Thauera aminoaromatica MZ1T Identified as a Polyhydroxyalkanoate-Producing Bacterium within a Mixed Microbial Consortium

Polyhydroxyalkanoates (PHAs) form a highly promising class of bioplastics for the transition from fossil fuel-based plastics to bio-renewable and biodegradable plastics. Mixed microbial consortia (MMC) are known to be able to produce PHAs from organic waste streams. Knowledge of key-microbes and their characteristics in PHA-producing consortia is necessary for further process optimization and direction towards synthesis of specific types of PHAs. In this study, a PHA-producing mixed microbial consortium (MMC) from an industrial pilot plant was characterized and further enriched on acetate in a laboratory-scale selector with a working volume of 5 L. 16S-rDNA microbiological population analysis of both the industrial pilot plant and the 5 L selector revealed that the most dominant species within the population is Thauera aminoaromatica MZ1T, a Gram-negative beta-proteobacterium belonging to the order of the Rhodocyclales. The relative abundance of this Thauera species increased from 24 to 40% after two months of enrichment in the selector-system, indicating a competitive advantage, possibly due to the storage of a reserve material such as PHA. First experiments with T. aminoaromatica MZ1T showed multiple intracellular granules when grown in pure culture on a growth medium with a C:N ratio of 10:1 and acetate as a carbon source. Nuclear magnetic resonance (NMR) analyses upon extraction of PHA from the pure culture confirmed polyhydroxybutyrate production by T. aminoaromatica MZ1T.

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Integration of Fossil Fuel-based with Bio-based Industries: The Use of Waste Streams and Biomass to Produce Syngas and Added Value Products

IFAC-PapersOnLine ◽

10.1016/j.ifacol.2019.06.131 ◽

2019 ◽

Vol 52 (1) ◽

pp. 616-621 ◽

Cited By ~ 3

Author(s):

Elham Ketabchi ◽

Laura Pastor-Perez ◽

Tomas Ramirez Reina ◽

Harvey Arellano-Garcia

Keyword(s):

Fossil Fuel ◽

Added Value ◽

Waste Streams

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Metagenomics Study To Compare The Taxonomy And Metabolism of a Lignocellulolytic Microbial Consortium Cultured in Different Carbon Conditions

10.21203/rs.3.rs-1076547/v1 ◽

2021 ◽

Author(s):

Qinggeer BORJIGIN ◽

Bizhou ZHANG ◽

Xiaofang Yu ◽

Julin Gao ◽

Xin ZHANG ◽

...

Keyword(s):

Microbial Consortium ◽

Agricultural Waste ◽

Taxonomic Diversity ◽

Taxonomic Composition ◽

Microbial Consortia ◽

Rich Diversity ◽

Cazy Database ◽

Taxonomic Affiliation ◽

In Situ Biodegradation

Abstract A lignocellulolytic microbial consortium holds promise for the in situ biodegradation of crop straw and the comprehensive and effective utilization of agricultural waste. In this study, we applied metagenomics technology to comprehensively explore the metabolic functional potential and taxonomic diversity of the microbial consortia CS (cultured on corn stover) and FP (cultured on filter paper).Analyses of the metagenomics taxonomic affiliation data showed considerable differences in the taxonomic composition and functional profile of the microbial consortia CS and FP. The microbial consortia CS primarily contained members from the genera Pseudomonas, Stenotrophomonas, Achromobacter, Dysgonomonas, Flavobacterium and Sphingobacterium, as well as Cellvibrio, Azospirillum, Pseudomonas, Dysgonomonas and Cellulomonas in FP. The COG and KEGG annotation analyses revealed considerable levels of diversity. Further analysis determined that the CS consortium had an increase in the acid and ester metabolism pathways, while carbohydrate metabolism was enriched in the FP consortium. Furthermore, a comparison against the CAZy database showed that the microbial consortia CS and FP contain a rich diversity of lignocellulose degrading families, in which GH5, GH6, GH9, GH10, GH11, GH26, GH42, and GH43 were enriched in the FP consortium, and GH44, GH28, GH2, and GH29 increased in the CS consortium. The degradative mechanism of lignocellulose metabolism by the two microbial consortia is similar, but the annotation of quantity of genes indicated that they are diverse and vary greatly. The lignocellulolytic microbial consortia cultured under different carbon conditions (CS and FP) differed substantially in their composition of the microbial community at the genus level. The changes in functional diversity were accompanied with variation in the composition of microorganisms, many of which are related to the degradation of lignocellulolytic materials. The genera Pseudomonas, Dysgonomonas and Sphingobacterium in CS and the genera Cellvibrio and Pseudomonas in FP exhibited a much wider distribution of lignocellulose degradative ability.

