scholarly journals Sporulation in solventogenic and acetogenic clostridia

2021 ◽  
Author(s):  
Mamou Diallo ◽  
Servé W. M. Kengen ◽  
Ana M. López-Contreras
Keyword(s):  
Current Knowledge ◽  
Carbon Sources ◽  
Cost Effective ◽  
Biotechnological Production ◽  
Key Points ◽  
Wide Range ◽  
Potential Applications ◽  
A Cell ◽  
Sporulation Initiation ◽  
Solventogenic Clostridia

AbstractThe Clostridium genus harbors compelling organisms for biotechnological production processes; while acetogenic clostridia can fix C1-compounds to produce acetate and ethanol, solventogenic clostridia can utilize a wide range of carbon sources to produce commercially valuable carboxylic acids, alcohols, and ketones by fermentation. Despite their potential, the conversion by these bacteria of carbohydrates or C1 compounds to alcohols is not cost-effective enough to result in economically viable processes. Engineering solventogenic clostridia by impairing sporulation is one of the investigated approaches to improve solvent productivity. Sporulation is a cell differentiation process triggered in bacteria in response to exposure to environmental stressors. The generated spores are metabolically inactive but resistant to harsh conditions (UV, chemicals, heat, oxygen). In Firmicutes, sporulation has been mainly studied in bacilli and pathogenic clostridia, and our knowledge of sporulation in solvent-producing or acetogenic clostridia is limited. Still, sporulation is an integral part of the cellular physiology of clostridia; thus, understanding the regulation of sporulation and its connection to solvent production may give clues to improve the performance of solventogenic clostridia. This review aims to provide an overview of the triggers, characteristics, and regulatory mechanism of sporulation in solventogenic clostridia. Those are further compared to the current knowledge on sporulation in the industrially relevant acetogenic clostridia. Finally, the potential applications of spores for process improvement are discussed.Key Points• The regulatory network governing sporulation initiation varies in solventogenic clostridia.• Media composition and cell density are the main triggers of sporulation.• Spores can be used to improve the fermentation process.

scholarly journals Burkholderia thailandensis E264 as a promising safe rhamnolipids’ producer towards a sustainable valorization of grape marcs and olive mill pomace

2021 ◽  
Author(s):  
Alif Chebbi ◽  
Massimiliano Tazzari ◽  
Cristiana Rizzi ◽  
Franco Hernan Gomez Tovar ◽  
Sara Villa ◽  
...  
Keyword(s):  
Energy Source ◽  
Olive Oil ◽  
Low Cost ◽  
Carbon Sources ◽  
Burkholderia Thailandensis ◽  
Rhamnolipid Production ◽  
Key Points ◽  
Wide Range ◽  
Long Chain ◽  
Olive Mill

Abstract Within the circular economy framework, our study aims to assess the rhamnolipid production from winery and olive oil residues as low-cost carbon sources by nonpathogenic strains. After evaluating various agricultural residues from those two sectors, Burkholderia thailandensis E264 was found to use the raw soluble fraction of nonfermented (white) grape marcs (NF), as the sole carbon and energy source, and simultaneously, reducing the surface tension to around 35 mN/m. Interestingly, this strain showed a rhamnolipid production up to 1070 mg/L (13.37 mg/g of NF), with a higher purity, on those grape marcs, predominately Rha-Rha C14-C14, in MSM medium. On olive oil residues, the rhamnolipid yield of using olive mill pomace (OMP) at 2% (w/v) was around 300 mg/L (15 mg/g of OMP) with a similar CMC of 500 mg/L. To the best of our knowledge, our study indicated for the first time that a nonpathogenic bacterium is able to produce long-chain rhamnolipids in MSM medium supplemented with winery residues, as sole carbon and energy source. Key points • Winery and olive oil residues are used for producing long-chain rhamnolipids (RLs). • Both higher RL yields and purity were obtained on nonfermented grape marcs as substrates. • Long-chain RLs revealed stabilities over a wide range of pH, temperatures, and salinities

scholarly journals Bioprocesses with Reduced Ecological Footprint by Marine Debaryomyces hansenii Strain for Potential Applications in Circular Economy

2021 ◽  
Vol 7 (12) ◽  
pp. 1028
Author(s):  
Silvia Donzella ◽  
Claudia Capusoni ◽  
Luisa Pellegrino ◽  
Concetta Compagno
Keyword(s):  
Ecological Footprint ◽  
Debaryomyces Hansenii ◽  
High Growth ◽  
High Growth Rate ◽  
Food Industries ◽  
Starting Point ◽  
Wide Range ◽  
Potential Applications ◽  
A Cell ◽  
Marine Strain

