Kinetic studies on optimized extracellular laccase from Trichoderma harzianum PP389612 and its capabilities for azo dye removal.

BACKGROUND: Azo dyes represent a common textile dye preferred for its high stability on fabrics in various harsh conditions. Although these dyes pose high-risk levels for all biological forms, fungal laccase is known as a green catalyst for its ability to oxidize numerous dyes. METHODS: Trichoderma isolates were identified and tested for laccase production. Laccase production was optimized using Plackett-Burman Design. Laccase molecular weight and the kinetic properties of the enzyme, including Km and Vmax, pH, temperature, and ionic strength, were detected. Azo dye removal efficiency by laccase enzyme was detected for Congo red, methylene blue, and methyl orange. RESULTS: Eight out of nine Trichoderma isolates were laccase producers. Laccase production efficiency was optimized by the superior strain T. harzianum PP389612, increasing production from 1.6 to 2.89 U/ml. In SDS-PAGE, purified laccases appear as a single protein band with a molecular weight of 41.00 kDa. Km and Vmax values were 146.12 µmol guaiacol and 3.82 µmol guaiacol/min. Its activity was stable in the pH range of 5-7, with an optimum temperature range of 40 to 50 °C, optimum ionic strength of 50 mM NaCl, and thermostability properties up to 90 °C. The decolorization efficiency of laccase was increased by increasing the time and reached its maximum after 72 h. The highest efficiency was achieved in Congo red decolorization, which reached 99% after 72 h, followed by methylene blue at 72%, while methyl orange decolorization efficiency was 68.5%. CONCLUSION: Trichoderma laccase can be used as an effective natural bio-agent for dye removal because it is stable and removes colors very well.

High ß-Lactam and Quinolone Resistance of Enterobacteriaceae from the Respiratory Tract of Sheep and Goat with Respiratory Disease.

During the last decade's increase of antimicrobial resistance (AMR) in animals, animal-human transmission has become a major threat. Therefore, the present study aimed to evaluate the genetic basis of AMR in Gram-negative bacteria recovered from sheep and goats with respiratory disease. Nasal and ocular swabs were collected from 69 diseased animals, and 76 Gram-negative bacterial isolates were identified from 59 animals. All isolates were checked phenotypically for resistance and genotypically for different resistance mechanisms, including ß-lactam, quinolone, and aminoglycoside resistance. Our results demonstrated that 9.2% (95% CI 4.5-17.8%) of the isolates were multidrug-resistant, with high resistance rates to ß-lactams and quinolones, and 11.8% (95% CI 6.4-21%) and 6.6% (95% CI 2.8-14.5%) of the isolates were phenotypically positive for AmpC and ESBL, respectively. Genotypically, blaTEM was the most identified ß-lactamase encoding gene in 29% (95% CI 20-40%) of the isolates, followed by blaSHV (14.5%, 95% CI 8.3-24.1%) and blaCTX-M (4%, 95% CI 1.4-11%). Furthermore, 7.9% (95% CI 3.7-16.2%) of the isolates harbored plasmid-mediated quinolone resistance gene qnrS. Our study revealed for the first time to our knowledge high ß-lactam and quinolone resistance associated with the bacteria recovered from sheep and one goat with respiratory disease. Furthermore, different antimicrobial resistant determinants were identified for the first time from animals in Africa, such as blaLEN-13/55, blaTEM-176 and blaTEM-198/214. This study highlights the potential role of sheep and goats in disseminating AMR determinants and/or resistant bacteria to humans. The study regenerates interest for the development of a One Health approach to combat this formidable problem.

Ginseng attenuates fipronil-induced hepatorenal toxicity via its antioxidant, anti-apoptotic, and anti-inflammatory activities in rats.

Fipronil (FPN) is a relatively new and broad spectrum insecticide that induces toxic effects to animals and humans through induction of oxidative stress. Ginseng is a medicinal plant that has antioxidant, anti-inflammatory, and anti-apoptotic activities. Thus, the current study was conducted to evaluate the anti-toxic potential of ginseng aqueous extract (GAE) against FPN-induced hepatorenal toxicity in rats. Thirty-two male Wistar albino rats were randomly allocated into four equal groups. Rats of the control group received distilled water. The second group was administrated with GAE at a dose of 200 mg/kg b.w. orally day by day for 6 weeks. The third group was intoxicated with FPN at a dose of 4.85 mg/kg b.w. orally day by day for 6 weeks. The fourth group was administrated with GAE 2 h before FPN intoxication. Intoxication of rats with FPN significantly elevated the activities of serum alanine aminotransferase and aspartate aminotransferase and serum levels of urea and creatinine, as well as increased malondialdehyde level and protein expressions of caspase-3 and cyclooxygenase-2 in hepatic and renal tissues. However, it significantly decreased hepatic and renal GSH content and catalase activity. In addition, it induced histopathological alterations in hepatic and renal tissue architectures. Conversely, concomitant oral administration of GAE ameliorated the FPN-induced biochemical, pathological, and histochemical alterations in both hepatic and renal tissues. This study indicated that ginseng attenuates FPN-induced hepatorenal toxicity, possibly via its antioxidant, anti-apoptotic, and anti-inflammatory properties. Graphical Abstract CAL ABSTRACTPHIRAG.

Moringa oleifera leaf extract ameliorates alloxan-induced diabetes in rats by regeneration of ß cells and reduction of pyruvate carboxylase expression.

Moringa oleifera Lam. contains many active ingredients with nutritional and medicinal values. It is commonly used in folk medicine as an antidiabetic agent. The present study was designed to investigate how an aqueous extract from the leaves of M. oleifera reveals hypoglycemia in diabetic rats. M. oleifera leaf extract counteracted the alloxan-induced diabetic effects in rats as it normalized the elevated serum levels of glucose, triglycerides, cholesterol, and malondialdehyde, and normalized mRNA expression of the gluconeogenic enzyme pyruvate carboxylase in hepatic tissues. It also increased live body weight gain and normalized the reduced mRNA expression of fatty acid synthase in the liver of diabetic rats. Moreover, it restored the normal histological structure of the liver and pancreas damaged by alloxan in diabetic rats. This study revealed that the aqueous extract of M. oleifera leaves possesses potent hypoglycemic effects through the normalization of elevated hepatic pyruvate carboxylase enzyme and regeneration of damaged hepatocytes and pancreatic ß cells via its antioxidant properties.