MMR_2024v14n2

Molecular Microbiology Research 2024, Vol.14, No.2, 79-91 http://microbescipublisher.com/index.php/mmr 80 Microbial decomposition in aquatic ecosystems is also of great importance. Decomposers in freshwater and marine environments break down organic matter, support nutrient cycling in the water, and directly affect water quality. Overactive decomposition processes may lead to rapid oxygen consumption, creating "dead zones" that threaten the survival of aquatic life (Tláskal et al., 2021). Furthermore, decomposition in water bodies is closely related to the global carbon cycle, influencing the release and absorption of dissolved organic carbon and indirectly affecting atmospheric CO2 concentrations (Bani et al., 2018). Despite many research achievements, many aspects of the microbial decomposition process still require further exploration. This study reviews current research on microbial decomposition and its impact on ecosystem health, discussing the roles of different microbial communities in decomposition, analyzing the environmental factors influencing decomposition rates, and assessing the role of decomposition in nutrient cycling and ecosystem functioning. By identifying gaps in research and proposing future directions, this study aims to provide theoretical support for further understanding the mechanisms of microbial decomposition and its critical role in ecosystem health. 2 Microbial Decomposition Processes Microbial decomposition is a complex process influenced by the interplay of microbial foraging strategies, community composition, substrate quality, and environmental conditions. Understanding these factors is essential for predicting carbon and nutrient cycling in ecosystems and managing soil health effectively. 2.1 Mechanisms of Microbial Decomposition Microbial decomposition is a critical process in ecosystems, driving the transformation of organic matter into simpler compounds, which are then cycled back into the environment. The kinetics of decomposition are influenced by microbial foraging strategies, where microbes optimize their growth rates based on substrate availability. This process can be modeled as an optimal control problem, where the decomposition rate is a control variable that scales with the substrate concentration (Manzoni et al., 2023). Additionally, microbial communities adapt to environmental conditions, modulating decomposition rates through changes in their metabolic activities and enzyme production (Brabcová et al., 2016; Burešová et al., 2019). 2.2. Types of Decomposer Microbes Decomposer microbes can be broadly categorized into bacteria and fungi, each playing distinct roles in the decomposition process. Bacteria are typically associated with the rapid turnover of easily degradable substrates, while fungi are more efficient at breaking down complex organic matter such as lignin and cellulose (Baldrian, 2017; Hicks et al., 2021). Specific microbial communities, including genera like Pedobacter, Pseudomonas, and Aspergillus, are associated with different stages of decomposition, highlighting the niche differentiation among decomposer species (Brabcová et al., 2016; Bhatnagar et al., 2018). The composition of these communities can vary significantly with environmental conditions, such as soil contact and moisture levels, which influence the relative abundance of bacterial and fungal decomposers (Gora et al., 2019). 2.3. Factors Influencing Decomposition Rates Multiple factors influence the rate of microbial decomposition, including substrate quality, environmental conditions, and the composition of microbial communities. Substrate quality, which refers to the chemical composition of organic matter, plays a crucial role in determining which microbial species become active decomposers. For example, high-quality carbon substrates do not necessarily favor bacterial decomposers over fungi, as both groups of microbes can increase their growth rates with better substrate quality (Hicks et al., 2021). Environmental conditions such as soil nutrient content, moisture, and temperature also significantly affect decomposition rates. The diversity and functional capabilities of microbial communities are also critical, as different species possess unique metabolic pathways and enzyme systems that contribute to the overall decomposition process (Crowther et al., 2019; Mason et al., 2023). In different microenvironments (e.g., soil, skin, and internal organs), these microbes break down complex organic compounds, controlling the fate of carbon and

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