VOLATILE FATTY ACIDS AS ELECTRON DONORS FOR THE REDUCTIVE DECHLORINATION OF CHLOROETHENES

Volatile fatty acids can be used as carbon sources for denitrification and are easily supplied as by-products from the anaerobic digestion of waste materials. Nitrification and denitrification processes were carried out in a single reactor feeding volatile fatty acids as electron donors and the changes in microbial communities in the reactor were investigated. The microbial communities in the alternating aerobic and anoxic systems were different, and their structure flexibly changed within one reactor. Bacteroidetes and Firmicutes were highly distributed during denitrification, whereas Proteobacteria was a major phylum during nitrification. In addition, in the denitrification system, the microbial community was substrate dependent. It showed the sequential nitrogen removal in one reactor and the microbial community also followed the change of environmental condition, cyclic nitrification, and denitrification.

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Bioremediation of trichloroethylene contaminated groundwater using anaerobic process

Water Science & Technology ◽

10.2166/wst.2008.830 ◽

2008 ◽

Vol 58 (11) ◽

pp. 2127-2132 ◽

Cited By ~ 4

Author(s):

Cheema Chomsurin ◽

Juthathip Kajorntraidej ◽

Kongrit Luangmuang

Keyword(s):

Contaminated Soil ◽

Reductive Dechlorination ◽

Volatile Fatty Acids ◽

Low Cost ◽

Ammonia Nitrogen ◽

Electron Donors ◽

Contaminated Groundwater ◽

Peanut Shell ◽

Fermentation System ◽

Set Up

Anaerobic remediation of trichloroethylene (TCE) contaminated soil and groundwater was studied in laboratory setups. In this process fermentation of polymeric organic materials (POMS) produced volatile fatty acids (VFAs) that were electron donors in reductive dechlorination of TCE. Shredded peanut shell was selected as low cost POM and the experiments were set up in 500 ml Erlenmeyer flasks. In the setups, approximately 25 mg of leachate contaminated soil was used as the main source of microorganisms and about 5 g of shredded peanut shell (0.5–2.36 mm) was added to produce VFAs for dechlorination of TCE. In the first set of experiments, fermentation of soil and shredded peanut shell was studied and it was found that VFAs were produced continuously with increasing concentration (5.63 mM as CH3COOH from the first day to 17.17 in the 10th day of the experiment). During the fermentation, concentration of ammonia-nitrogen was 22–50 mg/L, the ratio of VFA to NH3 was 15.29–23.44 and pH was 5.24–6.00. These results show that the system was appropriate for microorganism activities. In the second set of experiments, TCE (∼48 mg/L) was added to the fermentation system and remediation of TCE by reductive dechlorination was studied. It was found that 0.04(±0.01) mg TCE adsorbed to a gram of soil and peanut shells at the beginning of the experiment and based on mass balance of the system, TCE concentration in water was linearly reduced at the rate of 0.0098 mg/hr.

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Unravelling a microbial synergy to boost caproate production via carboxylates chain elongation with ethanol

HKIE Transactions ◽

10.33430/v26n2thie-2018-0041 ◽

2019 ◽

Vol 26 (2) ◽

pp. 63-71

Author(s):

Ling Leng ◽

Ying Wang ◽

Peixian Yang ◽

Takashi Narihiro ◽

Masaru Konishi Nobu ◽

...

Keyword(s):

Fatty Acids ◽

Volatile Fatty Acids ◽

Microbial Consortia ◽

Chain Elongation ◽

Desulfovibrio Vulgaris ◽

Rrna Gene ◽

Selective Enrichment ◽

Microbial Network ◽

Cost Efficient ◽

Rrna Gene Sequencing

Chain elongation of volatile fatty acids for medium chain fatty acids production (e.g. caproate) is an attractive approach to treat wastewater anaerobically and recover resource simultaneously. Undefined microbial consortia can be tailored to achieve chain elongation process with selective enrichment from anaerobic digestion sludge, which has advantages over pure culture approach for cost-efficient application. Whilst the metabolic pathway of the dominant caproate producer, Clostridium kluyveri, has been annotated, the role of other coexisting abundant microbiomes remained unclear. To this end, an ethanol-acetate fermentation inoculated with fresh digestion sludge at optimal conditions was conducted. Also, physiological study, thermodynamics and 16 S rRNA gene sequencing to elucidate the biological process by linking the system performance and dominant microbiomes were integrated. Results revealed a possible synergistic network in which C. kluyveri and three co-dominant species, Desulfovibrio vulgaris, Fusobacterium varium and Acetoanaerobium sticklandii coexisted. D. vulgaris and A. sticklandii (F. varium) were likely to boost the carboxylates chain elongation by stimulating ethanol oxidation and butyrate production through a syntrophic partnership with hydrogen (H2) serving as an electron messenger. This study unveils a synergistic microbial network to boost caproate production in mixed culture carboxylates chain elongation.

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МЕТАБОЛИТЫ ПРОБИОТИЧЕСКИХ БАКТЕРИЙ ОТВЕЧАЮТ ЗА ЭФФЕКТИВНОСТЬ ДЕЙСТВИЯ ПРОБИОТИКА "ПРОФОРТ®"

10.33845/0033-3239-2019-68-9-10-45-47 ◽

2019 ◽

Keyword(s):

Fatty Acids ◽

Volatile Fatty Acids ◽

Broiler Chicks ◽

Bacillus Sp

МЕЛИКИДИ В.Х., ТЮРИНА Д.Г., СЕЛИВАНОВ Д.Г., НОВИКОВА Н.И. ООО «БИОТРОФ», Санкт-Петербург Аннотация: Приведены данные исследования методом газожидкостной хроматомасс-спектрометрии метаболитов, синтезируемых пробиотическими бактериями, входящими в состав кормовой добавки «Профорт®». Проведен опыт в условиях интенсивного промышленного птицеводства по применению кормовой добавки «Профорт®» (50 тыс. голов бройлеров в группе). Среди метаболитов пробиотических штаммов Enterococcus sp. и Bacillus sp. обнаружены такие полезные вещества, как молочная кислота, уксусная, пропионовая и другие короткоцепочечные (летучие) жирные кислоты, активные пептиды. Результаты зоотехнического опыта показали, что при скармливании бройлерам пробиотика «Профорт®» (500 г/т) живая масса при убое в 40 дней была выше контроля на 6,9%, конверсия корма улучшилась на 3,0%, а европейский индекс продуктивности бройлеров - на 5,69%. Ключевые слова: ПРОБИОТИКИ, МЕТАБОЛИТЫ, ЛЕТУЧИЕ ЖИРНЫЕ КИСЛОТЫ, ЦЫПЛЯТА-БРОЙЛЕРЫ,ПРОДУКТИВНОСТЬ, PROBIOTICS, METABOLITES, VOLATILE FATTY ACIDS, BROILER CHICKS,PRODUCTIVITY

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