Antibiotic resistance has increased significantly in the recent years, and has become a global problem for human health and the environment. As a result, several technologies for the controlling of health-care associated infections have been developed over the years. Thus, the most recent findings in hydrogel fabrication, particularly antimicrobial hydrogels, could offer valuable solutions for these biomedical challenges. In this review, we discuss the most promising strategies in the development of antimicrobial hydrogels and the application of hydrogels in the treatment of microbial infections. The latest advances in the development of inherently and composite antimicrobial hydrogels will be discussed, as well as hydrogels as carriers of antimicrobials, with a focus on antibiotics, metal nanoparticles, antimicrobial peptides, and biological extracts. The emergence of CRISR-Cas9 technology for removing the antimicrobial resistance has led the necessity of new and performant carriers for delivery of the CRISPR-Cas9 system. Different delivery systems, such as composite hydrogels and many types of nanoparticles, attracted a great deal of attention and will be also discussed in this review.

A mud volcano (MV) is a naturally hydrocarbon-spiked environment, as indicated by the presence of various quantities of PAHs and aromatic isotopic shifts in its sediments. Recurrent expulsion of various hydrocarbons consolidates the growth of hydrocarbonoclastic bacterial communities in the areas around MVs. In addition to the widely-known availability of biologically malleable alkanes, MVs can represent hotbeds of polyaromatic hydrocarbons (PAHs), as well - an aspect that has not been previously explored. This study measured the availability of highly recalcitrant PAHs and the isotopic signature of MV sediments both by GC-MS and δ¹³C analyses. Subsequently, this study highlighted both the occurrence and distribution of putative PAH-degrading bacterial OTUs using a metabarcoding technique. The putative hydrocarbonoclastic taxa incidence are the following: Enterobacteriaceae (31.5%), Methylobacteriaceae (19.9%), Bradyrhizobiaceae (16.9%), Oxalobacteraceae (10.2%), Comamonadaceae (7.6%) and Sphingomonadaceae (5.5%). Cumulatively, the results of this study indicate that MVs represent polyaromatic hydrocarbonoclastic hotbeds, as defined by both natural PAH input and high incidence of putative PAH-degrading bacterial OTUs.

The species Salix alba L. and Salix purpurea L. are medicinal herbs, frequently used in the pharmaceutical industry. This study performs phytochemical and antibacterial analysis of ethanolic extracts from the bark of these two species. The qualitative and quantitative phytochemical analyses were performed by thin-layer chromatography identifying the salicin and salicylic acid; the salicin content was assessed by high performance liquid chromatography. The bark extracts yielded 4.300 μg/ml-1 salicin for Salix alba and 1.167 μg/ml-1 salicin for Salix purpurea. The plant extracts were tested on Gram negative and positive bacteria (Escherichia coli and Staphylococcus aureus). Both tested strains showed a mild resistance, but S. aureus showed slightly higher inhibition by all extract samples.

Salty soil samples from three zones of Cojocna (Cluj county, Romania) have been investigated physico-chemically and enzymologically. Rizosphere of some halophytes were investigated in order to assess saline stress on bacterial enzyme activities and halophytes adaptation mechanisms to enhanced salt content. Several physico-chemical parameters of salty soil were determinated: pH, conductivity and different mineral ion contents. Changeful bacterial enzymatic activities and mineral ion composition were detected according to soil salt content. Reduced values of all enzymatic activities were detected. Based on the studied enzyme activities the enzymatic indicators of soil quality (EISQ) were calculated. The EISQ values were low, between EISQ = 0.201 and 0.236. In the sudied salty area, only a few halophyte species were observed and identified, the most common are: Salicornia herbacea, Puccinellia distans, Artemisia santonica, Limonium gmelinii and Salsola soda. All three salty zones were classified as sodic and saline-sodic soils. Carpa et al Cojocna (PDF)

Cellulases production involving alternative substrates has been intensely researched, because it offers perspectives for lowering the costs for enzyme production, costs which are a major obstacle for the development of this field. The concentration, turnout, effectiveness of the enzyme production depends on the content of culture medium. In order to find a way to increase cellulase production, two culture media with different cellulosic substrates in submerged culture experiments were tested. We used a promising off-corn growth media that was efficient and the cellulases output due to substrate action was calculated. The reduction of the sugars released by the enzyme was noticed. On off-corn medium the measurements reached 0.188 mg of released glucose/mL/min/50ºC, while on PSM medium the strains reached the release of only 0.118 mg glucose/mL/min/50ºC. The abundance of the fungi and the pellet morphology were microscopically compared by optic and electronic means. Mycelia with hyphae and spores were also visible in these circumstances, suggesting that when the environment of the mycelium alters, part of the mycelium autolyses and spores are released to propagate. The present study also included the use of newly synthesized cellulases in order to obtain a plant protoplast culture. This study proves that cellulolytic enzymes with further application in laboratory can be provided by less expensive techniques. Carpa et al (PDF)