Deficiency of biodegradable plastic-degrading enzyme production in a gene-deletion mutant of phyllosphere yeast, Pseudozyma antarctica defective in mannosylerythritol lipid biosynthesis

Abstract

The basidiomycetous yeast Pseudozyma antarctica (currently designated Moesziomyces antarcticus ) produces extracellular enzymes and glycolipids, including mannosylerythritol lipids (MELs), which are biosurfactants. Strain GB-4(0) of this species was previously isolated from rice husks and produces biodegradable plastic-degrading enzyme ( Pseudozyma antarctica esterase; PaE). In this study, we generated a MEL biosynthesis-deficient strain (∆Pa EMT1 ) by deleting the gene Pa EMT1 , which is essential to MEL biosynthesis in strain GB-4(0). The resulting ∆Pa EMT1 strain showed deficient PaE activity, and the corresponding signal was hardly detected in its culture supernatant through western blotting analysis using rabbit anti-PaE serum. On the other hand, the relative expression of the gene Pa CLE1 , encoding PaE, was identical between GB-4(0) and ∆Pa EMT1 based on quantitative real-time PCR. When strain ∆Pa EMT1 was grown in culture media supplemented with various surfactants, i.e., Tween20, BRIJ35 and TritonX-100, and MELs, PaE activity and secretion recovered. We also attempted to detect intracellular PaE using cell-free extract, but observed no signal in the soluble or insoluble fractions of ∆Pa EMT1 . This result suggested that the Pa CLE1 gene was not translated to PaE, or that expressed PaE was degraded immediately in ∆Pa EMT1 . Based on these results, MEL biosynthesis is an important contributor to PaE production. Electronic supplementary material The online version of this article (10.1186/s13568-019-0825-2) contains supplementary material, which is available to authorized users.

High-quality genome resource of a basidiomycetous yeast, Moesziomyces antarcticus isolate RS1, isolated from rice seed

“…Moesziomyces spp. produce mannosylerythritol lipids (MELs), which are glycolipid biosurfactants ( 16 ). A comparative genome analysis via local BLAST search (BLAST+ v. 2.6.0) ( 17 ) for the known MEL biosynthesis genes ( Emt1 , Mac1 , Mac2 , Mmf1 , and Mat1 ) on RS1 with M. antarcticus ATCC 3488 and other strains confirmed all strains possess MEL-biosynthesis genes.…”

Promising Application, Efficient Production, and Genetic Basis of Mannosylerythritol Lipids

“…In 2017, Saika et al enhanced the production of MEL-B in the recombinant P. tsukubaensis strain 1E5 through the introduction of genes PaLIPAp and PaLIPBp derived from M. antarctica T-34 [161]. In a study conducted by Saika et al in 2019 [169], it was found that knockout of the PaEMT1 gene in the M. antarctica strain GB-4 resulted in a notable decrease in PaE (M. antarctica esterase) activity, while the addition of different surfactants, such as MEL, resulted in the restoration of PaE activity, suggesting a close relationship between MEL biosynthesis and the production of PaE in M. antarctica. In conclusion, the genetic basis of MEL production in M. antarctica represents a fascinating area of research with potential biotechnological and medical applications.…”

Detection and diversity of the mannosylerythritol lipid (MEL) gene cluster and lipase A and B genes of Moesziomyces antarcticus isolated from terrestrial sites chronically contaminated with crude oil in Trinidad

“…Understanding aa substitutions is important to bio-engineering the translated protein [ 49 ]. Importantly, Saika, et al [ 51 ] confirmed that MEL biosynthesis is required for extracellular lipase production and secretion in M. antarcticus strain GB-4. A study of MEL BGC of M. antarcticus isolates should, therefore, include simultaneous analysis of genes that encode extracellular lipases for oil/lipid metabolism [ 52 ].…”