Simplified Reactor Design for Mixed Culture-Based Electrofermentation toward Butyric Acid Production

Mixed microbial culture (MMC) electrofermentation (EF) represents a promising tool to drive metabolic pathways toward the production of a specific compound. Here, the MMC-EF process has been exploited to obtain butyric acid in simplified membrane-less reactors operated by applying a difference of potential between two low-cost graphite electrodes. Ten values of voltage difference, from −0.60 V to −1.5 V, have been tested and compared with the experiment under open circuit potential (OCP). In all the tested conditions, an enhancement in the production rate of butyric acid (from a synthetic mixture of glucose, acetate, and ethanol) was observed, ranging from 1.3- to 2.7-fold relative to the OCP. Smaller enhancements in the production rate resulted in higher values of the calculated specific energy consumption. However, at all applied voltages, a low flow of current was detected in the one-chamber reactors, accounting for an average value of approximately −100 µA. These results hold a substantial potential with respect to the scalability of the electrofermentation technology, since they pinpoint the possibility to control MMC-based bioprocesses by simply inserting polarized electrodes into traditional fermenters.

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Characterization of Nostoc muscorum NCCU-442 Derived Poly-3- hydroxybutyrate (PHB) and Polyethylene Glycol (PEG) Blends

The Natural Products Journal ◽

10.2174/2210315508666180810145127 ◽

2020 ◽

Vol 10 (3) ◽

pp. 200-207

Author(s):

Sabbir Ansari ◽

Tasneem Fatma

Keyword(s):

Thermal Properties ◽

Polyethylene Glycol ◽

Morphological Properties ◽

Morphological Alteration ◽

Nostoc Muscorum ◽

Microbial Culture ◽

Polymer Science ◽

Mixed Microbial Culture ◽

Scanning Calorimetry ◽

Casting Technique

Background: Poly-3-hydroxybutyrate (PHB) has attracted much consideration as biodegradable biocompatible polymer. This thermoplastic polymer has comparable material properties to polypropylene. Materials with more valuable properties may result from blending, a common practice in polymer science. Objective: In this paper, blends of PHB (extracted from cyanobacterium Nostoc muscorum NCCU- 442 with polyethylene glycol (PEG) were investigated for their thermal, tensile, hydrophilic and biodegradation properties. Methods: Blends were prepared in different proportions of PHB/PEG viz. 100/0, 98/2, 95/5, 90/10, 80/20, and 70/30 (wt %) using solvent casting technique. Morphological properties were investigated by using Scanning Electron Microscopy (SEM). Differential scanning calorimetry and thermogravimetric analysis were done for thermal properties determination whereas the mechanical and hydrophilic properties of the blends were studied by means of an automated material testing system and contact angle analyser respectively. Biodegradability potential of the blended films was tested as percent weight loss by mixed microbial culture within 60 days. Results: The blends showed good misciblity between PEG and PHB, however increasing concentrations of plasticizer caused morphological alteration as evidenced by SEM micrographs. PEG addition (10 % and above) showed significant alternations in the thermal properties of the blends. Increase in the PEG content increased the elongation at break ratio i.e enhanced the required plasticity of PHB. Rate of microbial facilitated degradation of the blends was greater with increasing PEG concentrations. Conclusion: Blending with PEG increased the crucial polymeric properties of cyanobacterial PHB.

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Preliminary evaluation of biopolymers production by mixed microbial culture from citrus wastewater in a MBR system using respirometric techniques

Journal of Water Process Engineering ◽

10.1016/j.jwpe.2021.102003 ◽

2021 ◽

Vol 41 ◽

pp. 102003

Author(s):

Santo Fabio Corsino ◽

Daniele Di Trapani ◽

Nicoletta Torregrossa ◽

Daniela Piazzese

Keyword(s):

Preliminary Evaluation ◽

Microbial Culture ◽

Mixed Microbial Culture

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Determination of Anaerobic and Anoxic Biodegradation Capacity of Sulfamethoxasole and the Effects on Mixed Microbial Culture

Biodegradation - Engineering and Technology ◽

10.5772/56049 ◽

2013 ◽

Cited By ~ 5

Author(s):

Zeynep Cetecioglu ◽

Bahar Ince ◽

Samet Azman ◽

Nazli Gokcek ◽

Nese Coskun ◽

...

Keyword(s):

Microbial Culture ◽

Mixed Microbial Culture

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Kinetics of growth and multi substrate degradation by an indigenous mixed microbial culture isolated from a wastewater treatment plant in Guwahati, India

Water Science & Technology ◽

10.2166/wst.2008.463 ◽

2008 ◽

Vol 58 (5) ◽

pp. 1101-1106

Author(s):

Pichiah Saravanan ◽

K. Pakshirajan ◽

P. K. Saha

Keyword(s):

Sewage Treatment ◽

Sewage Treatment Plant ◽

Treatment Plant ◽

Lag Phase ◽

Microbial Culture ◽

High Concentration ◽

Mixed Microbial Culture ◽

Phenol Biodegradation ◽

Low Concentration ◽

Culture Growth

An indigenous mixed culture of microorganisms, isolated from a sewage treatment plant, was investigated for its potential to simultaneously degrade phenol and m-cresol during its growth in batch shake flasks. 22 full factorial designs with the two substrates as the factors, at two different levels and two different initial concentration ranges, were employed to carry out the biodegradation experiments. For complete utilisation of phenol and m-cresol, the culture took a minimum duration of 21 hrs at their low concentration of 100 mg/L each, and a maximum duration of 187 hrs at high concentration of 600 mg/L each in the multisubstrate system. The biodegradation results also showed that the presence of phenol in low concentration range (100–300 mg/L did not inhibit m-cresol biodegradation; on the other hand, presence of m-cresol inhibited phenol biodegradation by the culture. Moreover, irrespective of the concentrations used, phenol was degraded preferentially and earlier than m-cresol. During the culture growth, a lag phase was observed above a combined concentration of 500 mg/L i.e., 200 mg/L m-cresol and 300 mg/L of phenol and above). Statistical analysis of the specific growth rate of the culture in the multisubstrate system was also performed in the form of ANOVA and Student ‘t’ test, which gave good interpretation in terms of main and interaction effects of the substrates.

