Control and Destruction of Microorganisms Basic Micro_Oct 12 PDF

Differential staining - May counterstain basically - Includes all (including endospores) - Physio-chemical – ex. Steam with formaldehyde (against vegetative cells) - Worn by almost all doctors in 1665 – great plague disease - Mask with a beak – beak contains sweet or strong odor...

Differential staining - May counterstain basically - Includes all (including endospores) - Physio-chemical – ex. Steam with formaldehyde (against vegetative cells) - Worn by almost all doctors in 1665 – great plague disease - Mask with a beak – beak contains sweet or strong odors o Believed na yung plague is caused by bad air “evil smells” - Moist heat – targets the macromolecules o More effective o Can penetrate more - Dry heat – direct heat usually - Used heat to prevent spoilage sa beer and wine - Temp used depends on the thermal death time o Duration it takes to kill a certain bacteria at a certain temp - Thermization – heating milk 57-68 C for 15 minutes - LTLT – kills spoilage microorganisms o Preserves yung quality ng sample - HTST -flash pasteurization o Pathogenic bacterial spores o “flowing” process o For yogurt and other products - UHT – targets the causative of Q fever (Coxiella burnetii) o For products in cartons o Sterilization of food cartons using h2o2 – 30% concentration at around 70C for 6 secs - Different autoclave for both sterilization and decontamination - It’s the high temp that’s achieved under the 15 psi pressure that kills the bacteria o At 15 psi, narreach yung 121 C - Useful when sterilizing glass plates - Common misconception – same principle w membrane filters - Hepa filter -.5 – 2 um - Diffusion – collision of particles with gas molecules thus hitting the glass fibers - Removal of moisture to prevnt microbial growth - Food could extend for a very long period of time if its properly packaged - Can remove 98% of water in food - Principle of sublimation - Maintains the properties of food (nutrients, etc) - If mataas yung solute concentration, maddraw out yung moisture thus preventing microbial growth - cause DNA damage - high penetration power o sterilize internal tissues - suitable for almost any type of materials - very risky for those who are exposed to this o can cause mutation - more expensive - at 260 nm, readily absorbed by DNA - triclosan – antibacterial and antifungal o polychlorophenoxy phenol o fat soluble o poisons or target certain enzyme ▪ ENR enzyme( Enoyl-acyl carrier protein reductase) - Pwede maaffect ng alcohol yung permeabilization of spore o 70% alcohol affects spore formation if coupled with high temp Silver – Copper Mercury – against skin mucus membranes - Fenton reaction -