1. Taq polymerase.
Polymerase chain reaction (PCR) is a way to replicate millions of copies of a specific piece of DNA in the lab. PCR works by utilizing the process of cellular DNA replication in an in vitro reaction. One of the steps of PCR is heating the reaction to 99C to denature the double stranded DNA. This kills the DNA polymerase, which is needed to for building the DNA strand. Taq is a DNA polymerase from Thermophilus aquaticus, a microbe that lives in very hot environments. Taq is heat stable, thus PCR can be run more efficiently without having to add new enzyme after every step.
2. Restriction enzymes
Restriction enzymes are enzymes found in bacteria that cut DNA at specific sites. Bacteria use restriction enzymes to cut foreign DNA that enters it (e.g. viruses trying to infect it). Scientists use restriction enzymes for cloning.