著者

Katsuya Nouzaki Ryoichi Tanaka Yuya Sato Tomohiro Inaba Tomo Aoyagi Tomoyuki Hori Hiroshi Yanagishita Hiroshi Habe

出版者

Japan Oil Chemists' Society

雑誌

Journal of Oleo Science (ISSN:13458957)

巻号頁・発行日

vol.72, no.3, pp.357-367, 2023 (Released:2023-03-03)

参考文献数

27

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The discharge of high-strength oily wastewater adversely affects the environment; therefore, the treatment of wastewater containing fats, oils, and grease from the food industry is of importance. In this study, we used a membrane bioreactor (MBR) to treat Ramen noodle-soup wastewater, and we evaluated the optimal oil concentration in the wastewater for the startup of the MBR treatment in winter and summer. The MBR system had a sufficient startup in both seasons when fed with a 20-fold dilution of the original oily wastewater, containing approximately 950 to 1,200 mg/L oil and approximately 3,000 to 4,400 mg/L biological oxygen demand (BOD; BOD-SS load of 0.1 to 0.2 kg/kg/d). The reactor performance in winter were relatively stable during the operation. While, activated sludge microbes in summer were not highly active with a 40-fold dilution of wastewater, because of the decreased mixed liquor suspended solid concentration during the operation period. Population shifts in the sludge microbiome with increasing oil concentrations were analyzed using high-throughput sequencing, and the relative abundance of operational taxonomic units belonging to the phylum Bacteroidetes were highest in both winter and summer when fed with 20-fold dilution of the wastewater. In particular, the family Chitinophagaceae was dominant, with relative abundances of 13.5% in winter and 5.1% in summer, suggesting that this family may play important roles in the startup of a MBR treating the wastewater.

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

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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

Takashi Narihiro Masaru Konishi Nobu Tomoyuki Hori Tomo Aoyagi Yuya Sato Tomohiro Inaba Hidenobu Aizawa Hideyuki Tamaki Hiroshi Habe

出版者

Japanese Society of Microbial Ecology · The Japanese Society of Soil Microbiology

雑誌

Microbes and Environments (ISSN:13426311)

巻号頁・発行日

pp.ME18108, (Released:2018-12-22)

被引用文献数

6

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The present study characterized the interactions of microbial populations in activated sludge systems during the operational period after an increase in the wastewater flow rate and consequential ammonia accumulation using a 16S rRNA gene sequencing-based network analysis. Two hundred microbial populations accounting for 81.8% of the total microbiome were identified. Based on a co-occurrence analysis, Nitrosomonas-type ammonia oxidizers had one of the largest number of interactions with diverse bacteria, including a bulking-associated Thiothrix organism. These results suggest that an increased flow rate has an impact on constituents by changing ammonia concentrations and also that Nitrosomonas- and Thiothrix-centric responses are critical for ammonia removal and microbial community recovery.

著者

Tomohiro Inaba Tomoyuki Hori Yuya Sato Tomo Aoyagi Dai Hanajima Atsushi Ogata Hiroshi Habe

出版者

日本微生物生態学会・日本土壌微生物学会

雑誌

Microbes and Environments (ISSN:13426311)

巻号頁・発行日

pp.ME17112, (Released:2017-12-12)

被引用文献数

13

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Limited information is currently available on the contribution of eukaryotes to the reactor performance of membrane bioreactors (MBRs). Using high-throughput Illumina sequencing of 18S rRNA genes and microscopic observations, we investigated eukaryotic microbiomes in membrane-attached biofilms in MBRs treating piggery wastewater. Protozoa preying on bacteria were frequently detected under stable conditions when membrane clogging was suppressed. However, the eukaryotes preying upon protozoa became predominant in biofilms when membrane fouling rapidly progressed. We herein demonstrated that a comprehensive investigation of eukaryotic microbiomes using high-throughput sequencing contributes to a better understanding of the microbial ecology involved in wastewater treatment.