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Updated: Nov 5, 2025

Medium Preparation for the Cultivation of Microorganisms under Strictly Anaerobic/Anoxic Conditions
Published on: August 15, 2019
Lower C/N ratio induces prior utilization of soluble microbial products with more dramatic variability and higher
Shuai Zhang1, Amjad Ali1, Junfeng Su1
1School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China; Shaanxi Key Laboratory of Environmental Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Abstract:
The emphasis of this study lies in how strain SYF15 regulates molecular weight (MW) fractions of soluble microbial products (SMPs) in response to low carbon to nitrogen (C/N) ratio, with high denitrification performance (over 99%). Results indicated SMPs with MW >100 and <50 kDa undoubtedly participated in denitrification before 12.0 h in C/N = 2.0, while sodium acetate was preferred in C/N = 5.0, indicating strain YSF15 was induced to degrade SMPs as a carbon source in low C/N. Additionally, lower C/N activated the extracellular metabolism, with increased fluorescence regional integration (FRI) volume amplitude by 48.08 and 53.43% (versus C/N = 5.0) in MW = 50-10 and 10-3 kDa, respectively. The FRI volume of proteins yielded greater with more degradable components than higher C/N in MW = 100-3 kDa, whereas polysaccharide and protein concentrations differed little with considerable biodegradability, implying components inside protein changed dramatically. This pioneering work contributed to the understanding of denitrification with carbon source deficiency.
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