1. From waste-biomass to biodegradable plastics
I will be present here today an overview of the projects our group is currently involved.
Our main focus is the upgrade of the nutrients in waste materials for the production of value-added products. This is typically CIRCULAR ECONOMY, which aims at the recycling of resources and at a zero waste situation.
M. Teresa Cesário, Štěpán Tůma,
J. Kepa Izaguirre, Mafalda Marques,
Pedro Fernandes and
M.Manuela da Fonseca
iBB, Bioengineering Department
IST - University of Lisbon, PORTUGAL

2. Sustainable feedstocks and processes
World population:
2018: 7 billion (7 E09)
2050: 10 billion (10 E09) people
Pressure to increase:
Food/ feed sources
Fuels
Chemicals/ materials
Sustainable feedstocks and processes
Decrease CO2 emissions (decarbonization)
Circular economy zero waste strategy
M. Teresa Cesário, iBB Técnico-Lisboa

3. Carbon platform: waste biomass
Goal 12: Responsible production and consumption
Terrestrial
Marine
Target 12.5:  By 2030, substantially reduce waste generation through prevention, reduction, recycling and reuse.
Wheat straw
OFMSW :
Organic fraction of the Municipal Solid Waste
Gelidium residues
SDG: sustainable development goals
Target 12.5
OFMSW : The waste feedstock was composed of domestic and garden wastes. OFMSW was collected from the local composting plant EPELE (Gipuzkoa, Spain)
Explicar que parajá estamos a trabalhar com Ulva inteira, mas a ideia para o futuro é utilizar resíduos (após extraccao da proteína – U Wag)
GOAL 14: Conserve and sustainably use the oceans, seas and marine resources for sustainable development
Ulva lactuca residues

4. Product: Bioplastics (polyhydroxyalkanoates)
Polyhydroxyalkanoates (PHAs) are biopolymers synthesized and accumulated intracellularly by over 200 microbial strains;
Properties similar to petroleum-derived plastics;
Biodegradable, even in marine environment
Applications in agriculture, medicine and packaging.
P (3HB) has properties similar to PP

5. Lignocellulosic agricultural residues
Lower the PHA production costs associated with the C-source
Use a residual, renewable, non- edible feedstock
Wheat straw
AFEX + enzymatic hydrolysis
glucose
(g/L)
xylose
arabinose
 465.3 
146.3
41.5
445.1
206.1
35.4
628.3
314.8
47.6
485.1
347.0
44.6
585.0
488.0
42.0
Abundant feedstock
High carbon content

6. Results Fed-batch cultivation on wheat straw hydrolysates
Burkholderia sacchari DSM (  70 % (g PHB/ g CDW))
Dr. Antonio A.Matos , CIIEM-ISCSEM, Monte de Caparica, Portugal
P(3HB) and copolymer P(3HB-4HB) volumetric productivities are the highest ever achieved on agricultural waste hydrolysates.
B. sacchari is able to consume xylose at a fairly good rate
Production (g/L)
Productivity
(g.L-1.h-1)
P( 3HB) 94
1.6
P(3HB-co-6% 4HB) 24
0.5

7. Seaweed as carbon platforms

8. Why seaweeds as C-platforms ?
ADVANTAGES
No competition for arable land
High carbohydrate content (up to 80 % dw )
No fresh water consumption
No lignin
IMTA –Integrated Multi-Trophic Aquaculture = integration of aquaculture with seaweed farming
GHG: green house gases
Naturally abundant feedstock
High photosynthetic rates
Cesário M.T. et al. (2018), Marine algal carbohydrates as carbon sources for the production of biochemicals and biomaterials. Biotechnology Advances 36,

9. Biomass characterization
Parameter
Value
Unit
Method
Dry-weight (DW)
93.90 ± 0.83
(%)
NREL 60956
Moisture
6.10 ± 0.83
Proteins
0.68
(% dw)
Kjeldahl method
Lipids
3.36
Idem
Soxhlet method
Ash
16.39 ± 1.15
Carbohydrates
44.80 ± 1.90
NREL 60957
Agar
7.3
NREL60957
Cellulose
37.05 ± 0.02
Starch
0.80 ± 0.33
Megazyme
Lyophilized Gelidium residues after agar extraction
16%

10. Selected microorganism
Moderately halophilic bacteria that are good PHA-producers
DSM 15516
Appropriate for Continuous Process Development
Reduce contamination risk
Allow the use of non-sterile conditions
Halomonas boliviensis DSM 15516
tolerates up to 25 % (w/w) NaCl
(NaCl opt = 4-5 % NaCl)
grows at pH 6-11 (pH opt = )
produces PHAs on glucose and galactose
Halomonas boliviensis DSM 15516 (

11. Hydrolysis of Gelidium polysaccharides
MILD ACID HYDROLYSIS
ENZYMATIC HYDROLYSIS
Milled
seaweed residues
Algal hydrolysate
Sulfamic acid , 121°C, 30 min
Cellulolytic enzymes
23 .1 g/L glucose, 0.01 g/L HMF; no galactose
HMF < 0.1 g/L

12. PHA production from Gelidium hydrolysate
Glucose (20 g/L)
Gelidium hydrolysate (20 g/L glucose)
CDW= 10.8 g/L
PHB = 5.0 g/L
% PHB= 46.7 %
CDW= 8.7 g/L
PHB = 3.3 g/L
% PHB= 38.0 %

13. Conclusions
Gelidium residues are sugar-rich feedstocks that can be upgraded to biomaterials:
Gelidium residues still contained 44 % (dw) carbohydrates:
37 % cellulose
7 % agar
Produced sugar-rich Gelidium hydrolysates with low inhibitor concentrations
Successful production of PHB based on algal hydrolysates but lower values when compared to commercial sugars.
Hydrolysate composition under study (C, N, P content).
We aim to find the right conditions to achieve very high productivities with algae hydrolysates as we have with wheat straw: optimize hydrolysate production and composition and PHA production conditions in the bioreactor.

14. Acknowledgements
The research leading to these results has received funding from the FCT projects (PTDC/BII-BIO/29242/2017) and (UID/BIO/04565/2013) and from Programa Operacional Regional de Lisboa 2020 (Project N ).
We are particularly thankful to:
Iberagar – Sociedade Luso-Espanhola de Colóides Marinhos SA for supplying Gelidium sesquipedale residues.

15. Thank you for your attention