scholarly journals Transformation of sugarcane molasses into fructooligosaccharides with enhanced prebiotic activity using whole-cell biocatalysts from Aureobasidium pullulans FRR 5284 and an invertase-deficient Saccharomyces cerevisiae 1403-7A

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Most Sheauly Khatun ◽  
Morteza Hassanpour ◽  
Solange I. Mussatto ◽  
Mark D. Harrison ◽  
Robert E. Speight ◽  
...  

AbstractFructooligosaccharides (FOS) can be used as feed prebiotics, but are limited by high production costs. In this study, low-cost sugarcane molasses was used to produce whole-cell biocatalysts containing transfructosylating enzymes by Aureobasidium pullulans FRR 5284, followed by FOS production from molasses using the whole-cells of A. pullulans. A. pullulans in molasses-based medium produced cells and broth with a total transfructosylating activity of 123.6 U/mL compared to 61.0 and 85.8 U/mL in synthetic molasses-based and sucrose-based media, respectively. It was found that inclusion of glucose in sucrose medium reduced both transfructosylating and hydrolytic activities of the produced cells and broth. With the use of pure glucose medium, cells and broth had very low levels of transfructosylating activities and hydrolytic activities were not detected. These results indicated that A. pullulans FRR 5284 produced both constitutive and inducible enzymes in sucrose-rich media, such as molasses while it only produced constitutive enzymes in the glucose media. Furthermore, treatment of FOS solutions generated from sucrose-rich solutions using an invertase-deficient Saccharomyces yeast converted glucose to ethanol and acetic acid and improved FOS content in total sugars by 20–30%. Treated FOS derived from molasses improved the in vitro growth of nine probiotic strains by 9–63% compared to a commercial FOS in 12 h incubation. This study demonstrated the potential of using molasses to produce FOS for feed application.

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 594
Author(s):  
Jesús Arenas ◽  
Elder Pupo ◽  
Coen Phielix ◽  
Dionne David ◽  
Afshin Zariri ◽  
...  

Whooping cough, or pertussis, is an acute respiratory infectious disease caused by the Gram-negative bacterium Bordetella pertussis. Whole-cell vaccines, which were introduced in the fifties of the previous century and proved to be effective, showed considerable reactogenicity and were replaced by subunit vaccines around the turn of the century. However, there is a considerable increase in the number of cases in industrialized countries. A possible strategy to improve vaccine-induced protection is the development of new, non-toxic, whole-cell pertussis vaccines. The reactogenicity of whole-cell pertussis vaccines is, to a large extent, derived from the lipid A moiety of the lipopolysaccharides (LPS) of the bacteria. Here, we engineered B. pertussis strains with altered lipid A structures by expressing genes for the acyltransferases LpxA, LpxD, and LpxL from other bacteria resulting in altered acyl-chain length at various positions. Whole cells and extracted LPS from the strains with shorter acyl chains showed reduced or no activation of the human Toll-like receptor 4 in HEK-Blue reporter cells, whilst a longer acyl chain increased activation. Pyrogenicity studies in rabbits confirmed the in vitro assays. These findings pave the way for the development of a new generation of whole-cell pertussis vaccines with acceptable side effects.


1998 ◽  
Vol 64 (11) ◽  
pp. 4269-4275 ◽  
Author(s):  
M. Carmen Balebona ◽  
Manuel J. Andreu ◽  
M. Angeles Bordas ◽  
Irene Zorrilla ◽  
Miguel A. Moriñigo ◽  
...  

ABSTRACT The in vivo and in vitro pathogenic activities of whole cells and extracellular products of Vibrio alginolyticus for cultured gilt-head sea bream were evaluated. The 50% lethal doses ranged from 5.4 × 104 to 1.0 × 106 CFU/g of body weight. The strains examined had the ability to adhere to skin, gill, and intestinal mucus of sea bream and to cultured cells of a chinook salmon embryo cell line. In addition, the in vitro ability ofV. alginolyticus to adhere to mucus and skin cells of sea bream was demonstrated by scanning electron microscopy. The biological activities of extracellular products of V. alginolyticus were hydrolytic activities; the products were able to degrade sea bream mucus. V. alginolyticus was cytotoxic for fish cell lines and lethal for sea bream. Moreover, the extracellular products could degrade sea bream tissues. However, experiments performed with the bath immersion inoculation technique demonstrated that V. alginolyticus should be considered a pathogen for sea bream only when the mucus layer is removed and the skin is damaged.


