The lactose operon from Lactobacillus casei is involved in the transport and metabolism of the human milk oligosaccharide core-2 N-acetyllactosamine

The lactose operon (lacTEGF) from Lactobacillus casei strain BL23 has been previously studied. The lacT gene codes for a transcriptional antiterminator, lacE and lacF for the lactose-specific phosphoenolpyruvate: phosphotransferase system (PTSLac) EIICB and EIIA domains, respectively, and lacG for the phospho-β-galactosidase. In this work, we have shown that L. casei is able to metabolize N-acetyllactosamine (LacNAc), a disaccharide present at human milk and intestinal mucosa. The mutant strains BL153 (lacE) and BL155 (lacF) were defective in LacNAc utilization, indicating that the EIICB and EIIA of the PTSLac are involved in the uptake of LacNAc in addition to lactose. Inactivation of lacG abolishes the growth of L. casei in both disaccharides and analysis of LacG activity showed a high selectivity toward phosphorylated compounds, suggesting that LacG is necessary for the hydrolysis of the intracellular phosphorylated lactose and LacNAc. L. casei (lacAB) strain deficient in galactose-6P isomerase showed a growth rate in lactose (0.0293 ± 0.0014 h-1) and in LacNAc (0.0307 ± 0.0009 h-1) significantly lower than the wild-type (0.1010 ± 0.0006 h-1 and 0.0522 ± 0.0005 h-1, respectively), indicating that their galactose moiety is catabolized through the tagatose-6P pathway. Transcriptional analysis showed induction levels of the lac genes ranged from 130 to 320-fold in LacNAc and from 100 to 200-fold in lactose, compared to cells growing in glucose

State of the world’s plants and fungi 2020

Kew’s State of the World’s Plants and Fungi project provides assessments of our current knowledge of the diversity of plants and fungi on Earth, the global threats that they face, and the policies to safeguard them. Produced in conjunction with an international scientific symposium, Kew’s State of the World’s Plants and Fungi sets an important international standard from which we can annually track trends in the global status of plant and fungal diversity

Antiproliferative and antibacterial activity evaluation of red microalgae Rhodosorus marinus

Antiproliferative activity of three extracts obtained from red microalgae Rhodosorus marinus was evaluated against cervical (HeLa), colon (HCT 116), lung (A549), prostate (22Rv-1) and breast (HCC38 and MDA-MB-231) cancer cell lines. Antibacterial activity of these extracts was also tested against Salmonella choleraesuis, Listeria monocytogenes and Staphylococcus aureus. All extracts were obtained from lyophilized biomass of red microalgae. Extract A was obtained using 40% ammonium sulfate precipitation and gel filtration chromatography with G-25 sephadex. Extract B was subjected to a similar process, but 60% ammonium sulfate precipitation was used. Extract C was obtained by methanol extraction and hydrophobicity chromatography using amberlite XAD-2. Protein concentration was determined in two extracts and total phenols in one extract, using Bradford and Folin techniques. Antiproliferative activity was evaluated at extract concentrations ranging from 0.125 to 1 mg/ml, using the spectrophotometric technique MTT (3 - (4,5 - dimetiltiazolyl - 2) - 2,5 - diphenyltetrazolium bromide). The antibacterial activity was evaluated by the impregnated disk test. Extract C showed antiproliferative activity against almost all cancer cell lines with an IC50 of 0.5 (HCT 116), 0.8 (HeLa), 0.9 (MDA-MB-231), 0.1 (HCC38), and 0.4 (22Rv-1) mg/ml, whereas none of the tested extracts showed antibacterial activity under experimental conditions.Keywords: Rhodosorus marinus, red microalgae, antibacterial activity, antiproliferative activity, methanolic extract. African Journal of Biotechnology, Vol 13(43) 4169-417

EVALUACIÓN DE LA ACTIVIDAD ANTIBACTERIANA IN VITRO DE ACEITES ESENCIALES CONTRA Clavibacter michiganensis subespecie michiganensis

Las plantas producen compuestos con propiedades antimicrobianas que pueden ser empleados en el combate de diferentes enfermedades en la producción de hortalizas. Con la finalidad de buscar alternativas naturales para el control de la bacteria Clavibacter michiganensis subespecie michiganensis, se evaluó la actividad antibacteriana in vitro de 19 aceites esenciales, de los cuales fueron seleccionados 6 por su actividad bactericida. La técnica utilizada para el análisis de la actividad  antimicrobiana fue la de difusión en agar, utilizando discos de papel filtro estériles embebidos con el aceite esencial, diluidos 1:1, 1:5 y 1:10 (v/v), en medio de cultivo específico (NBY) previamente inoculado con la cepa de estudio. El análisis de varianza mostró que existe diferencia significativa (

State of the World’s Plants and Fungi 2020. Royal Botanic Gardens, Kew

Kew’s State of the World’s Plants and Fungi project provides assessments of our current knowledge of the diversity of plants and fungi on Earth, the global threats that they face, and the policies to safeguard them. Produced in conjunction with an international scientific symposium, Kew’s State of the World’s Plants and Fungi sets an important international standard from which we can annually track trends in the global status of plant and fungal diversity

State of the World’s Plants and Fungi

International audienc