Organic matter recycling in a shallow coastal zone (NW Mediterranean): The influence of local and global climatic forcing and organic matter lability on hydrolytic enzyme activity

In the sediment, the lower protein: carbohydrate and chlorophyll-a: phaeopigment ratio values indicated higher OM refractivity than in the seawater, thus increasing the need for greater proteolytic activity, significantly increasing the leucine aminopeptidase: β glucosidase ratio values and the bacterial cell-specific proteolytic activity. Although the initial trophic quality of the OM was potentially worse than that of the seawater, the heterotrophic microbial component showed successful adaptations, such as Km values similar to those of seawater, higher cell-specific hydrolytic activities and significantly higher growth rates.