Journal of BioScience and Biotechnology

Antimicrobial activity of Hibiscus and Murraya leaf extracts against a variety of multidrug-resistant samples

Pal Neha — 2024-01-11

This research examined the antimicrobial properties of leaf extracts from Hibiscus rosa sinensis and Murraya koenigii against a range of human pathogenic bacteria, including E. coli, K. pneumoniae, P. aeruginosa, and S. aureus. The study utilized the disc diffusion method to assess the antimicrobial effects of benzene, acetone, and methanol extracts. Results showed that the extracts displayed broad-spectrum antibacterial activity against all of the tested pathogens. The most significant zone of inhibition was observed for P. aeruginosa, E. coli, and S. aureus in the benzene, acetone, and methanol extracts, respectively. Phytochemical screening identified several compounds, including terpenoids, tannins, alkaloids, and flavonoids, which may contribute to the antimicrobial activity of the plants. In conclusion, Hibiscus rosa sinensis and Murraya koenigii could be valuable sources of antibacterial agents against K. pneumoniae, E. coli, P. aeruginosa, and S. aureus.

Enterococci isolated from Uruguayan Colonia cheese – occurrence and antimicrobial resistance.

Marcela González — 2024-01-11

In recent years, there is a growing concern for antibiotic resistance of food-related enterococci. This study aims to provide data for occurrence and antimicrobial resistance of Enterococcus spp. isolated from Colonia cheese. The results showed that Enterococcus spp. were found in two thirds of the cheese samples (47 out of 70), of which 72% were identified as E. faecalis, 16% as E. faecium, 6% as E. mundtii, 4% as E. hirae and 2% as E. durans. The antimicrobial suceptibility showed that almost all Enterococcus spp. were sensible to ampicillin and gentamicin. The highest incidence of resistance was displayed against erythromycin, tetracycline, rifampicin and fosfomycin. E. faecalis isolates presented high percentages of resistance to high level streptomycin. The multiple antibiotic resistance index was elevated in half of the Enterococcus spp., reaching values as high as 0,8, indicating a potential risk for public health. In this research, several Enterococcus isolates could be considered as multidrug-resistant, most of them belonging to E. faecalis. Results of present study raise concerns about possible role of cheese enterococci as reservoirs of antibiotic resistance.

Genetically engineered insulin mediated by glucose transporter-2 (GLUT2) promoter for the biosynthesis of insulin in rat hepatocytes

Gehad Elsayed — 2024-01-11

The expression of insulin in hepatocytes by hepatic gene therapy is a promising treatment for diabetes. The conversion of immature proinsulin to mature insulin occurs only in cells that contain the enzymes responsible for the cleavage of proinsulin to insulin. For successful hepatic insulin gene therapy, insulin production must be tightly coupled to glucose concentration. Hepatocytes are excellent target cells for insulin gene therapy since, they are similar to pancreatic beta cells, they have the ability to rapidly adapt to blood glucose concentrations as they possess glucose-sensing components, such as Glucose Transporter-2 (GLUT2). So, we engineered rat proinsulin with the sites of cleavage (Furin Cleavable Sites) using site-directed mutagenesis for the removal of C-peptide to form the two chains A and B for mature insulin production. This engineered proinsulin was constructed into a non-viral expressing vector and regulated by glucose transporter-2 promoter (GLUT2 promoter) to control the amount of mature insulin expressed and to modulate the amount of glucose found in hepatocytes. The mature, active, and regulated expressed insulin was secreted according to the amount of glucose-regulated by the glucose transporter-2 (GLUT2) promoter.

Maize biofortification using SSR markers for Zn, Fe and provitamin A

Rakesh Kumar Chahota — 2024-01-11

Maize, India's third most significant crop, employs directly more than 12 million growers and accounts for 2% of the country's overall agricultural crop production value. Scientists are continuously working to counter the hidden hunger i.e. the micronutrient malnutrition. Therefore, marker assisted breeding approach has been deployed to increase the micronutrients Zn, Fe and pro-vitamin A content in the maize lines HPK-2 and CM-40 at HAREC, Kullu Himachal Pradesh, India. DNA isolation was carried out with leaf samples of 172 inbred and two parental lines (HPK-2 and CM-40). HPK-2 and CM-40 were utilized to screen 227 SSR primers of maize on PAGE/agarose gel for polymorphism. The mapping population was genotyped using 160 polymorphic SSR primers, phenotyped for Zn, Fe levels in the grain kernel through Atomic Absorption Spectrophotometer. Kernel Fe and Zn content were 35–60 ppm and 5–20 ppm, respectively. One QTL for Fe was found on chromosome I, while three QTLs for Zn were found on chromosomes I and IX. Further, IARI, New Delhi and CSKHP Agricultural University, Palampur have collaborated on two provitamin A donors for β-carotene enhancement in maize. Crossing scheme was created by combining lines with higher Zn and Fe content (BAJIM 6-01, BAJIM 6-15, BAJIM 6-08, BAJIM 6-10, BAJIM 6-06) with lines with higher β-carotene content (CIMMYT-13, CIMMYT-4). Plants containing the crtRB1 allele were selected in the foreground selection using primers HYD65F, HYD66R, and HYD62R up to BC2F4 and F6 generation. The highest β-carotene content was found in crosses between Bajim-06-10*CIMMYT-13 and BC2F4 generation, with 12.54ppm.

