Elemental　sulfur　(S-0)　is　widely　utilized　in　environmental　pollution　control,　while　its　low　bioavailability　has　become　a　bottleneck　for　S-0-based　biotechnologies.　Biogenic　sulfur　(bio-S-0)　has　been　demonstrated　to　have　superior　bioavailability,　while　little　is　known　about　its　mechanisms　thus　far.　This　study　investigated　the　bioavailability　and　relevant　properties　of　bio-S-0　based　on　the　denitrifying　activity　of　Thiobacillus　denitrificans　with　chemical　sulfur　(chem-S-0)　as　the　control.　It　was　found　that　the　conversion　rate　and　removal　efficiency　of　nitrate　in　the　bio-S-0　system　were　2.23　and　2.04　times　those　of　the　chem-S-0　system.　Bio-S-0　was　not　pure　orthorhombic　sulfur　[S:　96.88　+/-　0.25%　(w/w)].　Trace　organic　substances　detected　on　the　bio-S-0　surface　were　revealed　to　contribute　to　its　hydrophilicity,　resulting　in　better　dispersibility　in　the　aqueous　liquid.　In　addition,　the　adhesion　force　of　T.　denitrificans　on　bio-S-0　was　1.54　times　that　of　chem-S-0,　endowing　a　higher　bacterial　adhesion　efficiency　on　the　sulfur　particle.　The　weaker　intermolecular　binding　force　due　to　the　low　crystallinity　of　bio-S-0　led　to　enhanced　cellular　uptake　by　attached　bacteria.　The　mechanisms　for　the　superior　bioavailability　of　bio-S-0　were　further　proposed.　This　study　provides　a　comprehensive　view　of　the　superior　bioavailability　of　bio-S-0　and　is　beneficial　to　developing　high-quality　sulfur　resources.