In the absence of autoclave, one can use pressure cooker to sterilize the nutrient agar. The most important thing is that the temperature must be high enough to kill off any microbe present. The pressure cooker can be used in place of autoclave at the temperature of 121 degree Celsius for fifteen minutes.
Many reasons including that burning of them (including use in cars) creates greenhouse gases which lead to climate change. There are alternatives becoming available that lower the greenhouse gas emissions...healthier planet!
