Open AccessBioethanol production from urban cellulosic waste employing Alcaligenes faecalis HI-1 isolated from gut of termite Heterotermes indicola
Author(s) -
Mehwish Iqtedar,
Sidra Riaz,
Saima Shehzaad Mirza,
Mahwish Aftab,
Afshan Kaleem,
Rasedee Abdullah,
Ayesha Aihetasham,
Farheen Aslam,
Myra Wasim
Publication year - 2021
Publication title -
bioscience journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 19
eISSN - 1981-3163
pISSN - 1516-3725
DOI - 10.14393/bj-v37n0a2021-53598
Subject(s) - bioconversion , cellulosic ethanol , fermentation , chemistry , hydrolysis , food science , biofuel , alcaligenes faecalis , cellulose , cellulase , substrate (aquarium) , alcaligenes , bacteria , microbiology and biotechnology , biochemistry , biology , genetics , pseudomonas , ecology
This study assessed the potential of termite gut inhabiting bacteria towards bioconversion of cellulosic waste into biofuel. Total seven bacterial isolates from the gut of Heterotermes indicola were isolated. Among all the isolates, HI-1 produced the largest zone upon primary screening. Untreated paper had more cellulose content (73.03%) than acid (0.5%) treated paper that was used as a lignocellulosic substrate for saccharification. Among all the isolates tested, glucose yield (1.08mg/mL) was high for HI-1 isolate. Several factors were considered for optimizing augmented glucose yield (8.57mg/mL) and growth (8.07×108cfu/mL), such as temperature 37°C, pH 4.5, 5% (w/v) substrate concentration, 6 % bacterial inoculum size, agitation 150 rpm with PEG 0.25 % and Ca2+ ions 0.002 g/L. Overall 8-fold increase in glucose yield was achieved. Enzyme activity of HI-1 showed higher endoglucanase 0.29 ± 0.01 (U/mL/min) and exoglucanase 0.15±0.01 (U/mL/min) activity under optimum conditions, mentioned above. temperature 37°C, pH 4.5, substrate concentration 5%, inoculum size 6%, surfactants PEG 0.01%, ions Ca2+(0.002g/L) and agitation (120 rpm). Simultaneous saccharification and fermentation (SSF) of hydrolyzed office paper yielded 5.43mg/mL bioethanol. According to 16S rRNA sequence homology, the bacterial isolate H1 was identified as Alcaligenes faecalis. Bioethanol production from office paper untreated waste proved an effective strategy. Bacteria having natural tendency towards cellulosic waste consumption are promising for bioconversion of cellulosic waste to valuable products.