Investigation of the therapeutic properties of the leaves of Eriobotrya japonica (Thunb.) Lindl.

Tapwa Makaza — 2024-01-11

Following previous studies that have confirmed the therapeutic potential of medicinal plants, scientists are now focusing on the potential of these medicinal plants in resolving issues associated with adverse drug reactions. Reports have been made on medicinal plants having fewer adverse drug reactions than synthetic drugs though a few medicinal plants have been approved by the Food and Drug Administration for therapeutic uses. The main aim of this research was to investigate the therapeutic properties of the leaves of Eriobotrya japonica (Thunb.) Lindl. The leaf constituents of E. japonica were extracted and quantified using maceration methods. The therapeutic potential of these phytochemicals was then investigated focusing on the antioxidant, anti-inflammatory, and antibacterial properties. The antioxidant properties were investigated using a newly proposed method called the Nitrocellulose Permanganometry assay. The anti-inflammatory and antibacterial assays were investigated using the albumin denaturation assay and broth dilution technique respectively. Alkaloids, flavonoids, and saponins showed anti-inflammatory activity by inhibiting albumin denaturation, with alkaloids having the most anti-inflammatory activity as compared to flavonoids and saponins. The relative intensities representing antioxidant potential showed that tannins had the highest antioxidant potency compared to the other tested phytochemicals. All the phytochemicals showed antibacterial activity against Staphylococcus aureus with cardiac glycosides being the most potent. Thus, E. japonica proved to have therapeutic potential as all the phytochemicals obtained from this plant showed anti-inflammatory, antioxidant, and antibacterial activity. Toxicity studies are therefore required to recommend the use of E. japonica as a natural remedy.

Properties of snail shell-immobilized lipase of Aspergillus pseudotamarii and its application in butyl butyrate synthesis

Emmanuel O Garuba — 2024-01-11

In this study, attempts were made to evaluate shells of egg and snail, crystal beads, and kaolin clay as suitable carriers for the immobilization of purified lipase produced by Aspergillus pseudotamarii. The free and immobilized lipases were characterized and applied in the synthesis of butyl butyrate. Snail shell yielded 84.17% immobilization efficiency, surpassing other carriers. Optimal activity occurred at 40℃ and 45℃, yielding 2.0U/ml and 3.0U/ml for free and immobilized lipase, respectively. Immobilized lipase demonstrated superior thermal stability (62.6% vs. 0% at 300 min). pH influenced activity, with maxima at pH 7 and 6.5 for immobilized and free lipase. Kinetic parameters: Km, Vmax—3.17mM, 0.549 µM/min (free); 0.214mM, 0.894 µM/min (immobilized). Immobilized lipase exhibited better storage stability. Butyl butyrate synthesis favored immobilized lipase (71.85% vs. 52.38% yield). Optimization studies showed that the immobilized lipase achieved the highest conversion yield at a shorter reaction time and higher temperature compared to the free lipase. The immobilized lipase also exhibited excellent reusability, maintaining a stable conversion yield over multiple cycles. Overall, the immobilized lipase on snail shell showed promising characteristics and potential for butyl butyrate synthesis.

Study on the relation between some enzyme and protein polymorphism and the zebra mussel organism response to pesticide exposure

Ivan Stoyanov — 2024-01-11

In the present study, a biochemical-genetic analysis was performed to determine the relationship between isoenzyme polymorphism and the zebra mussel Dressena polymorpha organism response to the harmful effects of the pesticides Cypermethrin and Chlorpyrifos. The probable genetic control of four enzyme and protein groups - malate dehydrogenase, malate enzyme, superoxide dismutase, and soluble proteins - was determined as well. Different intensities of expression of allelic products have been reported in individuals exposed to short- and long-term exposure to the pesticides Cypermethrin and Chlorpyrifos. The observed variability in the expression of superoxide dismutases, malate dehydrogenases, and soluble proteins in control and experimental samples gives us reason to accept these enzyme and protein systems as markers for reporting the negative impact of the tested pesticides on the zebra mussel.