2020 ◽  
Vol 8 (1) ◽  
pp. 65-78
Author(s):  
Aditya Chaudhary ◽  
Khushbu Verma ◽  
Baljeet Singh Saharan

The present study assesses the feasibility of blueberry as a raw substrate for the production of the probiotic blueberry jam by lactic acid bacteria (L. plantarum DB-2, L. fermentum J-1, P. acidilactici M-3, L. plantarum SK-3, and P. pentosaceus SM-2). Changes in pH, titratable acidity (lactic acid), cell survival, antioxidant properties, and in vitro cholesterol reduction properties of lacto- fermented as well as non-fermented blueberry jam were examined during fermentation and up to 28 days of storage. All the strains grew well in a lacto-fermented blueberry jam after 48 h fermentation. Set A (5.88 g/100 ml) and Set B (5.96 g/100 ml) produced less lactic acid than Set C (6.67 g/100 ml) which has the consortia of probiotic strains. After 28 days of cold storage, all the tested strains survived the low-pH conditions in lacto-fermented blueberry jam. The blueberry jam fermented with the consortia of probiotic strains (Set C) had a high antioxidant capacity (71.47 ± 3.57) in comparison with Set A, Set B, and control which showed anti-oxidant capacity viz. 70.52 ± 3.52, 70.25 ± 3.18, and 64.12 ± 2.47, respectively after 28 days of refrigerated storage. The lacto- fermented blueberry jam in Set C (58.48%) had shown the in vitro cholesterol-lowering ability better than Set B (18.87%) whereas Set A and control did not show any in vitro reduction in cholesterol level after 28 days of storage. Sensory quality studies were carried out after 28 days of storage. Sensory evaluation data showed the considerable acceptability of the lacto-fermented blueberry jam. Finally, we found that L. plantarum DB-2, L. fermentum J-1, P. acidilactici M-3, L. plantarum SK-3, and P. pentosaceus SM-2 are optimal probiotics for fermentation with blueberry jam. In this investigation, the results could be an indicator of the development of health-promoting fruit jam. This lacto-fermented blueberry jam is a low-cost healthy food product, provide better nutrition and good health to the population.


2020 ◽  
Author(s):  
◽  
Kwaku Dwumah Tawiah

Aptamers are single chained, nucleic acid-based affinity probes that bind to their targets with strong affinity and specificity. They are made through an in vitro combinatorial selection method, wherein large libraries of nucleic acids with randomized sequences are subjected to an iterative process of affinity enrichment, partitioning, and amplification. Evolved libraries are sequenced, and the individual sequences are screened and characterized for their structure and function. Aptamers have been developed to target many molecules, including small molecules, purified proteins, whole cells, bacteria, and viruses. They have been developed for therapeutics and as research and diagnostic probes. Aptamers that have an affinity for virus surfaces are excellent probes for developing low-cost biosensors and potentially antiviral therapeutics. In this work, I present the development of aptamers that have an affinity for filovirus surfaces. I first describe the development of an improved method for purifying highly lytic vesicular stomatitis virus-based filovirus GP displayed surrogate viruses. Filoviruses are highly pathogenic and thus require highly secured containment facilities for their studies. The use of attenuated surrogates facilitates filovirus research at biosafety level 2 facilities. This work outlines the steps required to propagate and generate pure virus particles to be used as selection targets. I then describe the development of aptamer probes that differentially recognize GPs from MARV and EBOV. This work represents the first step in the development of aptamer based-low-cost point of care devices for filovirus disease diagnostics. Finally, this work describes the use of a hybrid selection approach that combines two different selection platforms to generate aptamers that bind to EBOV surfaces.


2021 ◽  
Author(s):  
Cristina Landeta ◽  
Adrian Mejia-Santana

Antimicrobial resistance is one of the greatest global health challenges today. For over three decades antibacterial discovery research and development has been focused on cell-based and target-based high throughput assays. Target-based screens use diagnostic enzymatic reactions to look for molecules that can bind directly and inhibit the target. Target-based screens are only applied to proteins that can be successfully expressed, purified and the activity of which can be effectively measured using a biochemical assay. Often times the molecules found in these in vitro screens are not active in cells due to poor permeability or efflux. On the other hand, cell-based screens use whole cells and look for growth inhibition. These screens give higher number of hits than target-based assays and can simultaneously test many targets of one process or pathway in their physiological context. Both strategies have pros and cons when used separately. In the past decade and a half our increasing knowledge of bacterial physiology has led to the development of innovative and sophisticated technologies to perform high throughput screening combining these two strategies and thus minimizing their disadvantages. In this review we discuss recent examples of high throughput approaches that used both target-based and whole-cell screening to find new antibacterials, the new insights they have provided and how this knowledge can be applied to other in vivo validated targets to develop new antimicrobials.


2020 ◽  
Author(s):  
Marcus Senra ◽  
Ana Lucia Fonseca

Tyrosinases (EC 1.14.18.1) are type-3 copper metalloenzymes with strong oxidative capacities and low allosteric selectivity to phenolic and non-phenolic aromatic compounds that have been used as biosensors and biocatalysts to mitigate the impacts of environmental contaminants over aquatic ecosystems. However, the widespread use of these polyphenol oxidases is limited by elevated production costs and restricted knowledge on their spectrum of action. Here, six tyrosinase homologs were identified and characterized from the genomes of 4 widespread freshwater ciliates using bioinformatics. Binding energies between 3D models of these homologs and ~1000 contaminants of emerging concern (CECs), including fine chemicals, pharmaceuticals, personal care products, illicit drugs, natural toxins, and pesticides were estimated through virtual screening, suggesting their spectrum of action and potential uses in environmental biotechnology might be considerably broader than previously thought. Moreover, considering that many ciliates, including those caring tyrosinase genes within their genomes are fast-growing unicellular microeukaryotes that can be efficiently culturable at large-scales under in vitro conditions, should be regarded as potential low-cost sources for the production of relevant biotechnological molecules.