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Current Advances in the Biodegradation and Bioconversion of Polyethylene Terephthalate

Microorganisms ◽

10.3390/microorganisms10010039 ◽

2021 ◽

Vol 10 (1) ◽

pp. 39

Author(s):

Xinhua Qi ◽

Wenlong Yan ◽

Zhibei Cao ◽

Mingzhu Ding ◽

Yingjin Yuan

Keyword(s):

Polyethylene Terephthalate ◽

Microbial Consortium ◽

Tricarboxylic Acid Cycle ◽

Tca Cycle ◽

Tricarboxylic Acid ◽

Microbial Consortia ◽

Plastic Pollution ◽

One Step ◽

Complex Polymers ◽

The One

Polyethylene terephthalate (PET) is a widely used plastic that is polymerized by terephthalic acid (TPA) and ethylene glycol (EG). In recent years, PET biodegradation and bioconversion have become important in solving environmental plastic pollution. More and more PET hydrolases have been discovered and modified, which mainly act on and degrade the ester bond of PET. The monomers, TPA and EG, can be further utilized by microorganisms, entering the tricarboxylic acid cycle (TCA cycle) or being converted into high value chemicals, and finally realizing the biodegradation and bioconversion of PET. Based on synthetic biology and metabolic engineering strategies, this review summarizes the current advances in the modified PET hydrolases, engineered microbial chassis in degrading PET, bioconversion pathways of PET monomers, and artificial microbial consortia in PET biodegradation and bioconversion. Artificial microbial consortium provides novel ideas for the biodegradation and bioconversion of PET or other complex polymers. It is helpful to realize the one-step bioconversion of PET into high value chemicals.

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Genetic transformation of Coniochaeta sp. 2T2.1, key fungal member of a lignocellulose-degrading microbial consortium

Biology Methods and Protocols ◽

10.1093/biomethods/bpz001 ◽

2019 ◽

Vol 4 (1) ◽

Cited By ~ 1

Author(s):

Nancy N Nichols ◽

Ronald E Hector ◽

Sarah E Frazer

Keyword(s):

Green Fluorescent Protein ◽

Genetic Transformation ◽

Pure Culture ◽

Ecological Niche ◽

Fluorescent Protein ◽

Microbial Consortium ◽

Transformed Cells ◽

Antibiotic Selection ◽

Green Fluorescent ◽

Selection Of

Abstract Coniochaeta sp. strain 2T2.1 is a key member of a microbial consortium that degrades lignocellulosic biomass. Due to its ecological niche and ability to also grow in pure culture on wheat straw, protocols for transformation and antibiotic selection of the strain were established. Hygromycin was found to be a reliable selectable transformation marker, and the mammalian codon-optimized green fluorescent protein was expressed and used to visualize fluorescence in transformed cells of strain 2T2.1.

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Analysis to Develop Hydrogen Production From Bio-Oils

Volume 15: Sustainable Products and Processes ◽

10.1115/imece2007-43225 ◽

2007 ◽

Author(s):

R. C. Ciocci ◽

I. Abu-Mahfouz ◽

S. S. E. H. Elnashaie

Keyword(s):

Air Pollution ◽

Fuel Cells ◽

Hydrogen Production ◽

Pilot Plant ◽

Fossil Fuel ◽

The United States ◽

Pure Hydrogen ◽

Clean Fuel ◽

Efficient Process ◽

Wide Range

The United States economy’s dependence on fossil fuels has historical significance but lacks vision for a long-lasting fuel consumption policy. Political complications, economic instabilities, supply shortages, and continued pollution contributions pose significant obstacles to continued reliance on oil. Alternative technologies based on renewable resources offer much more promise for a sustainable approach to meeting global energy needs. Recent research and applications have established hydrogen as a viable clean fuel source. Those applications, including fuel cells, have shown promise for the eventual migration from a fossil-fuel economy to one based on renewable energy sources. Air pollution, specifically contributions to greenhouse gases, is a major environmental hazard due to the use of fossil fuel-related hydrocarbons for fuel and industrial applications. An alternative, hydrogen, offers significant advantages as an ultra-clean fuel of the future when it is burned directly or processed through fuel cells. Currently, the main process for hydrogen production is catalytic steam reforming of natural gas. This process is relatively inefficient and does not allow the use of a wide range of feedstock materials including renewable sources. The objective of impending research is to develop this new, ultra-clean and efficient process, which converts a wide range of hydrocarbons, including renewable bio-oils, into pure hydrogen suitable for fuel cells and which also converts CO2 emission into syngas. The main impact is clearly on air pollution and global warming through the minimization of greenhouse gas emission and the economical production of pure hydrogen to foster the hydrogen economy. This new process will achieve considerable increase in hydrogen productivity and considerable decrease in the energy consumed to produce it. The technology will center on a circulating fluidized bed (CFB) that will separate hydrogen from bio-oils in an efficient process that greatly reduces polluting hydrocarbons compared to traditional fossil fuel processing. Early studies will include the mathematical modeling of computational fluid dynamics to identify process parameters. Eventually, a pilot plant will be used to verify/modify the mathematical model, for a wide range of conditions and renewable feedstocks. Testing the pilot plant will lead to the development of reliable design equations suitable for replication, build, and tight control of this novel process.

