Cultivation‐based strategies to find efficient marine biocatalysts

Abstract

Marine bacteria have evolved to survive in the marine environment by using unique physiological, biochemical and metabolic features and the ability to produce enzymes and compounds which may have commercial value. The Azores archipelago presents several ecosystems with strong volcanic activity where bacteria thrive under e.g. high temperatures. In this study, samples collected in the island of São Miguel were screened for biocatalysts possessing e.g. lipase, esterase, amylase, and inulinase activities. After isolation of several hundred bacterial strains, high throughput screening methods allowed the fast identification of biocatalysts. The first cultivation tests were performed on 24-wells microtiter plates with online oxygen monitoring and bacteria able to grow within 24 h were selected for further process development. Bacteria able to produce the desired enzymes were selected for the first round of tests. Four Bacillus strains presented high inulinase activity. The next step in process development was the determination of key parameters for enzyme activity such as temperature, pH, salinity and substrate concentration. The highest inulinase activity, 2.2 g sugars /g protein h, was attained when the supernatant of a culture of a Bacillus subtilis strain was used in a magnetically stirred bioreactor. This study demonstrates how bacterial strains from marine environments may be used successfully in biotechnological processes.

Applications of Marine-Derived Microorganisms and Their Enzymes in Biocatalysis and Biotransformation, the Underexplored Potentials

“…Hydrolysis reactions, in which water molecules are used for breaking molecular bonds, have been carried out employing marine bacteria, including the hydrolysis of polysaccharides and nitriles (Brandao and Bull, 2003; Rodrigues et al, 2017).…”

“…A high-throughput screening in solid medium was employed in the search for inulinase, amylase, esterase, and lipase activities in new marine bacteria (205 isolates) from Azores, Portugal (strains isolated from intertidal shallow-water hydrothermal vents, intertidal pools, and open waters). The highest inulinase activity (catalysis of the endohydrolysis of 2,1-β- D -fructosidic linkages in inulin) was presented by Bacillus subtilis 83, showing that the bacterial strains from this unique environment might be successful biocatalysts for biotechnological processes (Rodrigues et al, 2017).…”

“…These studies emphasized the importance of carrying out a screening of strains for a successful identification of new biocatalysts, since several strains were not able to perform the desired reactions, as observed for the kinetic resolution of β-hydroxy ketones (Chen et al, 2017). Moreover, the use of different bacterial strains promoted different reactions, as determined for the substrate propyl anti -2-oxotricyclo[2.2.1.0]heptan-7-carboxylate (De Vitis et al, 2015), and enzymatic activities, as inulinase (Rodrigues et al, 2017).…”

Harnessing Marine Biocatalytic Reservoirs for Green Chemistry Applications through Metagenomic Technologies

“…Hence, developing optimised culturing conditions and media supplements to culture these organisms has been the target of several research initiatives [ 91 , 92 ]. It is likely that a broad range of media will be required to access the biodiversity that is currently unavailable to us [ 93 ]. Counterintuitively, often low nutrient concentrations improve cultivation efficiencies [ 94 , 95 ].…”

Editorial: The European Symposium on Biochemical Engineering Sciences, Dublin 2016

“…This Special issue of the Biotechnology Journal , the official journal of the society, showcases some of the technical programe of the symposium and the advances and topics of interest in biochemical engineering, ranging from bioeconomy , sustainability and solvent free extractions , discovery and optimization of new biocatalysts , design of new biotherapeuticals , as well as new process control and design approaches based on modeling and predictive tools .…”