Which of the following microorganisms is commonly used for single-cell protein production?
E. coli
Saccharomyces cerevisiae
Streptococcus pyogenes
Aspergillus niger
Saccharomyces cerevisiae, also known as baker's yeast, is a commonly used microorganism for single-cell protein production. It is a fast-growing organism that can use a wide range of substrates, making it a versatile choice for SCP production. Hence option B is the correct answer.