The Second-Generation Biomethane from Mandarin Orange Peel under Cocultivation with Methanogens and the Armed Clostridium cellulovorans

Abstract

This study demonstrates that the consortium, which consists of the microbial flora of methane production (MFMP) and Clostridium cellulovorans grown with cellulose, can perform the direct conversion of cellulosic biomass to methane. The MFMP was taken from a commercial methane fermentation tank and was extremely complicated. Therefore, C. cellulovorans grown with cellobiose could not perform high degradation ability on cellulosic biomass due to competition by various microorganisms in MFMP. Focusing on the fact that C. cellulovorans was cultivated with cellulose, which is armed with cellulosome, so that it is now armed C. cellulovorans; the direct conversion was carried out by the consortium which consisted of MFMP and the armed C. cellulovorans. As a result, the consortium of C. cellulovorans grown with cellobiose and MFMP (CCeM) could not degrade the purified cellulose and mandarin orange peel. However, MFMP and the armed C. cellulovorans reduced 78.4% of the total sugar of the purified cellulose such as MN301, and produced 6.89 mL of methane simultaneously. Furthermore, the consortium consisted of MFMP and the armed C. cellulovorans degraded mandarin orange peel without any pretreatments and produced methane that was accounting for 66.2% of the total produced gas.

Effects of Different Carbon Sources on Biomethane Production with <em>Clostridium Cellulovorans</em> and Methanogens

“…Furthermore, since the combination of genome-centric metagenomics and metatranscriptomics successfully revealed individual functional roles of microbial members in methanogenic microcosms, these results assigned a multi-trophic role to Methanosarcina ssp., suggesting its ability to perform simultaneous methanogenesis from acetate, CO2 and methanol/methylamine [55]. MFMP used in this study originally consisted of C. butyricum (0.005%) identified as the same genus of C. celulovorans and M. mazei (1.34%) found among methanogens [32]. Furthermore, other methanogens such as Methanosaetaceae, Methanosaeta, and Methanospirillaceae were also identified in MFMP.…”

“…By the cocultivation of C. cellulovorans and C. beijerinckii, IBE fermentation was performed using mandarin orange wastes [30]. Moreover, methane was produced from sugar beet pulp [31] and mandarin orange peel [32] under cocultivation with C. cellulovorans and methanogens. Furthermore, two coculture models combining C. cellulovorans with Methanosarcina barkeri Fusaro or M. mazei Gö1 were established for the direct conversion of cellulose to CH4 [33].…”

“…0.5% (w/v) Glucose, 0.5% acetic acid (FUJIFILM Wako Chemicals, Japan), and 0.5% (w/v) cellobiose (Sigma, MO, USA) were used as the sole carbon source in 10 ml or 50 ml of C. cellulovorans media and was anaerobically cultivated. The microbial flora of methane production (MFMP) was obtained from methane fermentation digested liquid on January, 2017 at Gifu in Japan [32]. C. cellulovorans (C.c) was precultured with 0.5% cellobiose for 12 h at 37 °C and M. mazei (M.m) and MFMP were done with 0.5% glucose for 12 h at 37 °C, respectively.…”

Determining the Microbial Source of Methane Production in Anaerobic Digestion Systems Through High-Throughput Sequencing Technology

“…Many researchers have investigated the dominant bacterial groups in anaerobic digestion systems, whose results are consistent with the findings of this study. Tomita and Tamaru (2019) achieved biogenic methane production using beet pulp and citrus peel as feedstocks, respectively, with the hydrolytic bacterium Clostridium cellulovorans and methanogens as inoculum. In this study, the bacterial OTU with the highest average relative abundance, that is, B-OTU1, was 99% similar to Clostridium cellulovorans.…”

Effects of Different Carbon Sources on Biomethane Production with <em>Clostridium Cellulovorans</em> and Methanogens

“…By the cocultivation of C. cellulovorans and C. beijerinckii, IBE fermentation was performed using mandarin orange wastes [30]. Moreover, methane was produced from sugar beet pulp [31] and mandarin orange peel [32] under cocultivation with C. cellulovorans and methanogens. Furthermore, two coculture models combining C.…”