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Topic Review
Dynamics of Glucose Transport in Escherichia coli
Escherichia coli is the best-known model for the biotechnological production of many biotechnological products, including housekeeping and heterologous primary and secondary metabolites and recombinant proteins, and is an efficient biofactory model to produce biofuels to nanomaterials. Glucose is the primary substrate used as the carbon source for laboratory and industrial cultivation of E. coli for production purposes. Efficient growth and associated production and yield of desired products depend on the efficient sugar transport capabilities, sugar catabolism through the central carbon catabolism, and the efficient carbon flux through specific biosynthetic pathways. The genome of E. coli MG1655 is 4,641,642 bp, corresponding to 4702 genes encoding 4328 proteins. The EcoCyc database describes 532 transport reactions, 480 transporters, and 97 proteins involved in sugar transport. Nevertheless, due to the high number of sugar transporters, E. coli uses preferentially few systems to grow in glucose as the sole carbon source. E. coli nonspecifically transports glucose from the extracellular medium into the periplasmic space through the outer membrane porins. Once in periplasmic space, glucose is transported into the cytoplasm by several systems, including the phosphoenolpyruvate-dependent phosphotransferase system (PTS), the ATP-dependent cassette (ABC) transporters, and the major facilitator (MFS) superfamily proton symporters.
  • 1.8K
  • 27 Jun 2023
Topic Review
Brettanomyces bruxellensis
The Brettanomyces bruxellensis species plays various roles in both the industrial and food sectors. At the biotechnological level, B. bruxellensis is considered to be a promising species for biofuel production. Its presence in alcoholic beverages can be detrimental or beneficial to the final product; B. bruxellensis can contribute to spoilage of wine and beer, but can also produce good aromas.
  • 1.8K
  • 31 Aug 2021
Topic Review
MIRRI-IT: Italian Culture Collections
Microorganisms represent most of the biodiversity of living organisms in every ecological habitat. They have profound effects on the functioning of any ecosystem and, therefore, on the health of our planet and of human beings. Moreover, microorganisms are the main protagonists in food, medical and biotech industries, and have several environmental applications.Accordingly, the characterization and preservation of microbial biodiversity are essential not only for the maintenance of natural ecosystems but also for research purposes and biotechnological exploitation. In this context, culture collections (CCs) and microbial biological resource centres (mBRCs) are crucial for the safeguarding and circulation of biological resources, as well as for the progress of life sciences.
  • 1.8K
  • 30 Oct 2020
Topic Review
SV40
SV40 is an abbreviation for simian vacuolating virus 40 or simian virus 40, a polyomavirus that is found in both monkeys and humans. Like other polyomaviruses, SV40 is a DNA virus that has the potential to cause tumors in animals, but most often persists as a latent infection. SV40 has been widely studied as a model eukaryotic virus, leading to many early discoveries in eukaryotic DNA replication and transcription.
  • 1.8K
  • 26 Oct 2022
Topic Review
Postbiotics and Kidney Disease
Chronic kidney disease (CKD) is projected to become the fifth global cause of death by 2040 as a result of key shortcomings in the current methods available to diagnose and treat kidney diseases. In this regard, the novel holobiont concept, used to describe an individual host and its microbial community, may pave the way towards a better understanding of kidney disease pathogenesis and progression. Microbiota-modulating or -derived interventions include probiotics, prebiotics, synbiotics and postbiotics.
