A cellulolytic fungal biofilm enhances the consolidated bioconversion of cellulose to short chain fatty acids by the rumen microbiome

Xiros, Charilaos; Shahab, Robert; Studer, Michael Hans-Peter (2019). A cellulolytic fungal biofilm enhances the consolidated bioconversion of cellulose to short chain fatty acids by the rumen microbiome Applied Microbiology and Biotechnology, 103(8), pp. 3355-3365. Springer 10.1007/s00253-019-09706-1

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The ability of the multispecies biofilm membrane reactors (MBM reactors) to provide distinguished niches for aerobic and anaerobic microbes at the same time was used for the investigation of the consolidated bioprocessing of cellulose to short chain fatty acids (SCFAs). A consortium based consolidated bioprocess (CBP) was designed. The rumen microbiome was used as the converting microbial consortium, co-cultivated with selected individual aerobic fungi which formed a biofilm on the tubular membrane flushed with oxygen. The beneficial effect of the fungal biofilm on the process yields and productivities was attributed to the enhanced cellulolytic activities compared with those achieved by the rumen microbiome alone. At 30 °C, the MBMsystem with Trichoderma reesei biofilm reached a concentration 39% higher (7.3 g/L SCFAs), than the rumen microbiome alone (5.1 g/ L) using 15 g/L crystalline cellulose as the substrate. Fermentation temperature was crucial especially for the composition of the short chain fatty acids produced. The temperature increase resulted in shorter fatty acids produced. While a mixture of acetic, propionic, butyric, and caproic acids was produced at 30 °C with Trichoderma reesei biofilm, butyric and caproic acids were not detected during the fermentations at 37.5 °C carried out with Coprinopsis cinerea as the biofilm forming fungus. Apart from the presence of the fungal biofilm, no parameter studied had a significant impact on the total yield of organic acids produced, which reached 0.47 g of total SCFAs per g of cellulose (at 30 °C and at pH 6, with rumen inoculum to total volume ratio equal to 0.372).

Item Type:	Journal Article (Original Article)
Division/Institute:	School of Agricultural, Forest and Food Sciences HAFL > Resource-efficient agricultural production systems School of Agricultural, Forest and Food Sciences HAFL > Agriculture
Name:	Xiros, Charilaos; Shahab, Robert and Studer, Michael Hans-Peter0000-0003-1083-0967
Subjects:	Q Science > QH Natural history > QH301 Biology Q Science > QR Microbiology
ISSN:	0175-7598
Publisher:	Springer
Language:	English
Submitter:	Nadine Werndli
Date Deposited:	07 Jan 2020 15:39
Last Modified:	18 Dec 2020 13:29
Publisher DOI:	10.1007/s00253-019-09706-1
ARBOR DOI:	10.24451/arbor.9595
URI:	https://arbor.bfh.ch/id/eprint/9595