Question

fill in the blank question
the two major bacterial sources of antibiotics are the genera
\boxed{} and
\boxed{}.
need help? review these concept resources.

Explanation:

In microbiology (a subfield of Biology, which is part of Natural Science), the two major bacterial genera that are primary sources of antibiotics are Streptomyces and Penicillium (though Penicillium is a fungus, Streptomyces is a bacterium; another key bacterial genus is Bacillus). However, the most common bacterial genera for antibiotic production are Streptomyces and Bacillus. So the two major bacterial genera (sources of antibiotics) are Streptomyces and Bacillus (or Streptomyces and Penicillium, but Streptomyces is bacterial, Penicillium is fungal; the question specifies bacterial, so Streptomyces and Bacillus).

Answer:

The two major bacterial sources of antibiotics are the genera $\boldsymbol{Streptomyces}$ and $\boldsymbol{Bacillus}$ (or Streptomyces and Penicillium, but Streptomyces is bacterial, Penicillium is fungal; the question specifies bacterial, so Streptomyces and Bacillus).

(Note: If strictly bacterial, the standard answer is Streptomyces and Bacillus. If including fungal (though the question says bacterial), Penicillium is fungal. So the correct bacterial genera are Streptomyces and Bacillus.)