Comparison of mono‐rhamnolipids and di‐rhamnolipids on microbial enhanced oil recovery (MEOR) applications

Abstract

Rhamnolipids (RMLs) have more effectiveness for specific uses according to their homologue proportions. Thus, the novelty of this work was to compare mono‐RMLs and di‐RMLs physicochemical properties on microbial enhanced oil recovery (MEOR) applications. For this, RML produced by three strains of Pseudomonas aeruginosa containing different homologues proportion were used: a mainly mono‐RMLs producer (mono‐RMLs); a mainly di‐RMLs producer (di‐RMLs), and the other one that produces relatively balanced amounts of mono‐RML and di‐RML homologues (mono/di‐RML). For mono‐RML, the most abundant molecules were Rha‐C10C10 (m/z 503.3), for di‐RML were RhaRha‐C10C10 (m/z 649.4) and for Mono/di‐RML were Rha‐C10C10 (m/z 503.3) and RhaRha‐C10C10 (m/z 649.4). All RMLs types presented robustness under high temperature and variation of salinity and pH, and high ability for oil displacement, foam stability, wettability reversal and were classified as safe for environment according to the European Union Directive No. 67/548/EEC. For all these properties, it was observed a highlight for mono‐RML. Mono‐RML presented the lowest surface tension (26.40 mN/m), interfacial tension (1.14 mN/m), and critical micellar concentration (CMC 27.04 mg/L), the highest emulsification index (EI24 100%) and the best wettability reversal (100% with 25 ppm). In addition, mono‐RML showed the best acute toxicity value (454 mg/L), making its application potential even more attractive. Based on the results, it was concluded that all RMLs homologues studied have potential for MEOR applications. However, results showed that mono‐RML stood out and have the best mechanism of oil incorporation in micelles due their most effective surface‐active physicochemical features.

A Straightforward Assay for Screening and Quantification of Biosurfactants in Microbial Culture Supernatants

“…Hence, for N-acyltyrosine, HAA, and mRL, the CMC derived from VPBO assay matches the range of previously reported values, however, for C 10 -C 10 dRL, it does not. Nevertheless, other studies determined deviating CMCs for dRL (and for mRL as well) varying between 0.05 and 0.23 mg/ml probably dependent on impurities, mixtures, and variations in chain length and degree of saturation (Syldatk et al, 1985;Abalos et al, 2001;Nitschke et al, 2005;Dubeau et al, 2009;Tiso et al, 2017;Rocha et al, 2020). Furthermore, the CMC value depends on temperature, pH, and salt concentration, which may differ from the conditions in the present study (room temperature in LB medium adjusted to pH 7).…”

Antibiofilm effect of mono‐rhamnolipids and di‐rhamnolipids on carbon steel submitted to oil produced water

“…Furthermore, the most hydrophobic character of mono-RML was shown as well by the hydrophilic-lipophilic balance (HLB) results in previous work from our group. 21 In this same work, it was shown that the CMC of mono-RML was lower than that of mono/ di-RML and di-RML, respectively. This confirms the best adhesion ability of mono-RML.…”

“…Rhamnolipids production, quantification and tensoactive parameters, as well as structural analysis of rhamnolipids were previously published in a study from our group about rhamnolipids application on Microbial enhanced oil recovery (MEOR) 21 . Details of the methodology are provided following.…”

“…High-resolution mass spectrometry analysis showed that the three different strains of P. aeruginosa produced distinct relative abundances of congeners. According to the majority congeners percentages (Table 1), the lineages were named as Mono strain (ATCC9027, with 96% of mono-RML), Di strain (LFM1201, with 72% of di-rhamnolipids), and Mono/Di (LFM1151, with 61%/39% of mono/di-RML), as reported in 21 To simplify results discussion throughout this work, we will call the product generated by the Mono strain of mono-RML, the product generated by the Di strain of di-RML and the product generated by the Mono/Di strain of Mono/Di-RML.…”

Microbial Enhanced Oil Recovery (MEOR): Alternatif Peningkatan Produksi Migas di Indonesia

“…MEOR termasuk kedalam tertiary oil recovery atau kita kenal dengan Enhance Oil Recovery yang teknologi nya berbasis biological dengan metode metabolisme mikroba (biomassa, biopolimer, gas, asam, pelarut, enzym dan karbon aktif) dan aktivitas (metabolisme hidrokarbon, plugging) yang digunakan untuk meminimalisir residu minyak yang tertinggal pada reservoir (Purwasena et al, 2019) 2 . Microbial Enhanced Oil Recovery (MEOR) menjadi teknologi yang sudah mendapatkan visibilitas atas kemampuannya meningkatkan hasil produksi minyak pada dekade terakhir yang menggunakan bakteri atau bio-produk (Rocha et al, 2020).…”