iBB

Cassava (Manihot esculenta) cultivation is of great importance in many economies, particularly in Colombia. About 630,000 tons of C-rich cassava waste is produced annually and applications to high value products, applying the circular economy concept, must be developed. A recent publication in Journal of Polymers and the Environment assesses the potential use of cassava peel for the production of polyhydroxyalkanoates (PHAs) by Cupriavidus necator. A copolymer of P3HB-3HV was produced and processed into electrospun meshes of random and aligned microfibers, allowing the development of structures that can be applied in the context of tissue engineering. This work involved Manuela Fonseca, Frederico Ferreita and Teresa Cesário form BERG-IBB and has been done in collaboration with researchers from the University of Antioquia, Medellin-Colombia.

Teresa Cesário from BERG-iBB won one of the awards of "Mares Circulares", an iberian competition that supports projects that tackle the problem of marine waste and litter. The competition is part of the Mares Circulares wider initiative designed to preserve the oceans that was launched in 2018 by the Coca-Cola European Partners. The project submitted by Teresa is focused on the valorization of whole and residual macroalgae into bioplastics and protein ingredients. The competition was organized and coordinated by the Association Chelonia with the support of Liga para a Proteção da Natureza (LPN).

Photo: Underwater McMurdo Sound, NSF/USAP photo by Steve Clabuesch; Public domain, via Wikimedia Commons.

A biological process for the production of xylonic acid (XA) from xylose or from xylose-rich lignocellulosic hydrolysates has been patented by BERG-iBB researchers Teresa Cesário, Manuela Fonseca and Maryna Bondar (PT 115970). The ability of the wild strain Paraburkholderia sacchari (previously classified as Burkholderia sacchari) DSM 17165 to produce xylonic acid from renewable and sustainable feedstocks is claimed. XA is a potential substitute for gluconic acid (GA), namely in the pharma industry, as a chelating agent, as a precursor of 1,2,4-butanetriol, polyamides and polyesters, as well as in the production of solvents, paints, adhesives and dyes. Moreover, XA, like GA, can be used as a retardant of the setting time of cement paste. XA productivities in the range 4.8 g/(L.h) to 7.1 g/(L.h) and yields between 89% e 100% were achieved, with XA titres of 360 to 390 g/L, using one single, non-pressurised stirred tank reactor operating in the fed-batch mode under dissolved oxygen concentrations higher than 10%  saturation.

The 3rd Edition of iBB seminars will start on the 13th May with short talks from Tina Keller Costa - "Bioactive compounds from soft coral microbiomes – new chances for blue growth?" and Teresa Cesário - "Circular economy: from cellulosic wastes to biochemical and biopolymers". Join us next monday (13h00 h, room VA.1, IST-Alameda) to learn more about Tina's and Teresa's research at BSRG and BERG.

Paraburkholderia sacchari has the capacity to produce xylonic acid and xylitol, compounds ranked in the top 30 high-value chemicals from biomass. In a recent paper in Biochemical Engineering Journal, Maryna Bondar, Manuela Fonseca and Teresa Cesário from BERG-iBB reveal the outstanding ability of this bacterium to metabolize D-xylose to xylonic acid. D-xylonic acid is a five-carbon sugar acid that can replace gluconic acid in several applications. The biotechnological production of D-xylonic acid is advantageous over gluconic acid because it uses xylose as carbon source. Xylose is a very abundant sugar in nature and only few native bacterial strains can metabolize it. Fed-batch cultivations in a single bioreactor attained xylonic acid titers of 390 g L-1 and a productivity of 7.7 g L-1 h-1. This simplified process can significantly affect process economics, potentiating its translation to an industrial scale.

Macroalgae are an emerging alternative source of various chemicals and materials due to their unique structure, biochemical composition and high photosynthetic rates. They are promising feedstocks for the sustainable supply of commodities and specialties for food, feed, materials and energy. BERG researchers are heading the project "Smart Seaweed: Smart Valorization of Macroalgae" that aims at (i) the development of new products of biotechnological origin such as fermented seaweed, bioplastics and ectoines from marine resources and (ii) the utilization of by-products of the sea industries. Check the project web site here.

The organic fraction of municipal solid waste (OFMSW) accounts for approximately 30-40% of MSW in Europe. BERG-iBB researchers developed a process that uses this type of waste as a raw material or the production of the biodegradable biopolymer P(3HB). In a first step the complex carbohydrates in the waste are hydrolysed into simple monosaccharides. The hydrolysate is then used as a carbon source to feed and induce the bacterium Burkholderia sacchari to produce P(3HB). In order to overcome nutritional deficiencies and attain a significant polymer accumulation (58% g polymer/g CDW) the C/N ratio was adjusted and the hydrolysate was supplemented with minerals. This work demonstrates that an easily accessible waste can be transformed into valuable biodegradable bioplastics. The work was published in Bioresource Technology.

Photo details: municipal waste by OpenIDUser2, GFDL. 

Polyhydroxyalkanoates (PHAs) are biodegradable macromolecules produced as reserve materials by bacteria.  PHAs have the potential to replace the main polymers in the plastic market as long as price competitive production processes are developed. The goal of the project "AlgaePlas", which has recently been recommended for funding by FCT, is to use seaweed residues after hydrocolloid extraction, or whole seaweed with no current industrial applications, as novel sugar platforms for PHAs production by marine bacteria. The project, which falls within the scientific area of Industrial Biotechnology, is headed by Teresa Cesário from BERG-iBB and involves collaboration with the University of Minho. The proposal "AlgaePlas: Seaweed biorefinery for the upgrade of carbohydrates to sustainable bioplastics" was submitted in the context of the 2017 Call for SR&TD Project Grants.