A Novel Cold Active Esterase from a Deep Sea Sponge Stelletta normani Metagenomic Library

Abstract

Esterases catalyze the hydrolysis of ester bonds in fatty acid esters with short-chain acyl groups. Due to the widespread applications of lipolytic enzymes in various industrial applications, there continues to be an interest in novel esterases with unique properties. Marine ecosystems have long been acknowledged as a significant reservoir of microbial biodiversity and in particular of bacterial enzymes with desirable characteristics for industrial use, such as for example cold adaptation and activity in the alkaline pH range. We employed a functional metagenomic approach to exploit the enzymatic potential of one particular marine ecosystem, namely the microbiome of the deep sea sponge Stelletta normani. Screening of a metagenomics library from this sponge resulted in the identification of a number of lipolytic active clones. One of these encoded a highly, cold-active esterase 7N9, and the recombinant esterase was subsequently heterologously expressed in Escherichia coli. The esterase was classified as a type IV lipolytic enzyme, belonging to the GDSAG subfamily of hormone sensitive lipases. Furthermore, the recombinant 7N9 esterase was biochemically characterized and was found to be most active at alkaline pH (8.0) and displays salt tolerance over a wide range of concentrations. In silico docking studies confirmed the enzyme's activity toward short-chain fatty acids while also highlighting the specificity toward certain inhibitors. Furthermore, structural differences to a closely related mesophilic E40 esterase isolated from a marine sediment metagenomics library are discussed.

On giant shoulders: how a seamount affects the microbial community composition of seawater and sponges

“…An increase in nutrient concentrations with depth is consistent with our previous expectations (consider, e.g. Bristow et al, 2017) and can be explained by remineralization processes of sinking marine snow within the deep water layers. Decreasing O 2 concentrations from the intermediate water (NwArIW) to the deep water (NwDW) are also consistent with our expectation based on physical oceanography, as water layers more recently oxygenated at the ocean surface at their site of formation typically carry more oxygen (Jeansson et al, 2017).…”

Compositional and Quantitative Insights Into Bacterial and Archaeal Communities of South Pacific Deep-Sea Sponges (Demospongiae and Hexactinellida)

“…Most sponge microbiome studies have focused on demosponges that were collected from shallow coastal sites in temperate, subtropical, and tropical sampling locations (e.g., Schmitt et al, 2012;Moitinho-Silva et al, 2014;Naim et al, 2014;Thomas et al, 2016;Steinert et al, 2017;Helber et al, 2019). Considering that the deep-sea is the largest, still relatively underexplored habitat on earth, comparably few studies have been conducted on sponges from remote deep-sea or cold-water locations (e.g., Jackson et al, 2013;Kennedy et al, 2014;Reveillaud et al, 2014;Borchert et al, 2017). Antarctic shallow cold-water demosponges host dominant bacterial taxa that are known to be sponge-associated (Webster et al, 2004;Rodríguez-Marconi et al, 2015;Cárdenas et al, 2018Cárdenas et al, , 2019, and Antarctic deep-water demosponges display high levels of host-specificity (Steinert et al, 2019).…”

On giant shoulders: How a seamount affects the microbial community composition of seawater and sponges

“…Research records about seamount microbiology are sparse and comparably few studies have been conducted on deep-sea sponge microbiomes in general (Borchert et al, 2017;Jackson et al, 2013;Kennedy et al, 2014;Reveillaud et al, 2014). Our main aim was to assess whether and via which potential mechanisms a seamount can affect the community structure of pelagic and benthos (sponge)-associated microbial communities, using the Schulz Bank seamount as an exemplary field site.…”

“…The dichotomy between HMA and LMA sponges is considered a main driver of the microbial community structure associated with shallow water sponges (Moitinho-Silva et al, 2017). In comparison to shallow waters, comparably few studies have been conducted on the microbiology of deep-sea sponges (Borchert et al, 2017;Jackson et al, 2013;Kennedy et al, 2014;Reveillaud et al, 2014;Tian et al, 2016). However, for example for deep-sea sponges of the genus Geodia (G. barretti, G. macandrewii, G. phlegraei, G. atlantica), similar microbial phyla have been observed as in HMA shallow water sponges, such as Acidobacteria, Poribacteria and Chloroflexi (Luter et al, 2017;Radax et al, 2012;Schöttner et al, 2013).…”