  • 1.8K
  • 13 Oct 2022
Topic Review
Campylobacter Jejuni
Campylobacter jejuni (/ˈkæmpɪloʊˌbæktər dʒəˈdʒuːni/) is one of the most common causes of food poisoning in Europe and in the United States. The vast majority of cases occur as isolated events, not as part of recognized outbreaks. Active surveillance through the Foodborne Diseases Active Surveillance Network (FoodNet) indicates that about 20 cases are diagnosed each year for each 100,000 people in the US, while many more cases are undiagnosed or unreported; the CDC estimates a total of 1.5 million infections every year. The European Food Safety Authority reported 246,571 cases in 2018, and estimated approximately nine million cases of human campylobacteriosis per year in the European Union. Campylobacter jejuni is in a genus of bacteria that is among the most common causes of bacterial infections in humans worldwide. Campylobacter means "curved rod", deriving from the Greek kampylos (curved) and baktron (rod). Of its many species, C. jejuni is considered one of the most important from both a microbiological and public health perspective. C. jejuni is commonly associated with poultry, and is also commonly found in animal feces. Campylobacter is a helical-shaped, non-spore-forming, Gram-negative, microaerophilic, nonfermenting motile bacterium with a single flagellum at one or both poles, which are also oxidase-positive and grow optimally at 37 to 42 °C. When exposed to atmospheric oxygen, C. jejuni is able to change into a coccal form. This species of pathogenic bacteria is one of the most common causes of human gastroenteritis in the world. Food poisoning caused by Campylobacter species can be severely debilitating, but is rarely life-threatening. It has been linked with subsequent development of Guillain–Barré syndrome, which usually develops two to three weeks after the initial illness. Individuals with recent C. jejuni infections develop Guillain-Barré syndrome at a rate of 0.3 per 1000 infections, about 100 times more often than the general population. Another chronic condition that may be associated with Campylobacter infection is reactive arthritis. Reactive arthritis is a complication strongly associated with a particular genetic make-up. That is, persons who have the human leukocyte antigen B27 (HLA-B27) are most susceptible. Most often, the symptoms of reactive arthritis will occur up to several weeks after infection.
  • 1.8K
  • 10 Nov 2022
Topic Review
Quorum Sensing Regulation
Quorum sensing is a type of chemical communication by which bacterial populations control expression of their genes in a coordinated manner. This regulatory mechanism is commonly used by pathogens to control the expression of genes encoding virulence factors and that of genes involved in the bacterial adaptation to variations in environmental conditions. In phytopathogenic bacteria, several mechanisms of quorum sensing have been characterized. In this review, we describe the different quorum sensing systems present in phytopathogenic bacteria, such as those using the signal molecules named N-acyl-homoserine lactone (AHL), diffusible signal factor (DSF), and the unknown signal molecule of the virulence factor modulating (VFM) system. We focus on studies performed on phytopathogenic bacteria of major importance, including Pseudomonas, Ralstonia, Agrobacterium, Xanthomonas, Erwinia, Xylella,Dickeya, and Pectobacterium spp. For each system, we present the mechanism of regulation, the functions targeted by the quorum sensing system, and the mechanisms by which quorum sensing is regulated.
  • 1.8K
  • 05 Mar 2021
Topic Review
Genetic Engineering of Actinomycetes
The first antibiotic-producing actinomycete (Streptomyces antibioticus) was described by Waksman and Woodruff in 1940. This discovery initiated the “actinomycetes era”, in which several species were identified and demonstrated to be a great source of bioactive compounds. However, the remarkable group of microorganisms and their potential for the production of bioactive agents were only partially exploited. This is caused by the fact that the growth of many actinomycetes cannot be reproduced on artificial media at laboratory conditions. In addition, sequencing, genome mining and bioactivity screening disclosed that numerous biosynthetic gene clusters (BGCs), encoded in actinomycetes genomes are not expressed and thus, the respective potential products remain uncharacterized. Therefore, a lot of effort was put into the development of technologies that facilitate the access to actinomycetes genomes and activation of their biosynthetic pathways. In this review  (Antibiotics 2020, 9(8), 494; https://doi.org/10.3390/antibiotics9080494), we mainly focus on molecular tools and methods for genetic engineering of actinomycetes that have emerged in the field in the past five years (2015–2020). In addition, we highlight examples of successful application of the recently developed technologies in genetic engineering of actinomycetes for activation and/or improvement of the biosynthesis of secondary metabolites.
  • 1.8K
  • 28 Dec 2020
Topic Review
Bacillus licheniformis
Bacillus licheniformis produces several classes of antimicrobial substances, including bacteriocins, which are peptides or proteins with different structural composition and molecular mass: ribosomally synthesized by bacteria (1.4–20 kDa), non-ribosomally synthesized peptides and cyclic lipopeptides (0.8–42 kDa) and exopolysaccharides (>1000 kDa). Different bacteriocins act against Gram-positive or Gram-negative bacteria, fungal pathogens and amoeba cells.
