Differences in the Fatty Acid Profile, Morphology, and Tetraacetylphytosphingosine-Forming Capability Between Wild-Type and Mutant Wickerhamomyces ciferrii

Abstract

One tetraacetylphytosphingosine (TAPS)-producing Wickerhamomyces ciferrii mutant was obtained by exposing wild-type W. ciferrii to γ-ray irradiation. The mutant named 736 produced up to 9.1 g/L of TAPS (218.7 mg-TAPS/g-DCW) during batch fermentation in comparison with 1.7 g/L of TAPS (52.2 mg-TAPS/g-DCW) for the wild type. The highest production, 17.7 g/L of TAPS (259.6 mg-TAPS/g-DCW), was obtained during fed-batch fermentation by mutant 736. Fatty acid (FA) analysis revealed an altered cellular FA profile of mutant 736: decrease in C16:0 and C16:1 FA levels, and increase in C18:1 and C18:2 FA levels. Although a significant change in the cellular FA profile was observed, scanning electron micrographs showed that morphology of wild-type and mutant 736 cells was similar. Genetic alteration analysis of eight TAPS biosynthesis-related genes revealed that there are no mutations in these genes in mutant 736; however, mRNA expression analysis indicated 30% higher mRNA expression of TCS10 among the eight genes in mutant 736 than that in the wild-type. Collectively, these results imply that the enhancement of TAPS biosynthesis in mutant 736 may be a consequence of system-level genetic and physiological alterations of a complicated metabolic network. Reverse metabolic engineering based on system-level omics analysis of mutant 736 can make the mutant more suitable for commercial production of TAPS.

A strategy to enhance and modify fatty acid synthesis in Corynebacterium glutamicum and Escherichia coli: overexpression of acyl-CoA thioesterases

“…TesA overexpression significantly promoted the synthesis of LCFA in C. glutamicum but adversely affected LCFA production in E. coli . Some studies have reported the production of FFA with different carbon lengths by the TE AcTesA in E. coli and Synechocystis [ 29 ]. The differences in FA content and composition might be related to their heterologous expression.…”

Melanin biopolymer synthesis using a new melanogenic strain of Flavobacterium kingsejongi and a recombinant strain of Escherichia coli expressing 4-hydroxyphenylpyruvate dioxygenase from F. kingsejongi

“…6 D). Therefore, the observed diauxic growth pattern, which led to a reduced conversion yield and titer of melanin, might be avoided by optimizing feeding strategies in fed-batch fermentation of an F. kingsejongi strain constitutively expressing HPPD [ 37 , 38 ]. Furthermore, genetic inactivation of the hmg gene encoding homogentisate 1,2-dioxygenase, which further oxidizes homogentisate to fumarate and acetoacetate, might enhance the titer of melanin produced by F. kingsejongi .…”