Mycosynthesis of silver nanoparticles using marine fungi and their antimicrobial activity against pathogenic microorganisms.

OBJECTIVES: At the present time, there is a persistent need to get rid of environmental contaminants by eco-friendly, sustainable, and economical technologies. Uncontrolled disposal practices of domestic and industrial solid and liquid wastes led to water pollution which has negative impacts on public health, environment, and socio-economic development. Several water-borne diseases are spreading man to man by microorganisms such as pathogenic bacteria. For the protection of water bodies, all wastewater from various sources should be managed and remediated properly. Myco-remediation is a form of bioremediation in which fungi are used to get rid of contaminants. Fungi are attractive agents for the biosynthesis of nanoparticles especially silver nanoparticles (AgNPs) which are considered one of the most widely utilized nanoparticles because of their unique characteristics such as antibacterial, antiviral, antifungal, and anti-inflammatory properties. METHODS: This study uses silver nitrate and supernatants of four marine fungi; Penicillium simplicissimum, Aspergillus terreus, Aspergillus japonicus, and Aspergillus oryzae for extracellular biosynthesis of silver nanoparticles and to evaluate its activity against different pathogenic microorganisms. These nanoparticles may subsequently be applied for the treatment or nano-bioremediation of microbial contaminants in water bodies and improve water quality. RESULTS: Silver nanoparticles were synthesized and the results revealed that spherical and well-dispersed nanoparticles of different sizes were formed with sizes ranging between 3.8 and 23 nm. Characterization results approved the existence of stable nanocrystalline elemental silver. Antibacterial activity results revealed that AgNPs can be used as a powerful antimicrobial agent for several pathogenic bacteria, yeast, and fungi. Among the biosynthesized NPs mediated by the four marine fungi, AgNPs mediated by A. japonicus (5 mM) had the highest antibacterial activity, while AgNPs mediated by Penicillium simplicissmum (8 mM) had the highest antifungal activity. CONCLUSION: Marine fungi can biosynthesize stable AgNPs that exhibit potent antimicrobial activity against a variety of pathogens.

Multi-temporal shoreline analysis and future regional perspective for Kuwait coast using remote sensing and GIS techniques.

Coastal regions are of extraordinary significance for the financial and welfare of human communities. Unfortunately, coastal regions are naturally pressured by anthropogenic activities that increase their vulnerability. Hence, there is a drastic need to monitor coastal changes to protect and manage them sustainably. Since Kuwait's coast is inhabited by about 94% of the inhabitants and most of the metropolitan area and the urgent need for sustainable planning and management of Kuwait's coast, this paper aims to analyze the historical changes rate of Kuwait's coast and Kuwait islands over 40 years from 1980 to 2020 and to predict the future changes of the shoreline in 2035 using EPR model. The results show that the highest accretion rate of the shoreline is 32.79 m/year, while the lowest erosion rate is -23.45 m/year. EPR of the islands revealed a fluctuation between erosion and deposition at each island. The future predicted shoreline changes were also mapped for the shoreline and islands.