Biosurfactant production by native marine bacteria (Acinetobacter calcoaceticus P1‐1A) using waste carbon sources: Impact of process conditions

Abstract

The high cost of biosurfactant production is an obstacle for widespread commercial applications. Cost‐effective generation of biosurfactants could be achieved using industrial wastes and by‐products as substrates and tailoring cultural conditions. In this work, waste streams including refined waste cooking oil and crude glycerol were compared to each other and to commercial carbon sources. Based on this assessment, the waste cooking oil was selected for further studies. A response surface methodology (RSM) was then used to study biosurfactant production by Acinetobacter calcoaceticus P1‐1A strain (a strain indigenous to the North Atlantic Ocean) using the refined waste cooking oil as the sole carbon source. The concentrations of carbon, nitrogen, and NaCl, as well as the initial pH and temperature were varied. The emulsification index was measured as the response. The cultural conditions to reach the maximum emulsification index (68.17%) were 0.0435 v/v (4.35 vol.%) refined waste cooking oil, 6.5 g/L ammonium sulphate, 13.5 g/L NaCl, initial pH of 7.7, and temperature of 34.8°C. The experimental validation of the predicted response under optimum conditions was performed with 862 mg/L of the biosurfactant product generated. The product showed high thermal, pH, and salinity stability. The use of this indigenous bacteria combined with the use of a no‐cost carbon source from waste has the potential to not only reduce costs associated with biosurfactant production but also to produce a biosurfactant better suited to treat oil spills in the harsh environment of the North Atlantic and other cold waters.

Biosurfactant Production by Acinetobacter venetianus and Its Application in Bioremediation

“…Also, the surface tension of CB produced using MM‐NaCl was measured during the process, and it decreased by 38.3 ± 2 %, reaching the lowest value, approximately 40 mN m −1 , with 48 h of process. This result is consistent with literature data for biosurfactants produced by the Acinetobacter genus 14, 22, reinforcing the production of this surfactant agent.…”

“…Bacillus [9,18,19], Pseudomonas [13,20], Serratia [12], Candida [21], and Acinetobacter genus [22][23][24] are the main producers of biosurfactants. The last-mentioned genus has the ability to metabolize several carbon sources and produces effective biosurfactants with good dispersant action for application in bioremediation and in various fields [1,14].…”

A New Biosurfactant/Bioemulsifier from Gordonia alkanivorans Strain 1B: Production and Characterization

“…Using olive oil, the BS/BE pr duced revealed great plasticity in terms of application, demonstrating emulsifying acti ity for all hydrophobic liquids tested (Figure 3). The results obtained when using glycer were unexpected, since it has been described as a good alternative C-source to promo BS/BE production with several other bacteria [6,9,42,43]. It could be the case that, as o served with glucose, carbon is being preferentially diverted towards carotenoid produ tion [29,30], as the culture demonstrated intense coloration.…”

“…The costs of large-scale microbial surfactant production are greatly influenced by the carbon source and other nutrients in the culture medium [6,9]. One way to mitigate this problem, aiming to obtain a more sustainable bioprocess, is the use of cheaper C-sources.…”

“…Depending on the microorganisms, BS/BE production can be induced by culture conditions. In fact, several factors, such as oxygen concentration, agitation, pH, temperature, culture density, and/or concentration of different salts, can have both positive and negative influences [6][7][8]. One of the most influential factors is the carbon source, which, based on its nature and concentration, can change not only the amount of BS/BE produced but also its type and characteristics [9][10][11].…”