Integrating target-responsive microfluidic-based biosensing chip with smartphone for simultaneous quantification of multiple fluoroquinolones.

The presence of fluoroquinolone (FQs) antibiotic residues in the food and environment has become a significant concern for human health and ecosystems. In this study, the background-free properties of upconversion nanoparticles (UCNPs), the high specificity of the target aptamer (Apt), and the high quenching properties of graphene oxide (GO) were integrated into a microfluidic-based fluorescence biosensing chip (MFBC). Interestingly, the microfluidic channels of the MFBC were prepared by laser-printing technology without the need for complex preparation processes and additional specialized equipment. The target-responsive fluorescence biosensing probes loaded on the MFBC were prepared by self-assembly of the UCNPs-Apt complex with GO based on π-π stacking interactions, which can be used for the detection of the two FQs on a large scale without the need for multi-step manipulations and reactions, resulting in excellent multiplexed, automated and simultaneous sensing capabilities with detection limits as low as 1.84 ng/mL (enrofloxacin) and 2.22 ng/mL (ciprofloxacin). In addition, the MFBC was integrated with a smartphone into a portable device to enable the analysis of a wide range of FQs in the field. This research provides a simple-to-prepare biosensing chip with great potential for field applications and large-scale screening of FQs residues in the food and environment.

Exploiting the biocatalytic potential of co-expressed l-fucose isomerase and d-tagatose 3-epimerase for the biosynthesis of 6-deoxy-l-sorbose.

6-Deoxy-l-sorbose (6-DLS) is an imperative rare sugar employed in food, agriculture, pharmaceutical and cosmetic industeries. However, it is a synthetic and very expensive rare sugars, previously synthesized by chemo-enzymatic methods through a long chain of chemical processes. Recently, enzymatic synthesis of rare sugars has attracted a lot of attention due to its advantages over synthetic methods. In this work, a promising approach for the synthesis of 6-DLS from an inexpensive sugar l-fucose was identified. The genes for l-fucose isomerase from Paenibacillus rhizosphaerae (Pr-LFI) and genes for d-tagatose-3-epimerase from Caballeronia fortuita (Cf-DTE) have been used for cloning and co-expression in Escherichia coli, developed a recombinant plasmid harboring pANY1-Pr-LFI/Cf-DTE vector. The recombinant co-expression system exhibited an optimum activity at 50 °C of temperature and pH 6.5 in the presence of Co2+ metal ion which inflated the catalytic activity by 6.8 folds as compared to control group with no metal ions. The recombinant co-expressed system was stable up to more than 50 % relative activity after 12 h and revealed a melting temperature (Tm) of 63.38 °C exhibiting half-life of 13.17 h at 50 °C. The co-expression system exhibited, 4.93, 11.41 and 16.21 g/L of 6-DLS production from initial l-fucose concentration of 30, 70 and 100 g/L, which equates to conversion yield of 16.44 %, 16.30 % and 16.21 % respectively. Generally, this study offers a promising strategy for the biological production of 6-DLS from an inexpensive substrate l-fucose in slightly acidic conditions with the aid of co-expression system harboring Pr-LFI and CF-DTE genes.

Corrigendum: Probiotics: mechanism of action, health benefits and their application in food industries.

[This corrects the article DOI: 10.3389/fmicb.2023.1216674.].

Probiotics: mechanism of action, health benefits and their application in food industries.

Probiotics, like lactic acid bacteria, are non-pathogenic microbes that exert health benefits to the host when administered in adequate quantity. Currently, research is being conducted on the molecular events and applications of probiotics. The suggested mechanisms by which probiotics exert their action include; competitive exclusion of pathogens for adhesion sites, improvement of the intestinal mucosal barrier, gut immunomodulation, and neurotransmitter synthesis. This review emphasizes the recent advances in the health benefits of probiotics and the emerging applications of probiotics in the food industry. Due to their capability to modulate gut microbiota and attenuate the immune system, probiotics could be used as an adjuvant in hypertension, hypercholesterolemia, cancer, and gastrointestinal diseases. Considering the functional properties, probiotics are being used in the dairy, beverage, and baking industries. After developing the latest techniques by researchers, probiotics can now survive within harsh processing conditions and withstand GI stresses quite effectively. Thus, the potential of probiotics can efficiently be utilized on a commercial scale in food processing industries.

