Optimization of cryopreservation of pathogenic microbial strains

The preservation of pathogenic microbial strains is of great significance for basic research in microbiology and utilization of microbial resources.Appropriate preservation methods can maintain high survival rate and genetic stability of pathogenic microbial strains for a long time.This study summarizes the current status of preservation of strains,discusses the limitations and damaging factors of cryopreservation and prospects for optimization,and explores the mechanism of cryopreservation of strains.Our main objective is to provide a reference for the long-term effective preservation of microbial resources and guarantee of national biosafety.

Chlorine as an integrated approach for environmental health and hygiene:A case study on evaluation of the performance of waste stabilization ponds located at 11 governorates in Egypt

The current study summarizes the current status of wastewater stabilization ponds(WSPs)treatment plants that have already been built in 11 governorates throughout Egypt.Moreover,this study aims to determine the most appropriate chlorine dose for waste stabilization ponds(WSPs)effluents to ensure the treated effluents are suitable for reuse in unrestricted irrigation and to comply with the current legislation on direct discharge onto water bodies.According to the findings,the chlorine doses used as a disinfectant in the treated effluents of the majority of WSP treatment plants ranged from 3 to 13 mg/L.Meanwhile,two of the WSPs treatment plants effluents,the Qus WSPs treatment plant in Qena governorate and the Al Zarabii WSPs treatment plant in Asyut governorate used high chlorine doses reached to 17 and 19 mg/L,respectively.This is due to the fact that both the Qus and Al Zarabii WSPs treatment plants have a high organic load,which necessitated the use of more chlorine to achieve the optimum chlorine dose at 13 mg/L for Qus and 11mg/L for Al Zarabii.The findings demonstrated that chlorine has a powerful effect in completely removing bacteria.Furthermore,in most chlorine-treated wastewater final effluents,as the chlorine doses increased,the chlorophyll-a reading decreased.The amount of trihalomethanes(THMs)produced as disinfectant byproduct was measured.The results proved that the water can be used in unrestricted irrigation,and after adding chlorine,it can be dumped on water bodies without health risks.

Biosafety laboratory risk assessment

Biosafety laboratory risk assessment is a dynamic and systematic work.The scope of the assessment involves evaluation of pathogenic microbial hazards,experimental activities,facilities and equipment,personnel,experimental methods,etc.The four-level evaluation method for pathogenic microorganisms is used for hazard assessment.The aerosol exposure risk is the most common in experimental activities.Facilities and equipment are the basis for the safe operation of biosafety laboratories.Laboratory biosafety risk assessments should be conducted regularly to ensure the safe operation of the laboratory.

Plant biotic interactions

Plants are constantly under attack by pathogens,pests,and parasites,resulting in severe consequences on global food production and human health.While pathogens and pests find their ways to invade and communicate with their hosts,plants have evolved sophisticated immune systems to fight infections.