Unlocking the Value of Wastewater: Innovative Biotechnologies and Bioprocesses for Resource Recovery in a Circular Economy Approach

Cover image for research topic "Unlocking the Value of Wastewater: Innovative Biotechnologies and Bioprocesses for Resource Recovery in a Circular Economy Approach"
15.7K
views
55
authors
8
articles
Editors
0
Impact
Loading...
2,612 views
0 citations
Original Research
07 March 2024

A recent focus has been on the recovery of single-cell protein and other nutritionally valuable bioproducts, such as Coenzyme Q10 (CoQ10) from purple non-sulfur bacteria (PNSB) biomass following wastewater treatment. However, due to PNSB’s peculiar cell envelope (e.g., increased membrane cross-section for energy transduction) and relatively smaller cell size compared to well-studied microbial protein sources like yeast and microalgae, the effectiveness of common cell disruption methods for protein quantification from PNSB may differ. Thus, this study examines the efficiency of selected chemical (NaOH and EDTA), mechanical (homogenization and bead milling), physical (thermal and bath/probe sonication), and combined chemical–mechanical/physical treatment techniques on the PNSB cell lysis. PNSB biomass was recovered from the treatment of gas-to-liquid process water. Biomass protein and CoQ10 contents were quantified based on extraction efficiency. Considering single-treatment techniques, bead milling resulted in the best protein yields (p < 0.001), with the other techniques resulting in poor yields. However, the NaOH-assisted sonication (combined chemical/physical treatment technique) resulted in similar protein recovery (p = 1.00) with bead milling, with the former having a better amino acid profile. For example, close to 50% of the amino acids, such as sensitive ones like tryptophan, threonine, cystine, and methionine, were detected in higher concentrations in NaOH-assisted sonication (>10% relative difference) compared to bead-milling due to its less disruptive nature and improved solubility of amino acids in alkaline conditions. Overall, PNSB required more intensive protein extraction techniques than were reported to be effective on other single-cell organisms. NaOH was the preferred chemical for chemical-aided mechanical/physical extraction as EDTA was observed to interfere with the Lowry protein kit, resulting in significantly lower concentrations. However, EDTA was the preferred chemical agent for CoQ10 extraction and quantification. CoQ10 extraction efficiency was also suspected to be adversely influenced by pH and temperature.

2,853 views
4 citations
Open for submission
Frontiers Logo

Frontiers in Microbiology

Application of Extremophilic Microorganisms in Biohydrometallurgy
Edited by Srdjan Stanković, Ruiyong Zhang, Arevik Vardanyan
Deadline
06 June 2025
Submit a paper
Recommended Research Topics
Frontiers Logo

Frontiers in Environmental Science

Resource Recovery from Waste
Edited by Alfonso Jose Lag-Brotons, Kirk T Semple, Ian M Head, Anne P.M. Velenturf, Richard Crane, Phil Purnell
52K
views
51
authors
8
articles
Frontiers Logo

Frontiers in Microbiology

Microbial Biominerals: Towards New Functions and Resource Recovery
Edited by Lucian Constantin Staicu, Eric D. van Hullebusch, Christopher J Ackerson
22.3K
views
36
authors
6
articles
Frontiers Logo

Frontiers in Microbiology

Advanced Microbial Engineering and Biohybrid Technologies for Waste Biorefinery
Edited by Yong Jiang, Yan Dang, Daqian Jiang, ZHU Xiangdong, Lu Lu
28.3K
views
53
authors
7
articles
Frontiers Logo

Frontiers in Microbiology

Bioleaching and Biorecovery of Critical Raw Materials from Secondary Sources
Edited by Laura Castro, Ruiyong Zhang, JESUS ANGEL MUÑOZ, Wolfgang Sand
12.9K
views
29
authors
5
articles
16K
views
11
articles