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Response of mixed microbial culture to 2,6-dihydroxybenzoic acid and peptone mixture at low sludge age—effect of culture history

Journal of Environmental Science and Health Part A ◽

10.1080/10934521003709081 ◽

2010 ◽

Vol 45 (7) ◽

pp. 875-882 ◽

Cited By ~ 11

Author(s):

Tugce Katipoglu ◽

Emine U. Cokgor ◽

Guclu Insel ◽

Derin Orhon

Keyword(s):

Age Effect ◽

Microbial Culture ◽

Dihydroxybenzoic Acid ◽

Mixed Microbial Culture ◽

Culture History

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Effects of Aluminum Doping on The Phase Stability and Electrochemical Properties of LiCoO2 and LiMnO2

MRS Proceedings ◽

10.1557/proc-496-403 ◽

1997 ◽

Vol 496 ◽

Cited By ~ 3

Author(s):

Y.-I. Jang ◽

B. Huang ◽

H. Wang ◽

Y.-M. Chiang ◽

D. R. Sadoway

Keyword(s):

Single Phase ◽

Low Cost ◽

Reversible Capacity ◽

Open Circuit ◽

Teller Distortion ◽

Al Content ◽

Jahn Teller ◽

Li Battery ◽

Low Mass ◽

Jahn Teller Distortion

ABSTRACTAluminum is of interest as a constituent for Li battery electrodes due to its low cost and low mass, and because ab initio calculations indicate that solid solution of LiAlO2 with LiMO2 (M = transition metal) in the α-NaFeO2 structure can increase intercalation voltage [1]. In this study, we investigated the effect of Al doping on LiCoO2 and LiMnO2. Single phase LiAlyCo1-yO2 has been synthesized up to y = 0.5 by firing homogenous hydroxide precursors. A systematic increase in the open circuit voltage is observed with Al content. In LiAlyMn1-yO2, the addition of LiAlO2 stabilizes LiMnO2 in the α-NaFeO2 structure under conditions where neither endmember is stable in the structure. High reversible capacity was obtained over both a 4 V and 3 V plateau, indicating that the compound transforms to a spinel-related structure during cycling, but that the cooperative Jahn-Teller distortion is suppressed.

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Impact of Sodium Hexametaphosphate on the Flotation of Ultrafine Magnesite from Dolomite-Rich Desliming Tailings

Minerals ◽

10.3390/min11050499 ◽

2021 ◽

Vol 11 (5) ◽

pp. 499

Author(s):

Duong Huu Hoang ◽

Doreen Ebert ◽

Robert Möckel ◽

Martin Rudolph

Keyword(s):

Ultrafine Particles ◽

Raw Materials ◽

Low Cost ◽

Froth Flotation ◽

Open Circuit ◽

Ore Deposits ◽

Sodium Hexametaphosphate ◽

Low Grade ◽

Low Contrast ◽

The Impact

The depletion of ore deposits, the increasing demand for raw materials, the need to process low-grade, complex and finely disseminated ores, and the reprocessing of tailings are challenges especially for froth flotation separation technologies. Even though they are capable of handling relatively fine grain sizes, the flotation separation of very fine and ultrafine particles faces many problems still. Further, the flotation of low-contrast semi-soluble salt-type minerals with very similar surface properties, many complex interactions between minerals, reagents and dissolved species often result in poor selectivity. This study investigates the flotation beneficiation of ultrafine magnesite rich in dolomite from desliming, currently reported to the tailings. The paper especially focuses on the impact of the depressant sodium hexametaphosphate (SHMP) on the following: (i) the froth properties using dynamic froth analysis (DFA), (ii) the separation between magnesite and dolomite/calcite, and (iii) its effect on the entrainment. As a depressant/dispersant, SHMP has a beneficial impact on the flotation separation between magnesite and dolomite. However, there is a trade-off between grade and recovery, and as well as the dewatering process which needs to be considered. When the SHMP increases from 200 g/t to 700 g/t, the magnesite grade increases from 67% to 77%, while recovery decreases massively, from 80% to 40%. The open circuit with four cleaning stages obtained a concentrate assaying 77.5% magnesite at a recovery of 45.5%. The dolomite content in the concentrate is about 20%, where 80% of dolomite was removed and importantly 98% of the quartz was removed, with only 0.3% of the quartz in the final concentrate. Furthermore, the application of 1-hydroxyethylene-1,1-diphosphonic acid (HEDP) as a more environmentally friendly and low-cost alternative to SHMP is presented and discussed. Using only 350 g/t of HEDP can achieve a similar grade (76.3%), like 700 g/t of SHMP (76.9%), while obtaining a 17% higher magnesite recovery as compared to 700 g/t of SHMP. Interestingly, the proportion of hydrophilic quartz minerals ending up in the concentrate is lower for HEDP, with only 1.9% quartz at a recovery of 21.5% compared to the 2.7% of quartz at a recovery of 24.9% when using SHMP. The paper contributes in general to understanding the complexity of the depressant responses in froth flotation.

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