Author(s):  
Moema S. Santana ◽  
Rute Lopes ◽  
Isabela H. Peron ◽  
Carla R. Cruz ◽  
Ana M. M. Gaspar ◽  
...  

Background: Hepatitis C virus infection is a significant global health burden, which causes acute or chronic hepatitis. The acute hepatitis C is generally asymptomatic and progresses to cure, while persistent infection can progress to chronic liver disease and extrahepatic manifestations. Standard treatment is expensive, poorly tolerated, and has variable sustained virologic responses amongst the different viral genotypes. New therapies involve direct acting antivirals; however, it is also very expensive and may not be accessible for all patients worldwide. In order to provide a complementary approach to the already existing therapies, natural bioactive compounds are investigated as to their several biologic activities, such as direct antiviral properties against hepatitis C, and effects on mitigating chronic progression of the disease, which includes hepatoprotective, antioxidant, anticarcinogenic and anti-inflammatory activities; additionally, these compounds present advantages, as chemical diversity, low cost of production and milder or inexistent side effects. Objective: To present a broad perspective on hepatitis C infection, the chronic disease, and natural compounds with promising anti-HCV activity. Methods: This review consists of a systematic review study about the natural bioactive compounds as a potential therapy for hepatitis C infection. Results: The quest for natural products have yielded compounds with biologic activity, including viral replication inhibition in vitro, demonstrating antiviral activity against hepatitis C. Conclusion: One of the greatest advantages of using natural molecules from plant extracts is the low cost of production, not requiring chemical synthesis, which can lead to less expensive therapies available to low and middle-income countries.


2021 ◽  
pp. 088532822110134
Author(s):  
Sushant Singh ◽  
Udit Kumar ◽  
David Gittess ◽  
Tamil S Sakthivel ◽  
Balaashwin Babu ◽  
...  

Many studies have linked reactive oxygen species (ROS) to various diseases. Biomedical research has therefore sought a way to control and regulate ROS produced in biological systems. In recent years, cerium oxide nanoparticles (nanoceria, CNPs) have been pursued due to their ability to act as regenerative ROS scavengers. In particular, they are shown to have either superoxide dismutase (SOD) or catalase mimetic (CAT) potential depending on the ratio of Ce3+/Ce4+ valence states. Moreover, it has been demonstrated that SOD mimetic activity can be diminished by the presence of phosphate, which can be a problem given that many biological systems operate in a phosphate-rich environment. Herein, we report a CNP formulation with both SOD and catalase mimetic activity that is preserved in a phosphate-rich media. Characterization demonstrated a highly dispersed, stable solution of uniform-sized, spherical-elliptical shaped CNP of 12 ± 2 nm, as determined through dynamic light scattering, zeta potential, and transmission electron microscopy. Mixed valence states of Ce ions were observed via UV/Visible spectroscopy and XPS (Ce3+/Ce4+ > 1) (Ce3+∼ 62%). X-ray diffraction and XPS confirmed the presence of oxygen-deficient cerium oxide (CeO2-x) particles. Finally, the CNP demonstrated very good biocompatibility and efficient reduction of hydrogen peroxide under in-vitro conditions.


2021 ◽  
Vol 22 (3) ◽  
pp. 1124
Author(s):  
Mafalda Giovanna Reccia ◽  
Floriana Volpicelli ◽  
Eirkiur Benedikz ◽  
Åsa Fex Svenningsen ◽  
Luca Colucci-D’Amato

Neural stem cells represent a powerful tool to study molecules involved in pathophysiology of Nervous System and to discover new drugs. Although they can be cultured and expanded in vitro as a primary culture, their use is hampered by their heterogeneity and by the cost and time needed for their preparation. Here we report that mes-c-myc A1 cells (A1), a neural cell line, is endowed with staminal properties. Undifferentiated/proliferating and differentiated/non-proliferating A1 cells are able to generate neurospheres (Ns) in which gene expression parallels the original differentiation status. In fact, Ns derived from undifferentiated A1 cells express higher levels of Nestin, Kruppel-like factor 4 (Klf4) and glial fibrillary protein (GFAP), markers of stemness, while those obtained from differentiated A1 cells show higher levels of the neuronal marker beta III tubulin. Interestingly, Ns differentiation, by Epidermal Growth Factors (EGF) and Fibroblast Growth Factor 2 (bFGF) withdrawal, generates oligodendrocytes at high-yield as shown by the expression of markers, Galactosylceramidase (Gal-C) Neuron-Glial antigen 2 (NG2), Receptor-Interacting Protein (RIP) and Myelin Basic Protein (MBP). Finally, upon co-culture, Ns-A1-derived oligodendrocytes cause a redistribution of contactin-associated protein (Caspr/paranodin) protein on neuronal cells, as primary oligodendrocytes cultures, suggesting that they are able to form compact myelin. Thus, Ns-A1-derived oligodendrocytes may represent a time-saving and low-cost tool to study the pathophysiology of oligodendrocytes and to test new drugs.


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