Novel genetic modules encoding high-level antibiotic-free protein expression in probiotic lactobacilli

Lactobacilli are ubiquitous in nature, often beneficially associated with animals as commensals and probiotics, and are extensively used in food fermentation. Due to this close-knit association, there is considerable interest to engineer them for healthcare applications in both humans and animals, for which high-performance and versatile genetic parts are greatly desired. For the first time, we describe two genetic modules in Lactiplantibacillus plantarum that achieve high-level gene expression using plasmids that can be retained without antibiotics, bacteriocins or genomic manipulations. These include (i) a promoter, PtlpA, from a phylogenetically distant bacterium, Salmonella typhimurium, which drives up to 5-fold higher level of gene expression compared to previously reported promoters and (ii) multiple toxin-antitoxin systems as a self-contained and easy-to-implement plasmid retention strategy that facilitates the engineering of tuneable transient genetically modified organisms. These modules and the fundamental factors underlying their functionality that are described in this work will greatly contribute to expanding the genetic programmability of lactobacilli for healthcare applications

Landslide Susceptibility Assessment of a Part of the Western Ghats (India) Employing the AHP and F-AHP Models and Comparison with Existing Susceptibility Maps

Landslides are prevalent in the Western Ghats, and the incidences that happened in 2021 in the Koottickal area of the Kottayam district (Western Ghats) resulted in the loss of 10 lives. The objectives of this study are to assess the landslide susceptibility of the high-range local self-governments (LSGs) in the Kottayam district using the analytical hierarchy process (AHP) and fuzzy-AHP (F-AHP) models and to compare the performance of existing landslide susceptible maps. This area never witnessed any massive landslides of this dimension, which warrants the necessity of relooking into the existing landslide-susceptible models. For AHP and F-AHP modeling, ten conditioning factors were selected: slope, soil texture, land use/land cover (LULC), geomorphology, road buffer, lithology, and satellite image-derived indices such as the normalized difference road landslide index (NDRLI), the normalized difference water index (NDWI), the normalized burn ratio (NBR), and the soil-adjusted vegetation index (SAVI). The landslide-susceptible zones were categorized into three: low, moderate, and high. The validation of the maps created using the receiver operating characteristic (ROC) technique ascertained the performances of the AHP, F-AHP, and TISSA maps as excellent, with an area under the ROC curve (AUC) value above 0.80, and the NCESS map as acceptable, with an AUC value above 0.70. Though the difference is negligible, the map prepared using the TISSA model has better performance (AUC = 0.889) than the F-AHP (AUC = 0.872), AHP (AUC = 0.867), and NCESS (AUC = 0.789) models. The validation of maps employing other matrices such as accuracy, mean absolute error (MAE), and root mean square error (RMSE) also confirmed that the TISSA model (0.869, 0.226, and 0.122, respectively) has better performance, followed by the F-AHP (0.856, 0.243, and 0.147, respectively), AHP (0.855, 0.249, and 0.159, respectively), and NCESS (0.770, 0.309, and 0.177, respectively) models. The most landslide-inducing factors in this area that were identified through this study are slope, soil texture, LULC, geomorphology, and NDRLI. Koottickal, Poonjar-Thekkekara, Moonnilavu, Thalanad, and Koruthodu are the LSGs that are highly susceptible to landslides. The identification of landslide-susceptible areas using diversified techniques will aid decision-makers in identifying critical infrastructure at risk and alternate routes for emergency evacuation of people to safer terrain during an exigency

Novel genetic modules encoding high‐level antibiotic‐free protein expression in probiotic lactobacilli

Abstract Lactobacilli are ubiquitous in nature, often beneficially associated with animals as commensals and probiotics, and are extensively used in food fermentation. Due to this close‐knit association, there is considerable interest to engineer them for healthcare applications in both humans and animals, for which high‐performance and versatile genetic parts are greatly desired. For the first time, we describe two genetic modules in Lactiplantibacillus plantarum that achieve high‐level gene expression using plasmids that can be retained without antibiotics, bacteriocins or genomic manipulations. These include (i) a promoter, PtlpA, from a phylogenetically distant bacterium, Salmonella typhimurium, which drives up to 5‐fold higher level of gene expression compared to previously reported promoters and (ii) multiple toxin‐antitoxin systems as a self‐contained and easy‐to‐implement plasmid retention strategy that facilitates the engineering of tuneable transient genetically modified organisms. These modules and the fundamental factors underlying their functionality that are described in this work will greatly contribute to expanding the genetic programmability of lactobacilli for healthcare applications