One Stone Two Birds: An Upconversion Nanosensor for Sensitive Detection of Fluoroquinolones in Aquatic Products Based on Chelation Recognition.

Excessive residues of fluoroquinolones (FQs) in aquatic products have become a growing issue in recent years. Herein, we demonstrate an upconversion fluorescence nanosensor constructed by a one-stone-two-birds strategy, where Fe3+ not only quenches upconversion fluorescence with high efficiency but also specifically recognizes the bidentate ligand structure of FQs. Compared to existing methods, the proposed sensor is simpler to synthesize and cheap and has more storage stability due to the unification of the quencher and recognition molecule. Enrofloxacin (ENR) was chosen as a representative veterinary drug for FQs to verify the effectiveness of the nanosensor. Under optimal conditions, the range of detection for ENR was 2.0 × 10-2 to 2.0 × 102 µg/mL, with a limit of detection of 1.08 × 10-3 µg/mL. The developed nanosensor was further validated by high-performance liquid chromatography-ultraviolet (HPLC-UV) without significant differences in practical detection. Hence, this study offers a potential strategy for the detection of FQs.

Characterization of l-fucose isomerase from Paenibacillus rhizosphaerae to produce l-fuculose from hydrolyzed fucoidan and commercial fucose.

AIMS: l-Fuculose is a valuable rare sugar that is used to treat a variety of ailments, including HIV, cancer, Hepatitis B, human lysosomal disease (fucosidosis), and cardio-protective medications. The enzymatic approach for the production of l-fuculose using l-fucose as a substrate would be an advantageous method with a wide range of industrial applications. The objective of this study is the characterization of recombinant l-fucose isomerase from Paenibacillus rhizosphaerae (Pa-LFI) for the production of l-fuculose from an inexpensive and natural source (fucoidan) as well as its comparison with commercial l-fucose (Sigma-Aldrich). METHODS AND RESULTS: Fucoidan, a fucose-containing polysaccharide (FPs), was isolated from Undaria pinnatifida, subsequently hydrolyzed, and characterized before the enzymatic production of l-fuculose. The results elaborate that FPs contain 35.9% of fucose along with other kinds of monosaccharides. The purified Pa-LFI exhibited a single band at 65 kDa and showed it as a hexamer with a native molecular mass of 396 kDa. The highest activity of 104.5 U mg-1 of Pa-LFI was perceived at a temperature of 50°C and pH 6.5 in the presence of 1 mM of Mn2+. The Pa-LFI revealed a melting temperature (Tm) of 75°C and a half-life of 12.6 h at 50°C. It exhibited that Pa-LFI with aldose substrate (l-fucose), has a stronger isomerizing activity, disclosing Km,kcat, and kcat/Km 86.2 mM, 32 831 min-1, and 335 min-1 mM-1, respectively. After reaching equilibrium, Pa-LFI efficiently catalyzed the reaction to convert l-fucose into l-fuculose and the conversion ratios of l-fuculose from 100 g L-1 of FPs and commercial fucose were around 6% (5.6 g L-1) and 30% (30.2 g L-1), respectively. CONCLUSIONS: According to the findings of the current study, the Pa-LFI will be useful in the manufacturing of l-fuculose using an effective and easy approach that produces no by-products.

Cottonseed oil: A review of extraction techniques, physicochemical, functional, and nutritional properties.