  • 1.8K
  • 14 Jul 2023
Topic Review
The Biological Activities of Marine Exopolysaccharides
The unique living environment of marine microorganisms endows them with the potential to produce novel compounds with diverse biological activities. Exopolysaccharide (EPS) is a high molecular weight carbohydrate polymer secreted by microorganisms during growth and metabolism. The complex and diverse structures of EPS endow them with unique biological activities and functions. 
  • 1.8K
  • 23 Aug 2022
Topic Review
Coccidioides Species
Coccidioidomycosis is an important pathogenic fungal infection in much of the desert and semi-arid regions of the Western hemisphere. The incidence of the disease is increasing in both California and Arizona. Although not all infections result in clinical illness, the infection frequently causes serious disease in immunocompetent people and even self-limited coccidioidomycosis can be a prolonged illness requiring anti-fungal therapy. Coccidioidomycosis is a common cause of community-acquired pneumonia in the endemic area that is frequently misdiagnosed, and the cost of the disease is substantial. In patients where the infection is not self-limited, the disease can spread to skin, bone, and the central nervous system among many other organs. Although disseminated disease is unusual, it occurs in both immunocompetent and immunocompromised people, is frequently difficult to treat, and can be fatal. Prolonged treatment is usually required, and meningitis requires life-long therapy.
  • 1.8K
  • 08 Oct 2022
Topic Review
Salmonella enterica Outbreaks from Tahini and Tahini-Based Products
Salmonella is a leading cause of bacterial foodborne illness in the world. Although typically associated with foods of animal origin, low-moisture foods, such as tahini, are quickly gaining recognition as an important vehicle of Salmonella exposure.
  • 1.8K
  • 05 Dec 2022
Topic Review
Probiotics in cosmetics
Probiotics, defined as “live microorganisms that, when administered in adequate amounts, confer a health benefit on the host,” are becoming increasingly popular and marketable. The cosmetic industry has harnessed this potential by producing products claiming to contain probiotics. However, not all products marketed as such comply with the requirements for this claim.  
  • 1.8K
  • 10 Mar 2021
Topic Review
Probiotics in Obesity and IBD
The Firmicutes/Bacteroidetes (F/B) ratio is widely accepted to have an important influence in maintaining normal intestinal homeostasis. Increased or decreased F/B ratio is regarded as dysbiosis, whereby the former is usually observed with obesity, and the latter with inflammatory bowel disease (IBD). Probiotics as live microorganisms can confer health benefits to the host when administered in adequate amounts. There is considerable evidence of their nutritional and immunosuppressive properties including reports that elucidate the association of probiotics with the F/B ratio, obesity, and IBD. Orally administered probiotics can contribute to the restoration of dysbiotic microbiota and to the prevention of obesity or IBD. However, as the effects of different probiotics on the F/B ratio differ, selecting the appropriate species or mixture is crucial.
  • 1.7K
  • 19 Nov 2020
Topic Review
New Carbapenemase Inhibitors
Carbapenem resistance is a major global health problem that seriously compromises the treatment of infections caused by nosocomial pathogens. Production of carbapenemases (carbapenem-hydrolyzing enzymes) is the most important mechanism of carbapenem resistance. A new generation of promising carbapenemase inhibitors, together with the recently approved avibactam, relebactam and vaborbactam are being tested in clinical and pre-clinical trials.This review summarizes the main, most promising carbapenemase inhibitors synthesized to date. 
  • 1.7K
  • 30 Dec 2020
Topic Review
Plant Host Defense Peptides: Snakins
Plant host defense peptides (HDPs), also known as antimicrobial peptides (AMPs), are regarded as one of the most prevalent barriers elaborated by plants to combat various infective agents. HDPs are arbitrarily referred to as small, thermal stable, and positively charged peptides, generally comprising peptides of less than 100 amino acid residues with an overall net charge of +2 to +9, and molecular weight of 4 to 9 kDa. Plant HDPs can be classified into at least eight major families, including defensins, thionins, non-specific lipid-transfer proteins (LTPs), hevein-like peptides, Snakins, knottins, α-hairpinins, and cyclotides, among which the Snakin family peptide has been reported to be the most abundant potential AMP that is active against fungal and bacterial pathogens. The Snakin/GASA family peptides consist of 12 cysteine residues, being the foremost cysteine-rich peptides among different classes of plant HDPs.