Molecular Studies on the Nephroprotective Potential of Celastrus paniculatus against Lead-Acetate-Induced Nephrotoxicity in Experimental Rats: Role of the PI3K/AKT Signaling Pathway

Chemicals can induce nephrotoxicity, with damage to different segments of the nephron and deterioration of renal function. Nephrotoxicity due to exposure to a toxin such as carbon tetrachloride, sodium oxalate, or heavy metals is the most common cause of kidney injury. The current study aimed to evaluate the protective effects of Celastrus paniculatus seed extract against lead-acetate-induced nephrotoxicity by evaluating the histopathology, immunohistochemistry, ultrastructure, and phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway. Twenty-four rats were divided into four groups (n = 6 per group): group 1 contained normal animals and served as the control; group 2 received lead acetate (30 mg/kg body weight (b.w.)/day, oral); group 3 received lead acetate and the standard drug N-acetylcysteine (NAC, 200 mg/kg b.w./day, oral); and group 4 received lead acetate and the ethanolic extract of C. paniculatus seed (EECP; 800 mg/kg b.w./day, oral). Treatment was given for 28 consecutive days. The data were analyzed using one-way analysis of variance with SIGMA PLOT 13 using SYSTAT software followed by Newman–Keul’s test for comparison between the groups. EECP ameliorated the adverse changes caused by lead acetate. PI3K and AKT messenger RNA (mRNA) levels were diminished in lead-acetate-treated rats. Treatment with EECP inhibited the occurrence of shrunken cells, the atrophy of glomeruli, and degenerative changes in renal tubules caused by lead acetate. Interestingly, the PI3K and AKT mRNA levels were significantly increased in EECP-treated animals. Our results clearly evidence for the first time that C. paniculatus seed extract inhibits lead-acetate-induced detrimental changes in kidneys by regulating PI3K/AKT signaling pathways

Fluorine-Free Sustainable Three-Dimensional Superhydrophobic and Superoleophilic Robust Foam for Efficient Oil/Water Separation

The development of sustainable, environmentally friendly, and efficient materials for oil/water separation is the need of the hour. The utilization of renewable or waste resources to develop value-added materials poses as the key toward sustainability. This work reports the fabrication of an economical, salt-tolerant, superhydrophobic, and superoleophilic waste rice husk-derived silica (SiO2)/reduced graphene oxide (rGO)-coated polyurethane (PU) foam for effective oil/water separation. Herein, SiO2 and graphene oxide (GO) are synthesized from rice husk by using precipitation and thermal exfoliation methods. A simple dip-coating method was carried out to coat the materials on PU foam, followed by a reduction process to form SiO2/rGO@PU foam. The adhesion of SiO2 on rGO enhances the surface roughness and thus promotes superhydrophobic (water contact angle = 164°) and superoleophilic (oil contact angle = 0°) behaviors. The SiO2/rGO@PU foam exhibits excellent adsorption capacity of different oils as well as stability at extreme pH, ultraviolet irradiation, salt concentration, pressure, and humidity with a separation efficiency above 98%. The foam is used to separate a wide range of oil and water mixtures. Utilizing this foam, a device is fabricated, which demonstrated successfully the separation and recovery of crude oil from water. Therefore, the SiO2/rGO@PU foam has the potential to be a promising adsorbent for oil spill cleanup

Fluorine-Free Sustainable Three-Dimensional Superhydrophobic and Superoleophilic Robust Foam for Efficient Oil/Water Separation

The development of sustainable, environmentally friendly, and efficient materials for oil/water separation is the need of the hour. The utilization of renewable or waste resources to develop value-added materials poses as the key toward sustainability. This work reports the fabrication of an economical, salt-tolerant, superhydrophobic, and superoleophilic waste rice husk-derived silica (SiO2)/reduced graphene oxide (rGO)-coated polyurethane (PU) foam for effective oil/water separation. Herein, SiO2 and graphene oxide (GO) are synthesized from rice husk by using precipitation and thermal exfoliation methods. A simple dip-coating method was carried out to coat the materials on PU foam, followed by a reduction process to form SiO2/rGO@PU foam. The adhesion of SiO2 on rGO enhances the surface roughness and thus promotes superhydrophobic (water contact angle = 164°) and superoleophilic (oil contact angle = 0°) behaviors. The SiO2/rGO@PU foam exhibits excellent adsorption capacity of different oils as well as stability at extreme pH, ultraviolet irradiation, salt concentration, pressure, and humidity with a separation efficiency above 98%. The foam is used to separate a wide range of oil and water mixtures. Utilizing this foam, a device is fabricated, which demonstrated successfully the separation and recovery of crude oil from water. Therefore, the SiO2/rGO@PU foam has the potential to be a promising adsorbent for oil spill cleanup

