Skretting, Ctra. de la Estació n, Cojobar, Burgos 09620, Spain A novel Gram-stain-negative rod-shaped gliding bacterial strain, designated 35/09 T , was isolated from diseased European sea bass (Dicentrarchus labrax L.) in Spain. Colonies were pale-yellowpigmented with uneven edges and did not adhere to the agar. The DNA G+C content of the isolate was 31.3 mol%. 16S rRNA gene sequence analysis indicated affiliation to the genus Tenacibaculum (family Flavobacteriaceae, phylum 'Bacteroidetes'). Sequence similarities between the isolate and type strains of other members of the genus were 93.1-97.3 %. The major fatty acids (.5 % of the total fatty acids) were iso-C 15 : 0 (24.8 %), iso-C 15 : 0 3-OH (18.0 %), anteiso-C 15 : 0 (8.1 %), C 15 : 1 v6c (6.9 %) and iso-C 15 : 1 (6.2 %). Genotypic and phenotypic data indicate that strain 35/09 T should be classified as a representative of a novel species in the genus Tenacibaculum, for which the name Tenacibaculum dicentrarchi sp. nov. is proposed; the type strain is 35/09 T (5CECT 7612 T 5NCIMB 14598 T ).

Decomposition of soil organic matter by microorganisms is a major process governing the carbon balance between soil and atmosphere which needs to be fully understood. Extracellular enzyme activity is often the limiting factor for microbial utilization of soil organic matter. Contrary to expectations, we observed that enzymatic activity rises at increasing temperatures in soils and sediments. Current climatic change will induce the increase of global mean temperatures, frequency of extreme heat events and soil temperatures during the next decades. The relevance of the increase in activity at high temperature is dependent on latitude. At latitudes around and below 40°a significant number of days per year present high temperatures. Results suggest that the hydrolytic activity of microbial extracellular enzymes is currently underestimated mainly at medium and low latitudes where soil temperatures frequently reach high values (often above 40°C). This report contributes to understand (1) the hydrolysis of soil organic matter within a latitude-dependent scenario of global warming and (2) the role of microorganisms in processing soil organic matter and their influence in carbon cycling.

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