Related Experiment Video
Updated: Sep 26, 2025
08:17
Coupling Carbon Capture from a Power Plant with Semi-automated Open Raceway Ponds for Microalgae Cultivation
Published on: August 14, 2020
5.3K
Sulfite-based pretreatment promotes volatile fatty acids production from microalgae: Performance, mechanism, and
Qi Lu1, Mingting Du1, Qing Xu1
1College of Environmental Science and Engineering, Hunan University, Changsha 410082, PR China; Key Laboratory of Environmental Biology and Pollution Control (Hunan University), Ministry of Education, Changsha 410082, PR China.
Bioresource Technology
|April 18, 2022
Summary
Sulfite pretreatment enhances volatile fatty acids (VFAs) production from microalgae by improving organic solubilization and substrate availability. This method significantly boosts VFA yield and acetate proportion through cell wall disruption and microbial activity.
Area of Science:
- Biotechnology
- Environmental Science
- Biochemistry
Background:
- Anaerobic fermentation of microalgae for volatile fatty acids (VFAs) production is limited by low organic solubilization and substrate availability.
- Microalgal cell walls present a barrier to efficient hydrolysis and acidification processes.
Purpose of the Study:
- To develop and evaluate a sulfite-based pretreatment method to enhance VFA production from microalgae.
- To investigate the mechanisms by which sulfite pretreatment improves microalgal biomass conversion.
Main Methods:
- Microalgae were subjected to sulfite-based pretreatment at varying concentrations (200 mg sulfite-S/L).
- Anaerobic fermentation was conducted, and VFA concentrations and acetate proportions were measured.
- Microalgal cell wall integrity was assessed via particle size and surface area analysis.
- Enzyme activities (β-glucanase, β-glucosidase, acetate kinase) and microbial populations (sulfate-reducing bacteria) were monitored.
Main Results:
- The optimal sulfite pretreatment (200 mg sulfite-S/L) yielded a maximum VFA concentration of 467.5 mg COD/g VSS and an acetate proportion of 54.5% after 8 days.
- Pretreatment resulted in a 2.1-fold increase in VFA concentration and a 1.9-fold increase in acetate proportion compared to the control.
- Sulfite pretreatment released more biodegradable organics and disrupted the microalgal cell wall, increasing accessibility for hydrolysis.
- Sulfite-induced sulfate-reducing bacteria and enhanced enzyme activities (β-glucanase, β-glucosidase, acetate kinase) were observed, facilitating acetate generation.
Conclusions:
- Sulfite-based pretreatment is an effective strategy to overcome the limitations of microalgal biomass conversion for VFA production.
- The enhanced VFA yield is attributed to improved organic solubilization, increased substrate accessibility, and facilitated microbial metabolic pathways.
Related Concept Videos
01:20Sulfur Assimilation
96
Sulfur is an essential element in biological systems, contributing to synthesizing key biomolecules, including amino acids such as cysteine and methionine, and cofactors such as coenzyme A and biotin. Microorganisms primarily assimilate sulfur as sulfate (SO₄²⁻) from the environment, which must undergo a series of biochemical transformations before it can be incorporated into cellular components. As sulfate is highly oxidized, it must undergo assimilatory sulfate reduction to...
96
01:25Lipid Catabolism
200
Triglycerides serve as crucial long-term energy storage molecules in microorganisms, providing a dense source of metabolic energy. Their breakdown is mediated by lipases, which hydrolyze triglycerides into glycerol and free fatty acids. Each of these components follows distinct metabolic pathways, ultimately contributing to ATP synthesis and cellular energy homeostasis.Glycerol MetabolismGlycerol, released from triglyceride hydrolysis, is phosphorylated by glycerol kinase to form...
200
01:23Microbial Fermentation
443
Fermentation is a crucial anaerobic metabolic process that enables microbes to derive energy from sugar without relying on oxygen or an electron transport chain. This process is fundamental to various biological and industrial applications and is classified based on the metabolic products generated.Role of Pyruvate in FermentationPyruvate and its derivatives serve as key electron acceptors in fermentative pathways. The oxidation of NADH to regenerate NAD+ is essential for the continuation of...
443
01:20Fates of Pyruvate
9.2K
Pyruvate is the end product of glycolysis, where glucose is oxidized to pyruvate, simultaneously reducing NAD+ to NADH. Two molecules of ATP are also produced by substrate-level phosphorylation.
In aerobic organisms, pyruvate is metabolized via the citric acid cycle to produce reduced coenzymes NADH and FADH2. These coenzymes are then oxidized in the electron transport chain to produce ATP and, in the process, regenerate the NAD+ and FAD. As seen in some cell types and organisms, fermentation...
In aerobic organisms, pyruvate is metabolized via the citric acid cycle to produce reduced coenzymes NADH and FADH2. These coenzymes are then oxidized in the electron transport chain to produce ATP and, in the process, regenerate the NAD+ and FAD. As seen in some cell types and organisms, fermentation...
9.2K
01:21Green Algae
239
Green algae, also referred to as chlorophytes, are different from red algae in having the chloroplasts containing chlorophylls a and b, which give them their distinct green hue. However, they lack phycobiliproteins, preventing them from developing the red or blue-green pigmentation seen in red algae. In terms of photosynthetic pigment composition, green algae closely resemble plants and share a close evolutionary relationship with them. Taxonomically Green algae belong to Phylum Chlorophyta in...
239