Characterization of Linoleate 10-Hydratase of Lactobacillus plantarum and Novel Antifungal Metabolites

Abstract

Lactobacilli convert linoleic acid to the antifungal compound 10-hydroxy-12-octadecenoic acid (10-HOE) by linoleate 10-hydratase (10-LAH). However, the effect of this conversion on cellular membrane physiology and properties of the cell surface have not been demonstrated. Moreover, Lactobacillus plantarum produces 13-hydroxy-9-octadecenoic acid (13-HOE) in addition to 10-HOE, but the antifungal activity of 13-HOE was unknown. Phylogenetic analyses conducted in this study did not differentiate between 10-LAH and linoleate 13-hydratase (13-LAH). Thus, linoleate hydratases (LAHs) must be characterized through their differences in their activities of linoleate conversion. Four genes encoding putative LAHs from lactobacilli were cloned, heterologous expressed, purified and identified as FAD-dependent 10-LAH. The unsaturated fatty acid substrates stimulated the growth of lactobacilli. We also investigated the role of 10-LAH in ethanol tolerance, membrane fluidity and hydrophobicity of cell surfaces in lactobacilli by disruption of lah. Compared with the L. plantarum lah deficient strain, 10-LAH in wild-type strain did not exert effect on cell survival and membrane fluidity under ethanol stress, but influenced the cell surface hydrophobicity. Moreover, deletion of 10-LAH in L. plantarum facilitated purification of 13-HOE and demonstration of its antifungal activity against Penicillium roqueforti and Aspergillus niger.

Lactic Acid Bacteria as Antifungal and Anti‐Mycotoxigenic Agents: A Comprehensive Review

“…There has been great progress in understanding and exploring novel antifungal metabolites of LAB during the last few years. Apart from some novel antifungal peptides produced by many LAB species (Gerez, Torres, Font de Valdez, & Rollán, 2013;Luz et al, 2017;McNair et al, 2018;Muhialdin et al, 2016;Muhialdin, Hassan, & Saari, 2018;Rather et al, 2013), many other novel antifungal metabolites of LAB have been reported recently that included 10-hydroxy-12-octadecenoic acid (10-HOE), 13-hydroxy-9-octadecenoic acid (Chen, Liang, Curtis, & Ganzle, 2016), benzeneacetic acid, 2-propenyl ester (Wang, Yan, Wang, Zhang, & Qi, 2012), phenolic antioxidants (such as, 2,4 di-tert-butyl phenol) (Sellamani et al, 2016;Varsha et al, 2015), 2-hydroxy-(4-methylthio) butanoic acid, 2-hydroxy-3-methylbutanoic (Honoré et al, 2016) and spermine-like and short cyclic polylactates (Mosbah et al, 2018). Aunsbjerg et al (2015) reported the role of volatile compounds (diacetyl) produced by Lactobacillus paracasei DGCC 2132 in inhibiting the growth of two fungal species belonging to the genus Penicillium: P. solitum DCS 302 and Penicillium sp.…”

The Fatty-Acid Hydratase Activity of the Most Common Probiotic Microorganisms

“…Nevertheless, only few relevant exceptions to this general trend have been reported. An important example concerns some strains of Lactobacillus acidophilus [39][40][41] and Lactobacillus plantarum [42] that As stated previously, HFAs are usually formed with high regio-and stereoselectivity. According to our recent work [12], the widely used probiotic Lactobacillus rhamnosus LGG converts acids 1-3 into the corresponding 10-hydroxy derivatives, namely (R)-10-hydroxystearic acid (4), (S)-(12Z)-10-hydroxy-octadecenoic acid (6), and (S)-(12Z,15Z)-10-hydroxy-octadecadienoic acid (10), respectively, in very high enantiomeric purity (ee > 95%).…”

“…Nevertheless, only few relevant exceptions to this general trend have been reported. An important example concerns some strains of Lactobacillus acidophilus [39][40][41] and Lactobacillus plantarum [42] that possess both 10and 13-hydratase activity, most likely due to the simultaneous activity of two different enzymes. Therefore, the whole-cell biotransformation of linolenic acid using the latter microorganisms can afford a mixture of (S)-(12Z)-10-hydroxy-octadecenoic acid (6), (S)-(9Z)-13-hydroxy-octadecenoic acid (8), and (10S,13S)-10,13-dihydroxy-octadecenoic acid (9).…”

Use of Lactobacillus rhamnosus (ATCC 53103) as Whole-Cell Biocatalyst for the Regio- and Stereoselective Hydration of Oleic, Linoleic, and Linolenic Acid

“…The hydration reaction of unsaturated fatty acids was discovered in the early 1960s, during a study on the hydration of oleic acid using a Pseudomonas strain [9,10]. Afterwards, a number of other microorganisms proved to be able to perform this transformation [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] but the enzymes responsible for the hydration step (oleate hydratases) have been characterized only recently [26], receiving growing attention both from chemists and biologists [27][28][29][30][31][32][33][34][35][36][37]. It is worth noting that different putative oleate hydratase have been cloned from a number of bacteria strains, but none of them have been used for the industrial synthesis of HFAs.…”