mechanisms of anaerobic biodegradation

Electron Acceptors

In anaerobic conditions, microorganisms utilize various chemicals as electron acceptors, including:

Nitrate (NO3-) reduction: Microorganisms reduce nitrate to nitrite (NO2-) and eventually to nitrogen gas (N2).

Sulfate (SO4^2-) reduction: Sulfate-reducing bacteria reduce sulfate to hydrogen sulfide (H2S).

Carbon dioxide (CO2) reduction: Some microorganisms can use CO2 directly as an electron acceptor.

Microbial Metabolism

Anaerobic biodegradation involves complex microbial metabolic pathways. The degradation pathways vary depending on the type of organic compound and electron acceptor involved [4]. Common metabolic pathways include:

Fermentation: Initial breakdown of organic compounds into simpler molecules like organic acids, alcohols, and gases.

Anaerobic respiration: Utilization of alternative electron acceptors to produce energy and metabolites.

Methanogens: Production of methane (CH4) from carbon dioxide or acetate by methanogen archaea.

Types of anaerobic biodegradation

Hydrolysis: The first step in anaerobic degradation involves hydrolysis, where complex organic molecules are broken down into simpler compounds like sugars, amino acids, and fatty acids.

Acidogenesis: During acidogenesis, the simpler compounds produced from hydrolysis are further metabolized into organic acids, alcohols, and gases like hydrogen and carbon dioxide [5,6].

Methanogens: In the final step, methanogen microorganisms convert organic acids, alcohols, and carbon dioxide into methane and carbon dioxide.

Significance of anaerobic biodegradation

Environmental impacts: Anaerobic biodegradation plays a crucial role in nutrient cycling and organic matter decomposition in various ecosystems. It helps maintain soil fertility, purifies groundwater, and reduces environmental pollution by breaking down hazardous organic pollutants.

Industrial applications: Anaerobic biodegradation has several industrial applications, including wastewater treatment, biogas production, and bioenergy generation. Anaerobic digesters are commonly used to treat organic waste and produce biogas, a renewable energy source.

Challenges and future directions: Despite its significance, anaerobic biodegradation faces challenges such as slow degradation rates, limited substrate range, and susceptibility to environmental factors. Future research should focus on optimizing microbial communities, enhancing degradation efficiency, and exploring new electron acceptors and metabolic pathways [7-10].

Conclusion

Anaerobic biodegradation is a complex biochemical process wherein microorganisms degrade organic compounds using alternative electron acceptors in the absence of oxygen. It plays a vital role in environmental sustainability, industrial applications, and biogeochemical cycles. Understanding the mechanisms and types of anaerobic biodegradation is crucial for developing sustainable waste management strategies and harnessing bioenergy from organic waste.

Acknowledgment

None

Conflict of Interest

None

References

1. Martin K (2011) Electronic overload: The impact of excessive screen use on child and adolescent health and wellbeing. Perth, Western Australia: Dep Sport Recreat.

Google Scholar

2. Lucena JM, Cheng LA, Cavalcante TL, Silva VA, Farias Junior JC (2015) Prevalence of excessive screen time and associated factors in adolescents]. Revista paulista de pediatria: orgao oficial da Sociedade de Pidiatric de Sao Paulo 33: 407-414.

Indexed at, Google Scholar

3. Carson V, Pickett W, Janssen I (2011) Screen time and risk behaviours in 10 to16-year-old Canadian youth. Preventive Medicine 52: 99-103.

Indexed at, Google Scholar, Cross Ref

4. Rideout VJ, Foehr UG, Roberts DF (2010) Generation M Media in the Lives of 8-to 18-Year-Olds. Henry J Kaiser Family Foundation.

Google Scholar

5. Granich J, Rosenberg M, Knuiman MW, Timperio A (2011) Individual, social and physical environment factors associated with electronic media use among children: sedentary behavior at home. J Phys Act Health 8: 613.

Indexed at, Google Scholar

6. Rey-Lopez JP, Vicente-Rodriguez G, Ortega FB (2010) Sedentary patterns and media availability in European adolescents: The HELENA study. Prev Med 51: 50-55.

Indexed at, Google Scholar, Cross Ref

7. Wang C, Li K, Kim M, Lee S, Seo D-C (2019) Association between psychological distress and elevated use of electronic devices among US adolescents: Results from the youth risk behavior surveillance 2009-2017. Addictive Behaviors 90:112-118.

Indexed at, Google Scholar, Cross Ref

8. Strasburger VC, Hogan MJ, Mulligan DA (2013) Children adolescents, and the media. Pediatrics 132:958-961.

Google Scholar

9. Lobel A, Granic I, Stone LL, Engels RC (2014) Associations between children's video game playing and psychosocial health: information from both parent and child reports. Cyber psychology, Beh Social Net 17:639-643.

Indexed at, Google Scholar, Cross Ref

10. Mathers M, Canterford L, Olds T, Hesketh K, Ridley K et al. (2009) Electronic media use and adolescent health and well-being: cross-sectional community study. Academic Pediatrics 9: 307-314.

Google Scholar, Cross Ref