scholarly journals Improvement of 1,3-Propanediol Production From Crude Glycerol by Co-cultivation of Anaerobic and Facultative Microbes Under Non-strictly Anaerobic Conditions

2021 ◽  
Author(s):  
Yaqin Sun ◽  
Lingyun Liang ◽  
Yafeng Zheng ◽  
Jindong Han ◽  
Zhilong Xiu
Keyword(s):  
Batch Fermentation ◽  
Crude Glycerol ◽  
Abundance Ratio ◽  
Microbial Consortia ◽  
Strictly Anaerobic ◽  
Anaerobic Conditions ◽  
Diverse Range ◽  
Aerobic Conditions ◽  
Fed Batch Fermentation ◽  
Synthetic Microbial Consortia

Abstract Background: Natural microbial consortia could efficiently produce 1,3-propanediol, the most promising bulk biochemical derived from glycerol that can be used as a monomer in the synthesis of polytrimethylene terephthalate (PTT). While natural microbial communities are made up of a diverse range of microbes with frequently unknown functions, the construction of synthetic microbial consortia allows for creating more defined systems with lower complexity.Results: In this study, the synthetic microbial consortia were constructed by combing facultative microbes of Klebsiella pneumoniae DUT2 (KP) and/or Escherichia coli DUT3 (EC) cultures with the strict anaerobic microbe of Clostridium butyricum DUT1 (CB) cultures under micro-aerobic conditions. The function of EC and KP during the fermentation process was to deplete oxygen and provide an anaerobic environment for CB. Furthermore, KP competes with CB to consume crude glycerol and produce 1,3-PDO. The interaction of commensalism and competition resulted in synthetic microbial consortia that could efficiently convert crude glycerol to 1,3-PDO even under micro-aerobic conditions. In a batch fermentation, the synthetic CB:KP co-culture at an initial abundance ratio of 92.5:7.5 yielded a maximum 1,3-PDO concentration of 52.08 g/L, with a yield of 0.49 g/g and a productivity of 1.80 g/(L.h), which increased by 10%, 9%, and 12%, respectively, when compared to the CB mono-culture under strictly anaerobic conditions. Compared to the KP mono-culture, the final 1,3-PDO concentration, yield, and productivity by the synthetic CB:KP consortia increased by 16%, 19%, and 84%, respectively. The synthetic CB:KP:EC co-culture achieved the highest 1,3-PDO flux of 49.17% at an initial abundance ratio of 85:7.5:7.5, while 7.43%, 5.77%, 3.15% 4.24%, and 2.13% of flux was distributed to butyric acid, acetic acid, lactic acid, ethanol, and succinic acid pathways. In a fed-batch fermentation, synthetic CB:KP:EC co-culture demonstrated a maximum 1,3-PDO concentration of 77.68 g/L with a yield of 0.51 g/g which is 30% and 13% higher than the production by the CB mono-culture at 0.02 vvm N2 supply. The initial abundance of CB guaranteed to be at least 85% facilitates 1,3-PDO production from crude glycerol efficiently by the development of synthetic microbial consortia. Conclusion: Under micro-aerobic conditions, the synthetic microbial consortia demonstrated excellent performance on 1,3-propanediol production via the interaction of commensalism and competition. The experimental results demonstrated the potential benefit of using the synthetic microbial consortia to produce 1,3-propanediol from crude glycerol.

Production and Degradation of Formate by Veillonella dispar ATCC 17745

1986 ◽  
Vol 65 (6) ◽  
pp. 903-905 ◽  
Author(s):  
E. Hoshino ◽  
M. Sato
Keyword(s):  
Strictly Anaerobic ◽  
Resting Cells ◽  
Cell Free Extract ◽  
Anaerobic Conditions ◽  
Pyruvate Formate Lyase ◽  
Aerobic Conditions ◽  
Lyase Activity