  • 1.7K
  • 01 Apr 2021
Topic Review
Urbanization alters soil microbial communities
Urban development is one of the leading causes of biodiversity change. Understanding how soil microorganisms respond to urbanization is particularly important because they are crucial for the provisioning of ecosystem functions and services. Our results showed that microbial richness and community composition exhibited nonsignificant changes over time regardless of the location. Soil fungal richness was lower in moderately and highly urbanized locations, but soil bacterial/archaeal richness was not significantly different among locations. Both bacteria/archaea and fungi exhibited significant differences in community composition across locations. After inferring potential functional groups, soils in the highly urbanized location had lower proportions of arbuscular mycorrhizal fungi and soil saprotrophic fungi but had higher proportions of bacterial taxa involved in aromatic compound degradation, human pathogens, and intracellular parasites. Furthermore, ammonia-oxidizing bacteria were more abundant in the highly urbanized location, but ammonia-oxidizing archaea were more abundant in lowly and moderately urbanized locations. Together, these results highlight the significant changes in belowground microbial communities across an urbanization gradient, and these changes might have important implications for aboveground–belowground interactions, nutrient cycling, and human health.
  • 1.7K
  • 21 Jul 2021
Topic Review
COVID-19-Associated Candidiasis
The recent global pandemic of COVID-19 has predisposed a relatively high number of patients to acute respiratory distress syndrome (ARDS), which carries a risk to develop secondary infections. Candida species are major constituents of the human mycobiome and the main cause of invasive fungal infections with a high mortality rate, and are also increasingly reported as complication of severe COVID-19. Despite the marked immune dysregulation in COVID-19, no prominent defects have been reported in immune cells that are critically required for immunity to Candida. This suggests that relevant clinical factors, including prolonged ICU stays, use of central venous catheters and often broad-spectrum antibiotics may dominate over immune-mediated mechanisms to drive susceptibility to candidemia in the setting of COVID-19. Although diagnostic performance evaluations are often lacking in COVID-19 patients, a combination of serological and molecular techniques may present promising diagnostic options for identification of COVID-19-associated candidiasis. Clinical awareness and screening of invasive candidiasis is needed, as those are difficult to diagnose, particular in the setting of severe COVID-19. Echinocandins and azoles are the primary antifungal used to treat invasive candidiasis, yet therapeutic failures exerted by prominent nosocomial pathogens such as C. auris and C. glabrata calls for the development of new antifungal drugs with novel mechanisms of action.
  • 1.7K
  • 26 Oct 2020
Topic Review
Microbial Cell-Cell Chemical Communication Systems
The microbial cell–cell chemical communication systems include QS and host–pathogen communication systems. In 1994, Fuqua et al., coined the term of “quorum sensing” to describe an environmental sensing system that monitors the population density to coordinate the social behaviors of microorganisms. QS regulatory systems are characterized by the fact that microorganisms produce and release to the surrounding environment a diffffusible autoinducer or QS signal, which accumulates along with bacterial growth and induces target gene transcriptional expression when reaching a threshold concentration. Typically, a QS system contains a signal synthase, which produces QS signals, and a signal receptor that detect and response to QS signal in a population-dependent manner. In addition, microbial pathogens can also exploit the chemical molecules produced by host organisms as cross-kingdom signals to regulate virulence gene expression.
  • 1.7K
  • 18 Dec 2020
Topic Review
Microbial Pyrrolnitrin
Pyrrolnitrin (PRN) is a microbial pyrrole halometabolite of immense antimicrobial significance for agricultural, pharmaceutical and industrial implications. The compound and its derivatives have been isolated from rhizospheric fluorescent or non-fluorescent pseudomonads, Serratia and Burkholderia. They are known to confer biological control against a wide range of phytopathogenic fungi, and thus offer strong plant protection prospects against soil and seed-borne phytopathogenic diseases. Although chemical synthesis of PRN has been obtained using different steps, microbial production is still the most useful option for producing this metabolite. In many of the plant-associated isolates of Serratia and Burkholderia, production of PRN is dependent on the quorum-sensing regulation that usually involves N-acylhomoserine lactone (AHL) autoinducer signals. When applied on the organisms as antimicrobial agent, the molecule impedes synthesis of key biomolecules (DNA, RNA and protein), uncouples with oxidative phosphorylation, inhibits mitotic division and hampers several biological mechanisms. 
  • 1.7K
  • 01 Sep 2021
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