Fluorine-Free Sustainable Three-Dimensional Superhydrophobic and Superoleophilic Robust Foam for Efficient Oil/Water Separation

The development of sustainable, environmentally friendly, and efficient materials for oil/water separation is the need of the hour. The utilization of renewable or waste resources to develop value-added materials poses as the key toward sustainability. This work reports the fabrication of an economical, salt-tolerant, superhydrophobic, and superoleophilic waste rice husk-derived silica (SiO2)/reduced graphene oxide (rGO)-coated polyurethane (PU) foam for effective oil/water separation. Herein, SiO2 and graphene oxide (GO) are synthesized from rice husk by using precipitation and thermal exfoliation methods. A simple dip-coating method was carried out to coat the materials on PU foam, followed by a reduction process to form SiO2/rGO@PU foam. The adhesion of SiO2 on rGO enhances the surface roughness and thus promotes superhydrophobic (water contact angle = 164°) and superoleophilic (oil contact angle = 0°) behaviors. The SiO2/rGO@PU foam exhibits excellent adsorption capacity of different oils as well as stability at extreme pH, ultraviolet irradiation, salt concentration, pressure, and humidity with a separation efficiency above 98%. The foam is used to separate a wide range of oil and water mixtures. Utilizing this foam, a device is fabricated, which demonstrated successfully the separation and recovery of crude oil from water. Therefore, the SiO2/rGO@PU foam has the potential to be a promising adsorbent for oil spill cleanup

Fluorine-Free Sustainable Three-Dimensional Superhydrophobic and Superoleophilic Robust Foam for Efficient Oil/Water Separation

The development of sustainable, environmentally friendly, and efficient materials for oil/water separation is the need of the hour. The utilization of renewable or waste resources to develop value-added materials poses as the key toward sustainability. This work reports the fabrication of an economical, salt-tolerant, superhydrophobic, and superoleophilic waste rice husk-derived silica (SiO2)/reduced graphene oxide (rGO)-coated polyurethane (PU) foam for effective oil/water separation. Herein, SiO2 and graphene oxide (GO) are synthesized from rice husk by using precipitation and thermal exfoliation methods. A simple dip-coating method was carried out to coat the materials on PU foam, followed by a reduction process to form SiO2/rGO@PU foam. The adhesion of SiO2 on rGO enhances the surface roughness and thus promotes superhydrophobic (water contact angle = 164°) and superoleophilic (oil contact angle = 0°) behaviors. The SiO2/rGO@PU foam exhibits excellent adsorption capacity of different oils as well as stability at extreme pH, ultraviolet irradiation, salt concentration, pressure, and humidity with a separation efficiency above 98%. The foam is used to separate a wide range of oil and water mixtures. Utilizing this foam, a device is fabricated, which demonstrated successfully the separation and recovery of crude oil from water. Therefore, the SiO2/rGO@PU foam has the potential to be a promising adsorbent for oil spill cleanup

Monoclonal antibodies against all known variants of EspA: development of a simple diagnostic test for enteropathogenic Escherichia coli based on a key virulence factor

Enteropathogenic Escherichia coli (EPEC) are a major cause of infant diarrhoea in developing countries and a significant public health issue in industrialized countries. Currently there are no simple tests available for the diagnosis of EPEC. Serology of O-antigens is widely used routinely in many laboratories throughout the world, even though it has been known for many years to be an unreliable indicator of EPEC virulence. We have developed a simple, low-cost immunodiagnostic test based on the EspA filament, an essential virulence factor of EPEC and the related enterohaemorrhagic E. coli (EHEC). Using recombinant proteins of the five major variants of EspA as immunogens, we raised a panel of three monoclonal antibodies in mice that detects all variants of the native target in bacterial cultures. The antibodies proved suitable for application in sandwich-type assays, including ELISA and lateral flow immunoassays (LFI). Prototypes for both assays were specific for EPEC and EHEC strains when tested against a panel of control micro-organisms. We have also developed a simple, affordable culture medium, A/E medium, which optimizes expression of EspA allowing improved sensitivity of detection compared with standard Dulbecco’s modified Eagle’s medium. Together these reagents form the basis of robust, informative tests for EPEC for use especially in developing countries but also for routine screening in any clinical laboratory