Under strictly anaerobic conditions, the resting cells of V. dispar ATCC 17745 produced formate as well as acetate and propionate from pyruvate or from lactate. Pyruvate formate-lyase activity was found when the activity was assayed under strictly anaerobic conditions. Under aerobic conditions, however, the resting cells did not produce formate from pyruvate or from lactate, though the cells actively metabolized pyruvate or lactate (mainly to acetate). This was ascribed to pyruvate formate-lyase activity being easily lost when the cell-free extract was exposed to the air. A part of the produced formate was further degraded to CO2 by the resting cells.

scholarly journals Nitric oxide induces Zn2+ release from metallothionein by destroying zinc–sulphur clusters without concomitant formation of S-nitrosothiol

1999 ◽  
Vol 344 (1) ◽  
pp. 253-258 ◽  
Author(s):  
Charuvila T. ARAVINDAKUMAR ◽  
Jan CEULEMANS ◽  
Marc DE LEY
Keyword(s):  
Nitric Oxide ◽  
Reaction Mechanism ◽  
Strictly Anaerobic ◽  
Common Belief ◽  
Anaerobic Conditions ◽  
Electrophilic Attack ◽  
Subsequent Formation ◽  
Aerobic Conditions ◽  
Percentage Loss ◽  
Zinc Release

The reaction of nitric oxide (NO) with metallothionein (MT) has been investigated at neutral pH under strictly anaerobic conditions. It is observed that NO mediates zinc release from MT by destroying zinc-sulphur clusters, but that it does not by itself S-nitrosylate MT in contrast to common belief. Zinc release and loss of thiolate groups under anaerobic conditions is found to be much slower than under aerobic conditions. The observed percentage loss of Zn2+ and thiolate groups after 3 h of NO treatment are 62 and 39%, respectively. The reaction of NO with cysteine is reinvestigated and it is found that cysteine is quantitatively converted to cystine after 5 min of NO treatment at pH 7.3. At lower pH, a much lower rate of conversion is observed confirming the base-catalysed nature of the reaction of NO with thiols. On the basis of these results, a reaction mechanism involving electrophilic attack of NO on thiolate groups and subsequent formation of a nitrogen-centred radical, MTSN•OH, as intermediate is proposed for the reaction of NO with MT that leads to zinc release.

Improved production of 1,3-propanediol from biodiesel-derived crude glycerol by Klebsiella pneumoniae in fed-batch fermentation

2018 ◽  
Vol 349 ◽  
pp. 25-36 ◽  
Author(s):  
Xiaoguang Yang ◽  
Han Suk Choi ◽  
Ju Hun Lee ◽  
Soo Kwon Lee ◽  
Sung Ok Han ◽  
...  
Keyword(s):  
Klebsiella Pneumoniae ◽  
Batch Fermentation ◽  
Crude Glycerol ◽  
Fed Batch ◽  
Fed Batch Fermentation

Biodegradation of household chemicals in river water under untreated discharge conditions

2000 ◽  
Vol 42 (7-8) ◽  
pp. 377-382 ◽  
Author(s):  
C.-G. Peng ◽  
T. Arakaki ◽  
K. Jung ◽  
E. Namkung
Keyword(s):  
River Water ◽  
Decay Rates ◽  
Strictly Anaerobic ◽  
Anaerobic Conditions ◽  
Aerobic Conditions ◽  
Untreated Sewage ◽  
Additional Testing ◽  
Lag Period ◽  
Low Levels ◽  
Household Chemicals

A series of batch die-away tests was conducted to evaluate the decay rates of MBAS and COD under conditions simulating untreated discharge. Under aerobic conditions, decay of MBAS was consistently faster than that of COD, and dilution into river water had no effect on either rate. Under strictly anaerobic conditions, neither MBAS nor COD decreased in concentration. Additional testing examined the fate of 14C-LAS and the results showed that LAS disappeared and was mineralized after a lag period. Half-lives were 8–10 hours for loss of parent and 11–12 hours for mineralization. Addition of 14C-LAS in sewage to systems previously exposed to raw sewage resulted in no lag and shorter half-lives. This work indicates that MBAS and LAS degrade more rapidly than COD, suggesting these materials would be at low levels once a stream had recovered from the addition of untreated sewage.