Seed oils are the richest source of vitamin-E-active compounds, which contribute significantly to antioxidant activities. Cottonseed oil (CS-O) is attaining more consideration owing to its high fiber content and stability against auto-oxidation. CS-O has gained a good reputation in the global edible oil market due to its distinctive fatty acid profile, anti-inflammatory, and cardio-protective properties. CS-O can be extracted from cottonseed (CS) by microwave-assisted extraction (MAE), aqueous/solvent extraction (A/SE), aqueous ethanol extraction (A-EE), subcritical water extraction, supercritical carbon dioxide extraction (SC-CO2), and enzyme-assisted extraction (E-AE). In this review, the importance, byproducts, physicochemical characteristics, and nutritional profile of CS-O have been explained in detail. This paper also provides a summary of scientific studies existing on functional and phytochemical characteristics of CS-O. Its consumption and health benefits are also deliberated to discover its profitability and applications. CS-O contains 26-35% saturated, 42-52% polyunsaturated, and 18-24% monounsaturated FA. There is approximately 1000 ppm of tocopherols in unprocessed CS-O, but up to one-third is lost during processing. Moreover, besides being consumed as cooking oil, CS-O discovers applications in many fields such as biofuel, livestock, cosmetics, agriculture, and chemicals. This paper provides a comprehensive review of CS-O, its positive benefits, fatty acid profile, extraction techniques, and health applications.HighlightsCS-O is a rich source of exceptional fatty acids.Various techniques to extract the CS-O are discussed.Numerous physicochemical properties of CS-O for the potential market are assessed.It has a wide range of functional properties.Nutritional quality and health benefits are also evaluated.

Fucoidan-based nanomaterial and its multifunctional role for pharmaceutical and biomedical applications.

Fucoidans are promising sulfated polysaccharides isolated from marine sources that have piqued the interest of scientists in recent years due to their widespread use as a bioactive substance. Bioactive coatings and films, unsurprisingly, have seized these substances to create novel, culinary, therapeutic, and diagnostic bioactive nanomaterials. The applications of fucoidan and its composite nanomaterials have a wide variety of food as well as pharmacological properties, including anti-oxidative, anti-inflammatory, anti-cancer, anti-thrombic, anti-coagulant, immunoregulatory, and anti-viral properties. Blends of fucoidan with other biopolymers such as chitosan, alginate, curdlan, starch, etc., have shown promising coating and film-forming capabilities. A blending of biopolymers is a recommended approach to improve their anticipated properties. This review focuses on the fundamental knowledge and current development of fucoidan, fucoidan-based composite material for bioactive coatings and films, and their biological properties. In this article, fucoidan-based edible bioactive coatings and films expressed excellent mechanical strength that can prolong the shelf-life of food products and maintain their biodegradability. Additionally, these coatings and films showed numerous applications in the biomedical field and contribute to the economy. We hope this review can deliver the theoretical basis for the development of fucoidan-based bioactive material and films.

A review of the enzymatic, physical, and chemical modification techniques of xanthan gum.

Xanthan gum (XG), a bacterial polysaccharide has numerous valuable characteristics in the food, biomedical, pharmaceuticals, and agriculture sector. However, XG has also its particular limitations such as its vulnerability to microbial contamination, inadequate mechanical and thermal stability, unusable viscosity, and poor water solubility. Therefore, XG's structure and conformation need to be modified enzymatically, chemically, or physically to improve its optimistic features and decrease the formation of crystals, increase antioxidant ability, and radical scavenging activity. We have found out different means to modify XG and elaborate the importance and significance of the modified structure of XG. In this review, different enzymes are reviewed for XG degradation, which modifies their structure from different points (main chain or side chain). This article also reviews various physical methods (ultrasound, shear, pressure, sonication, annealing, and heat treatments) based on prevailing publications to alter XG conformation and produce low molecular weight (LMW) and less viscous end-product. Moreover, some chemical means are also discussed that result in modified XG through crosslinking, grafting, acetylation, pyruvation, as well as by applying different chemical agents. Overall, the current progress on XG degradation is very auspicious to develop a new molecule with considerable uses, in various industries with future assessments.

A review on selective l-fucose/d-arabinose isomerases for biocatalytic production of l-fuculose/d-ribulose.