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Contributions of Microbial “Contact Leaching” to Pyrite Oxidation under Different Controlled Redox Potentials

Minerals ◽

10.3390/min10100856 ◽

2020 ◽

Vol 10 (10) ◽

pp. 856

Author(s):

Bingxu Dong ◽

Yan Jia ◽

Qiaoyi Tan ◽

Heyun Sun ◽

Renman Ruan

Keyword(s):

Redox Potential ◽

Dissolution Rate ◽

Elemental Sulfur ◽

Microbial Consortium ◽

Pyrite Oxidation ◽

Microbial Consortia ◽

Redox Potentials ◽

Sulfur Passivation ◽

Sulfur Oxidizing ◽

Contact Oxidation

The function of microbial contact leaching to pyrite oxidation was investigated by analyzing the differences of residue morphologies, leaching rates, surface products, and microbial consortia under different conditions in this study. This was achieved by novel equipment that can control the redox potential of the solution and isolate pyrite from microbial contact oxidation. The morphology of residues showed that the corrosions were a little bit severer in the presence of attached microbes under 750 mV and 850 mV (vs. SHE). At 650 mV, the oxidation of pyrite was undetectable even in the presence of attached microbes. The pyrite dissolution rate was higher with attached microbes than that without attached microbes at 750 mV and 850 mV. The elemental sulfur on the surface of pyrite residues with sessile microorganisms was much less than that without attached microbes at 750 mV and 850 mV, showing that sessile acidophiles may accelerate pyrite leaching by reducing the elemental sulfur inhibition. Many more sulfur-oxidizers were found in the sessile microbial consortium which also supported the idea. The results suggest that the microbial “contact leaching” to pyrite oxidation is limited and relies on the elimination of elemental sulfur passivation by attached sulfur-oxidizing microbes rather than the contact oxidation by EPS-Fe.

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Seed Pretreatment for Increased Hydrogen Production Using Mixed-Culture Systems with Advantages over Pure-Culture Systems

Energies ◽

10.3390/en12030530 ◽

2019 ◽

Vol 12 (3) ◽

pp. 530 ◽

Cited By ~ 15

Author(s):

Vinayak Laxman Pachapur ◽

Prianka Kutty ◽

Preetika Pachapur ◽

Satinder Kaur Brar ◽

Yann Le Bihan ◽

...

Keyword(s):

Hydrogen Production ◽

Mixed Culture ◽

Pure Culture ◽

Wide Spectrum ◽

Low Cost ◽

Production Costs ◽

Microbial Consortia ◽

Culture Systems ◽

Seed Pretreatment ◽

Media Supplements

Hydrogen is an important source of energy and is considered as the future energy carrier post-petroleum era. Nowadays hydrogen production through various methods is being explored and developed to minimize the production costs. Biological hydrogen production has remained an attractive option, highly economical despite low yields. The mixed-culture systems use undefined microbial consortia unlike pure-cultures that use defined microbial species for hydrogen production. This review summarizes mixed-culture system pretreatments such as heat, chemical (acid, alkali), microwave, ultrasound, aeration, and electric current, amongst others, and their combinations to improve the hydrogen yields. The literature representation of pretreatments in mixed-culture systems is as follows: 45–50% heat-treatment, 15–20% chemical, 5–10% microwave, 10–15% combined and 10–15% other treatment. In comparison to pure-culture mixed-culture offers several advantages, such as technical feasibility, minimum inoculum steps, minimum media supplements, ease of operation, and the fact it works on a wide spectrum of low-cost easily available organic wastes for valorization in hydrogen production. In comparison to pure-culture, mixed-culture can eliminate media sterilization (4 h), incubation step (18–36 h), media supplements cost ($4–6 for bioconversion of 1 kg crude glycerol (CG)) and around 10–15 Millijoule (MJ) of energy can be decreased for the single run.

