Periodic Reporting for period 1 - VALUABLE (VALorisarion of fUngAl Biomass using noveL Enzymatic technology)
Reporting period: 2022-09-01 to 2024-02-29
The concept of biorefineries relies on the constant availability of sustainable biomass feedstocks to secure a steady supply for industrial production. In this context, underutilised residual biomass streams from different industries are of special interest as sustainable raw materials for future biorefinery platforms. Moreover, modern biorefinery concepts aim for a zero-waste approach by also valorising in-process side/waste streams besides their conventional feedstock.
The VALUABLE project separates residual Aspergillus niger biomass from the citric acid production into two fractions: a) chitin as building block for bio-based chemicals and b) a nutrient rich solution to cultivate oleaginous yeast. Microbial oil from yeast biomass is subsequently extracted, employing a patented process. The obtained yeast oil can serve as a substitute for fossil- and plant-based oils. This allows not only for saving fossil oil resources but also for a return of land use towards food production as well as preservation of biodiversity e.g. by replacing problematic palm oil.
The VALUABLE project separates residual Aspergillus niger biomass from the citric acid production into two fractions: a) chitin as building block for bio-based chemicals and b) a nutrient rich solution to cultivate oleaginous yeast. Microbial oil from yeast biomass is subsequently extracted, employing a patented process. The obtained yeast oil can serve as a substitute for fossil- and plant-based oils. This allows not only for saving fossil oil resources but also for a return of land use towards food production as well as preservation of biodiversity e.g. by replacing problematic palm oil.
The first reporting period was mainly characterized by experimental optimization of the VALUABEL process on a laboratory scale. Nevertheless, some very interesting and promising results could be generated already.
The work, regarding the Aspergillus niger (A. niger) biomass treatment and chitin extraction process, showed the eligibility of the dried A. niger biomass for the utilization in the newly designed VALUABLE biorefinery process. An efficient strategy for the enzymatic hydrolysis of the raw material could be developed, resulting in a higher degree of biomass solubilisation (D2.1 & D3.1) compared to standard chemical hydrolysis with acid or base. The mild reaction conditions applied for the hydrolysis result in a solution rich in non-chitin sugars, peptides and amino acids, showing excellent properties as fermentation medium for the single cell oil production employing the unconventional oleaginous yeast Cutaneotrichosporon oleaginosus (C. o.).
The efficient enzymatic hydrolysis process further generates a chitin fraction of high purity that can either be utilized directly (e.g. in adhesive formulations; see below), or further be modified to generate chitosan and / or chitooligosaccharides (CHOS). In this context, an enzymatic conversion process for the derivatisation of chitin to chitosan and CHOS has successfully been developed, representing a new alternative to the chemically produced crustacean-derived chitosan / CHOS.
The chitin/chitosan produced from A. niger biomass has already been tested with regard to its properties in the formulation of adhesives for the plywood panel production and resulted in significant improvements, compared to the standard formulation. The utilisation of the fungal chitin/chitosan leads to higher mechanical strength of the plywood panels. Thus, the addition of chitin/chitosan increases the water resistance of the wood composite material, making the material more suitable for the usage in humid application areas.
Further, the yeast oil, recovered from the C. o. fermentation, was tested for its utilisation in the resin formulation, replacing unfavourable palm oil in the formulation. The first findings showed that the yeast derived microbial oil represents an excellent drop-in alternative to previously used vegetable oils in the resin production.
The work, regarding the Aspergillus niger (A. niger) biomass treatment and chitin extraction process, showed the eligibility of the dried A. niger biomass for the utilization in the newly designed VALUABLE biorefinery process. An efficient strategy for the enzymatic hydrolysis of the raw material could be developed, resulting in a higher degree of biomass solubilisation (D2.1 & D3.1) compared to standard chemical hydrolysis with acid or base. The mild reaction conditions applied for the hydrolysis result in a solution rich in non-chitin sugars, peptides and amino acids, showing excellent properties as fermentation medium for the single cell oil production employing the unconventional oleaginous yeast Cutaneotrichosporon oleaginosus (C. o.).
The efficient enzymatic hydrolysis process further generates a chitin fraction of high purity that can either be utilized directly (e.g. in adhesive formulations; see below), or further be modified to generate chitosan and / or chitooligosaccharides (CHOS). In this context, an enzymatic conversion process for the derivatisation of chitin to chitosan and CHOS has successfully been developed, representing a new alternative to the chemically produced crustacean-derived chitosan / CHOS.
The chitin/chitosan produced from A. niger biomass has already been tested with regard to its properties in the formulation of adhesives for the plywood panel production and resulted in significant improvements, compared to the standard formulation. The utilisation of the fungal chitin/chitosan leads to higher mechanical strength of the plywood panels. Thus, the addition of chitin/chitosan increases the water resistance of the wood composite material, making the material more suitable for the usage in humid application areas.
Further, the yeast oil, recovered from the C. o. fermentation, was tested for its utilisation in the resin formulation, replacing unfavourable palm oil in the formulation. The first findings showed that the yeast derived microbial oil represents an excellent drop-in alternative to previously used vegetable oils in the resin production.
To date, the most promising achievements (that are already beyond the state of the art) could be made in the enzymatic conversion of the chitin to different, high-value chitin derivatives (colloidal chitin, chitosan or CHOS). In this field, the work performed by the Partner NMBU in the VALUABLE project could fundamentally change the praxis of chitin processing, having a huge effect especially on the environmental aspects of the process. Further, the application of chitin and its derivatives in the formulation of plywood panel adhesives shows very promising results that might be of interest for future IP protection.
However, the processes are further developed in the second reporting period and also the work in the remaining WPs has the potential to produce results that exceed the current state of the art.
However, the processes are further developed in the second reporting period and also the work in the remaining WPs has the potential to produce results that exceed the current state of the art.