Microbial Lipid Accumulation through Bioremediation of Palm Oil Mill Wastewater by Bacillus cereus

Abstract

The wastewater burden and increased energy demands have spurred interest in finding possible solutions that could concomitantly address both issues. Microbial lipid production, together with the bioremediation of wastewater, could be a promising solution to address both problems. In this context, the present study was designed to evaluate the potential of Bacillus cereus (B. cereus) for accumulating microbial lipids through the bioremediation of palm oil mill effluent (POME) in batch mode fermentation. Different dilutions of POME media (25%, 50%, 75%, and 100%) were used to determine the optimum POME concentration for enabling the maximum yield of biomass and maximum lipid production. The 50% (v/v) POME was found to have potential for the highest biomass growth (8.09 g/L) and lipid accumulation (1.46 g/L), with a lipid content of 18.04% (dry weight basis). B. cereus accumulated a higher biomass and lipid content than other bacterial strains, such as Rhodococcus opacus and Pseudomonas aeruginosa, under similar conditions. On the other hand, the degree of bioremediation was assessed by evaluating several wastewater parameters and determining the seed germination index (GI) of Vigna radiata. POME treated with B. cereus displayed higher GI values than the untreated samples due to the significant remediation of detrimental organics present in the POME. This finding was further confirmed by the substantial reduction in pollution load, particularly in chemical oxygen demand (COD) and biochemical oxygen demand (BOD) for 50% POME, thus demonstrating removal efficiencies of 79.35% and 72.65%, respectively. Therefore, the results of this study suggest that B. cereus cultivation in POME could be a promising technique for attaining higher biomass growth and lipid production in conjunction with the bioremediation of POME. The approach of achieving dual objectives that is utilized in the present study provides a novel strategy for palm oil millers.

Fermentation of Palm Oil Mill Effluent in the Presence of Lysinibacillus sp. LC 556247 to Produce Alternative Biomass Fuel

“…Simultaneously, these factors could affect the metabolic process and the growth of the Lysinibacillus sp. LC 556247 in POME fermentation as well [9]. These components, such as the inhibiting agents that have been found to exist in POME, have been widely reported to have both phytotoxic and antibiotic properties [53].…”

“…The high percentage of removal was due to the superior performance of the Bacillus sp. isolated from the POME source, which has been well-documented previously [9,62,63]. The microbe was touted to have the metabolic ability to biodegrade and metabolize organic compounds, such as oil, into simpler byproducts of organic acids, volatile fatty acids, carbon dioxide, methane, and water (63).…”

“…Oil palm wastes, especially POME, is a major problem in palm oil factories because of their abundance and disposal problems. Currently, POME has been valorized using fermentation techniques, such as aerobic, anaerobic, or dark conditions to produce various value-added products [9][10][11][12]. The valorization of industrial wastewater as a feedstock to produce alternative renewable biofuels, in lieu of the over-reliance on fossil fuels, could be an ideal option and could simultaneously minimize the environmental burden posed by the oil palm factories.…”

Utilizing palm oil mill effluent (POME) for the immobilization of Aspergillus oryzae whole‐cell lipase strains for biodiesel synthesis

“…To preserve the environment, an efficient and sustainable management system in the treatment and utilization of these by‐products is needed. Palm oil mill effluent can be a reliable nutrient for microorganisms because it has a high organic content that includes carbohydrates, proteins, nitrogenous compounds, lipids, and minerals 27–29 . There have been many attempts to use POME as a basal medium for microbial production, but a use for the fat fraction of the wastewater has yet to be found (Table 1).…”

“…Palm oil mill effluent can be a reliable nutrient for microorganisms because it has a high organic content that includes carbohydrates, proteins, nitrogenous compounds, lipids, and minerals. [27][28][29] There have been many attempts to use POME as a basal medium for microbial production, but a use for the fat fraction of the wastewater has yet to be found (Table 1). Hermansyah et al 12 utilized POME as a medium for cultivating Pseudomonas aeruginosa to produce lipase using submerged fermentation.…”