According to the text, Saccharomyces cerevisiae (yeast) is used for fermenting malted cereals and fruit juices to produce ethanol , . The other options are mismatched: Methanobacterium produces methane (biogas) , ; Penicillium notatum produces the antibiotic Penicillin ; and Acetobacter aceti produces acetic acid . Lactic acid is produced by Lactobacillus .