L-Fuculose and D-ribulose are kinds of rare sugars used in food, agriculture, and medicine industries. These are pentoses and categorized into the two main groups, aldo pentoses and ketopentoses. There are 8 aldo- and 4 ketopentoses and only fewer are natural, while others are rare sugars found in a very small amount in nature. These sugars have great commercial applications, especially in many kinds of drugs in the medicine industry. The synthesis of these sugars is very expensive, difficult by chemical methods due to its absence in nature, and could not meet industry demands. The pentose izumoring strategy offers a complete enzymatic tactic to link all kinds of pentoses using different enzymes. The enzymatic production of L-fuculose and D-ribulose through L-fucose isomerase (L-FI) and D-arabinose isomerase (D-AI) is the inexpensive and uncomplicated method up till now. Both enzymes have similar kinds of isomerizing mechanisms and each enzyme can catalyze both L-fucose and D-arabinose. In this review article, the enzymatic process of biochemically characterized L-FI & D-AI, their application to produce L-fuculose and D-ribulose and its uses in food, agriculture, and medicine industries are reviewed.

Drug nanodelivery systems based on natural polysaccharides against different diseases.

Drug nanodelivery systems (DNDSs) are fascinated cargos to achieve outstanding therapeutic results of various drugs or natural bioactive compounds owing to their unique structures. The efficiency of several pharmaceutical drugs or natural bioactive ingredients is restricted because of their week bioavailability, poor bioaccessibility and pharmacokinetics after orally pathways. In order to handle such constraints, usage of native/natural polysaccharides (NPLS) in fabrication of DNDSs has gained more popularity in the arena of nanotechnology for controlled drug delivery to enhance safety, biocompatibility, better retention time, bioavailability, lower toxicity and enhanced permeability. The main commonly used NPLS in nanoencapsulation systems include chitosan, pectin, alginates, cellulose, starches, and gums recognized as potential materials for fabrication of cargos. Herein, this review is centered on different polysaccharide-based nanocarriers including nanoemulsions, nanohydrogels, nanoliposomes, nanoparticles and nanofibers, which have already served as encouraging candidates for entrapment of therapeutic drugs as well as for their sustained controlled release. Furthermore, the current article explicitly offers comprehensive details regarding application of NPLS-based nanocarriers encapsulating several drugs intended for the handling of numerous disorders, including diabetes, cancer, HIV, malaria, cardiovascular and respiratory as well as skin diseases.

Characterization of a recombinant l-ribose isomerase from Mycetocola miduiensis and its application for the production of l-ribulose.

An enzyme, l-ribose isomerase (l-RI), mostly catalyzes the isomerization of l-ribose and l-ribulose. These so-called rare sugars are essential for the treatment of cancer and other viral diseases. In the present study, l-ribose isomerase produced from a bacterium, Mycetocola miduiensis (Mm-LRIse), by using l-ribose as a carbon source. The recombinant l-ribose isomerase gene was cloned and overexpressed from M. miduiensis and purified with an exclusive band of 32 kDa by nickel-affinity chromatography. This gene possessed 267 amino acids protein having an estimated molecular weight of 29,568.17 Da. The native molecular weight of Mm-LRIse estimated by HPLC was 134.84 kDa. The recombinant l-ribose isomerase was highly active in sodium phosphate (50 mM) buffer at 40 °C and pH 7.5, showing the specific activity up to 47.40 U mg-1. Mm-LRIse showed no significant enhancement in activity with metallic ions except Mn2+ and Co2+. The values of Km, Kcat, Kcat/Km and Vmax of Mm-LRIse against l-ribose substrate were 42.48 mM, 9259.26 min-1, 217.43 min-1 mM-1, and 277.78 U mg-1 respectively. At equilibrium, the l-ribulose transformation rate was nearly 32 % (6.34 g L-1) using 20 g L-1 of l-ribose. The results revealed that the Mm-LRIse enzyme has a potential for L-ribulose production from l-ribose.

Biochemical characterization of recombinant L-fucose isomerase from Caldanaerobius polysaccharolyticus for L-fuculose production.

