Optimizing the catalytic activities of methanol and thermotolerant Kocuria flava lipases for biodiesel production from cooking oil wastes

Abstract

In this study, two highly thermotolerant and methanol-tolerant lipase-producing bacteria were isolated from cooking oil and they exhibited a high number of catalytic lipase activities recording 18.65 ± 0.68 U/mL and 13.14 ± 0.03 U/mL, respectively. Bacterial isolates were identified according to phenotypic and genotypic 16S rRNA characterization as Kocuria flava ASU5 (MT919305) and Bacillus circulans ASU11 (MT919306). Lipases produced from Kocuria flava ASU5 showed the highest methanol tolerance, recording 98.4% relative activity as well as exhibited high thermostability and alkaline stability. Under the optimum conditions obtained from 3D plots of response surface methodology design, the Kocuria flava ASU5 biocatalyst exhibited an 83.08% yield of biodiesel at optimized reaction variables of, 60 ○C, pH value 8 and 1:2 oil/alcohol molar ratios in the reaction mixture. As well as, the obtained results showed the interactions of temperature/methanol were significant effects, whereas this was not noted in the case of temperature/pH and pH/methanol interactions. The obtained amount of biodiesel from cooking oil was 83.08%, which was analyzed by a GC/Ms profile. The produced biodiesel was confirmed by Fourier-transform infrared spectroscopy (FTIR) approaches showing an absorption band at 1743 cm−1, which is recognized for its absorption in the carbonyl group (C=O) which is characteristic of ester absorption. The energy content generated from biodiesel synthesized was estimated as 12,628.5 kJ/mol. Consequently, Kocuria flava MT919305 may provide promising thermostable, methanol-tolerant lipases, which may improve the economic feasibility and biotechnology of enzyme biocatalysis in the synthesis of value-added green chemicals.

Utilization of microalgae for agricultural runoff remediation and sustainable biofuel production through an integrated biorefinery approach

“…The FTIR analysis showed a peak at 1735.17 cm −1 , which confirmed the production of biodiesel. The results of this study agreed with the findings of Najjar et al (Najjar et al 2021 ) who reported produced biodiesel has showed an absorption band at 1743 cm −1 by (FTIR).…”

“…However, low growth was observed at 15% methanol concentration at 24, 48, and 72 h at 37 °C. Other study results obtained for the lipase enzyme activity of microbes also showed that, there was a sharp reduction at higher concentrations of methanol (Najjar et al 2021 ). The current results depicted that although the growth was reduced at higher concentrations of methanol, strain Q4 was not completely inhibited or killed by methanol.…”

Production of Methanol Tolerant Cell-bound Lipase of Magnusiomyces spicifer SPB2 and Application as Whole-cell Biocatalyst in Transesterification Reaction

“…The results showed that the whole-cells lipase from M. spicifer preferred branched alcohol (2-butanol and iso-butanol) to the linear ones (methanol, ethanol, propanol and 1-butanol). The results were not in agreement with the previously reported, in which methanol was more favorable than the longer-chain alcohols for whole-cells lipases developed from Rhodotorula mucilaginosa [10], Kocuria flava ASU5 [25] and Bacillus circulans ASU11 [25]. Moreover, the biodiesel production using longer and branched chain length alcohol provided product advantages of low temperature performance, which is important when using diesel engines in winter or cold climates [33].…”

“…Correspondingly, an initial pH of 5 was found to be the optimum for CBL activity of M. spicifer SPB2 in this study. However, pH showed no significant in lipase production for Kocuria flava [15,25]. Carbon sources displayed to be less influent than nitrogen sources and surfactants on hydrolytic CBL production of M. spicifer SPB2.…”

Biodiesel Production through Rhodotorula toruloides Lipids and Utilization of De-Oiled Biomass for Congo Red Removal

“…The oven temperature was 80 • C for 5 min, then the temperature was increased at the rate of 10 • C min −1 to 150 • C and 200 • C for 10 min each, and finally, the oven temperature was raised at an increasing rate of 5 • C min −1 to 250 • C for 13 min. The injector temperature was 250 • C and the detector temperature was 300 • C. The percent of FAMEs yield was estimated by comparison with the peak area of internal standards at the specific retention time [40].…”