A pH shift induces high-titer liamocin production in Aureobasidium pullulans

Saur, Katharina Maria; Brumhard, Oliver; Scholz, Karen; Hayen, Heiko; Tiso, Till

doi:10.1007/s00253-019-09677-3

Cited by 30 publications

(28 citation statements)

References 54 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A similar activity can be found in the black yeast fungus Aureobasidium pullulans. In this strain, liamocin, a glycolipid consisting of mannitol linked with three or four 3,5-dihydroxydecanoic ester groups, is produced (53). Our survey for RhlA in microorganisms showed its presence mainly in the Betaproteobacteria and Gammaproteobacteria phyla, with little evidence in other phyla.…”

Section: Discussionmentioning

confidence: 76%

Exploiting the Natural Diversity of RhlA Acyltransferases for the Synthesis of the Rhamnolipid Precursor 3-(3-Hydroxyalkanoyloxy)Alkanoic Acid

Germer

Tiso

Müller

et al. 2020

Appl Environ Microbiol

Self Cite

View full text Add to dashboard Cite

While rhamnolipids of the Pseudomonas aeruginosa type are commercially available, the natural diversity of rhamnolipids and their origin have barely been investigated. Here, we collected known and identified new rhlA genes encoding the acyltransferase responsible for the synthesis of the lipophilic rhamnolipid precursor 3-(3-hydroxyalkanoyloxy)alkanoic acid (HAA). Generally, all homologs were found in Betaproteobacteria and Gammaproteobacteria. A likely horizontal gene transfer event into Actinobacteria is the only identified exception. The phylogeny of the RhlA homologs from Pseudomonas and Burkholderia species is consistent with the organism phylogeny, and genes involved in rhamnolipid synthesis are located in operons. In contrast, RhlA homologs from the Enterobacterales do not follow the organisms’ phylogeny but form their own branch. Furthermore, in many Enterobacterales and Halomonas from the Oceanospirillales, an isolated rhlA homolog can be found in the genome. The RhlAs from Pseudomonas aeruginosa PA01, Pseudomonas fluorescens LMG 05825, Pantoea ananatis LMG 20103, Burkholderia plantarii PG1, Burkholderia ambifaria LMG 19182, Halomonas sp. strain R57-5, Dickeya dadantii Ech586, and Serratia plymuthica PRI-2C were expressed in Escherichia coli and tested for HAA production. Indeed, except for the Serratia RhlA, HAAs were produced with the engineered strains. A detailed analysis of the produced HAA congeners by high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS) highlights the congener specificity of the RhlA proteins. The congener length varies from 4 to 18 carbon atoms, with the main congeners consisting of different combinations of saturated or monounsaturated C10, C12, and C14 fatty acids. The results are discussed in the context of the phylogeny of this unusual enzymatic activity. IMPORTANCE The RhlA specificity explains the observed differences in 3-(3-hydroxyalkanoyloxy)alkanoic acid (HAA) congeners. Whole-cell catalysts can now be designed for the synthesis of different congener mixtures of HAAs and rhamnolipids, thereby contributing to the envisaged synthesis of designer HAAs.

show abstract

Section: Discussionmentioning

confidence: 76%

Exploiting the Natural Diversity of RhlA Acyltransferases for the Synthesis of the Rhamnolipid Precursor 3-(3-Hydroxyalkanoyloxy)Alkanoic Acid

Germer

Tiso

Müller

et al. 2020

Appl Environ Microbiol

Self Cite

View full text Add to dashboard Cite

show abstract

“…Furthermore, no exophilins were produced by A. melanogenum 6-1-2 whereas they were produced by A. pullulans strain NRRL 50380 [3]. It has been reported that Man-3C 10 , Ara-3C 10 , Man-Ac C 10 -2C 10 , 3C 10 (exophilins), Man-4C 10 , Ara-4C 10 , Ac C 10 -2C 10 and 4C 10 (exophilins) were also produced by A. pullulans NRRL62031 [27]. This meant that the core structure of the liamocins produced by A. melanogenum 6-1-2 was the same as that of the liamocins produced by A. pullulans strain NRRL 50380 and A. pullulans NRRL62031.…”

Section: Hplc-ms Analysis Of the Extracted Liamocins Produced By A Mmentioning

confidence: 98%

“…Especially, deletion of the PKS gene alone, the EST1 gene alone and all the MPDH gene, the MtDH gene, the ArDH gene could totally stop liamocin biosynthesis (Figure 3). Similarly, the liamocins produced by A. pullulans NRRL62031 [27] also contain mannitol and arabitol as their headgroups. However, all the liamocins produced by A. pullulans strain NRRL 50380 [3] did not contain arabitol as their headgroup.…”

Section: The Genes Required For Core Liamocin Biosynthesismentioning

confidence: 99%

Genetic evidences for the core biosynthesis pathway, regulation, transport and secretion of liamocins in yeast-like fungal cells