Lipid production from fed-batch fermentation of crude glycerol directed by the kinetic study of batch fermentations

Fuel ◽  
2017 ◽  
Vol 209 ◽  
pp. 1-9 ◽  
Author(s):  
Jiaxin Chen ◽  
Xiaolei Zhang ◽  
Song Yan ◽  
Rajeshwar Dayal Tyagi ◽  
Patrick Drogui
Keyword(s):  
Kinetic Study ◽  
Batch Fermentation ◽  
Crude Glycerol ◽  
Lipid Production ◽  
Fed Batch ◽  
Fed Batch Fermentation

1,3-Propanediol Fermentation with the by-Product Glycerol from Biodiesel Production by a Genetic Modified Klebsiella pneumoniae

2012 ◽  
Vol 512-515 ◽  
pp. 323-329 ◽  
Author(s):  
Hong Juan Liu ◽  
Yu Jie Zhou ◽  
Zhong Zhen Cai ◽  
Yan Sun ◽  
Jian An Zhang ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Acid Concentration ◽  
Batch Fermentation ◽  
Crude Glycerol ◽  
Acid Synthesis ◽  
Biodiesel Production ◽  
Klebsiella Pneumonia ◽  
Lactic Acid Concentration ◽  
Fed Batch ◽  
Fed Batch Fermentation

Nowadays, the utilization of the by-product glycerol has become a common problem with the large amount of biodiesel production. This paper studied the conversion of the by-product glycerol of biodiesel production by Klebsiella pneumonia to 1,3-propanediol. The crude glycerol could be used directly without refining by a lactate dehydrogenase deficient K. pneumoniae and the lactic acid concentration was very low. In the fed-batch fermentation of 7L fermenter, 93.3g/l 1,3-propanediol was obtained and lactic acid concentration was just 2g/l. Analysis showed that D-type lactic acid synthesis was reduced obviously. The fermentation also was scaled up on the 42L fermenter. 1,3-propanediol and 2,3-Butanediol concentration reached 81.5g/l and 33.8g/l, respectively. No lactic acid was detected. The demonstration fermentation in 5000L fermenter was also successfully performed. The final 1,3-propanediol concentration and productivity was 87g/l and 1.2g/(lh). This work was considered useful to the integrated production of biodiesel and 1,3-propanediol.

scholarly journals A simple strategy to effectively produce d-lactate in crude glycerol-utilizing Escherichia coli

2019 ◽  
Vol 12 (1) ◽  
Author(s):  
Yao-De Wang ◽  
Jin-Yi Liao ◽  
Chung-Jen Chiang ◽  
Yun-Peng Chao
Keyword(s):  
Escherichia Coli ◽  
Batch Fermentation ◽  
Crude Glycerol ◽  
High Titer ◽  
Fed Batch ◽  
High Productivity ◽  
Simple Strategy ◽  
Production Scheme ◽  
Fed Batch Fermentation ◽  
Fermentation Strategy

Abstract Background Fed-batch fermentation has been conventionally implemented for the production of lactic acid with a high titer and high productivity. However, its operation needs a complicated control which increases the production cost. Results This issue was addressed by simplifying the production scheme. Escherichia coli was manipulated for its glycerol dissimilation and d-lactate synthesis pathways and then subjected to adaptive evolution under high crude glycerol. Batch fermentation in the two-stage mode was performed by controlling the dissolved oxygen (DO), and the evolved strain deprived of poxB enabled production of 100 g/L d-lactate with productivity of 1.85 g/L/h. To increase productivity, the producer strain was further evolved to improve its growth rate on crude glycerol. The fermentation was performed to undergo the aerobic growth with low substrate, followed by the anaerobic production with high substrate. Moreover, the intracellular redox of the strain was balanced by fulfillment of the anaerobic respiratory chain with nitrate reduction. Without controlling the DO, the microbial fermentation resulted in the homofermentative production of d-lactate (ca. 0.97 g/g) with a titer of 115 g/L and productivity of 3.29 g/L/h. Conclusions The proposed fermentation strategy achieves the highest yield based on crude glycerol and a comparable titer and productivity as compared to the approach by fed-batch fermentation. It holds a promise to sustain the continued development of the crude glycerol-based biorefinery.

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