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The effect of heavy metals on thiocyanate biodegradation by an autotrophic microbial consortium enriched from mine tailings

10.1101/2020.06.13.149401 ◽

2020 ◽

Author(s):

Farhad Shafiei ◽

Mathew P. Watts ◽

Lukas Pajank ◽

John W. Moreau

Keyword(s):

Heavy Metals ◽

Mine Tailings ◽

Energy Demand ◽

High Efficiency ◽

Microbial Consortium ◽

Bacterial Consortium ◽

Process Efficiency ◽

Microbial Consortia ◽

List Type ◽

Gold Mine Tailings

AbstractBioremediation systems represent an environmentally sustainable approach to degrading industrially-generated thiocyanate (SCN-), with low energy demand and operational costs, and high efficiency and substrate specificity. However, heavy metals present in mine tailings effluent may hamper process efficiency by poisoning thiocyanate-degrading microbial consortia. Here we experimentally tested the tolerance of an autotrophic SCN--degrading bacterial consortium enriched from gold mine tailings for Zn, Cu, Ni, Cr, and As. All of the selected metals inhibited SCN- biodegradation to different extents, depending on concentration. At pH of 7.8 and 30°C, complete inhibition of SCN- biodegradation by Zn, Cu, Ni, and Cr occurred at 20, 5, 10, and 6 mg L-1, respectively. Lower concentrations of these metals decreased the rate of SCN- biodegradation, with relatively long lag times. Interestingly, the microbial consortium tolerated As even at 500 mg L-1, although both the rate and extent of SCN- biodegradation were affected. This study highlights the importance of considering metal co-contamination in bioreactor design and operation for SCN- bioremediation at mine sites.Key pointsBoth the efficiency and rate of SCN- biodegradation were inhibited by heavy metals, to different degrees depending on type and concentration of metalThe autotrophic microbial consortium was capable of tolerating high levels of As

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Evaluation of PET Degradation Using Artificial Microbial Consortia

Frontiers in Microbiology ◽

10.3389/fmicb.2021.778828 ◽

2021 ◽

Vol 12 ◽

Author(s):

Xinhua Qi ◽

Yuan Ma ◽

Hanchen Chang ◽

Bingzhi Li ◽

Mingzhu Ding ◽

...

Keyword(s):

Weight Loss ◽

Bacillus Subtilis ◽

Terephthalic Acid ◽

Microbial Consortium ◽

Microbial Consortia ◽

Breakdown Product ◽

Complex Polymers ◽

Pet Film ◽

Pet Hydrolase ◽

Rhodococcus Jostii

Polyethylene terephthalate (PET) biodegradation is regarded as an environmentally friendly degradation method. In this study, an artificial microbial consortium composed of Rhodococcus jostii, Pseudomonas putida and two metabolically engineered Bacillus subtilis was constructed to degrade PET. First, a two-species microbial consortium was constructed with two engineered B. subtilis that could secrete PET hydrolase (PETase) and monohydroxyethyl terephthalate hydrolase (MHETase), respectively; it could degrade 13.6% (weight loss) of the PET film within 7 days. A three-species microbial consortium was further obtained by adding R. jostii to reduce the inhibition caused by terephthalic acid (TPA), a breakdown product of PET. The weight of PET film was reduced by 31.2% within 3 days, achieving about 17.6% improvement compared with the two-species microbial consortium. Finally, P. putida was introduced to reduce the inhibition caused by ethylene glycol (EG), another breakdown product of PET, obtaining a four-species microbial consortium. With the four-species consortium, the weight loss of PET film reached 23.2% under ambient temperature. This study constructed and evaluated the artificial microbial consortia in PET degradation, which demonstrated the great potential of artificial microbial consortia in the utilization of complex substrates, providing new insights for biodegradation of complex polymers.

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A Unique Sulfotransferase-Involving Strigolactone Biosynthetic Route in Sorghum

Frontiers in Plant Science ◽

10.3389/fpls.2021.793459 ◽

2021 ◽

Vol 12 ◽

Author(s):

Sheng Wu ◽

Yanran Li

Keyword(s):

Cytochrome P450 ◽

Biochemical Characterization ◽

Microbial Consortium ◽

Microbial Consortia ◽

Synthetic Route ◽

Germination Stimulant ◽

Catalytic Function

LOW GERMINATION STIMULANT 1 (LGS1) plays an important role in strigolactones (SLs) biosynthesis and Striga resistance in sorghum, but the catalytic function remains unclear. Using the recently developed SL-producing microbial consortia, we examined the activities of sorghum MORE AXILLARY GROWTH1 (MAX1) analogs and LGS1. Surprisingly, SbMAX1a (cytochrome P450 711A enzyme in sorghum) synthesized 18-hydroxy-carlactonoic acid (18-hydroxy-CLA) directly from carlactone (CL) through four-step oxidations. The further oxidated product orobanchol (OB) was also detected in the microbial consortium. Further addition of LGS1 led to the synthesis of both 5-deoxystrigol (5DS) and 4-deoxyorobanchol (4DO). Further biochemical characterization found that LGS1 functions after SbMAX1a by converting 18-hydroxy-CLA to 5DS and 4DO possibly through a sulfonation-mediated pathway. The unique functions of SbMAX1 and LGS1 imply a previously unknown synthetic route toward SLs.

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