The possibility to perform bioprocesses with reduced ecological footprint to produce natural compounds and catalyzers of industrial interest is pushing the research for salt tolerant microorganisms able to grow on seawater-based media and able to use a wide range of nutrients coming from waste. In this study we focused our attention on a Debaryomyces hansenii marine strain (Mo40). We optimized cultivation in a bioreactor at low pH on seawater-based media containing a mixture of sugars (glucose and xylose) and urea. Under these conditions the strain exhibited high growth rate and biomass yield. In addition, we characterized potential applications of this yeast biomass in food/feed industry. We show that Mo40 can produce a biomass containing 45% proteins and 20% lipids. This strain is also able to degrade phytic acid by a cell-bound phytase activity. These features represent an appealing starting point for obtaining D. hansenii biomass in a cheap and environmentally friendly way, and for potential use as an additive or to replace unsustainable ingredients in the feed or food industries, as this species is included in the QPS EFSA list (Quality Presumption as Safe—European Food Safety Authority).

scholarly journals Genomic Islands in Mycoplasmas

Genes ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 836 ◽  
Author(s):  
Christine Citti ◽  
Eric Baranowski ◽  
Emilie Dordet-Frisoni ◽  
Marion Faucher ◽  
Laurent-Xavier Nouvel
Keyword(s):  
Current Knowledge ◽  
Close Contact ◽  
Genomic Islands ◽  
Host Cells ◽  
Integrative And Conjugative Elements ◽  
Wide Range ◽  
Full Capacity ◽  
A Cell ◽  
Multiple Species ◽  
Genome Analyses

Bacteria of the Mycoplasma genus are characterized by the lack of a cell-wall, the use of UGA as tryptophan codon instead of a universal stop, and their simplified metabolic pathways. Most of these features are due to the small-size and limited-content of their genomes (580–1840 Kbp; 482–2050 CDS). Yet, the Mycoplasma genus encompasses over 200 species living in close contact with a wide range of animal hosts and man. These include pathogens, pathobionts, or commensals that have retained the full capacity to synthesize DNA, RNA, and all proteins required to sustain a parasitic life-style, with most being able to grow under laboratory conditions without host cells. Over the last 10 years, comparative genome analyses of multiple species and strains unveiled some of the dynamics of mycoplasma genomes. This review summarizes our current knowledge of genomic islands (GIs) found in mycoplasmas, with a focus on pathogenicity islands, integrative and conjugative elements (ICEs), and prophages. Here, we discuss how GIs contribute to the dynamics of mycoplasma genomes and how they participate in the evolution of these minimal organisms.

scholarly journals RNA Virus-Encoded miRNAs: Current Insights and Future Challenges

2021 ◽  
Vol 12 ◽  
Author(s):  
Asuka Nanbo ◽  
Wakako Furuyama ◽  
Zhen Lin
Keyword(s):  
Viral Replication ◽  
Rna Viruses ◽  
Current Knowledge ◽  
Rna Virus ◽  
Transcriptional Level ◽  
Emerging Viruses ◽  
Wide Range ◽  
Future Challenges ◽  
Eukaryotic Gene ◽  
Potential Applications

MicroRNAs are small non-coding RNAs that regulate eukaryotic gene expression at the post-transcriptional level and affect a wide range of biological processes. Over the past two decades, numerous virus-encoded miRNAs have been identified. Some of them are crucial for viral replication, whereas others can help immune evasion. Recent sequencing-based bioinformatics methods have helped identify many novel miRNAs, which are encoded by RNA viruses. Unlike the well-characterized DNA virus-encoded miRNAs, the role of RNA virus-encoded miRNAs remains controversial. In this review, we first describe the current knowledge of miRNAs encoded by various RNA viruses, including newly emerging viruses. Next, we discuss how RNA virus-encoded miRNAs might facilitate viral replication, immunoevasion, and persistence in their hosts. Last, we briefly discuss the challenges in the experimental methodologies and potential applications of miRNAs for diagnosis and therapeutics.

scholarly journals Development of a tunable 3D wrinkled platfom for designing cellular three-dimensional communication networks

2021 ◽  
Author(s):  
Bethany R. Hughes
Keyword(s):  
Communication Networks ◽  
Three Dimensional ◽  
Cell Communication ◽  
Cellular Growth ◽  
Clinical Aspects ◽  
Wide Range ◽  
Cellular Communication Network ◽  
Potential Applications ◽  
A Cell ◽  
Washing Method

