10.22376/ijpbs.2019.10.1.p1-12 Volume 12 Issue 3 2021 (July-September) Aquatic fungi, which belong to the hyphomycetes family, are filamentous fungi that live in water and are mostly saprobic. They are common in both occurrence and distribution, and they prefer to live on partially decomposed leaf litter in flowing freshwater (rarely in marine water). In the aquatic environment, these fungi play a significant role in biological processes. The present investigation was carried out to analyse the active constituents present in the ethyl acetate extract of lessThan i greaterThan Geotrichum europaeum lessThan /i greaterThan , an aquatic hyphomycete. Secondary metabolites are chemical compounds that are also referred to as phytochemicals. The peak area, retention time, molecular weight, and molecular formula are used to identify phytochemical compounds. The GC-MS analysis showed four major compounds in ethyl acetate with 49.99% is the highest occupied by Trimethoxy-3-piperidyl 2, 2-binaphthalene-1, 1, 4, 4-tetrone, 1,2-Benzenedicarboxylic acid-butyl 2-methylpropyl ester (6.13%), Phenol 5-chloro-2 (2,4-dichloro phenoxy) acetate, Triclosan (1.30%) and Trilinolein (2.5%). Many bioactive compounds were contained in the GC-MS study, including flavonoids, alcohols, aldehydes, aromatic compounds, fatty acid methyl esters, terpenoids, phenolics, and steroids, all of which have antibacterial, anticancer and antioxidant effects. Ethyl extract of bioactive compounds of lessThan i greaterThan Geotrichum europaeum lessThan /i greaterThan was investigated against four pathogenic bacterial strains lessThan i greaterThan i.e. lessThan /i greaterThan lessThan i greaterThan Escherichia coli lessThan /i greaterThan (MTCC 82), lessThan i greaterThan Staphylococcus aureus lessThan /i greaterThan (MTCC 87), lessThan i greaterThan Bacillus subtilis lessThan /i greaterThan (MTCC 441) and lessThan i greaterThan Pseudomonas aeruginosa lessThan /i greaterThan (MTCC 424) and the highest inhibitory activity was obtained against lessThan i greaterThan Bacillus subtilis lessThan /i greaterThan . The diameters of inhibition zones ranged from 5 mm to 27 mm against the selected human pathogenic bacteria. Shivani Raghuwanshi and I. B. Prasher Aquatic hyphomycete, antibacterial activity, Geotrichum europaeum, GC-MS. 104-111