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Marine bacteria present enzymatic activities that result from extensive evolution necessary for cell survival under the harsh and continuously changing conditions found in the marine environment. Metagenomic techniques and cultivation of not-yet-cultured bacteria, combined with high-throughput screening techniques, have allowed the identification of new biocatalysts and the development of industrial processes. In a recently published paper, Carlos J.C. Rodrigues and Carla C.C.R. de Carvalho (iBB) review the latest studies related to growth of marine bacteria under laboratorial conditions, screening techniques, and bioprocess development.

A team of researchers from iBB-BERG, including Carlos Rodrigues, Ricardo Pereira, Pedro Fernandes, Prof. Joaquim Sampaio Cabral and led by Carla de Carvalho, will contribute to the development of enzymes for a new generation of environmentally friendly consumer products in the EU project FuturEnzyme. The consortium of 16 leading academic and industrial partners, led by Dr. Manuel Ferrer from CSIC (Spain), will develop innovative solutions that will combine big biodata mining and bio-prospecting, disruptive machine learning and protein engineering, nano-biotechnology, fermentation and downstream-processing systems, and pre-industrial testing. Innovative solutions will be proposed to discover, design, optimize and formulate new enzymes to develop detergents, textiles and cosmetics that combine a high level of functionality with improved sustainability, thus responding to the demands from consumers and industries.

The development of bioprocesses for industrial applications is often hampered by the use of time-consuming systems needed to find and characterize new biocatalysts. In particular, transaminases for the synthesis of optically pure chiral amines usually require multi-enzymatic and/or expensive high throughput equipment. In a recent published paper, Carlos JC Rodrigues (BERG-iBB), João M Sanches (LARSyS, ISR), and Carla CCR de Carvalho (BERG-iBB), developed an automatic time-lapse imaging system allowing both the identification of the most promising transaminases, and the determination of their kinetic parameters. The developed method reduces the time required for detection and quantification of specific transaminase activity, thus contributing to the success of biocatalyst application in industrial processes.

It is usually accepted that only 0.1-1% of marine bacteria may be cultivated under laboratory conditions. This resulted mainly from the observation that only a small fraction of the total bacteria determined by microscopic counts could be enumerated by culture plate techniques, and has been a justification for the widely implementation of cultivation-independent molecular techniques. In a recent published paper, Carlos J.C. Rodrigues and Carla C.C.R. de Carvalho (BERG-iBB) promoted the growth of bacteria from a marine rock pond by culture dependent techniques and compared the results with culture independent methods. The highest efficiency of cultivation was 45% attained in marine agar. The study shows that it is possible to grow more than the traditionally considered 1% of bacteria from a seawater sample using standard agar plate techniques and laboratorial conditions, and to find bacteria not detected by molecular approaches.

The ocean is an excellent source for new biocatalysts due to the tremendous genetic diversity of marine microorganisms, and it may contribute to the development of sustainable industrial processes. In a recent paper published in Microorganisms, Carlos J.C. Rodrigues and Carla C.C.R. de Carvalho (iBB-BERG) used a marine bacterium for the conversion of benzaldehyde to benzyl alcohol, which is an important chemical employed as a precursor for producing esters for cosmetics and other industries. A stirred reactor, using a fed-batch approach, enabled a 1.5-fold increase in benzyl alcohol productivity when compared with batch mode. However, product accumulation in the reactor hindered the conversion. The use of a continuous flow reactor packed with immobilized cells enabled a 9.5-fold increase in productivity when compared with the fed-batch stirred reactor system.

Carlos JC Rodrigues and Carla CCR de Carvalho (iBB-BERG) presented their work in EFB2021, the major scientific conference organised by the European Federation of Biotechnology. The two studies presented focused on the marine environment as a source of biocatalysts for suitable bioprocesses, and on using microbial heterogeneity to improve bioprocesses. The virtual conference took place during May 10th-14th.

During crude oil extraction, the reduction in temperature and pressure results in the precipitation of paraffin wax, which may accumulate inside production tubes, pipelines, and also in tankers during petroleum transportation. Few bacterial strains are able to degrade this type of solid substrates. In a paper, published  in Biotechnology Journal, Carlos Rodrigues and Carla CCR de Carvalho (BERG-iBB) evaluate the biodegradation of paraffin by Rhodococcus erythropolis cells. The cells could grow as a thick biofilm over the solid substrate and rapidly degrade paraffin when it was supplied in the form of microparticles. The phenotypic adaptations allowing the cells to degrade the 20-40 chain hydrocarbons are discussed in the paper.