Xue

Liu

Chi

et al. 2020

Biochemical Journal

View full text Add to dashboard Cite

So far, it has been still unknown how liamocins are biosynthesized, regulated, transported and secreted. In this study, a highly reducing polyketide synthase (HR-PKS), a mannitol- 1-phosphate dehydrogenase (MPDH), a mannitol dehydrogenase (MtDH), an arabitol dehydrogenase (ArDH) and an esterase (Est1) were found to be closely related to core biosynthesis of extracellular liamocins in Aureobasidium melanogenum 6-1-2. The HR-PKS was responsible for biosynthesis of 3,5-dihydroxydecanoic acid. The MPDH and MtDH were implicated in mannitol biosynthesis and the ArDH was involved in arabitol biosynthesis. The Est1 catalyzed ester bond formation of them. A phosphopantetheine transferase (PPTase) activated the HR-PKS and a transcriptional activator Ga11 activated expression of the PKS1 gene. Therefore, deletion of the PKS1 gene, all the three genes encoding MPDH, MtDH and ArDH, the EST1, the gene responsible for PPTase and the gene for Ga11 made all the disruptants (Dpks13, Dpta13, Dest1, Dp12 and Dg11) totally lose the ability to produce any liamocins. A GLTP gene encoding a glycolipid transporter and a MDR1 gene encoding an ABC transporter took part in transport and secretion of the produced liamocins into medium. Removal of the GLTP gene and the MDR1 gene resulted in a Dgltp1 mutant and a Dmdr16 mutant, respectively, that lost the partial ability to secrete liamocins, but which cells were swollen and intracellular lipid accumulation was greatly enhanced. Hydrolysis of liamocins released 3,5-dihydroxydecanoic acid, mannitol, arabitol and acetic acid. We proposed a core biosynthesis pathway, regulation, transport and secretion of liamocins in A. melanogenum.

show abstract

“…Different sources of inorganic and organic nitrogen can influence biosurfactants synthesis. The corn-steep liquor (CAS 66071-94-1), yeast extract and urea are organic sources, as well as nitrate and ammonium salts are inorganic sources commonly used [ 250 , 251 ] Normally, during cell growth excess carbon and nitrogen sources is suggested, followed by depletion of the nitrogen source [ 29 , 252 ]. The C/N ratio can interfere with biosurfactant production, so it is recommended to maintain a high C/N ratio during cultivation, observing a range of 16:1–18:1 [ 34 , 193 ].…”

Section: New Production Technologiesmentioning

confidence: 99%

“…The ideal pH reported for biosurfactant production is slightly acid, preferably between 5 and 7 (Table 2 ). In some bioprocesses, the pH of the medium strongly influences biosurfactant production and the transport of various components across the cell membrane [ 55 , 252 ]. The pH should be kept stable to avoid cell lysis, however, change in its value may trigger biosurfactant production, its value, however, is usually slightly reduced by the end of the cultivation [ 136 , 252 ].…”

Section: New Production Technologiesmentioning

confidence: 99%

Fungal biosurfactants, from nature to biotechnological product: bioprospection, production and potential applications

Silva

Banat

Giachini

et al. 2021

Bioprocess Biosyst Eng

View full text Add to dashboard Cite

Biosurfactants are in demand by the global market as natural commodities that can be added to commercial products or use in environmental applications. These biomolecules reduce the surface/interfacial tension between fluid phases and exhibit superior stability to chemical surfactants under different physico-chemical conditions. Biotechnological production of biosurfactants is still emerging. Fungi are promising producers of these molecules with unique chemical structures, such as sophorolipids, mannosylerythritol lipids, cellobiose lipids, xylolipids, polyol lipids and hydrophobins. In this review, we aimed to contextualize concepts related to fungal biosurfactant production and its application in industry and the environment. Concepts related to the thermodynamic and physico-chemical properties of biosurfactants are presented, which allows detailed analysis of their structural and application. Promising niches for isolating biosurfactant-producing fungi are presented, as well as screening methodologies are discussed. Finally, strategies related to process parameters and variables, simultaneous production, process optimization through statistical and genetic tools, downstream processing and some aspects of commercial products formulations are presented.

show abstract

A pH shift induces high-titer liamocin production in Aureobasidium pullulans

Cited by 30 publications

References 54 publications

Exploiting the Natural Diversity of RhlA Acyltransferases for the Synthesis of the Rhamnolipid Precursor 3-(3-Hydroxyalkanoyloxy)Alkanoic Acid

Exploiting the Natural Diversity of RhlA Acyltransferases for the Synthesis of the Rhamnolipid Precursor 3-(3-Hydroxyalkanoyloxy)Alkanoic Acid

Genetic evidences for the core biosynthesis pathway, regulation, transport and secretion of liamocins in yeast-like fungal cells

Fungal biosurfactants, from nature to biotechnological product: bioprospection, production and potential applications

Contact Info

Product

Resources

About