Natural Clay Minerals as Potential Arsenic Sorbents from Contaminated Groundwater: Equilibrium and Kinetic Studies.

Arsenic (As) contaminated groundwater is a worldwide concern due to its chronic effects on human health. The objectives of the study were to evaluate natural inexpensive raw laterite (RL) and kaolinite (RK) for their potential use as As sorbents and to understand the As sorption on laterite and kaolinite by employing sorption and kinetic models. Raw laterite and RK were tested for EC, pH, XRF and CEC as basic parameters. Batch sorption and kinetic experiments data were fitted in the sorption (Langmuir and Freundlich) model and kinetic (pseudo-first and pseudo-second order) reaction equations, respectively. Morphological and structural changes were observed in RL and RK samples before and after As saturation by employing FTIR and SEM. The major constituent in RL was Fe and Al oxides while in RK major oxides were silica and Al. The Freundlich sorption model well explained the experimental data, indicating a greater sorption capacity of RL on a hetero-layered surface compared to RK. The kinetic reaction equations showed that equilibrium was achieved after a contact time of 240 min and the adsorption was chemisorption in nature. The RL and RK were found to be effective sorbents for As removal, however, RL showed maximum As adsorption and thus superior in comparison with RK. Structural and morphological characterization reveals the role of Fe and Al oxides in the case of RL, and Al oxides in the case of RK, in the adsorption of As. Hence this study concludes that these naturally occurring inexpensive resources can be used as sorbent agents for As-contaminated drinking water treatment.

Correction: Ishaque et al. Iriflophenone-3-C-ß-d Glucopyranoside from Dryopteris ramosa (Hope) C. Chr. with Promising Future as Natural Antibiotic for Gastrointestinal Tract Infections. Antibiotics 2021, 10, 1128.

At the request of Dr. Markus Bacher, Dr. Johann Schinnerl, and Dr. Karin Valant-Vetschera, they have been removed as authors of the paper [...].

Biological Transformation of Zearalenone by Some Bacterial Isolates Associated with Ruminant and Food Samples.

Zearalenone (ZEA) is a secondary metabolite produced by Fusarium spp., the filamentous fungi. Food and feed contamination with zearalenone has adverse effects on health and economy. ZEA degradation through microorganisms is providing a promising preventive measure. The current study includes isolation of 47 bacterial strains from 100 different food and rumen samples. Seventeen isolates showed maximum activity of ZEA reduction. A bacterial isolate, RS-5, reduced ZEA concentration up to 78.3% through ELISA analysis and 74.3% as determined through HPLC. Ten of the most efficient strains were further selected for comparison of their biodegradation activity in different conditions such as incubation period, and different growth media. The samples were analyzed after 24 h, 48 h, and 72 h of incubation. De Man Rogosa Sharp (MRS) broth, Tryptic soy broth, and nutrient broth were used as different carbon sources for comparison of activity through ELISA. The mean degradation % ± SD through ELISA and HPLC were 70.77% ± 3.935 and 69.11% ± 2.768, respectively. Optimum reducing activity was detected at 72 h of incubation, and MRS broth is a suitable medium. Phylogenetic analysis based on 16S rRNA gene nucleotide sequences confirmed that one of the bacterial isolate RS-5 bacterial isolates with higher mycotoxin degradation is identified as Bacillus subtilis isolated from rumen sample. B05 (FSL-8) bacterial isolate of yogurt belongs to the genus Lactobacillus with 99.66% similarity with Lactobacillus delbrukii. Similarly, three other bacterial isolates, D05, H05 and F04 (FS-17, FSL-2 and FS-20), were found to be the sub-species/strains Pseudomonas gessardii of genus Pseudomonas based on their similarity level of (99.2%, 96% and 96.88%) and positioning in the phylogenetic tree. Promising detoxification results were revealed through GC-MS analysis of RS-5 and FSL-8 activity.

Iriflophenone-3-C-ß-d Glucopyranoside from Dryopteris ramosa (Hope) C. Chr. with Promising Future as Natural Antibiotic for Gastrointestinal Tract Infections.

Ethnopharmacological approaches provide clues for the search of bioactive compounds. Dryopteris ramosa (Hope) C. Chr. (plant family: Dryopteridaceae) is an ethnomedicinal plant of the Galliyat region of Pakistan. The aqueous fraction (AqF) of D. ramosa is being used by inhabitants of the Galliyat region of Pakistan to treat their gastrointestinal tract ailments, especially those caused by bacteria. The aims of the present study were as follows: (i) to justify the ethnomedicinal uses of the AqF of D. ramosa; (ii) to isolate a bioactive compound from the AqF of D. ramosa; and (iii) to evaluate the antibacterial and cytotoxic potential of the isolated compound. Column chromatography (CC) techniques were used for the isolation studies. Spectroscopic techniques (UV-Vis, MS, 1&2D NMR) were used for structural elucidation. The agar-well diffusion method was used to evaluate the antibacterial potential of "i3CßDGP" against five bacterial strains, and compare it with the known antibiotic "Cefixime". The brine shrimp lethality test (BSLT) was used for cytotoxic studies. The AqF of D. ramosa afforded "iriflophenone-3-C-ß-D glucopyranoside (i3CßDGP)" when subjected to LH20 Sephadex, followed by MPLC silica gel60, and purified by preparative TLC. The "i3CßDGP" showed a strong potential (MIC = 31.1 ± 7.2, 62.5 ± 7.2, and 62.5 ± 7.2 µg/mL) against Klebsiella pneumoniae, Staphylococcus aureus, and Escherichia coli, respectively. On the other hand, the least antibacterial potential was shown by "i3CßDGP" (MIC = 125 ± 7.2 µg/mL), against Bacillus subtilis, in comparison to Cefixime (MIC = 62.5 ± 7.2 µg/mL). The cytotoxicity of "i3CßDGP" was significantly low (LD50 = 10.037 ± 2.8 µg/mL) against Artemia salina nauplii. This study not only justified the ethnomedicinal use of D. ramosa, but also highlighted the importance of ethnomedicinal knowledge. Further studies on AqF and other fractions of D. ramosa are in progress.