The study of cell-cell communication is hindered by the absence of a platform which is capable of specifically directing cellular growth while allowing examination of the communication between cells. In this thesis, a tuneable micro-to-nano scale wrinkled nonplanar platform was developed and optimized through the use of photolithography and a microfluidic washing method. The platform demonstrated the ability to create micro and nanowrinkled structures in a wide range of flow conditions. The developed platform was then used as a cell culture platform to investigate the spacing dependence of bovine fibroblasts. The identification of a critical bridging distance for bovine fibroblasts provided a means to optimized the platform for culturing a cellular communication network between bovine fibroblasts. The cellular network which resulted demonstrated, via FRAP (Fluorescence-recovery-after-photobleaching), the capacity for communication between cells. Creating multilevel length scaled structures on a tunable platform which directed cellular growth while maintaining communication presents potential applications in research, industry and clinical aspects.

scholarly journals Marine Bacteria versus Microalgae: Who Is the Best for Biotechnological Production of Bioactive Compounds with Antioxidant Properties and Other Biological Applications?

Marine Drugs ◽  
2019 ◽  
Vol 18 (1) ◽  
pp. 28 ◽  
Author(s):  
Masoud Hamidi ◽  
Pouya Safarzadeh Kozani ◽  
Pooria Safarzadeh Kozani ◽  
Guillaume Pierre ◽  
Philippe Michaud ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Marine Environment ◽  
Biological Diversity ◽  
Current Knowledge ◽  
Antioxidant Properties ◽  
Biological Properties ◽  
Marine Microorganisms ◽  
Biotechnological Production ◽  
Potential Applications ◽  
Chemical Conditions

Natural bioactive compounds with antioxidant activity play remarkable roles in the prevention of reactive oxygen species (ROS) formation. ROS, which are formed by different pathways, have various pathological influences such as DNA damage, carcinogenesis, and cellular degeneration. Incremental demands have prompted the search for newer and alternative resources of natural bioactive compounds with antioxidant properties. The marine environment encompasses almost three-quarters of our planet and is home to many eukaryotic and prokaryotic microorganisms. Because of extreme physical and chemical conditions, the marine environment is a rich source of chemical and biological diversity, and marine microorganisms have high potential as a source of commercially interesting compounds with various pharmaceutical, nutraceutical, and cosmeceutical applications. Bacteria and microalgae are the most important producers of valuable molecules including antioxidant enzymes (such as superoxide dismutase and catalase) and antioxidant substances (such as carotenoids, exopolysaccharides, and bioactive peptides) with various valuable biological properties and applications. Here, we review the current knowledge of these bioactive compounds while highlighting their antioxidant properties, production yield, health-related benefits, and potential applications in various biological and industrial fields.

3D printing in tissue engineering: a state of the art review of technologies and biomaterials

2020 ◽  
Vol 26 (7) ◽  
pp. 1313-1334 ◽  
Author(s):  
Nataraj Poomathi ◽  
Sunpreet Singh ◽  
Chander Prakash ◽  
Arjun Subramanian ◽  
Rahul Sahay ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
3D Printing ◽  
Regenerative Medicine ◽  
State Of The Art ◽  
Three Dimensional ◽  
Cost Effective ◽  
Cochrane Library ◽  
Content Type ◽  
Wide Range ◽  
Potential Applications

Purpose In the past decade, three-dimensional (3D) printing has gained attention in areas such as medicine, engineering, manufacturing art and most recently in education. In biomedical, the development of a wide range of biomaterials has catalysed the considerable role of 3D printing (3DP), where it functions as synthetic frameworks in the form of scaffolds, constructs or matrices. The purpose of this paper is to present the state-of-the-art literature coverage of 3DP applications in tissue engineering (such as customized scaffoldings and organs, and regenerative medicine). Design/methodology/approach This review focusses on various 3DP techniques and biomaterials for tissue engineering (TE) applications. The literature reviewed in the manuscript has been collected from various journal search engines including Google Scholar, Research Gate, Academia, PubMed, Scopus, EMBASE, Cochrane Library and Web of Science. The keywords that have been selected for the searches were 3 D printing, tissue engineering, scaffoldings, organs, regenerative medicine, biomaterials, standards, applications and future directions. Further, the sub-classifications of the keyword, wherever possible, have been used as sectioned/sub-sectioned in the manuscript. Findings 3DP techniques have many applications in biomedical and TE (B-TE), as covered in the literature. Customized structures for B-TE applications are easy and cost-effective to manufacture through 3DP, whereas on many occasions, conventional technologies generally become incompatible. For this, this new class of manufacturing must be explored to further capabilities for many potential applications. Originality/value This review paper presents a comprehensive study of the various types of 3DP technologies in the light of their possible B-TE application as well as provides a future roadmap.

