RESUMO
In this study, waste peach (WP) liquid culture conditions for the maintenance of high triacylglycerol (TG)-accumulation ability in Lipomyces wild-type strain, obtained from WP plate medium were investigated. As the concentration of WP juice was high, the medium viscosity became high, and TG accumulation ability was suppressed. In a 5-L jar fermenter, the negative influence of viscosity on TG-accumulation ability was significantly improved by an agitation speed of 150 rpm (0.4 vvm). Where a bench scale pilot plant (90-L jar fermenter) was operated at 40 rpm, TG-accumulation ability reached 6.8 mg/108cells. This ability was 85% of that obtained with WP plate medium.
Assuntos
Meios de Cultura/metabolismo , Sucos de Frutas e Vegetais/microbiologia , Lipomyces/metabolismo , Prunus persica/microbiologia , Triglicerídeos/biossíntese , Reatores Biológicos , Meios de Cultura/química , Fermentação , Eliminação de Resíduos/métodos , ViscosidadeRESUMO
The yeast Lipomyces accumulates triacylglycerols (TAGs) as intracellular fat globules, and these TAGs can be used as source materials for biodiesel production. In this study, we aimed to use this yeast to produce lipids from renewable resources. Using plate culture and micrograph methods, strains with a high lipid-accumulation ability were screened from 15,408 types of systems combining renewable resources, strains, and culture temperatures. The lipid-accumulation ability of the strains was estimated from the fat globule volume, which was calculated using a micrograph. The reliability of this method was examined, and strains with a high lipid-accumulation ability were identified for each renewable resource. Seventy-seven Lipomyces strains (7 deposit, 68 wild-type, 2 mutants) with a high lipid-accumulation ability were selected. A few strains possessed the ability to accumulate large amounts of TAGs from more than four different renewable resources. We found that strains with a high lipid-accumulation ability could efficiently convert consumed carbon sources into TAGs, which could be easily recovered from the fat globules of these strains through physical disruption.
Assuntos
Biocombustíveis/microbiologia , Conservação de Recursos Energéticos/métodos , Metabolismo dos Lipídeos/genética , Lipomyces/genética , Biocombustíveis/análise , Carbono/metabolismo , Meios de Cultura , Microbiologia Industrial , Gotículas Lipídicas/metabolismo , Lipomyces/metabolismo , Reprodutibilidade dos Testes , Triglicerídeos/metabolismoRESUMO
Four novel Lipomyces strains were isolated from soil collected in the Okinawa and Yamanashi prefectures, Japan. Based on their morphological and biochemical characteristics, along with sequence typing using the D1/D2 domain of the LSU rRNA, internal transcribed spacer (ITS) region including 5.8S rRNA, and translation elongation factor 1 alpha gene (EF-1α), the four strains were shown to represent two novel species of the genus Lipomyces, described as Lipomyces okinawensis sp. nov. (type strain No.3-a(35)T=NBRC 110620T=CBS 14747T) and Lipomyces yamanashiensis f.a., sp. nov. (type strain No.313T=NBRC 110621T=CBS 14748T).
