Ultrafiltration fouling behavior of natural organic matter: a perspective of EEM and molecular weight distribution

As the natural organic matter (NOM) can cause serious ultrafiltration (UF) membrane fouling, most previous studies on UF fouling caused by NOM focused on the contribution of NOM characteristics. In this study, the correlation of molecular weight and fluorescence characteristics was examined and the fouling behavior of NOM were examined in a comprehensive manner through a lot of analysis including the redundancy analysis (RDA), parallel factor analysis (PARAFAC) and atomic force microscope (AFM). The results showed that NOM from Tong Xin river was composed of humic acid (500 Da–8,000 Da), tryptophan-like substance, soluble microbial product (SMP) and aromatic protein (600,000 Da–2,000,000 Da).Notably, UF performance was significantly affected by the humic acid-like substance. Concurrently, the combined mechanism (CM) model was adopted to evaluate the fouling mechanism of NOM. The results indicated that cake-intermediate model played an important part during membrane fouling and the cake layer fouling had a larger predominance over the intermediate blocking which can be further proved in the membrane morphology detection.

Violacein, A Microbial Antiviral Product: Does Play Key Role as Active Agent Against SARS-CoV-2?

Violacein, a microbial product was characterized after continuous attempts to feature it, based on degradation and synthesis procedures, at the University of Liverpool (England), from 1958 to 1960 and only at 2001 was chemically synthesized. It is a quite known antimicrobial and antiviral natural product. New attempts to solve the infection caused by, or find the proper therapy for, COVID19, must adopt multidisciplinary approach. The aim of the current study is to address the targets, possible strategies and perspectives of new technologies and therapies on COVID19. It also hypothesizes the potential of using the therapeutic drug called violacein as multifunctional agent to treat patients at different COVID19 contamination stages. Our experience and knowledge about violacein has led us to extrapolate the potential use of this pigment. Violacein multiple biological activities as also knowledge on its toxicity and antiviral activity enabled suggesting that it could be the new important agent used to treat COVID19. Violacein is highly likely to act as protease inhibitor, at ACE2 receptor level and as immunotherapeutic drug against Covid19. In term of chemotherapy, it will be discussed the actual antiviral used against COVID19, such as, thalidomide, ivermectin and melatonin, among others.

Impact of Innovative Films Used for the Production of Silage on Biochemical and Microbial Product Qualities

The production of silage is carried out in cylindrical bales covered with polyethylene foils. In this study, a novel approach was tested towards obtaining an innovative composition of these films. In the first stage of the experiment, different additives, including microcellulose and nanosilver particles, were analyzed. The second stage was aimed at testing the applicability of recycled polyethylene as a film component. The forage value after ensiling was assessed during storage. In order to evaluate the microbial forage quality, the abundance of lactic acid bacteria was determined and compared with the number of aerobic bacteria, yeasts, and molds. The foil properties were also analyzed with the appropriate chemical and microbiological methods. The results showed no significant differences (p < 0.05) between the standard commercial films and tested formulae. In the second stage, obtained results suggested that the film with the addition of nanosilver may be successfully used in agriculture.

Complete biosynthesis of a sulfated chondroitin in Escherichia coli

Sulfated glycosaminoglycans (GAGs) are a class of important biologics that are currently manufactured by extraction from animal tissues. Although such methods are unsustainable and prone to contamination, animal-free production methods have not emerged as competitive alternatives due to complexities in scale-up, requirement for multiple stages and cost of co-factors and purification. Here, we demonstrate the development of single microbial cell factories capable of complete, one-step biosynthesis of chondroitin sulfate (CS), a type of GAG. We engineer E. coli to produce all three required components for CS production–chondroitin, sulfate donor and sulfotransferase. In this way, we achieve intracellular CS production of ~27 μg/g dry-cell-weight with about 96% of the disaccharides sulfated. We further explore four different factors that can affect the sulfation levels of this microbial product. Overall, this is a demonstration of simple, one-step microbial production of a sulfated GAG and marks an important step in the animal-free production of these molecules.