- 著者
- Tokuma Fukuoka Tomotake Morita Azusa Saika Hiroshi Habe
- 出版者
- Japan Oil Chemists' Society
- 雑誌
- Journal of Oleo Science (ISSN:13458957)
- 巻号頁・発行日
- vol.67, no.12, pp.1609-1616, 2018 (Released:2018-12-01)
- 参考文献数
- 26
- 被引用文献数
- 5 12
Surface properties of cast films of poly(lactic acid) (PLA) containing 1 wt% of several glycolipid-type biosurfactants (BSs) were investigated. The wettability of PLA films containing a homologue of mannosylerythritol lipids (MEL-B), lactone-form sophorolipid (LSL), or cellobiose lipid (CL) was drastically higher than that of untreated PLA and several synthetic surfactants-containing PLA. Surface wettability was also dependent on the hydrophilicity of the substrate used during solvent casting of the PLA films. The wetting behavior of the opposing sides of MEL-B-containing films prepared on glass substrates differed significantly; the contact angle on the side of the film that had been in contact with the glass surface was significantly lower than that obtained on the side of the film that had been in contact with air. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis results showed that the MEL in MEL-B-containing thin PLA cast films was localized to a thin surface layer. These results suggest self-assembly of MEL-B and micro-phase separation between the PLA matrix and MEL-B domains. This resulted in the localization and orientation of MEL-B at the surface of the cast PLA film, which determined its specific wetting behavior.
- 著者
- Masaaki Konishi Tomotake Morita Tokuma Fukuoka Tomohiro Imura Shingo Uemura Hiroyuki Iwabuchi Dai Kitamoto
- 出版者
- Japan Oil Chemists' Society
- 雑誌
- Journal of Oleo Science (ISSN:13458957)
- 巻号頁・発行日
- vol.67, no.4, pp.489-496, 2018 (Released:2018-04-01)
- 参考文献数
- 34
- 被引用文献数
- 18 37
We discovered that Candida floricola ZM1502 is capable of selectively producing the promising hydrophilic biosurfactants, acid-form sophorolipids (SLs), from glycerol. However, productivity was very low (approximately 3.5 g L–1) under the initial culture conditions. Here, we describe the design of culture medium for abundant production of acid-form SLs by C. floricola ZM1502 using waste glycerol and hydrophobic substrates in order to develop a method for SL production and disposal of waste glycerol produced by oleo-chemical industries. Urea provided the best nitrogen source for acid-form SL production from glycerol among four nitrogen sources tested [urea, NaNO3, NH4NO3, and (NH4)2SO4]. Among carbon sources we compared, hydrophobic substrates (soybean oil and oleic acid) led to productivities of approximately 20 g L–1, indicating that hydrophobic substrates provided fatty acid moieties for SL production. Addition of olive oil and oleic acid to waste glycerol enhanced acid-form SL production to 42.1 ± 0.9 and 37.5 ± 3.4 g L–1, respectively. To develop a potential industrial process, we explored other suitable hydrophobic substrates for SL production, which were obtained on site from oleo-chemical industries. Alkyl C18 esters (Pastell M-182), along with waste glycerol, increased acid-form SL production to 48.0 ± 3.4 g L–1 over a 7-d period. Furthermore, we demonstrated abundant production of acidic SLs at the mini-jar fermenter scale, obtaining 169 g L–1 over 180 h using a fed-batch cultivation technique. Efficient acid-form SL production by C. floricola could have a great impact on the development of bio-industrial processes using waste glycerol as a substrate.
- 著者
- Tokuma Fukuoka Sayaka Nakamura Tomotake Morita Takayuki Ohmura Masahiro Kotani Yasuhide Naito Hiroaki Sato
- 出版者
- Japan Oil Chemists' Society
- 雑誌
- Journal of Oleo Science (ISSN:13458957)
- 巻号頁・発行日
- pp.ess21084, (Released:2021-07-09)
Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a promising tool for the screening of glycolipid-type biosurfactants (BSs) from a crude extract of microbial products. However, it is unsuitable for the detection of lower molecular weight products because the observed ions are overlapped with matrix-derived ions at lower mass range. In this study, we applied a “matrix-free” surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) analysis using a through-hole alumina membrane as an ionization-assisting substrate. Using this method, we could detect a variety of lower molecular weight products in an extract of a glycolipid BS producer with good sensitivity. In addition, the culture solution could be analyzed directly by this method.
- 著者
- Shun Sato Tokuma Fukuoka Azusa Saika Tatsuyuki Koshiyama Tomotake Morita
- 出版者
- Japan Oil Chemists' Society
- 雑誌
- Journal of Oleo Science (ISSN:13458957)
- 巻号頁・発行日
- vol.68, no.12, pp.1287-1294, 2019 (Released:2019-12-01)
- 参考文献数
- 16
- 被引用文献数
- 10
We applied matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS) to screen for glycolipid-type biosurfactant (BS) producers. A crude extract of Pseudozyma antarctica, a well-known mannosylerythritol lipid (MEL) producer, was initially subjected to MALDI-TOF/MS. The spectrum of the extract showed the accumulation of diacylated MELs in culture. We then screened 80 environmental samples for BS-producing yeasts, and extracts from broth cultures of the selected five strains were examined using MALDI-TOF/MS. The results showed that all five strains produced MELs, whereas four strains also produced cellobiose lipids (CLs). By D1/D2 region sequence analysis, the MEL-producing strain was assigned to P. antarctica while the four MEL- and CL-producing strains were assigned to P. hubeiensis. These results demonstrate that MALDI-TOF/MS is a rapid and reliable tool to detect BS molecules in crude extracts of broth cultures to screen for glycolipid-type BS producers.