scholarly journals Recent Developments in Carbon Quantum Dots: Properties, Fabrication Techniques, and Bio-Applications

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 388
Author(s):  
Rehan M. El-Shabasy ◽  
Mohamed Farouk Elsadek ◽  
Badreldin Mohamed Ahmed ◽  
Mohamed Fawzy Farahat ◽  
Khaled N. Mosleh ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Green Synthesis ◽  
Graphene Quantum Dots ◽  
Carbon Sources ◽  
Carbon Quantum Dots ◽  
Synthesis Methods ◽  
Wide Range ◽  
Recent Developments ◽  
Potential Applications ◽  
Harsh Conditions

Carbon dots have gained tremendous interest attributable to their unique features. Two approaches are involved in the fabrication of quantum dots (Top-down and Bottom-up). Most of the synthesis methods are usually multistep, required harsh conditions, and costly carbon sources that may have a toxic effect, therefore green synthesis is more preferable. Herein, the current review presents the green synthesis of carbon quantum dots (CQDs) and graphene quantum dots (GQDs) that having a wide range of potential applications in bio-sensing, cellular imaging, and drug delivery. However, some drawbacks and limitations are still unclear. Other biomedical and biotechnological applications are also highlighted.

scholarly journals High-cell-density fed-batch cultivations of Vibrio natriegens

2021 ◽  
Author(s):  
Isabel Thiele ◽  
Björn Gutschmann ◽  
Linus Aulich ◽  
Marcel Girard ◽  
Peter Neubauer ◽  
...  
Keyword(s):  
Cell Density ◽  
High Cell Density ◽  
Carbon Sources ◽  
Industrial Biotechnology ◽  
High Cell ◽  
Fed Batch ◽  
Biotechnological Production ◽  
Deep Well ◽  
Wide Range ◽  
Different Temperatures

Abstract Objectives With generation times of less than 10 min under optimal conditions, the halophilic Vibrio natriegens is the fastest growing non-pathogenic bacterium isolated so far. The availability of the full genome and genetic engineering tools and its ability to utilize a wide range of carbon sources make V. natriegens an attractive host for biotechnological production processes. However, high-cell-density cultivations, which are desired at industrial-scale have not been described so far. Results In this study we report fed-batch cultivations of V. natriegens in deep-well plates and lab-scale bioreactor cultivations at different temperatures in mineral salt medium (MSM). Upon switching from exponential glucose to constant glucose-feeding cell death was induced. Initial NaCl concentrations of 15–18 g L−1 and a temperature reduction from 37 to 30 °C had a positive effect on cell growth. The maximal growth rate in MSM with glucose was 1.36 h−1 with a specific oxygen uptake rate of 22 mmol gCDW−1 h−1. High biomass yields of up to 55 g L−1 after only 12 h were reached. Conclusions The shown fed-batch strategies demonstrate the potential of V. natriegens as a strong producer in industrial biotechnology.

scholarly journals Development of a tunable 3D wrinkled platfom for designing cellular three-dimensional communication networks

2021 ◽  
Author(s):  
Bethany R. Hughes
Keyword(s):  
Communication Networks ◽  
Three Dimensional ◽  
Cell Communication ◽  
Cellular Growth ◽  
Clinical Aspects ◽  
Wide Range ◽  
Cellular Communication Network ◽  
Potential Applications ◽  
A Cell ◽  
Washing Method

The study of cell-cell communication is hindered by the absence of a platform which is capable of specifically directing cellular growth while allowing examination of the communication between cells. In this thesis, a tuneable micro-to-nano scale wrinkled nonplanar platform was developed and optimized through the use of photolithography and a microfluidic washing method. The platform demonstrated the ability to create micro and nanowrinkled structures in a wide range of flow conditions. The developed platform was then used as a cell culture platform to investigate the spacing dependence of bovine fibroblasts. The identification of a critical bridging distance for bovine fibroblasts provided a means to optimized the platform for culturing a cellular communication network between bovine fibroblasts. The cellular network which resulted demonstrated, via FRAP (Fluorescence-recovery-after-photobleaching), the capacity for communication between cells. Creating multilevel length scaled structures on a tunable platform which directed cellular growth while maintaining communication presents potential applications in research, industry and clinical aspects.

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