Valorization of lignocellulosic waste for PHA production using the thermophile Caldimonas thermodepolymerans

Valorization of lignocellulosic waste for PHA production using the thermophile Caldimonas thermodepolymerans

Abstrakt

In recent years, there have been major advances in industry which, in addition to improving the quality of everyday life, has also caused massive enviromental pollution such as plastic pollution. This issue could be solved by replacing the petrochemical plastics in certain fields by in nature biodegrable materials such as polyhydroxyalkanoates (PHAs). PHAs can be produced by various microbial producers for example by thermophilic bacterium Caldimonas thermodepolymerans. This thermophile is very promising due to is ability to grow on xylose as a carbon source. This ability to utilize xylose opens up the possibility of using lignocellulosic waste from the agricultural industry as a carbon source to reduce the cost of PHA production. This study examines the process of preparing hydrolysate from wheat residues (straw) using acid and thermal hydrolysis employing oxalic acid. Hydrolysates were prepared using this method because the use of oxalic acid breaks down hemicellulose, resulting in a hydrolysate with a high proportion of xylose and a minimum amount of glucose, which Caldimonas thermodepolymerans is unable to metabolize. After optimizing the hydrolysis preparation conditions (e.g., time, temperature, etc.) and subsequent analysis using HPLC different methods of detoxification of hydrolysates by extraction with suitable solvents were also tested. After that, the hydrolysate containing the highest concentration of xylose was used as a carbon source for the production of PHAs by Caldimonas thermodepolymerans bacterium.

In recent years, there have been major advances in industry which, in addition to improving the quality of everyday life, has also caused massive enviromental pollution such as plastic pollution. This issue could be solved by replacing the petrochemical plastics in certain fields by in nature biodegrable materials such as polyhydroxyalkanoates (PHAs). PHAs can be produced by various microbial producers for example by thermophilic bacterium Caldimonas thermodepolymerans. This thermophile is very promising due to is ability to grow on xylose as a carbon source. This ability to utilize xylose opens up the possibility of using lignocellulosic waste from the agricultural industry as a carbon source to reduce the cost of PHA production. This study examines the process of preparing hydrolysate from wheat residues (straw) using acid and thermal hydrolysis employing oxalic acid. Hydrolysates were prepared using this method because the use of oxalic acid breaks down hemicellulose, resulting in a hydrolysate with a high proportion of xylose and a minimum amount of glucose, which Caldimonas thermodepolymerans is unable to metabolize. After optimizing the hydrolysis preparation conditions (e.g., time, temperature, etc.) and subsequent analysis using HPLC different methods of detoxification of hydrolysates by extraction with suitable solvents were also tested. After that, the hydrolysate containing the highest concentration of xylose was used as a carbon source for the production of PHAs by Caldimonas thermodepolymerans bacterium.

PHA, Caldimonas thermodepolymerans, lignocellulose materials, valorization, hydrolysates

PHA, Caldimonas thermodepolymerans, lignocellulose materials, valorization, hydrolysates

PACASOVÁ, V.; HÁJKOVÁ, X.; FAJTOVÁ, Z.; RAKETH, M.; CONSTANTÍ, M.; OBRUČA, S.

13.04.2026

AMCA, spol. s.r.o.

Praha

116

117

2

https://amca-admin.rachel.puxdesign.cz/ICCT/media/2026/program_icct_2026_web.pdf