Author/Editor		Faganeli, J
Title		Mikrobni biogeokemični procesi razgradnje sedimentirane organske snovi v Tržaškem zalivu
Translated title		Microbial degradation of sedimentary organic matter in the Gulf of Trieste (northern Adriatic)
Type		članek
Source		In: Bole-Hribovšek V, Ocepek M, Klun N, editors. Zbornik s programom 2. kongres slovenskih mikrobiologov z mednarodno udeležbo; 1998 sep 27-30; Portorož. Ljubljana: Slovensko mikrobiološko društvo,
Publication year		1998
Volume		str. 201-4
Language		slo
Abstract		In this contribution the present understanding of benthic microbial processes involved in the degradation of sedimentary organic matter in the Gulf of Trieste (northern Adriatic) is explored. This analysis focuses on two major processes governing the benthic microbial biogeochemistry in the Gulf: (1) sources and reactivities of sedimentary organic matter and (2) benthic microbially-mediated degradation of organic matter in sediments and nutrient regeneration. The sedimentary organic matter in the Gulf is of entirely marine, phytoplanktonic and microphytobenthic, origin in the central part of the Gulf while in the northern and southern parts the contribution of terrigenous of prevalently matter by riverine discharges (especially Soca in the north) is significant. Degradation of prevalently marine sedimentary organic matter is dominated by anaerobic mineralization processes and among them sulphate reduction accounts for the majority of organic matter decomposition especially during bottom water O2 depletion and higher temperatures. In lower temperatures when microbial activities are lower the increased penetration of oxygen in surfical sediment leads to a predominance of metal (Mn and Fe) reduction. During warm period when microbial activity, bioturbation and bottom water O2 content are high, the activities of infauna mantain a subsurface cycling of redox sensitive elements enhancing the metal reduction. Denitrification would account only for minor percentage of sedimentary organic matter decomposition. Sulphate and metal reduction rates appear to be similar in magnitude to sediment O2 consumption, moreover, the majority of O2 consumption would occur via oxidation of reduced species rather by O2 respiration.
Descriptors		SEAWATER GEOLOGIC SEDIMENTS BIODEGRADATION OXYGEN METALS