Advances in the detection of ß-lactamase: A review.

ß-lactamase, an enzyme secreted by bacteria, is the main resistant mechanism of Gram-negative bacteria to ß-lactam antibiotics. The resistance of bacteria to ß-lactam antibiotics can be evaluated by testing the activity of ß-lactamase. Traditional phenotypic detection is a golden principle, but it is time-consuming. In recent years, many new methods have emerged, which improve the efficiency by virtue of their sensitivity, low cost, easy operation, and other advantages. In this paper, we systematically review these researches and emphasize their limits of detection, sample operation, and test duration. Noteworthily, some detection systems can identify the ß-lactamase subtype conveniently. We mainly divide these tests into three categories to elaborate their characteristics and application status. Both advantages and disadvantages of these methods are discussed. Additionally, we analyze the recent 5 years published researches to predict the trend of development in this field.

Lanthanum ferrite nanoparticles modification onto biochar: derivation from four different methods and high performance for phosphate adsorption.

To effectively remove phosphate pollution and convectively reuse phosphate resource, straw biochar was firstly functionalized with lanthanum ferrite (LaFeO3) via four different methods, including one-step co-precipitation (S-C), two-step co-precipitation (B-C), one-step impregnation (S-E), and two-step impregnation (B-E). LaFeO3/biochar was characterized systematically by a series of characterization methods. The influence of preparation methods, operation conditions on adsorption process, and the regenerability were studied. The products prepared by four methods displayed different physical morphology and chemical analysis proved chemical composition were similar. LaFeO3/biochar exhibited high adsorption capacity, the pseudo-second-order and Sips models were fitted for the adsorption equilibrium. The LaFeO3/biochar exhibited outstanding phosphate adsorption performance with pH values ranging from 2.3 to 10.6; La ions release was similarly negligible, when pH value was higher than 5.27. The adsorption mechanism was studied and inferred that La species is the key to adsorption ability. The results obtained provide better understanding of the adsorption phenomena and indicate the available preparation technologies and potential usefulness of LaFeO3/biochar for removing phosphate pollution. Graphical abstract "."