L-fuculose is a rare sugar that is useful for the agriculture and medicine industries. L-fucose isomerase (E.C.5.3.1.25), which is an aldose-ketose isomerase, plays a significant role in producing rare sugars. A recommended L-fucose isomerase gene was cloned from Caldanaerobius polysaccharolyticus and purified with a single band of 65 kDa using nickel-affinity chromatography, with a specific activity of 108.23 U mg-1. The native molecular mass existed with 214 kDa was a trimer. The purified enzyme showed a maximum activity in 1 mM Mn2+ at 55 °C and pH 6.5 with a melting temperature (Tm) of 80.3 °C in the presence of one molecule per monomer. L-fucose isomerase from C. polysaccharolyticus (Capo-LfIase) exhibited the highest activity of L-fucose with Km, kcat and Kcat/km values of 94.2 mM, 23854 min-1 and 253.3 min-1 mM-1, respectively. Capo-LfIase showed more than 50% thermostability after 20 h of incubation at 45, 55, 65, 75 and 85 °C. The 9 putative active site residues of the L-fucose substrate were described using a homology model, and the results showed that Tyr440, Met185, Trp499 and Asn527 are the candidates of metal-binding residues, while Ser393, Glu337, Glu302, His528 and Asp361 would be involved in substrate binding. The conversion rate of L-fuculose from L-fucose was almost 28.2%, with 80 g L-1 L-fucose, and no byproduct was found. To the best of our knowledge, Capo-LfIase produces high yield of L-fuculose from L-fucose by enzymatic methods.

Characterization of a novel d-arabinose isomerase from Thermanaeromonas toyohensis and its application for the production of d-ribulose and l-fuculose.

d-Ribulose and l-fuculose are potentially valuable rare sugars useful for anticancer and antiviral drugs in the agriculture and medicine industries. These rare sugars are usually produced by chemical methods, which are generally expensive, complicated and do not meet the increasing demands. Furthermore, the isomerization of d-arabinose and l-fucose byDd-arabinose and l-fucose by d-arabinose isomerase from bacterial sources for the production of d-ribulose and l-fuculose have not yet become industrial due to the shortage of biocatalysts, resulting in poor yield and high cost of production. In this study, a thermostable d-ribulose- and l-fuculose producing d-arabinose isomerase from the bacterium Thermanaeromonas toyohensis was characterized. The recombinant d-arabinose isomerase from T. toyohensis (Thto-DaIase) was purified with a single band at 66 kDa using His-trap affinity chromatography. The native enzyme existed as a homotetramer with a molecular weight of 310 kDa, and the specific activities for both d-arabinose and l-fucose were observed to be 98.08 and 85.52 U mg-1, respectively. The thermostable recombinant Thto-DaIase was activated when 1 mM Mn2+ was added to the reactions at an optimum pH of 9.0 at 75 °C and showed approximately 50% activity for both d-arabinose and l-fucose at 75 °C after 10 h. The Michaelis-Menten constant (Km), the turnover number (kcat) and catalytic efficiency (kcat/Km) for d-arabinose/l-fucose were 111/81.24 mM, 18,466/10,688 min-1, and 166/132 mM-1  min-1, respectively. When the reaction reached to equilibrium, the conversion rates of d-ribulose from d-arabinose and l-fuculose from l-fucose were almost 27% (21 g L-1) and 24.88% (19.92 g L-1) from 80 g L-1 of d-arabinose and l-fucose, respectively.

In vitro survival of Bifidobacterium bifidum microencapsulated in zein-coated alginate hydrogel microbeads.

The Bifidobacterium bifidum susceptibility in gastrointestinal conditions and storage stability limit its use as potential probiotics. The current study was design to encapsulate B. bifidum using sodium alginate (SA, 1.4% w/v) and different concentration of zein as coating material, that is, Z1 (1% w/v), Z2 (3% w/v), Z3 (5% w/v), Z4 (7% w/v), Z5 (9% w/v). The resultant microbeads were further investigated for encapsulation efficiency, survival in gastrointestinal conditions, release profile in intestinal fluid, storage stability and morphological characteristics. The highest encapsulation efficiency (94.56%) and viable count (>107 log CFU/g) was observed in Z4 (7% w/v). Viable cell count of B. bifidum was >106 log CFU/g in all the zein-coated microbeads as compare to free cells (103 log CFU/g) and SA (105 log CFU/g) at 4 °C after 32 days of storage. Therefore, B. bifidum encapsulated in zein-coated alginate microbeads present improved survival during gastric transit and storage.