ABSTRACT
The microbial profile during the anaerobic
co-digestion of cassava peels and poultry droppings for biogas production was
investigated. The aim was to evaluate the biogas production from mono and co-digestion of cassava peels and poultry
droppings using cattle rumen fluid as inoculum, while
characterising the microbiota extensively. To achieve this, four biodigesters of 20 liter capacity
with gas collection systems were designed and constructed. Fresh cassava peels
were collected from a
cassava processing unit.
Twenty-four-hour-old poultry droppings were collected from a poultry farm at Ahiaeke.
These served as the feedstock. The rumen content
was collected from freshly killed cattle at Ubakala abattoir. All were taken immediately after collection in sterile
containers to the laboratory for analyses. The substrates were prepared and
charged up to three-quarter of the biodigesters’ volume. An inoculum to substrate ratio (ISR) of 2:1 was
employed. The experimental
setup was operated under the batch-feed system at a hydraulic retention time of 45 days. The cattle rumen content
was also used as the control. The proximate composition and
physicochemical analyses were evaluated using standard methods, while the
microbiota were characterised using the metagenomics approach. The quantity and
components of biogas produced were determined using the water displacement
method and gas chromatography respectively. The proximate composition analysis
showed the substrates were good feedstock for biogas generation. The
results of physicochemical analysis of
the process parameters, gave
a pH range of 4.5 to 7.5 and a temperature range of 300C to 350C
throughout the digestion period. The Total Solids (TS) contents decreased from
87.64%, 86.00%, 89.35% and 80.98% to 61.00%, 60.25%, 66.75% and 59.77% while
Volatile Solids (VS) contents decreased from 82.48%, 77%, 79.85% and 69.95% to
55%, 35.89%, 47.28% and 40% for (CP:
RC), (PD: RC), (CP: PD: RC) and (RC) digesters respectively. The cumulative mean biogas yield from the four
digesters where 1203.37 mL, 1929.34 mL, 1738.69 mL and 1978.26 mL (CP: RC),
(PD: RC), (CP: PD: RC) and (RC) respectively. Gas chromatographic analysis of
the biogas composition showed that the methane content was the highest amongst
other gases present. Methane content ranged from 64.12% in the control (RC)
digester to 52.35% substrate blend (CP: RC) digester. The metagenomic analysis identified 3 kingdoms, 18 phyla, 30
classes, 52 orders, 100 families, 165 genera and 222 species of the microbiota
profile. The result revealed that the most
abundant phylum was Firmicutes, most
abundant class was Bacilli and Lactobacillales were the highest abundant order. The archaea community were less diverse
compared to those of bacteria. The metagenomic result identified three classes of methanogens
(archaeal kingdom) as methanobacteria,
methanococci and methanomicrobia, three genera
as Methanococcus, Methanosarcina and Methanobrevibacter and four species
as Methaoncoccus maripaludis,
Methanosarcina mazei, Methanosarcina acetivorans and Methanobrevibacter spp. One-way Analysis of variance (ANOVA) for
the physicochemical parameters indicated a significant difference (P ≤ 0.05) in
all the treatments. The results prove that the
anaerobic co-digestion of cassava peels and poultry droppings can be used to produce
biogas while giving a deep insight into the microbial community present.
KELECHI, M (2024). Microbial Profile during the Anaerobic Co-Digestion of Cassava Peels and Poultry Droppings for Biogas Production:- Ukaegbu-Obi, Kelechi M.. Repository.mouau.edu.ng: Retrieved Sep 07, 2024, from https://repository.mouau.edu.ng/work/view/microbial-profile-during-the-anaerobic-co-digestion-of-cassava-peels-and-poultry-droppings-for-biogas-production-ukaegbu-obi-kelechi-m-7-2
MARY, KELECHI. "Microbial Profile during the Anaerobic Co-Digestion of Cassava Peels and Poultry Droppings for Biogas Production:- Ukaegbu-Obi, Kelechi M." Repository.mouau.edu.ng. Repository.mouau.edu.ng, 18 Jul. 2024, https://repository.mouau.edu.ng/work/view/microbial-profile-during-the-anaerobic-co-digestion-of-cassava-peels-and-poultry-droppings-for-biogas-production-ukaegbu-obi-kelechi-m-7-2. Accessed 07 Sep. 2024.
MARY, KELECHI. "Microbial Profile during the Anaerobic Co-Digestion of Cassava Peels and Poultry Droppings for Biogas Production:- Ukaegbu-Obi, Kelechi M.". Repository.mouau.edu.ng, Repository.mouau.edu.ng, 18 Jul. 2024. Web. 07 Sep. 2024. < https://repository.mouau.edu.ng/work/view/microbial-profile-during-the-anaerobic-co-digestion-of-cassava-peels-and-poultry-droppings-for-biogas-production-ukaegbu-obi-kelechi-m-7-2 >.
MARY, KELECHI. "Microbial Profile during the Anaerobic Co-Digestion of Cassava Peels and Poultry Droppings for Biogas Production:- Ukaegbu-Obi, Kelechi M." Repository.mouau.edu.ng (2024). Accessed 07 Sep. 2024. https://repository.mouau.edu.ng/work/view/microbial-profile-during-the-anaerobic-co-digestion-of-cassava-peels-and-poultry-droppings-for-biogas-production-ukaegbu-obi-kelechi-m-7-2